1.Facial Appearance and Restorative Dental Treatment
2. Cracked Tooth Syndrome
3. Dental Implants Placement With Computed Tomography (CT) Scan
4. Restoring Congenitally Missing Teeth With Dental Implants
5. The Goal of Modern Implant DentistryM
6. Advantages of Implant Supported Teeth
7. Cracked Tooth Syndrome/CERAMIC or GOLD Inlay/Onlay
8. Creating Smiles With Complete Dentures
9. Implant Dentistry/Bone Expansion (Long)
10. Replacing a Failed Resin-Bonded Bridge With a Single Tooth Implant
11. Implant-Supported Prostheses (Teeth) for Cleft Palate Patients
12. Cosmetic Dentistry/Ceramic/Inlay/Onlay
13. Your Bite — Why It’s So Important to Your Dental Health
14. Tooth Extraction With Immediate Implant Replacement
15. Cosmetic Dentistry/Improving Color & Strength of Teeth
16. Dental Implant/Dentures and Natural Appearance
17. Dental Implants/Sinus Lift
18. Dental Implants/Bone Strengthening/Nerve Repositioning
19. Dental Implants/How Many?
20. Dental Implants and Facial Appearance
21. Cosmetic Dentistry/Ceramic VS PFM Crowns
22. Comprehensive Implant Dentistry With Fixed Bridgework
23. Dental Implants Provide Similar Function, Appearance and Feel of Natural Teeth
24. Implant Dentistry/One-Appointment Subperiosteal Implant
25. Dental Implants/Types of Subperiosteal Implants
26. Dental Implants/Bone Grafting/The Healing Phase
27. Implant Dentistry/Types of Implants
28. Implant dentistry With Cosmetic Improvement of Facial Appearance
29. The Process of Alveolar Distraction Osteogenesis for Improved Implant Placement
30. Understanding How Your Body’s Natural Growth Factors Can Help Accelerate the Healing Process
31. Understanding Combination Syndrome and How to Correct This Dental Problem
32. Benefits of Conservative and Cosmetic Periodontal & Restorative Dentistry
33. Extractions With Immediate Implant Placement With PTFE Membrane, Mineralized Bone Grafting
34. TEETH TODAY: Extractions with Immediate Implant Placement and Loading with Immediate Placement of Teeth
Article #1: Facial Appearance and Restorative Dental Treatment
Q: I have never been happy with the shape and color of my teeth. What are my options?
A: A prosthodontist treating a patient can do much to improve the appearance and natural beauty of the face. The entire lower half of the face depends on where the teeth are positioned, as well as their shape, form, surface texture and color. It is usually not difficult on casual meeting to detect a person who has artificially constructed crowns. A dark line at the gum tissue or bulky thick teeth detract from realism. The upper lip often appears lengthened and tense or wrinkled in an attempt to conceal the anterior teeth. The result is the appearance of premature aging that is caused not by age itself but by the change of facial appearance from the soft tissue compensating for lack of an aesthetic dental smile.
An approach to improved facial and tooth appearance is with thin porcelain cosmetic veneers. This would be indicated in cases where extensive wear or existing tooth position and/or fillings would not be improved by home bleaching. Many times, there might be rotations that create shadows, and these can be corrected by veneering the teeth with porcelain to create a more symmetrical arrangement. Whenever veneering is done, designing the final shapes of the teeth prior to treatment is important.
Correcting tooth appearance with traditional crowns involves more tooth reduction. These may be all porcelain that are bonded to the teeth or porcelain that is fused to a metal substructure. Since these crowns are often in the aesthetic zone, appearance is important. The type of porcelain used can determine how real the color and appearance is. The more sophisticated porcelain crowns use a multi-layering technique, and the color is built in. The simpler crowns might have only three layers of color while the more cosmetic ones may have eight or more layers. The margins or junction of the crowned teeth also might be made totally out of porcelain and blend into the root without a dark line. Finally, the artistic skill of the dentist and technician determines the end result.
Since the laboratory plays such an important role in the treatment result, the closer the laboratory, such as an in-office dental laboratory, the better. The type of material used in building the teeth as well as the skill of the technician are the final determinants for the result.
Dr. EDward M. Amet, an American board-certified prosthodontist and American board-certified implant dentist, provides comprehensive dental treatment. He founded the Reconstructive & Implant Dental Center in 1988 and has been in practice for 30 years. He has extensive training and experience in both the surgical and the prosthodontic phases of implant therapy, with skilled and talented on-site dental technicians. These on-site dental technicians can make the prosthodontics personalized for each patient. “Our goal,” states Dr. Amet, “is to provide our patients with the finest quality of care as comfortably and pain-free as possible.”
Article #2: Cracked Tooth Syndrome
Q: I have many posterior teeth that have existing large amalgam or plastic composite fillings. Several of these teeth are now sensitive to biting pressure and cold food or drinks, but there is no apparent decay. What could be the problem and the solution to the discomfort?
A: Discomfort in chewing is the most frequent symptom of a cracked tooth, with unexplained sensitivity to cold experienced by the patient. The chief complaint is that it hurts to bite on one or both sides of the mouth, but it may not be apparent which tooth is involved or whether the pain is in the upper or lower jaw. A cracked tooth should be suspected when pain is experienced when chewing hard foods.
The dentist should be suspicious that a tooth is cracked if no caries or sensitive cementum is found and the tooth structure appears normal on the X-ray examination. These cracks can occur in any of the posterior teeth.
Unfortunately, most cracked posterior teeth have been restored, often with silver amalgam or plastic composite restorations. These obscure the cracks and necessitate the use of other diagnostic procedures, including localized biting pressure, transillumination or staining with dye to locate the cracks.
The frequency with which mandibular molars crack is an indication of the “nutcracked” effect of the jaws. The upper molars wedge the lower molars apart, either by excessive force or biting pressure such as ice chewing.
Treatment to prevent further cracking and root canal therapy is a must. Cast gold inlay/onlay restorations are a conservative way to treat teeth that have vertical fractures that may not have previously had an amalgam filling in place. Gold inlays and onlays have been available for more than 150 years, and they restore teeth without having to cut the entire tooth down for a full crown. Another important feature is the cement used to secure the gold inlay/onlay to the tooth. The use of resin modified glassionomer cement releases fluoride and bonds to the tooth, is extremely strong and helps prevent recurrent decay.
Another conservative treatment for cracked teeth is a very durable and aesthetic restorative material, a Leucite-reinforced pressed glass ceramic. This is a type of ceramic material that not only exhibits similar hardness to natural tooth structure but also closely resembles its color. Another important feature is the method of cementation of these restorations. They are actually bonded to the remaining tooth structure. This results in the saving of existing tooth structure and can also re-establish its original strength and decrease tooth sensitivity.
Article #3: Dental Implants/Placement With Computed Tomography (CT) Scan
Q: What type of radiographic (X-ray) evaluation is needed before dental implant placement?
A: The success of osseointegrated implants is making implant dentistry a part of everyday dental practice. The increased demand for dental implants has resulted in technology by the dental product industry to improve and expand the currently available implant placement planning options. This new technology has provided the capability for the most accurate presurgical evaluation, easier surgical care and more aesthetic final restorations.
Traditionally, the clinical evaluation of the implant patient is based on visual examination, manual palpation, gauging tissue thickness, mounted diagnostic casts and traditional dental panoramic X-rays. The analysis provides a tremendous amount of preoperative diagnostic information on the available bone, its location and the potential prosthetic outcome. However, it was not uncommon to discover conditions at the time of surgery that differed from what was anticipated based on the diagnostic information obtained. For example, the bone may have been too thin for implant placement or may not have been where it was necessary for placement of usable prosthetic abutments and crown placement. The proper alignment of abutments may not have been possible due to implant angulation. When these situations occurred, it became necessary for the surgeon and the restorative dentist to decide mid-surgery where to place the implants. If the restorative dentist was not present, this decision had to be made by the surgeon, who might or might not have been capable of deciding if the implant could be restored.
Advanced computer technology has enabled this type of decision-making a problem of the past. Computed tomography (CT scans) aided by specially designed software has made it possible to download the information from the optical disk of the CT scan, processed at an imaging center and then e-mailed to the PC (personal computer) of the dentist surgically planning and placing them. With this capability, a three-dimensional view can be made instead of the normal two=dimensional dental X-ray. This allows better visualization and implant placement planning prior to surgery. Using the special computer program, implants can be placed and the bone height, thickness and density evaluated. This can be done in the implant dentist’s office without the patient needing to be present and provides the capability for more accurate presurgical evaluation, easier surgical care and more aesthetic final restorations.
Article #4: Restoring Congenitally Missing Teeth With Dental Implants
Q: My daughter will be completing orthodontic treatment soon, and she has a congenitally missing permanent upper lateral incisor. What are her options for replacing that missing tooth?
A: The single edentulous space in a dental arch allows for several restorative options. Conventional techniques include a removable partial denture, a cemented fixed bridge and a resin-bonded fixed bridge. Each of these options can be successfully used. However, none of these alternatives can actually replace the original tooth and the way it emerges from the gingival tissue and its ability to maintain the bone height. A prosthetic tooth, supported by an endosteal implant, may be the closest match to the natural tooth.
