In our previous paper (Oral Health, April 2007) we discussed the importance of managing the dentogingival complex during routine restorative procedures to avoid black triangles, biologic width violations and recession. Even more attention to detail is required around implants if our goal is to create ideal esthetics (Figs. 1 & 2).
Unfortunately as difficult as it is to esthetically replace a single missing tooth with an implant, it becomes even more difficult to manage cases when there are multiple missing adjacent teeth. Why? When there are two or more adjacent teeth missing and the treatment plan calls for implant restorations, any surgical mismanagement may lead to failures, which may be difficult or impossible to correct prosthodontically1 (Figs. 3A-D).
What do we know about managing tissues around implants? Tarnow showed that when the contact point between two natural teeth is 5mm or less from the alveolar bone the papilla will fill the embrasure 100% of the time.2 Choquet showed it was also true around implants.3 In another paper, Garber and Salama compared the amount of soft tissue that can be AUGMENTED above the bony housing between teeth, pontics, implants and every combination thereof.4 There results showed the following vertical soft tissues limitations; tooth-tooth 5.0mm, tooth-pontic 6.5mm, pontic-pontic 6.0mm, tooth-implant 4.5mm, implant-pontic 5.5mm and implant-implant 3.5mm.
Knowing that we can support 5.5mm between an implant and a pontic and only 3.5mm between two adjacent implants, it follows that we can create better papilla form (shape and height) and therefore better esthetics around an implant adjacent to a pontic than we can around two adjacent implants. In fact as a general rule, never place implants side by side if you can avoid it.
Consider pontics and even orthodontics to move teeth if necessary.
Let’s look at this closer by reviewing the case in Fig. 4. Here a three unit bridge was traumatized in a sporting accident and the central incisor was rendered unrestorable (Fig. 4 panorex). The obvious option was to place one implant for each missing tooth. However a better (and less expensive) option would be to place one implant in the central position and cantilever a pontic in the lateral position as per Salama-Garber’s work.4 This works especially well when replacing the maxillary lateral because the occlusion can be easily managed. Figures 4A-G shows the progress of papilla formation using one implant and a pontic. How do we know if the tissues will fill in? Unfortunately here you can’t measure the sulcus. Instead here you must either sound to bone or use radiographs to measure the contact point to the bone.5,6 Notice how the embrasure has completely filled in by six months. This would not have been the case if two implants were placed side by side as in the case from the Journal of Prosth (see earlier).
In the next case we need to master mixed restorations to achieve ideal esthetics. This patient was referred to our office with a request from the referring dentist for two implants to replace the missing right and left maxillary lateral incisors. However on examination, her anterior teeth were found to be short and unaesthetic measuring only 7-8mm, (average length of maxillary central incisors is approx. 10-12mm).7,8 Furthermore, the CEJ could not be probed clinically. Radiographs revealed normal sized teeth but not fully erupted through the alveolus. There was in a sense no biologic width (i.e. there were no connective tissue and no epithelial attachments to the root surface, which probably contributes to the angry looking tissues). The alveolus was in direct contact with the CEJ. This is actually a case of altered active eruption.9
Had implants been placed without consultation regarding her short clinical crowns, the patient would have been committed to short unaesthetic teeth forever. Why? Once the implants are placed any future thought of larger teeth would have required crown lengthening procedures and would have been contraindicated due the inevitable exposure of the implant collars or worse, implant threads. After consultation with the patient regarding her overall smile, an alternative treatment plan was worked out to include crown lengthening procedures from second premolar to second premolar to improve the overall length of her anterior teeth, and simultaneous implant placement in the right and left lateral positions to replace the missing laterals. How much bony removal and at what height to placed the implants follows the guidelines set out in Gargiulo10 and Vacek’s11 work. (Figs. 5A- R). Final result at insert shows much better length/ width proportions.
Can use this information to create papillas where no adjacent teeth exist? Yes, but there must be adequate height and volume of tissue present. If it doesn’t exist you must generate it.12 Let’s look at Patricia’s case (Figs. 6A-E). An implant restoration would seem to ideal here. The soft tissues height was good but the soft tissue width and bony requirements were inadequate. The CT scan reveals no labial plate of bone and the patient’s ramus and mental areas were inadequate donor sites for the volume of bone required to regenerate the missing alveolus. Since the patient wasn’t willing to undergo multiple grafting procedures, the only option was to rely on conventional crown and bridge procedures to replace the missing teeth paying careful attention to the occlusion and using surgery to create proper pontic form and papilla.
Pontic sites can be surgically carved into the soft tissues13 (and hard tissue if necessary), but you must ensure that at least 2mm of space exists between the underside of the pontic and the final bone position (this is actually the same biologic width requirements that’s necessary around teeth). With careful planning the restorations can appear to have life like papillas. Figure 6C shows the soft tissue response the same day of surgery and provisionalization. Managing this occlusion is beyond the scope of this article, but suffices to say the anterior guidance must be kept on the cuspids both in lateral and straight protrusive excursions.
In summary, lack of proper papilla form or black triangles can only be managed once we know why they exist. They can be best diagnosed by probing the sulcus or by sounding to bone. There are only three possibilities for lack of proper papilla form:
1. Inadequate interproximal contact. The natural dentition or the restorations have inadequate interproximal contacts (i.e. the contacts are more than 5mm away from the interproximal bone).
2. Tissues were inadvertently displaced. This is only a temporary problem.
3. Periodontal disease. The bone doesn’t exist to begin with (Fig. 7). If the bone is too apical due to periodontal disease, then the tissue will be too apical and the papilla won’t fill the space. Furthermore, attempts directed at the tissue in these cases will be futile. YOU CANNOT GROW PAPILLAS! If the interproximal sulcus depth is 3mm or more a black triangle may develop, and treatment will need to be directed toward the periodontal problem.
REFERENCES: PART TWO
1.Saad A et al Nonsurgical management of interdental papilla associated with multiple maxillary implants. Journal Prosth, 2005; 93: 212-215.
2.Tarnow, D.P., et al J Clin Perio 1992: Dec 63 (12): 995-60.
3.Choquet V, et al J. Periodontology, 2001; 72:1364-71
4.Salama and Garber, Practical Periodontics Aesthetic Dentistry 1998: 10: 1131-1141.
5.Altering gingival levels: the restorative connection. J. Esthetic Dent. 1994; 6(1):3-9 Kois JC.
6.The restorative-periodontal interface: biologic parameters. Periodontology 2000, 1996; 11:29-38 Kois JC.
7.Ufuk H et al Analysis of maxillary anterior teeth. Facial and dental proportions. J Prosth, 2005; 94: 530-538
8.Rufenacht CR Fundamentals of esthetics. Chicago: Quint, 1994: 87-94.
9.”Diagnosis of Gummy smiles”, F. Spear, Seattle Institute, Washington Seattle Jan.
10.Dimensions and relations of the dentogingival junction in humans. Gargiulo, Wentz, Orban, J. periodontal 1961; 32: 261-267.
11.Vacek J.S. et al, Intl Journal of Prosthodontics and Restorative Dentistry, Vol. 14, #2, 1994.
12.Abrams L. Augmentation of the deformed residual ridge. Compendium CE Dent. 1980, 1: 205-214.
13.Seibert JS Reconstruction of deformed ridges using grafts Compendium CE Dent. 1983, 4: 549-562.
Sulcus Depth and the Dentogingival Complex (PART III)