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1 Implants or Pontics: Decision Making for Anterior Tooth Replacement Frank Spear J Am Dent Assoc 2009;140; The following resources related to this article are available online at jada.ada.org ( this information is current as of July 11, 2011): Updated information and services including high-resolution figures, can be found in the online version of this article at: This article cites 15 articles, 0 of which can be accessed free: Information about obtaining reprints of this article or about permission to reproduce this article in whole or in part can be found at: Downloaded from jada.ada.org on July 11, American Dental Association. The sponsor and its products are not endorsed by the ADA.

2 PERSPECTIVES CLINICAL DILEMMAS Implants or pontics Decision making for anterior tooth replacement Science has provided today s restorative dentist with continually improving tools for the replacement of missing teeth, and providing esthetically pleasing outcomes for single missing anterior teeth is a highly predictable procedure in the hands of most clinicians. The predictability decreases substantially when significant bone and soft tissue also have been lost; however, even in this scenario, a competent interdisciplinary team generally can produce an acceptable result by using an implant or a fixed partial denture with an ovate pontic to replace the missing tooth. When the loss is not of one tooth but of numerous teeth, particularly if those teeth are adjacent to each other, the esthetic challenge is immensely more complex. As implants have improved and placement techniques have evolved to take advantage of those improvements, the Frank Spear, DDS, MSD informed clinician may gravitate toward use of implants as the preferred solution for all missing teeth. As implant science continues to improve, the use of fixed partial dentures may become an anachronism, much like the specialized preparations of hemisectioned molars re - quired in perioprosthodontics. At one time, the technique for creating these unusual preparations was taught in every dental school; today, it is a lost art. Fortunately, the loss is realized only in situations in which bone grafting, implant placement or both are impossible an everdecreasing occurrence. Although it may be preferable to have a root wherever a tooth is missing, the esthetic challenges presented by multiple missing anterior teeth often require the combination of implants and ovate pontics to achieve acceptable esthetic results. The average papillary height above bone between natural teeth is 4.5 millimeters. 1,2 When a single-tooth implant is placed, papillary levels are determined by the height of the bone on the adjacent natural teeth, not by that of the bone around the implant. 3-5 Therefore, the papillary height between a tooth and an implant will be similar to what it was before tooth removal. The facial gingival margin around the implant is related to the bone levels on the implant, as well as to the thickness and position of the free gingival margin before tooth removal. 6,7 SINGLE MISSING ANTERIOR TEETH The least predictable soft-tissue outcome with a single anterior implant is associated with interproximal bone loss in the adjacent natural teeth. Because interproximal bone determines papillary height, creating esthetic papillary heights can be difficult. If the newly edentulous space is to receive not an implant but rather a pontic as part of a fixed partial denture, the bone level on the teeth adjacent to the space still will determine the papillary heights JADA, Vol September 2009

3 The most significant difference between a pontic and an implant is that the clinician can significantly alter the soft tissue that will surround a pontic and create a papilla by means of soft-tissue grafting procedures. When the clinician places a softtissue graft, the amount of tissue above the bone between a pontic and a natural tooth, or between a pontic and an implant, averages 6.5 mm an increase of 2.0 mm, or 44 percent. In some patients, the tissue height after grafting can be as high as 9.0 mm. 8 When natural teeth adjacent to a single edentulous space have bone loss, soft-tissue ridge augmentation followed by placement of a pontic always will achieve greater coronal papillary height than will a singletooth implant placed into the edentulous space. In a situation in which the papilla, to be esthetically acceptable, must be more than 4.5 mm above the level of the bone, placement of a fixed partial denture with an ovate pontic is the most appropriate treatment decision. MULTIPLE MISSING ANTERIOR TEETH When multiple teeth are missing or require removal, the soft-tissue ramifications are different because of the biology of the periodontium and the responses of the bone and soft tissues. To understand these ramifications, it is helpful to consider the biological response of the soft tissue after tooth removal. In a case involving the removal of two central incisors, the interproximal bone height on the lateral incisors will determine the papillary height be - tween the lateral incisors and whatever is placed in the space. The soft tissue on the mesial side of the lateral incisor will act exactly as it would in the case of a single-tooth replacement. The facial free gingival margin height in each central incisor site also will be similar in response to a single missing tooth. The facial bone level and tissue thickness will determine the height at which the facial gingival margin stabilizes. The difference between the single The restorative challenge created by the loss of both central incisors relates directly to the osseous scallop that existed between those incisors. edentulous space and the space created by removal of the two central incisors is what happens to the papilla that existed between them before the extractions. 