For a single missing tooth, the conventional removable partial denture would be an option of last resort. It is bulky, unaesthetic and can be difficult to wear. The three-unit fixed cemented bridge is certainly a time-tested prosthetic treatment option. However, it requires that adjacent teeth, often intact, be prepared as terminal abutments. The acid-etched resin bonded bridge was first introduced as a conservative approach to tooth replacement. Most resin-bonded bridges involve non-restored teeth, with minimal tooth preparations, to serve as retention. This bridge often results in over-contoured attachments on the lingual, resulting in plaque traps. In a 10-year retrospective study, an overall debonding rate of 31 percent occurred.
The implant-supported fixed prosthesis is an excellent alternative to replace a missing tooth if there is adequate width and height of remaining alveolar bone. Therefore, treatment planning for an endosteal root form implant requires accurate planning but can result in a very realistic natural appearance that aids in maintaining bone height. The ability to restore the fully edentulous mandible and maxilla through the use of endosteal implants has expanded to include the partially edentate population. Conventional dental treatment options, such as the removable partial denture, the three-unit fixed bridge and the resin-bonded retainer, may need to be reconsidered now that endosteal root form implants have been proven effective. The prosthetic tooth, supported by an endosteal implant, emerges from the tissue attached to a “root” (the implant) in a manner that more closely resembles the natural tooth it replaces than any other treatment option available. In a clinical situation where there is adequate bone and adjacent virgin teeth, the single tooth implant restoration can certainly be considered the primary treatment alternative.
Article #5: The Goal of Modern Implant Dentistry
Q: What is the goal of modern implant dentistry?
A: The goal of modern implant dentistry is to return patients to oral health in a predictable fashion. The partially and completely edentulous patient may be unable to recover normal function, aesthetics, comfort or speech with traditional removable prosthesis.
The patient’s function when wearing a complete denture may be reduced to 25 to 40 percent of that formerly experienced with the natural dentition. An implant prosthesis, however, may return the function to near normal limits. The aesthetics of the edentulous patient are also affected as a result of bone atrophy. The continued bone resorption leads to irreversible facial changes. Endosteal implants stimulate bone in a manner similar to healthy natural teeth to maintain bone size. As a result of this bone maintenance, the facial features are not compromised by lack of support. In addition, implant-supported restorations, as compared to complete dentures, are positioned in relation to aesthetics, function and speech, not in the “neutral zones” of soft tissue support.
The soft tissues of the edentulous patients are often tender from the effects of thinning mucosa, decreased saliva flow, and unstable or unretentive prostheses. The implant-retained restoration does not require soft tissue support and improves oral comfort. Finally, speech and function are compromised with removable prostheses, as it may move as much as 10mm from the supporting lower jaw structure during use. The tongue and perioral musculature are used to limit the movement of the mandibular prosthesis thus interfering with mastication and speech. The implant abutment prosthesis is stable and retentive without the efforts of the musculature and, therefore, offers more predictable function in mastication and speech. Thus, implant-supported teeth offer a more predictable treatment course than removable dentures. The dental profession and public are becoming increasingly aware of this. Between 1983 and 1987, there was a four-fold increase in the number of implants placed. Since that time, or every four years, there has been a four-fold increase in the number of implants placed.
Article #6: Advantages of Implant-Supported Teeth
Q: If dental implants are used to provide support for replacement teeth, what are the advantages compared to the use of traditional removable complete dentures?
A: The goal of modern implant dentistry is to return patients to oral health in a predictable fashion. The partial and completely edentulous patient may be unable to recover normal function, aesthetics or speech with traditional removable dentures.
The patient’s function when wearing a denture may be reduced to 25 to 40 percent of that formerly experienced with natural teeth. Implant-supported teeth may return the function to near normal limits. The aesthetics of the edentulous patient are also affected as a result of bone loss and atrophy. This continued resorption leads to irreversible facial changes. An implant stimulates the bone and maintains its dimension in a manner similar to healthy natural teeth. As a result, the facial features are not compromised by lack of support. In addition, implant-supported restorations are positioned in relation to aesthetics, function and speech, not in the “neutral zones” of soft tissue support.
The soft tissues of the edentulous patients are tender from the effects of thinning mucosa, decreased salivary flow, and unstable or unretentive dentures. The implant-retained restoration does not require soft tissue support and improves oral comfort. Speech and function are compromised with lower dentures, which may move 10mm from the supporting structure during use. The tongue and perioral musculature may be compromised to limit the movement of the mandibular denture. The implant abutment teeth are stable and retentive without the efforts of the musculature.
Implant-supported teeth offer a more predictable treatment course than removable dentures. The dental profession and public are becoming increasingly aware of this. Between 1983 and 1987, there was a four-fold increase in the number of implants placed.
Article #7: Cracked Tooth Syndrome/CERAMIC or GOLD Inlay/Onlay
Q: I have many posterior teeth that have existing large silver amalgam fillings. Several of these teeth are now sensitive to biting pressure and cold food or drinks, but there was no apparent decay at my last dental examination. What could be the problem and the solution to the discomfort?
A: Discomfort in chewing is the most frequent symptom of a cracked tooth, with unexplained sensitivity to cold experienced by the patient. The chief complaint is that it hurts to bite on one side of the mouth, but it may not be apparent which tooth is involved or whether the pain is in the upper or lower teeth. A cracked tooth should be suspected when pain is experienced when chewing tough foods.
The dentist should be suspicious that a tooth is cracked if no caries or sensitive cementum is found and the tooth structure appears normal on the X-ray examination. Cracks occur most frequently in lower molar teeth but may occur in any of the posterior teeth.
Most posterior teeth that develop vertical fractures or cracks have been restored with silver amalgam. This material often obscures the underlying vertical fracture, necessitating the use of other diagnostic procedures for detection, including localized biting pressure and transillumination. The teeth can also be stained with a dye to locate cracks.
The frequency with which mandibular molars crack is an indication of the “nutcracker” effect of the jaws. The upper molars wedge the cusps of the lower molars apart, either from excessive clenching forces or constant trauma from bruxing and ice chewing.
There is a direct relationship between the size of an amalgam restoration and the number of teeth cracked. The more extensive and deeper the restoration, the less tooth remaining to support the load.
Treatment to prevent further cracking is a must. Today, very durable and aesthetic restorative materials are available as well traditional cast-gold restorations. The types of ceramic materials available not only exhibit similar hardness as natural tooth structure but also closely resemble its color. Another important feature is the method of cementation of these restorations. They are bonded to the remaining tooth structure. This results in re-establishment of the original tooth strength with less removal of existing tooth structure and also with decreased tooth sensitivity. Traditional cast-gold restoration, if well done, will often last 35 to 40 years.
Article #8: Creating Smiles With Complete Dentures
Q: I have never been happy with my complete dentures for eating or my facial appearance. What are my options?
A: The success of facial appearance and prosthetic dental treatment is directly related to good treatment planning. The prosthodontist treating a patient can do much to improve the appearance and natural beauty of the face as well as the ability of the patient to eat.
The entire lower half of the face depends on where the teeth are positioned, as well as their shape, form, surface texture and color. It is usually not difficult on casual meeting to detect a person who has artificially constructed teeth or completed dentures. Small, evenly set denture teeth detract from realism. The upper lip often appears lengthened and tense or wrinkled in an attempt to conceal the anterior teeth, which may be set too far posterior in the mouth. The result is the appearance of premature aging that is caused not by age itself but by the change of facial appearance from the chin and nose seemingly so close together and the soft tissue compensating for this incorrect distance between these parts of the face. The result is the lack of an aesthetic dental smile with premature aging.
The goal of modern dentistry is to achieve integration of dental implants and restorative treatment that replaces a missing tooth or teeth and lost supporting structures, as well as restores proper aesthetics and function. In order to achieve this goal, it is necessary for the patient and dentist to be able to visualize the final prosthetic results prior to surgical treatment. Therefore, it is essential for the dentist to have a thorough understanding of all phases of treatment in order to diagnose, treat and restore natural appearance.
Since the dental laboratory plays such an important role in treatment, having an in-office laboratory is desirable to achieve the final aesthetic and functional result. Finally, the artistic skill of the dentist and technician determines the end result.
Dr. EDward M. Amet, an American board-certified prosthodontist and American board-certified implant dentist, provides comprehensive dental treatment. He founded the Reconstructive & Implant Dental Center in 1988 and the Reconstructive & Implant Dental Laboratory in 1994 and has been in practice for 33 years. He has extensive training and experience in both the surgical and prosthodontic phases of prosthodontic and implant therapy, with skilled and talented on-site dental technicians. The selection of the most ideal tooth shape and size as well as the arrangement for the patient is done by Dr. Amet. This can make the prosthetics personalized for each patient. “Our goal,” states Dr. Amet, “is to provide our patients with the finest quality of care as comfortably and pain-free as possible.”
Article #9: Bone Grafting for Dental Implant Placement
Q: I have been advised that I need extensive bone grafting for dental implant placement. Are there alternatives to this procedure that would allow implant placement and not compromise the result?
A: The standard method of preparing a bone site (the osteotomy) to receive an endosteal dental implant involves the removal of bone with a graded series of drills of increasing sizes. The largest drill in the series approximates the length and diameter of the implant to be inserted. In areas where there is adequate bone of good quality, a careful surgical technique with a drill can produce consistent results.
In the lower jaw (mandible), Branemark classification type I and II bone predominates. In this area, drilling is the practical and convenient means of placing implants. A dense outer layer of bone is generally available for the initial fixation of the implant. Often, the implant can be placed to take advantage of one or both the inner and outer cortical bone plates. Placing implants in the upper jaw (maxilla) presents a different set of surgical problems compared to the mandible. In the maxilla, the bone is generally type III or IV. The hard outer layer of bone is thin or entirely absent. Resorption and prominent sinuses often limit the number of good sites available for a routine placement. Spiny ridge areas, too narrow in width for drilling, are common.
The quality of maxillary bone can be extremely variable in a single location. It is likely that a maxilla will contain voids, fatty marrow and fibrous inclusions. The resorbed maxilla is generally undercut in shape so that the surgeon is forced to place implants with a flared inclination toward the lip. The arch form results in more steep emergence angulations and complex abutment needs. Because of the problems of drilling in the maxilla, this author prefers a means of osteotomy preparation in which the bone is not removed. This method is called the “bone expansion technique.” The objective of this technique is to maintain, if possible, all of the existing maxillary bone by pushing the bone aside with minimal trauma while developing an accurately shaped osteotomy. The bone expansion technique attempts to retain all of the bone that is present and to take advantage of the softer bone quality by relocating the bone to suit the needs of the surgery. This potential compacting of bone helps to maintain fixation of the newly placed implants.
In contrast to drilling, the bone expansion technique improves maxillary anatomy by widening the ridge as the instruments are inserted. The instruments, developed by the author, are shaped so that the next larger instrument tip fits into the opening created by the previous instrument. The inner and outer bone is pushed or expanded laterally from the opening of the implant site development with successive penetrations of the larger instruments. In a narrow ridge, expansion of the bone at the site is an inherent beneficial characteristic of this technique. The author has used the bone expansion technique in the maxilla or upper jaw since 1992 with consistently excellent results. Drilling does not improve local anatomy or bone quality. This technique allows a simple means to expand the ridge, deepen sites, create more usable sites and improve bone quality. The bone expansion technique is heatless and offers excellent tactile sensitivity, control and visibility. Torque from the handpiece is nonexistent, and access is as good or better than drills in the posterior maxilla.
The bone expansion technique is a useful and predictable procedure for implant placement in soft maxillary bone. This technique improves the chances of placing implants throughout the maxilla, especially around the sinus and in the tuberosity as a routine office procedure. The bone expansion technique is gentle, does not generate heat and takes advantage of available bone by relocating it in a variety of surgical applications. For many patients, the bone expansion technique can help simplify implant surgery by reducing the need for more traumatic, time-consuming and costly grafting procedures.
Article #10: Replacing a Failed Resin-Bonded Bridge With a Single Tooth Implant
Q: I have a resin-bonded or “Maryland” bridge that periodically needs to be recemented. I am concerned with developing decay under it. I do not want my teeth next to the space ground down for bridge work, so would a dental implant be possible?
A: The single edentulous space in a dental arch allows for several restorative options. Conventional techniques include a removable partial denture, a cemented fixed bridge and a resin-bonded fixed bridge. Each of these options can be successfully used. However, none of these alternatives can actually replace the original tooth, the way it emerges from the gingival tissue and its ability to maintain the bone height. A prosthetic tooth, supported by an endosteal implant, may be the closest match to the natural tooth.
For a single missing tooth, the conventional removable partial denture would be an option of last resort. It is bulky and unaesthetic and can be difficult to wear. The three-unit fixed cemented bridge is certainly a time-tested prosthetic treatment option. However, it requires that adjacent teeth, often intact, be prepared as terminal abutments. The acid-etched resin-bonded bridge was first introduced as a conservative approach to tooth replacement. Most resin-bonded bridges involve non-restored teeth, with minimal tooth preparations, to serve as retention. This bridge often results in over-contoured attachments on the lingual, resulting in plaque traps. In a 10-year retrospective study, an overall debonding (falling-off) rate of 31 percent occurred.
The implant-supported crown is an excellent alternative to replacing a missing tooth if there is adequate width and height of remaining alveolar bone. Therefore, treatment planning for an endosteal root form implant requires accurate planning but can result in a very realistic natural appearing result that aids in maintaining bone height.
The ability to restore the fully edentulous mandible and maxilla through the use of endosteal implants has expanded to include the partially edentulous population. Conventional dental treatment options, such as the removable partial denture, the three-unit fixed bridge and the resin-bonded retainer, may need to be reconsidered now that endosteal root form implants have been proven effective. The prosthetic tooth, supported by an endosteal implant, emerges from the tissue attached to a “root” (the implant) in a manner that closely resembles the natural tooth it replaces. In a clinical situation where there is adequate bone and adjacent virgin teeth, the single tooth implant restoration can certainly be considered the primary treatment alternative.
Article #11: Implant-Supported Prosthesis (Teeth) for Cleft Palate Patients
Q: I have difficulty with my complete upper denture staying in position since I have a cleft palate. Can dental implants be used to help make this more secure?
A: Adult patients with cleft palates often have an upper jaw with deficient bone and soft tissue irregularities. Surgically altered cleft palates are often associated with deformities of the upper jaw or maxilla. The dental and periodontal status in these adult patients are commonly in a compromised state from providing long-term support and retention for prostheses (teeth) that aid in speech. Oropharyngeal rehabilitation of adult patients with cleft palate can be a perplexing clinical situation.
Most adult patients with cleft palates who have undergone numerous surgical procedures for closure of alveolar palatal or pharyngeal defects have large areas of scar tissue present. Scar tissue is less resilient and more difficult to border mold, and this inhibits formation of an acceptable denture border seal. The palatal vault often contains numerous scar bands, is flat and extends no higher than the back of the residual alveolus with little underlying bone. These tissue characteristics and anatomic irregularities make fabrication of an acceptably stable and retentive prosthesis difficult.
Prosthetic evaluation involves an analysis to determine the type of restoration that is required, which may be a fixed or removable partial or complete denture with or without a pharyngeal extension. The aim of this prosthesis is to improve speech, deglutition, mastication and aesthetics. To achieve these goals, the prosthesis must have adequate retention and stability, provide appropriate functions and be hygienically maintainable by the patient.
Titanium self-tapping implants can successfully achieve osseointegration in the maxillary alveolus and pterygoid plates of the patient with a cleft palate. The use of implants can provide adequate retention and stability for the prosthetic restoration of oropharyngeal structures, thus improving speech, deglutition, mastication and aesthetics.
Article #12: Cosmetic Dentistry/Ceramic or Gold Inlay/Onlay
Q: I have many posterior teeth that need existing silver amalgam fillings replaced and would like to have my teeth restored with natural-appearing fillings without them being completely cut down for porcelain crowns. What are my options for cosmetic dentistry?
A: For many years, dentistry has tried to create restorative materials that resemble natural tooth structure both in color and hardness. Many materials have been developed and tried over the past 100 years, yet few, if any, have met all the requirements needed for filling restorations in the posterior region of the mouth. Gold restorations are long-lasting and silver restorations are less expensive, yet neither meet the aesthetic considerations requested by many patients. Composite or plastic restorations are very aesthetic but tend to wear down. Previous porcelain inlays were aesthetic and wear-resistant but are prone to fracturing.
Today, a very durable and aesthetic ceramic reinforced leucite restorative material is now available. This is a type of ceramic material that not only exhibits similar hardness to natural tooth structure but also closely resembles its color. Another important feature is the method of cementation of these restorations. They are actually bonded to the remaining tooth structure. This results in the saving of existing tooth structure and can also re-establish its original strength and decrease tooth sensitivity.
Today, conventional impressions, temporary fillings and multiple appointment visits can be a thing of the past. The CEREC system by the Siemen’s Corporation allows us to provide the highest quality aesthetic restorations in a single appointment visit. A revolutionary CAD/CAM, computer aided design/computer aided milling, procedure replaces the conventional laboratory fabrications of the restoration. Through an optical scanning procedure, which takes a few minutes, the computer provides all the information necessary for the CAD/CAM machine to make the CEREC restoration from a block of high-quality ceramic material. The result is an aesthetic high-quality ceramic restoration with no conventional impressions or multiple appointment visits. It also allows more of the tooth to remain intact by bonding the restoration, which also strengthens the tooth. Finally, this restoration usually has less cost to the patient than traditional crowns.
Click here to learn more about Cosmetic Dentistry
Article #13: Your Bite — Why It’s Important to Your Dental Health
Q: Since I have had crown and bridgework completed on my upper front eight teeth, my bite feels strange. My dentist has adjusted my bite, but that has not made a difference. There is no pain when I bite, and none of the teeth have a problem. My jaw muscles feel tight, and a space has been created between two of my back teeth. What should be done?
A: Like your blood pressure, your bite can change as you grow older or as a result of wear disease or extensive dental restorative treatment. The way your teeth come together, your occlusion or bite, is one of the most important aspects of your oral health. Improper occlusion, which may include excessive tooth forces, damaging sliding contacts or contacts that interfere with your ideal bite, can result in serious dental problems, such as open contacts, like you have developed between your back teeth.