9,10 If we assume no periodontal disease existed before tooth removal, the osseous crest around both central incisor sites will follow the scalloped form of the cementoenamel junction. The gingiva on the facial bone will be positioned so that, on average, the free gingival margin is 3.0 mm coronal to the osseous crest. As the cemento - enamel junction flows from the facial aspect into the interproximal aspect, the bone follows, and an average osseous scallop of 3.0 mm is created. Because soft tissue follows the scallop of the bone, the osseous scallop presumably should result in a gingival scallop of 3.0 mm. However, when teeth are present, an interesting phenomenon occurs: the papilla is 1.5 mm more coronal to the osseous crest than to the facial tissue. This additional 1.5 mm added to the 3.0-mm average osseous scallop results in the tip of the papilla s matching the 4.5-mm average noted previously (Figure 1). The restorative challenge created by the loss of both central incisors relates directly to the osseous scallop that existed between those incisors. Replacement of the central incisors with two single implants adjacent to each other is one of the prosthetic restorative options available. During placement, the clinician places the implant apically until the platform is level with the facial osseous crest. Most implants in use today are not scalloped; because the bone is scalloped, the interproximal platform of the implant may be apical to the interproximal osseous crest by as much as 3.0 mm. Although implant placement retains bone that would be lost if the site remained edentulous, a certain amount of bone adjacent to the implant is expected to resorb across time, usually to the level of the first thread of the implant. 11,12 Resorption of the interproximal osseous crest results in a flattening of the osseous crest. Maintaining a minimum distance of 3.0 mm between implants seems to lessen this flattening, but researchers agree that, regardless of the distance between implants, the crestal bone undergoes some degree of resorption and flattening. 13 The visible and esthetic issue in these osseous changes is the corresponding flattening of the gingival architecture. Tarnow and colleagues 13 identified a papillary height of 4.5 mm above bone between two adjacent teeth JADA, Vol September

4 Figure 1. The average osseous scallop is 3.0 millimeters from the facial aspect to the interproximal aspect, and the average gingival scallop is 4.5 mm from the facial aspect to the interproximal aspect between natural teeth. and of 4.5 mm above bone between a natural tooth and an adjacent implant. With the placement of adjacent implants, papillary height between the implants changes from 4.5 mm to between 3.0 and 3.5 mm above the bone. 13 This change represents a dramatic and potentially devastating esthetic challenge to the replacement of teeth with implants. Even if the interproximal osseous crest could be maintained perfectly between two implants, the papilla will stabilize 1.0 to 1.5 mm apical to where it was between the teeth simply because of the change in softtissue levels above the bone (Figure 2). Adding this 1.0- to 1.5-mm difference to the osseous changes affecting the interproximal crestal bone height makes it clear why maintenance of an esthetically correct papillary height between adjacent implants is such a difficult proposition. The use of pontics to replace the two central incisors involves its own challenges. 14,15 The soft tissue between the central incisor pontics and the lateral incisor abutments, as well as the facial soft tissue, will behave as described above when a pontic replaces a single tooth. The challenge is the papilla between the adjacent pontics, just as it is between adjacent implants. The interproximal crestal bone be - tween the extracted central incisors will resorb, creating a flat bony ridge with subsequent loss of potential papillary height. This esthetic challenge differs from that posed by the implants because of the ability to augment the soft-tissue height above the flattened os - seous crest between the lateral incisors to an average 6.5 mm. MAKING AN APPROPRIATE DECISION Thorough evaluation, careful diagnosis of the existing condition and a clear understanding of the responses of the hard and soft tissues provide a basis for predicting treatment outcome. The following manifestations are the four most common esthetic dilemmas created by multiple missing teeth. dthe teeth are present and need to be removed; there is no periodontal disease