Dentists have always been aware of the dangers that poor occlusion can have:
• Early failure or discomfort in fillings, crowns, bridges, implants or dentures
• Aggravation of periodontal conditions that lead to tooth loss
• TMD syndrome — a painful joint or muscular disorder of the face and neck
• Excessive tooth wear
Identifying and measuring bite problems can be difficult. Your occlusion is dynamic. It changes because of wear, stress, fatigue and other factors. Some changes in your bite may be symptoms of problems that are much better treated sooner rather than later.
Evaluating the occlusion or bite is done by analyzing diagnostic casts made from dental impressions that have been mounted on an articulating instrument, with traditional marking paper that leaves a spot on the teeth where they bite into it and now with a computed diagnostic instrument. Through the use of this new computed diagnostic instrument, the T-Scan, your dentist can evaluate your bite more easily and more precisely and make occlusal corrections and establish harmony. The T-Scan works with a thin plastic sensor that you bite on. The sensor sends a movie of your occlusion to a color video screen. Both you and your dentist can view the movie and discuss your bite.
Article #14: Tooth Extraction With Implant Replacement
Q: I am a young woman in my early 30s and am thinking about having a front tooth that has a failing root canal replaced with a dental implant. Since it is in front, I am very concerned with the appearance. Can you help me with the type of implant procedure to be used?
A: The type of implant procedure with an endosteal root form implant is important along with the newer tapered implant shapes. The surgical procedure can vary from a one-stage one-appointment with the healing abutment placed through the soft tissue at the time of placement to considerations for infection and need for bone grafting. There is also a simple procedure to expand bone with instruments called osteotomes and eliminate the time and cost needed for grafting if done as a separate procedure. The amount and height of the bone is essential for good aesthetics with the final restoration or crown.
The implant is allowed to heal in the bone for a period of zero to six months and become integrated, or securely attached to the bone. The newer generation of implants are more secure at time of placement and can be restored more rapidly than the older generation implant of straight design.
Since the front tooth is failing from an old root canal, when it is removed, a bone graft may be needed to rebuild the ridge and restore the “gum tissue” or soft tissue for correct contour of the prosthetic tooth or crown. This bone grafting procedure is called a ridge augmentation. When there has been acute or chronic infection, such as a failing root canal, there may be bone loss that needs to be addressed before the implant is placed. If possible, the graft is completed at the time of implant placement. If a graft is completed, the position of the implant and the resulting soft tissue will create a natural appearance for the crown. Careful planning is necessary for the best result along with the prosthetics or laboratory support. It is the prosthetics or laboratory work that is finally seen by the patient, and although the crown or teeth are really separate from the surgical implant work, they are very related to the health of the tissue and the final aesthetics.
Since the laboratory plays such an important role in the final result, the closer the laboratory is, such as an in-office dental laboratory, the better. The type of material used in building the teeth as well as the skill of the technician are the final determinants for the result. The appearance of the crown or realism will be greatly influenced by the type of porcelain that it is made with. An in-office laboratory can work with the more sophisticated and aesthetic porcelain, and the quality can be excellent.
Article #15: Cosmetic Dentistry/Improving Color & Strength of Teeth
Q: I am approaching middle age and have never been happy with the color of my teeth. What are my options?
A: The most conservative approach is the home bleaching systems provided by dental offices. These usually consist of custom trays that have been designed to hold the home bleaching gel, a 10 to 20% carbamine peroxide, in intimate contact with the teeth for an hour or more at a time. This procedure is often done at night while sleeping for 5 to 10 nights. The amount of lightening of the teeth is dependent on the length of time the bleaching agent is used, its concentration and the repeated daily application. The safety of the system has been reported to have no damage to the teeth and only an occasional tooth sensitivity that is very transient. The lighter color of the teeth tends to remain, but some return to original color after a number of months. This can be reversed by a reapplication of the bleaching solution. Another approach is to have a one-visit power bleaching at the office.
Another approach to improved tooth appearance is with thin porcelain cosmetic veneers. This would be indicated in cases where extensive wear or existing tooth position and/or fillings would not be improved by home bleaching. Many times, there might be rotations that create shadows, and these can be corrected by veneering the teeth with porcelain to create a more symmetrical arrangement. Whenever veneering is done, designing the final shapes of the teeth for treatment is important. This is usually done by a diagnostic wax-up and/or with cosmetic imaging. The wax-up helps the technician who is going to make the veneers, and the cosmetic imaging allows the patient to visualize the results at chairside in color on a TV screen prior to their fabrication. The wax-up also helps the doctor as the teeth need to be reduced on the front surface to about the thickness of a fingernail to allow room for the porcelain veneers. These are then bonded to the teeth and are very strong.
The final approach to lightening and correcting tooth appearance would be with traditional crowns, which involves more tooth reduction. These may be all porcelain that are bonded onto the teeth or porcelain that is fused to a metal substructure. Since these crowns are often in the aesthetic zone, appearance is important. The type of porcelain used can determine how real the color is. The more sophisticated porcelain crowns use a multi-layering technique, and the color is built in. The simpler crowns might have only three layers of color while the more cosmetic ones may have eight or more layers. The margins or junction of the crowned teeth also might be made totally out of porcelain and blend into the root without a dark line. Finally, the artistic skill of the dentist and technician determines the end result. Usually, these cases are preplanned with a wax-up and imagery before being started when the highest cosmetic result is desired. These are then either bonded or cemented on and are very strong.
The type of material used in building the teeth as well as the skill of the technician are the final determinants for the result. The appearance of the crown or realism will be greatly influenced by the type of porcelain that it is made with. An in-office laboratory can work with the more sophisticated and aesthetic porcelains, and the quality can be excellent.
Article #16: Dental Implant/Dentures and Natural Appearance
Q: Why do dentures often look like false teeth?
A: The treatment of a patient with missing teeth has much to do with natural appearance and facial expression. The appearance of the entire lower half of the face depends on the teeth and their supporting structures. It is usually not difficult on casual meeting to detect a person who is wearing poorly constructed dentures. The characteristic thin, drooping upper lip that appears lengthened and has a reduced red vermilion border is typical of malpositioned anterior teeth as well as reduced vertical dimension between the chin and nose. Tense, wrinkled lips often reveal the person’s efforts to hold the dentures in place. The drooping corners of the mouth tell the story of the misshaped and misplaced dental arch form of the anterior teeth, the thin denture borders and often reduced vertical facial dimension.
The result is the appearance of premature aging, which is caused not by age itself but by the lack of support for the lips and cheeks due to the loss of or improper placement of teeth. The apparent extra fullness of the lower lip may be the result of too broad a lower dental arch or the elimination of the natural groove below the lower lip, the mentolabial sulcus. This may indicate that the lower anterior teeth have been placed too far toward the tongue or that the lower denture flange is over-extended or too thick.
It is also not uncommon for the treating prosthodontist to find that the laboratory denture setup has resulted in very small, perfectly set teeth that have been placed too far above or below the lips, thus giving the patient a false, unnatural appearance. By the prosthodontist arranging the denture setup himself, this can be prevented.
An implant stimulates the bone and maintains its dimension and density in a manner similar to healthy, natural teeth. As a result, the patient’s facial features are not compromised by lack of proper support. In addition, implant-supported prostheses are positioned in relation to aesthetics, function and speech, not in “neutral zones” of soft tissue support.
If you have dentures and feel that your appearance could be improved, many times by stabilizing the denture base with dental implants and focusing on individualized tooth setups, a more natural appearance can be achieved. Having on-staff dental technicians aids in personalized care.
Article #17: Dental Implants and Maxillary Sinus Lift
Q: I have been wearing a removable partial denture to replace my upper molar teeth for many years. Can I have implants placed in that area?
A: One of dentistry’s goals is to make implant treatment available to all patients who may benefit from it. Unfortunately, the advanced bone loss that accompanies long-term wearing of an upper complete denture or upper removable partial denture renders these same patients poor candidates for dental implant treatment.
The patient with advanced bone loss in the posterior upper jaw poses serious challenges for implant therapy. Generally, the type of bone available in the upper jaw is spongy bone with its large spaces and non-dense, soft nature. This is not the quality of bone suited for dental implant therapy. Another factor influencing dental implant treatment in the upper jaw is with the loss of upper posterior teeth, enlargement of the sinuses occurs, which encroaches on what little bone remains. Successful implant therapy in the maxillary jaw is dramatically reduced if poor bone quality is combined with a lack of sufficient bone height and density. Management of these conditions is accomplished with the use of larger or wider and longer implants with a bioactive coating and sinus grafting.
Subantral augmentation or sinus grafting is a way to improve results in the severely resorbed posterior upper jaw. By increasing bone in the sinus region, the subantral augmentation enables the practitioner to use larger and longer implants that are indicated in the posterior region to replace molars in order to withstand the biting forces exerted there. Sinus augmentation should be considered whenever a lack of alveolar bone height prevents the use of implants of 10mm in length. Ridge augmentation or bone expansion is also advisable if the alveolar bone width is less than 4mm.
Article #18: Dental Implants/Bone Strengthening/Nerve Repositioning
Q: If inadequate bone is present to support dental implants, what are the available options for patients needing dental implants?
A: Many times, patients will be missing teeth in the posterior region of the jaws. Because they have been missing for a number of years, the bone has resorbed and there is inadequate support for dental implants. In the posterior region of the upper jaw, the bone resorbs and the maxillary sinus enlarges, eliminating the bone needed to hold the dental implants. This has been managed for many years by performing a procedure called a sinus lift with subantral augmentation. A window is made into the maxillary sinus and the area receives a bone graft. Dental implants may be placed at the same time. The bone can be taken from the patient’s hip, however, the results from using bone from bone banks has proven as effective and easier for the patient. This bone has been sterilized and is very safe.
When there is inadequate bone in the front or anterior of either jaw, the area receives a bone graft again using banked bone and a technique with a “barrier” that helps the body restore bone. This has been done for more than 20 years and is very predictable as well as very safe. If the area is extremely deficient in bone volume, bone from the patient may need to be transferred from one part of the mouth or head and secured to the area with bone screws.
In the posterior region of the lower jaw, it may be possible to use any of the grafting procedures used in the anterior region of the jaws, but there still may be insufficient room to place dental implants. If the root form type is used, then the nerve is repositioned to allow the full thickness of the jaw bone for the implant. There is always a risk of numbness if this is done, but this procedure has been documented in literature since the late ‘60s and has been very effective.
Article #19: Dental Implants/How Many for a Lower Jaw?
Q: After wearing complete dentures for many years, I find that my lower jaw no longer has an adequate ridge to support a complete lower denture. I have been told that two root form implants could be used but four or five would be better. Would you please explain the difference? I also have a fear of dental procedures.
A: Most people that have been wearing complete dentures for 10 to 15 years will have a greatly reduced foundation for the lower denture. Usually for these people, implants can only be placed in the anterior region of the lower jaw. If only two implants are placed, then the lower teeth will only be supported in the front and not in the rear, where most of the normal chewing takes place. This results in movement of the lower denture, food collecting under the teeth with discomfort, as when a raspberry or tomato seed is lodge under a lower denture.
However, when four or five implants are placed in the anterior lower jaw region, the total weight of the biting forced can be directed down through the implants to the bone and the teeth will feel solid like natural teeth. This physiological bone loading promotes spontaneous bone strengthening in the areas of advanced bone loss of the mandible, resulting in greater bone strength. An implant-connecting bar is used to support the teeth and connects the implants together, which strengthens the system. The teeth resting on the implant-connecting bar will have total support and stability, which prevents them from moving and pressing into the gun tissue when eating. Food cannot get under the teeth and cause discomfort. The comfort and satisfaction in having stable lower teeth is extremely rewarding to the recipient. Another major implant benefit is that now the prosthodontist can set the teeth and position them where they belong, and thus the appearance becomes very natural.
For any patient having a surgical procedure done, the comfort in having monitored IV sedation with medications to eliminate post-operative swelling and resulting pain is the standard of care. Patients are always surprised at how little post-operative swelling and discomfort they have and how little they remember of the procedure.
Article #20: Dental Implants and Facial (Aesthetics) Appearance
Q: At age 79, I find that my lower denture makes eating difficult and none of the five sets of dentures that have been made for me over the years seem to make my face appear natural. Will having dental implants placed help in restoring a more normal facial appearance?
A: The treatment of a patient with missing teeth by a prosthodontist has as much to do with the beauty of the face as any other medical specialist. The appearance of the entire lower half of the face depends on where the teeth are positioned. It is usually not difficult on casual meeting to detect a person who is wearing poorly constructed dentures. The characteristic thin, drooping upper lip that appears lengthened and has a reduced red vermilion border is typical of malpositioned anterior teeth and a reduced vertical facial height. Tense, wrinkled lips often reveal the person’s efforts to hold the dentures in place. The drooping corners of the mouth tell the story of the misshaped and misplaced dental arch form of the anterior teeth, the thin denture borders and often reduced vertical facial height.
The result is the appearance of premature aging, which is caused not by age itself, but by the lack of support for the lips and cheeks due to the loss or improper placement of teeth. The apparent extra fullness of the lower lip may be the result of too broad a lower dental arch or the elimination of the natural groove below the lower lip, the mentolabial sulcus. This may indicate that the lower anterior teeth have been placed too far toward the tongue or that the lower denture flange is over-extended or too thick.
One must study normal facial landmarks before attempting to achieve the goal of natural and pleasing facial expressions with implant teeth. The facial landmarks of the lower third of the face have a direct relationship to the presence of the natural teeth. The contours of the lips depend on their intrinsic structure and the support for them provided by the teeth and soft tissue or denture bases behind them. When the natural teeth are lost, these landmarks and surrounding facial tissues become distorted. To reestablish normal appearance and function, implant teeth must be replaced in the same position as the natural teeth that were lost. You may have dentures and feel that your appearance needs to be improved. This can be done by stabilizing the denture base with dental implants and the prosthodontist focusing on a personalized denture setup, resulting in a natural appearance.
Since the laboratory plays such an important role in the final result, having the laboratory in office and the prosthodontist complete the setup results in a natural appearance. The type of material used in the teeth as well as the skills of the prosthodontist are the final determinants for success.
Article #21: Cosmetic Dentistry/Ceramic vs. PFM Crowns
Q: Currently, I have porcelain-fused-to-metal crowns that have dark areas around them at the gum line. Will the new crowns being placed in the front of my mouth have this same result long term or can this be eliminated?
A: Porcelain-fused-to-metal crowns have become the most popular crowns in dentistry. Their acceptance began in the late 1950s, culminating in their current widespread use. Practitioners also know that gold crowns provide greater longevity with less wear of opposing teeth than PFM crowns. Today, all-ceramic crowns have higher aesthetic possibilities without metal to stimulate metal allergies.
PFM crowns may have a chalky, opaque or gray appearance. Because of previous experience with soft tissue recession and display of metal, patients may ask if their new crowns will have a gray or black portion at the gumline. But this negative appearance is not necessary if dentists have prepared teeth properly and if PFM crowns are constructed properly by technicians. In my opinion, after 33 years as a dentist and from observing tens of thousands of crowns, most PFM crowns can be discerned easily from natural teeth by an untrained observer.
The primary reasons for unacceptable aesthetics include:
• An inadequate amount of tooth reduction by dentists, which lets opaque porcelain and metal show
• Technicians’ use of external coloration techniques instead of internal pigmentation, which allows crown colors to change after a few years of exposure to mouth conditions and dissolution of the external coloration
If practitioners plan to provide PFM crowns that look like real teeth, they will be willing to pay higher-than-average laboratory fees and provide excellent, well-reduced tooth preparations for technicians. Do ceramic (non-metal containing) crowns have better appearance than PFM crowns? Well-controlled, documented research is not available, but surveys and studies have reported on the relative aesthetic acceptability of porcelain veneers to PFM crowns. Porcelain veneers are overwhelmingly considered to have better aesthetic acceptability than PFM crowns. Several conservative types of ceramic crowns are really large versions of porcelain veneers.
It’s easy to see that their aesthetic characteristics are better than typical PFM crowns, without regard to practitioner or technician. Although both PFM and all-ceramic crowns can have excellent aesthetics, all-ceramic crowns, as placed in the United States today, are usually better in appearance.
Article #22: Comprehensive Implant Dentistry with Fixed Bridgework
Q: I have worn an upper denture with a lower removable partial for five years and would like to have implants with teeth that are not removable. Would this be possible? Presently, I have five lower front teeth.
A: If the five lower teeth have good bone support and good tooth position, then this would be an advantage as they would help determine where the remaining teeth should be positioned for appearance, speech and function. The first step would be a screening panoramic X-ray and mounted diagnostic casts or models on a dental articulator. This helps determine the present and final tooth position when the treatment is completed as well as visualize the amount of gum tissue change or bone loss that has occurred from having the teeth removed and wearing the complete denture and lower removable partial denture. The more the gum tissue has changed or bone loss has occurred over the years, the larger the upper teeth need to be. If fixed bridgework is to be made, a grafting procedure would be needed to augment or rebuild the upper ridge in order to replace normal size teeth. Often, the posterior upper jaw will have little bone as the maxillary sinuses enlarge over the years, and a procedure known as a sinus lift would be needed to recreate the necessary bone support for the implants that hold the teeth.
Whenever there is a question about the amount of bone present or position of the implant to be placed or a vital structure is in close proximity, a CAT scan or CT (Computed Tomography) X-ray should be taken to aid in the determination of the bone thickness, height and length. These are done at an imaging center or a hospital, and by reformatting the X-ray slices, the computer is able to show the thickness and height of bone present. This aids in the positioning of the implant prior to surgery as well as determining if grafting is needed.
When patients have worn an upper complete denture for many years with a few remaining lower anterior teeth and a lower removable partial denture, they often develop “combination syndrome.” This means that the upper jawbone tends to lose bone in the anterior region, making the complete denture unstable. They also have bone loss in the lower posterior jaw. This type of loss usually requires some bone grafting to compensate for these changes. A good diagnostic workup is important to determine the length of treatment time, the cost and treatment options that could include fixed bridgework or teeth that are not removable. Finally, the teeth then could be made out of porcelain fused to metal that is cemented or screwed onto the implants. The screw-retained bridge allows it to be removed by the dentist. If bruxism is a problem, then the teeth might be made of a material that allows some wear so the lower five teeth would not have a wear problem as would occur if porcelain were used in the upper teeth.