affecting the teeth to be removed. dthe teeth are present and need to be removed; there is Figure 2. When adjacent implants are placed 3.0 or more millimeters apart and the facial and interproximal osseous crest is retained (red lines), the papilla between the implants may be within 1.0 to 1.5 mm of the original papillary height (yellow line). periodontal disease affecting the teeth to be removed. dthe teeth are missing and the osseous and soft-tissue ridge are flattened; the free gingival margin location on the ridge is acceptable as a papillary position. dthe teeth are missing and the osseous and soft-tissue ridge are flattened; the free gingival margin is positioned significantly apically to an acceptable papillary position. With knowledge of the usual behavior of the bone and soft tissue, we can discuss each of the four manifestations and select the most appropriate treatment. Tooth removal and re - placement in the absence of periodontal disease. The most predictable situation is one in which the patient requires removal of multiple teeth in the absence of periodontal disease. The challenges in this situation are related first to the choice between implants and a fixed partial denture and, second, if implants are chosen, how many should be placed and where. The appropriate choices depend on which teeth are being removed. For example, if the two maxil JADA, Vol September 2009

5 lary central incisors are being removed and they are supported by healthy bone, placing adjacent implants can result in a predictable and esthetic final result. The papilla between the central incisor implants and the adjacent lateral incisors will be excellent, the facial gingival margins can be augmented easily, if required, and the papilla between the central incisor implants should remain within 1.0 to 2.0 mm of the preextraction papillary level if the clinician places the implants 3.0 mm apart and most of the interproximal osseous crest is maintained (Figure 3). The clinician could treat this same patient with a fixed prosthesis by using the lateral incisors as abutments. Since the interproximal bone between the extracted central incisors most likely will be lost, the risk of soft-tissue recession in the area in which a papilla needs to be created between central incisor pontics is an esthetic challenge. As described previously, soft-tissue augmentation before completing the restoration creates significant tissue height that could be used to form an excellent papilla between the pontics. When the teeth to be removed involve a central incisor and a lateral incisor, or a lateral incisor and a canine, the treatment choices become much less clear. The difficulty encountered is twofold. First, placement of adjacent implants in the central incisor and lateral incisor sites, or the lateral incisor and canine sites, is difficult if the surgeon is to maintain a minimum of 3.0 mm between the platforms of the implants. This situation means there is a high risk that interproximal osseous crest will be lost between the implants A Figure 3. A. A patient who required the extraction of both central incisors. Note the excellent bone level and papillary height. B. Because the interproximal osseous crest was maintained and the soft tissue supported at the time of tooth removal, an excellent interimplant papilla exists. C. Final restorations exhibit minimal change in papillary height when compared with pre-extraction height. Even in this ideal situation, the difference is 1.0 to 1.5 millimeters apically. Photographs courtesy of Dr. Greggory Kinzer. B C across time, with subsequent loss of papillary height (Figure 4). Second, when papillary height is lost between the central incisor and lateral incisor on one side while natural teeth exist on the other side, the discrepancy in papillary height is much more noticeable than a slight loss of papillary height in the middle of the face between adjacent central incisor im - plants. These reasons combined with the fact that use of adjacent implants to replace a central incisor and a lateral incisor, or a lateral incisor and a canine, is not required for force management in the anterior aspect make placement of a single implant in the site of the central incisor or the canine, with a cantilever replacing the lateral incisor as an ovate pontic, esthetically more predictable and functionally acceptable. An alternative for prosthetic replacement of a missing central incisor and lateral incisor or lateral incisor and canine is surgical soft-tissue augmentation and placement of a fixed partial denture. Although this method can create a pleasing esthetic result, it is a much more complex restoration structurally and functionally, particularly when the lateral incisor and the canine are being replaced by pontics. When removal of three or four adjacent anterior teeth with good periodontal support is required, my preference is placement of implants separated by one or two pontics. If both central incisors and one lateral incisor need to be removed, I would choose placement of one implant in the proximal central incisor site, placement of a central incisor ovate pontic and placement of the second implant in the lateral incisor site. This design allows the creation of excellent papillary heights in all locations because of the predictability of the soft-tissue augmentation in the ovate pontic site (Figure 5). JADA, Vol September