Article #23: Dental Implants Provide Similar Function, Appearance and Feel of Natural Teeth
Q: Would you like to eat out with your friends at a restaurant but feel apprehensive? Would you like to go dancing but just can’t face meeting new people? Are you daring enough to talk or laugh in public although your loose-fitting dentures limit your sense of expression due to the fullness in the roof of your mouth that may cause them to dislodge or fall out?
A: These feelings may be familiar to anyone who wears removable partials or dentures. Even people with well-made removable dental appliances may experience some or all of these problems, but now there is an answer.
Modern advances in dental implant technology and surgical techniques mean that more and more people who have lost some or all of their natural teeth can live fuller, richer, happier lives. Dental implants may take the form of a single substitute tooth root that provides a stable foundation for the missing tooth, or it may take the form of a framework and support many teeth. The implant is anchored firmly into or onto the jawbone through a natural process where the bone and the implant become integrated, providing the same stability as natural teeth. This means that replacement teeth can look, feel and function just like real teeth.
Since dental implants, like teeth, are embedded in or on the jawbone, the painful chewing associated with removable teeth is eliminated, as implants put no chewing pressure directly on the gums. While implants have been available for many years, new advances make them available to more people. Bone can be strengthened to provide support for implants where they could not have been placed before.
With dental implants, you can enjoy a greater variety of foods. Your mouth is restored as closely as possible to its original state, with increased comfort and preservation of the facial structure and with a good possibility that jaw deterioration will be eliminated. Best of all, you will be able to smile more naturally, and you can be confident in normal activities such as talking and laughing.
Dr. EDward M. Amet, American Board-Certified Prosthodontist, founded the Reconstructive & Implant Dental Center in 1988 and has been in practice for 33 years. He has extensive training and experience in both the surgical and prosthodontic phases of prosthodontic and implant therapy, with skilled and talented on-site dental technicians. These on-site dental technicians make the prosthetics personalized for each patient. “Our goal,” states Dr. Amet, “is to provide our patients with the finest quality of care as comfortably and pain-free as possible.”
Article #24: Implant Dentistry/One-Appointment Subperiosteal Implant
Q: I am interested in knowing more about dental implants that would be indicated in cases where advanced bone loss has occurred. I have been told that bone grafting would be needed that might be obtained from the hip or some other location inside the mouth. What other type of dental implant procedure can be done in these cases?
A: The full and partial subperiosteal implant has been used successfully for more than 40 years as a viable treatment method in oral implantology and is ADA approved. This implant is placed with no drilling in the jawbone, and it strengthens the remaining jaw by resting on top of the bone under the gum tissue and supports the front and back to increase the strength of the thin jaw. During the 1978 Harvard Consensus Conference and the 1988 Consensus Development Conference on dental implants, a panel of experts determined that the subperiosteal implant compared favorably with the success averages for other more standard dental treatments such as fixed multiple-unit crowns and bridges. However, placement of the implant has required two surgeries: one for a more difficult bone impression and another easier one for implant placement. The necessity of the two-stage procedure has often discouraged both patient and dentist from consideration of this treatment modality.
Through advanced computer and X-ray technology, it is now possible to create an exact replica of the bone of the mandible or maxilla, thus eliminating the need for the bone impression surgery. A computed tomography (CT) scan X-ray is taken, and the image is transferred to a magnetic tape and entered into a computer. An exact 3D image of the bone is generated. From this image, via CAM (computer assisted manufacturing) methods, a precise model of the bone is created on which the custom implant can be constructed.
In the early 80s, it was discovered and pioneered that a naturally occurring substance in the body called hydroxylapatite (H.A.) could be placed on the outer surface of dental implants. This H.A. coating, when placed on the outer surface of the subperiosteal implant, has resulted in success rates of 97.7 percent, as reported by Dr. Robert James. The CT-scan-generated, H.A.-coated subperiosteal implant technology has been available since March 29, 1984. Today, the one surgery can be done with only three small incisions as opposed to the original extensive incision, and this decreases the healing time. The implant can also be put into function from the first day so that the patient is never without teeth.
Article #25: Dental Implants/Types of Subperiosteal Implants
Q: I am interested in knowing more about a type of dental implant called the subperiosteal implant.
A: The mandibular subperiosteal implant has played a successful role in selected cases in the past, and with current technology, eliminates the necessity for two surgeries. This does not mean that it is the implant of choice for the mandible with advanced resorption: it has limitations. Currently it does not fit the description of contemporary implant dentistry.
Limitations of subperiosteal implants are:
• The one-piece design, implant and connecting bar
• The added cost of this type of procedure, especially when only one surgery is performed
• The need to custom make this device and the limited availability of laboratory technical support
• The limited number of patients that may be treated with the device. Advanced bone loss or excess alveolar bone will create problems, compromise medical status, controlled diabetic, etc.
• The limitations of retreatment
• Only the mandibular dental arch can be considered for successful long-term therapy
Current Contemporary Implant Dentistry uses a definition of individual implant components, in other words, the implant is separate from the abutment(s) and implant connecting bar and the overlaying prosthesis. Currently any case being treated with a mandibular subperiosteal implant can be more easily treated with endosteal implants to obtain a totally implant-supported and stabilized prosthesis.
Threaded endosteal implants may be used in the mandible with advanced bone loss. In 1994, David Hockwald and Michael Marshall published an article in Oral and Maxillofacial Surgery Clinics Nov 1994; 765-779. Marshall again reported at the March 1998 AO meeting on “Spontaneous Ridge Growth Associated With Dental Implants.” Hans Bosker also reported this in Oral Surg Oral Diagn, Pub Freo r.,y. Kuopio, Finland 2:1991
Using the symphysis for bone anchorage implants and only loading the mandible through these for a totally implant supported prosthesis, brings Wolf’s law into action and there is “Spontaneous Ridge Growth Associated With Dental Implants.” This only occurs with advanced bone loss in a thin mandible and is a normal physiological phenomena. This does not occur with the mandibular subperiosteal implant with advanced bone loss. This also eliminates the need for bone grafting in most patients.
Prior to the surgical procedure, it is necessary to obtain a computed tomography scan or (CT) scan for bone density and dimension determination. The type of implant, its width and length can then be determined. Most patients with advanced bone loss and only a portion of the basal bone remaining at 7 to 10mm are easily converted, with bone anchored implants and a connecting bar prosthesis, to an implant-supported and stabilized prosthesis. There can be immediate loading of these short implants the day of surgery. The patient’s existing mandibular denture is converted into a treatment overdenture.
Two variations of bone strengthening that I have found very successful in very thin mandibles with minimal basal bone remaining are:
1. Bone from the osteotomy sites is harvested with a bone collection aspirator and then placed into the osteotomy sites prior to implant placement. This is pushed by the implant through the osteotomy and the drilled opening of the mandible and displaces the periosteum from the symphysis and aids in bone strengthening in that area. This coupled with the posterior strengthening increases bone thickness in the mandible without grafting in most very advanced atrophied cases.
• The other variation is as published in my recent article on Ramus Frame Implants. This does not involve autogenous bone grafting from the hip, rather using banked bone in a non-loaded manner using a tunneling technique for mandibular bone strengthening.
One final point to remember is that as the patient becomes geriatric, the ability to maintain hygiene may be compromised. An infection of the subperiosteal implant could result in the need for implant resection or removal with loss of the entire implant and prosthesis. The patient may have to undergo this procedure at a time when replacement may not be possible and related lack of eating problems may occur. When threaded, non-H.A.-coated endosteal implants have been well-placed in the mandible, these same types of complications do not seem to occur even with decreased hygiene.
Article #26: Dental Implants/Bone Grafting/The Healing Phase
Q: I am interested in knowing more about dental implants, as I have been told that I have advanced bone loss from wearing a complete upper denture and a lower removable partial denture with six lower anterior teeth for the last 30 years with resulting “Combination Syndrome.”
A: When teeth are lost, the bone in the jaws begins to resorb or shrink because it is no longer needed to support the teeth. This is accelerated by the wearing of complete dentures or removable partials as they rest on the gum tissue. This shrinking of the jawbone may make it impossible to wear a denture satisfactorily or to place root form dental implants without grafting. In such a situation, careful planning is necessary.
Many times, using another type of implant called a “blade implant,” which also osseointegrates and has the approval of the American Dental Association, can eliminate the need for complex grafting. The type of grafting that must be undertaken if root form or cylinder-type implants are placed can be from bone taken from another area of the jaw or from a membrane. Blade implants, however, are designed to be placed in areas where the bone is thin or lower in height such as the lower posterior jaw, thus eliminating complex grafting. Since you have a complete upper denture, you would continue to wear this after the lower blade implants have been placed. You will never be without teeth. The upper jaw can have a sinus elevation with subantral augmentation while the lower jaw is healing for eventual implant placement with fixed bridgework.