6 A Figure 4. A. Adjacent implants placed in central and lateral positions. Note excellent interproximal bone but minimal interimplant distance. B. At insertion, no black triangle was present; however, six months after insertion, papilla has receded as bone is lost. C. Twelve months after implant placement, soft tissue has migrated apically as bone between the implants has continued to resorb. A C Figure 5. A. A patient with three ankylosed teeth but with excellent bone levels. B. Teeth nos. 8, 9 and 10 were removed and immediate implants placed at no. 8 and no. 10. C. Connective-tissue grafting in pontic area no. 9 and over implant no. 10. D. Final restoration after grafting: a three-unit zirconia prosthesis consisting of an implant abutment at no. 8, a pontic at no. 9 and an abutment at no. 10. If removal of all four incisors is required and good periodontal support exists, the clinician has two equally acceptable options for implant prostheses. One is placement of implants in both lateral incisor locations, with the replacement of both central B C B D incisors as ovate pontics. The second is placement of the implants in the central incisor locations with a mediating space of at least 3.0 mm; the lateral incisor ovate pontics then can be cantilevered from the central incisors. Both options produce acceptable esthetic, structural and functional results. Tooth removal and re - placement in the presence of periodontal disease. Considering the same manifestations discussed previously, but adding the presence of pre-existing bone loss resulting from periodontal disease, provides new challenges. Foremost among these is the loss of predictability of the papillary height after tooth removal in the areas of periodontal disease. When periodontal disease is present, the bone does not always respond as it would if it were healthy, which often leads to greater resorption of bone and a greater degree of papillary recession. Therefore, to avoid an open gingival embrasure, the clinician must position contacts more apically than is esthetically desirable. The clinician is left with the challenge of using implant restorations that will be acceptable functionally and structurally but less so esthetically, or of forgoing the use of implants and using soft-tissue grafting with fixed partial dentures in areas in which grafting and pontics can produce significantly more soft tissue over the interproximal bone. The difference between tissue heights of 3.5 and 6.5 mm above bone can be the difference between an esthetic success and an esthetic failure. The final decision about which modality is best suited for success will be based on the esthetic requirements created by the lip line and mobility and the condition of the remaining teeth. If the adjacent teeth are unrestored, it may be preferable to conserve tooth structure by using implants rather than preparing unrestored teeth. Some esthetic compromise may 1164 JADA, Vol September 2009

7 A C E Figure 6. A. A patient requiring extraction of teeth nos. 8 and 9 because of extensive bone loss. Note excellent papillary levels. B. Significant bone loss has occurred, creating an esthetic dilemma regarding soft-tissue position. C. Orthodontic eruption was used to attempt to move the bone coronally. D. After the eruption, there has been minimal if any improvement. E. Implant placement. F. Final restorations. Note the minimal gingival scallop caused by an apically placed papilla and a long contact. This esthetic compromise was expected owing to the patient s significant interproximal bone loss before implant placement. Photographs courtesy of Dr. David Mathews and Dr. Vince Kokich. be in the patient s best interest and should not be dismissed without serious consideration and discussion. Slow orthodontic eruption before extraction is another option to consider when it is necessary to remove multiple adjacent teeth with periodontal disease. 15 Although eruption of a single tooth that is to be ex - tracted does not alter the final papillary heights, because those heights are dictated by the bone on the adjacent teeth, the eruption of multiple teeth before extraction may move interproximal bone coronally. This movement of the bone is not highly predictable, however, so the clinician must inform the patient that a perfect esthetic result is unlikely and that short papillae, long contacts and more rectangular final restorations could be expected (Figure 6). Tooth replacement in the presence of a flattened ridge. The final two manifestations, both involving a flattened ridge, are the most difficult to manage esthetically. When multiple teeth are removed, the bony ridge tends to flatten rapidly unless the clinician does something to alter the process. In cases in which the teeth have been missing for a significant time, the interproximal osseous crest will be gone completely. Recreating vertical bone height in situations in which multiple teeth have been removed is difficult and unpredictable. For this reason, when the teeth are missing before any treatment, use of adjacent implants results in inadequate papillary height. Using a connective graft and pontics, however, can create and maintain significantly more soft tissue above the interproximal bone than is possible with adjacent implants. Therefore, the clinician must inform the patient that the best esthetic result may involve pontics rather than implants in some sites. Selection of the most appropriate sites for using connective-tissue grafting and a pontic next to an implant will B D F minimize esthetic compromises and can achieve an excellent esthetic result (Figure 7). CONCLUSION Patients who have multiple missing anterior teeth, or patients for whom removal of multiple anterior teeth is JADA, Vol September