The sinus grafting material used would be irradiated bone from a tissue bank. Since this material has become available, the results are equal for simultaneous or delayed implant placement. This has become the material of choice for my patients. The upper complete denture would be able to be used during the entire healing time. Once your lower implants are restored with fixed bridgework, the upper denture would be much more stable. The implants placed into the sinus elevation would support the upper denture so that the last grafting procedure could be done for the pre-maxilla. This is the hardest area to graft under a denture and could only be done once the denture is stabilized. Bone would be taken from the chin or ramus and the bone material placed into that area allows the body to restore the missing bone. The section of bone from the chin or ramus would be attached to the upper anterior jaw (pre-maxilla) with tiny small screws and then dental implants placed. After the upper implants and graft have all integrated, either fixed bridgework or a secure bar overdenture could be made to satisfy the missing teeth, gum tissue and appearance.
Article #27: Implant Dentistry/Types of Implants
Q: I am 59 years old and have worn complete dentures for 30 years. I have been told a lower complete denture will not fit my jaw well because of little remaining bone. I have also been told that in order to have bone anchored implants placed, I would need to go through a lengthy bone grafting procedure and it might take a year or more for the implants to take. Are there any other implants that are American Dental Association approved that might work and not be as difficult to perform, take as long to heal or be as expensive?
A: There are several types of dental implants that have ADA approval and the most common one used is the root form or screw implant. These are placed into the lower anterior jawbone. Often, as in your case, after wearing a lower complete denture for many years, the bone has resorbed and little is left for a denture foundation. The bone graft is to build up the lower jaw to have room as well as strength to accept this type of implant. The bone grafting usually takes six months to heal, then three to six additional months for the implants to heal. However, even in cases of advanced bone loss, I have not found the necessity for bone grafting after using a CT scan. Usually, the implants are placed with one-stage surgery with healing abutments in place through the soft tissue the day of surgery. This then allows the patient’s existing lower teeth to be placed on top of the implants that day, eliminates second-stage surgery, and the treatment for the new teeth can be started after 4 weeks.
Another type of ADA-approved implant that is only placed in the anterior portion of the lower jaw is the transosseous implant, but this type often involves general anesthesia because of its extensive nature. An incision is made directly underneath the chin and results in very little appearance change from it. The implant is primarily in the anterior portion of the lower jaw as it passes through the bone in order to be anterior to the jaw nerve. The prosthesis, or teeth, for this type of implant is not routinely supported in the posterior of the jaw and the teeth must then rest on the gum tissue in addition to the implant.
Another type of dental implant that has been in use since the late 1940s is the subperiosteal implant. It has approval by the ADA and with the advent of the CT scan X-ray, only one surgical appointment is needed to place it. This implant is indicated in cases where there is advanced bone loss, and the implant is put into function the day it is placed. No drilling is done in the jawbone to place this type of implant. Rather, it rests on top of the bone under the gum tissue. The implant can also be put into function the day of surgery and there is not a waiting period before the prosthesis or teeth can be used on top of the implant.
Article #28: Implant dentistry With Cosmetic Improvement of Facial Appearance
Q: Currently, I have a removable partial denture replacing my upper six front teeth with some bone loss and facial cosmetic changes apparent. Can dental implants be used to restore this area and will bone grafting be needed?
A: The cosmetic restoration of facial appearance and improved dental function with implant prosthodontics is directly related to restoring missing intraoral hard and soft tissues and the aesthetics and technical abilities of the dentist and dental technician. The use of dental implants for oral rehabilitation has revolutionized prosthodontics over the past three decades. Multiple studies have proven the efficacy and excellent long-term prognosis with dental implants.
While initial research and clinical use were directed primarily toward the edentulous patient, more recent studies have focused on the aesthetic and functional use of implants in the partially edentulous patient. The most challenging area of modern implant dentistry remains the “aesthetic zone” in the anterior maxilla and mandible. Replacing multiple anterior teeth in the otherwise dentate patient requires careful consideration of the location and volume of residual bone, soft tissue aesthetics, and room for the implants and prosthesis.
Most dental implants are placed in a delayed manner, after tooth extraction, allowing for both hard and soft tissues to heal prior to implantation. Unfortunately, this allows for resorption of the alveolar ridge in both the buccolingual and corono apical directions. Studies have shown that as much as 3 to 4 mm of resorption can occur during the first six months after extraction without the intervention of tissue grafting or strengthening techniques.
Since facial appearance depends on where the teeth are positioned, as well as their shape, form, surface texture and color, it is often not difficult on casual meeting to detect a person who has complete dentures or an implant-fixed partial denture. Small evenly set teeth in complete dentures can detract from realism. The lips will often appear lengthened and tense or thin in an attempt to conceal the anterior teeth, which may be set too far posterior in the mouth. The result is the appearance of premature aging, which is caused not by age itself but by the change of facial appearance from the chin and nose being too close together with the soft tissue compensating for this decreased distance between these parts of the face. The result is the lack of an aesthetic dental smile and premature aging. Dental implants, if placed with a delayed surgical technique for an implant ceramometal reconstruction with only residual native bone, may develop teeth of unnatural length with spaces between the root structures.
If a delayed placement protocol is used or if grafting procedures are ineffective, the prosthetic phase of implant dentistry must restore the missing structures artistically and functionally to integrate with the existing dental structures. The implant-supported removable partial denture provides for restoration of soft and hard tissues while enhancing the aesthetic results of the replaced dentition through a unique removable implant prosthesis design.
Article #29: The Process of Alveolar Distraction Osteogenesis for Improved Implant Placement
Q: Currently, I have a removable partial denture replacing my upper six front teeth with some bone loss and facial cosmetic changes apparent. Can dental implants be used to restore this area? Will bone grafting be needed, and if so, what types are indicated?
A: Dental implants can be used to restore this area, and the type of bone improvement or grafting could be done with distraction osteogenesis. This is a surgical process for reconstruction of skeletal deformities. It involves gradual, controlled displacement of surgically created fractures, which results in simultaneous expansion of soft and hard tissues with increase in bone volume. It is the ability to reconstruct combined deficiencies in bone and soft tissue that makes this process unique and invaluable to all types of reconstructive surgeons. Gavriel Ilizarov, a Russian orthopedic surgeon, is credited with developing the armamentarium and describing the biological basis of this process for the management of orthopedic limb deformities. The concepts described by Ilizarov have been adapted and modified for use in maxillofacial surgery. Although the majority of surgical experience with distraction technology has been in orthopedics, early results indicate the process to be equally effective in facial skeletal reconstruction. It is now possible to apply distraction technology to deformities of the jaws and dentoalveolar processes. Development of miniature, internal distraction devices have made this clinically feasible and practical.
The process of alveolar distraction osteogenesis involves mobilization, transport and fixation of a healthy segment of bone adjacent to the deficient site. A mechanical device, the alveolar distraction device, is used to provide gradual, controlled transport of a mobilized alveolar segment. When the desired repositioning of the bone segment is achieved, the distraction device is left in a static mode to act as a fixation device. Displacement of the osseous segment results in positioning of a healthy portion of bone into a previously deficient site. Because the soft tissue is left attached to the transport segment, the movement of the bone also results in expansion of the soft tissue adjacent to the bone segment. Left at the original location of the segment is a chamber that has a natural capacity to heal by filling with bone. This propensity of the chamber to heal by filling with bone instead of fibrous tissue is a function of the surrounding, healthy cancellous bone walls and location within the skeletal functional matrix. As a result of the gradual distraction, the alveolar housing, including the osseous and soft tissue components, are enlarged in a single, simultaneous process, and implants of normal size may be placed.
Article #31: Understanding Combination Syndrome and How to Correct This Dental Problem
Q: Currently, I have been told that I have a dental condition titled “Combination Syndrome.” What is this and how can it be corrected? I have been wearing an upper complete denture for over 20 years and cannot seem to get a new upper denture that will fit. I also wear a lower partial and have six lower front teeth.
A: COMBINATION SYNDROME is a description of a dental condition that is the result of long-term use of a few (often six) remaining lower anterior teeth, usually #22-27, against a complete maxillary denture with all other natural teeth missing and a mandibular Kennedy class I removable partial denture. The normal biting pressure or forces are directed from the remaining mandibular anterior teeth and transmitted through the anterior contact of the maxillary denture, with resulting resorption of bone, slow auto-rotation and tilting of the denture upward and backward and with the maxillary anterior teeth becoming less visible and the posterior teeth becoming more visible as the denture is rotated from function with bone loss of the premaxilla.
There are seven characteristics usually associated with this condition:
1. Bone loss in the premaxilla.
2. Dropping of the posterior maxillae (tuberosities).
3. Extrusion of the lower anterior teeth.
4. Posterior bone loss in the mandible under the RPD.
5. Papillary hyperplasia of the maxilla.
6. Decreased occlusal vertical dimension.
7. Facial aesthetics often altered dramatically.
The change in facial aesthetics and function from the resulting syndrome is a prosthodontic challenge to restore as solutions with traditional dentistry are limited, the age of the patient is often a limitation and financial costs are usually of concern.
Many cases have been completed to date using a one-surgical visit technique to place the mandibular endosteal implants, with a cantilevered implant connecting bar with prosthesis and placement of an HA graft in the maxillary ridge to correct for the lost and moveable soft tissue, with the final prosthesis inserted the same day. The design of the lower implant support system allows a stabilized occlusion for the maxillary prosthesis to aid in predictable ridge graft healing. Treatment time has been compressed with reduction from six or more months to one surgical visit. Ninety-five percent of the treatment is completed in one surgical visit and four prosthetic visits in the same week. A technique that decreases treatment time and costs with an excellent aesthetic result is possible with this technique.
Article #32: Conservative Periodontal & Cosmetic Restorative Dentistry “Short Tooth Syndrome”
Q: I have been told that I should have porcelain cosmetic veneers on my six upper front teeth. My teeth, however, are in good shape and do not have any fillings or crowns and I am only 19 years old. I do not want my teeth cut down and veneers placed but do want treatment to correct some spaces and improve the color and short appearance of the teeth. What is another, more conservative type of treatment?
A: You have several good questions and they all deserve an adequate answer. The need for cosmetic correction of the appearance of short teeth is very common following orthodontic treatment procedures, taking certain kinds of medications, having less than ideal hygiene or nightly or daily tooth grinding. Often, the natural teeth will have an appearance of being too small or too short for a pleasing smile. A “gummy” smile is often the result. Also, if any spaces are present between the anterior teeth, it may be the result of the natural teeth being too narrow. If this is present, (usually it’s the lateral incisor) and orthodontic treatment cannot correct this, the soft tissues or gum tissues tend to grow and fill the space(s). This makes the cosmetic correction of tooth size less predictable and more challenging for the dentist when closure is attempted using only cosmetic composite bonding or porcelain cosmetic veneer procedures alone. Porcelain veneers also have to be replaced every few years and full crowns may be needed for replacements.
The most natural looking conservative and cosmetic dental result can be achieved by first correcting the excessive soft tissue contours to restore natural tooth length and contour. Cosmetic periodontal surgery can be done either with or without sedation dentistry and can be combined with wisdom teeth removal when sedation dentistry is used. The soft tissue corrections can be done without discomfort or bleeding with primary closure. The final results of the conservative and cosmetic periodontal care will enable teeth to have a normal length-to-width ratio and will often achieve the ideal golden proportion appearance. The teeth may then be bleached, if necessary, to improve their color and the tooth with the space(s) next to it can be bonded with a composite resin and not have to be cut down to place a veneer or FULL CROWN. The aesthetic future of the bonded composite restorations may eventually dictate its replacement, and the restoration can easily be removed and replaced if needed. Again, the tooth will not need to be cut down as with a porcelain veneer or a full crown.
Many cases have been completed to date using a one-surgical-visit technique to correct the gummy “short tooth syndrome” problem and wisdom teeth removal at the same appointment. The natural shape of the anterior teeth is usually very pleasing and the treatment results are very rewarding, partially because of the conservative treatment and partially because of the decreased costs. Treatment time has been compressed with reduction from three to six weeks for veneers to one surgical visit for cosmetic periodontal care. 95 percent of the treatment is completed in one surgical visit and two to four prosthetic visits. A conservative and cosmetic technique that decreases treatment time and costs with an excellent aesthetic result is possible with this approach.
Article #33: Extractions With Immediate Implant Placement With PTFE Membrane and Mineralized Bone Grafting
IMMEDIATE IMPLANT PLACEMENT IN ADVANCED DENTAL BREAKDOWN CASE
Q: I am a woman in my early 40s and am thinking about having some teeth that are failing replaced with dental implants. Since it involves several teeth, I am very concerned with the procedure, how long it will take and if grafting is needed. Can you help me with the type of implant procedure to be used?
A: The type of implant procedure for teeth with advanced dental breakdown is important, along with the newer, tapered implant shapes. The surgical procedure can vary from a one-stage, one-appointment procedure with the healing abutment placed through the soft tissue at the time of placement to considerations for infection and the need for bone grafting. There is also a simple procedure to expand bone with instruments called osteotomes and eliminate the time and cost needed for grafting if done as a separate procedure. The amount and height of the ridge (bone) is essential for good aesthetics with the final restoration or crown.
The implant is allowed to heal in the bone for a period of zero to six months and become integrated, or securely attached to the bone. The newer generation of tapered implants are more secure at time of placement and can be restored more rapidly than the older generation implants of straight design.
Since the posterior teeth are failing from an advanced dental breakdown, when they are removed a bone graft may be needed to rebuild the ridge and restore the gum tissue, or soft tissue, for correct contour of the prosthetic tooth or crown. This bone grafting procedure is called a ridge augmentation. When there has been acute or chronic infection, such as a failing root canal or infected teeth, there may be bone loss that needs to be addressed before or at the time the implant is placed using a nonresorbable PTFE membrane. If possible, the graft is completed at the time of implant placement. If a graft is completed, the position of the implant and the resulting soft tissue will create a natural appearance for the crown. Careful planning is necessary for the best result, and the use of a 3D type X-ray or CBCT (cone beam computerized tomography), along with a guided surgery protocol. The prosthetics laboratory support is needed for the surgical phase of implant dentistry. Finally, the prosthetics or laboratory work is seen by the patient, and although the crown or teeth are really separate from the surgical implant work, they are very related to the health of the tissue and the final aesthetics.
Since the laboratory plays such an important role in the final result, the closer the laboratory is, such as an in-office dental laboratory, the better. The type of material used in building the teeth as well as the skill of the technician are the final determinants for the result. The appearance of the crown will be greatly influenced by the type of porcelain that it is made with. An in-office laboratory can work with the more sophisticated and aesthetic porcelains and the quality can be excellent.
Article #34: TEETH TODAY: Extractions With Immediate Implant Placement and Loading With Immediate Placement of Teeth
Q: I am a lady in my early 70s and am thinking about having all my teeth that are failing replaced with dental implants. Since it involves all my teeth, I am very concerned with the procedure. Can you tell me about the type of implant procedure to be used?
A: If you’re missing a tooth or many teeth, you may find that there are other things you are missing. You may wish for a natural smile and the ability to chew enjoyable foods and speak clearly. You may feel self-conscious about the missing teeth and changes in your mouth or concerned as other teeth shift position with time. Perhaps you have experienced a change in facial aesthetics or how the mouth and face are changing with an appearance of an older individual. The effect of tooth loss varies from person to person and depends on what exactly has been lost. When a tooth with its root is lost, the bone around the tooth will gradually shrink or atrophy, and the remaining teeth may shift, and chewing will become more difficult with time, and negative facial changes may occur. There are a number of ways to replace teeth. When a single tooth is lost, an implant and crown are the first choice for replacement. When all teeth are lost, the patient is forced to replace all teeth and gum tissue with either complete dentures or with an implant supported prosthesis. When all teeth are lost and their replacement does not require replacement with an implant per tooth, fewer implants are required.
Older techniques associated with dental implants would often require many months or longer to complete treatment. Dr. EDward M. Amet is a suburban Overland Park, Kansas, prosthodontist and Diplomate of The American Board of Prosthodontics and Diplomate of The American Board of Oral Implantology/Implant Dentistry. He has been placing implants since 1974 and has developed and perfected many techniques that enable patients to literally have “Teeth Today”!
As Dr. Amet explains the concept of “teeth-in-a-day,” this refers to replacement of natural and prosthetic teeth with dental implants that are placed so that not only do patients get their new teeth the same day, they will have more natural-looking teeth and gum tissue because of the shortened treatment time. Replacing the tooth or teeth immediately has many advantages over extended implant times. For instance, delayed placement of a tooth or teeth allows the surrounding gums and bone tissues to shrink. Later, when the dentist attempts to place an implant, the gums may have receded to create an unnatural looking gum line, or there may be inadequate bone remaining. Other advantages of this cutting-edge technology include dramatic reduction in treatment time and the number of appointments, immediate full function of the new tooth or teeth, a very real natural look, and much less discomfort. Many of Dr. Amet‘s patients have reported almost no pain after the procedure.
Typically, dental implants are allowed to heal from 12 weeks to 6 or more months before they are used to support new teeth. The “teeth-in-a-day” concept can usually be used to replace a single tooth, several teeth or a full mouth of teeth, upper or lower, with remarkable comfort, predictability and aesthetics. Other procedures like extractions can also be accomplished at the same time. As Dr. Amet reports, it is possible to walk into the office missing one tooth or a whole mouthful of teeth and leave with a completely new set that are firmly anchored, unlike complete dentures or removable temporaries.
“While extractions with implant replacement and prosthetic replacement may seem like extensive treatment for a patient to go through in one day, most patients respond very favorably with little discomfort, swelling or disruption in their daily schedules,” says Dr. Amet. He has performed this procedure on patients ranging in ages from teens to 90s with similar success. Patients who have undergone the procedure rarely take more than over-the-counter pain medication for a few days afterward. Also, they report a dramatic improvement in aesthetics, chewing ability, security and overall dental comfort as compared to failing teeth or loose irritating dentures.
“Anyone who is missing one or more of their teeth due to injury, disease or decay may be a candidate for dental implants,” says Dr. Amet. If one, a few or all teeth are missing, dental implants are the best option. Occasionally, older patients express concern that their age may prevent them from the benefits that dental implants offer. However, health is more of a determining factor than age. If you’re healthy enough to have a tooth extracted, you’re probably healthy enough to receive dental implants.