8 A B C Figure 7. A. A patient with a significant ridge defect and previously placed adjacent implants in the lateral and canine position. B. The lateral incisor implant has been covered with soft tissue rather than used and the canine implant uncovered after soft-tissue grafting. C. The final restoration: the lateral incisor is now cantilevered off of a canine implant. Photographs courtesy of Dr. David Mathews. required to restore dental health, bring with them significant issues in ensuring an acceptable esthetic result. Careful evaluation of the bone available; the periodontal health when teeth are still present; the amount of tooth displayed during normal activities; the functional and structural requirements of the restorations; and the patient s esthetic concerns, demands and expectations will lead the dentist and the patient through a therapeutic decision tree, each branch requiring a choice. This series of thoughtful choices ultimately ensures that the clinician will achieve the best solution for each patient. The solution may include compromises in the interest of giving greater importance to a portion or portions of the desired outcome, but they will be compromises made with the full knowledge and understanding of all parties. In the end, investing the time, thought and communication necessary to make the right choice creates two beautiful smiles in a pleased patient and a happy dentist. Dr. Spear is the founder and director, Seattle Institute for Advanced Dental Education, 600 Broadway, Suite 490, Seattle, Wash Address reprint requests to Dr. Spear. Disclosure. Dr. Spear did not report any disclosures. The views expressed are those of the author and do not necessarily reflect the opinions or official policies of the American Dental Association. The author thanks Dr. Greggory Kinzer for the photographs in Figure 3; Dr. David Mathews and Dr. Vince Kokich for the photographs in Figure 6; and Dr. David Mathews for the photographs in Figure Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol 1992;63(12): van der Velden U. Regeneration of the interdental soft tissues following denudation procedures. J Clin Periodontol 1982;9(6): Choquet V, Hermans M, Adriaenssens P, Daelemans P, Tarnow DP, Malevez C. Clinical and radiographic evaluation of the papilla level adjacent to single-tooth dental implants: a retrospective study in the maxillary anterior region. J Periodontol 2001;72(10): Grunder U. Stability of the mucosal topography around single-tooth implants and adjacent teeth: 1-year results. Int J Periodontics Restorative Dent 2000;20(1): Kan JY, Rungcharassaeng K, Umezu K, Kois JC. Dimensions of peri-implant mucosa: an evaluation of maxillary anterior single implants in humans. J Periodontol 2003;74(4): Kois JC. Predictable single-tooth periimplant esthetics: five diagnostic keys. Compend Contin Educ Dent 2004;25(11): , 898, Smukler H, Castellucci F, Capri D. The role of the implant housing in obtaining aesthetics: generation of peri-implant gingivae and papillae part 1. Pract Proced Aesthet Dent 2003;15(2): Salama H, Salama MA, Garber D, Adar P. The interproximal height of bone: a guidepost to predictable aesthetic strategies and soft tissue contours in anterior tooth replacement. Pract Periodontics Aesthet Dent 1998;10(9): Elian N, Jalbout ZN, Cho SC, Froum S, Tarnow DP. Realities and limitation in the management of the interdental papilla between implants: three case reports. Pract Proced Aesthet Dent 2003;15(10): Saadoun AP, Le Gall MG, Touati B. Current trends in implantology, part II: treatment planning, aesthetic considerations, and tissue regeneration. Pract Proced Aesthet Dent 2004; 16(10): Hermann JS, Cochran DL, Nummikoski PV, Buser D. Crestal bone changes around titanium implants: a radiographic evaluation of unloaded nonsubmerged and submerged implants in the canine mandible. J Periodontol 1997;68(11): Hermann JS, Buser D, Schenk RK, Cochran DL. Crestal bone changes around titanium implants: a histometric evaluation of unloaded nonsubmerged and submerged implants in the canine mandible. J Periodontol 2000;71(9): Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol 2000;71(4): Spear FM. Maintenance of the interdental papilla following anterior tooth removal. Pract Periodontics Aesthet Dent 1999;11(1): Salama H, Salama M, Kelly J. The orthodontic-periodontal connection in implant site development. Pract Periodontics Aesthet Dent 1996;8(9): JADA, Vol September 2009