International Journal of Periodontics & Restorative Dentistry, 02/2005

There are biologic limits of the soft tissue dimension around implants; therefore, the limiting factor for the esthetic result of implant therapy is the bone level at the implant site. Clinicians must focus on the 3-D bone-to-implant relationship to establish the basis for an ideal and harmonic soft tissue situation that is stable over a long period. In some situations, missing bone is a limiting factor for esthetics; in others, it is possible to regenerate new bone around implants. As a certain amount of bone resorption occurs around implants as soon as the implant is in contact with the oral environment, the distance between an implant and adjacent tooth, as well as the distance between two implants, is as important as the bone volume on the buccal side of the implant head and in the papillary area, especially for the long-term result. This article discusses the 3-D bone-to-implant relationship and its influence on soft tissue esthetics around implants.

A surgical protocol for the placement of Emdogain during new attachment procedures was published in this journal in 1999. Three cases with infrabony defects were treated, and significant periodontal attachment level gain, probing depth reduction, and bone fill were evident upon clinical probing and reentry procedures after 1 year. The patients were enrolled in a maintenance protocol with 3- month recall visits. After 7 years, the clinical parameters were stable, as was the radiographic evaluation. Surgical reentry after 7 years in two cases and 5 years in one case demonstrated the stability of the previous findings. These data show the long-term efficacy of enamel matrix derivative in new attachment procedures.

This clinical study was undertaken to evaluate the use of tissue-engineered bone, mesenchymal stem cells, platelet-rich plasma, and beta-tricalcium phosphate as grafting materials for maxillary sinus floor augmentation or onlay plasty with simultaneous implant placement in six patients with 3- to 5-mm alveolar crestal bone height. All 20 implants were clinically stable at second-stage surgery and 12 months postloading. A mean increase in mineralized tissue height of 7.3 ± 4.6 mm was evident when comparing the pre- and postsurgical radiographs. Injectable tissue-engineered bone provided stable and predictable results in terms of implant success.

The present study clinically and histologically evaluated healing of human intrabony defects following treatment with a combination of enamel matrix derivative (EMD) and bioactive glass (BG) or BG alone. Six patients displaying either combined oneand two-walled (five patients) or three-walled (one patient) intrabony defects around teeth scheduled for extraction were included. A notch was placed at the most apical extent of the calculus on the root surface to serve as a reference. Six months after surgery, the teeth or roots were extracted, together with some of their surrounding soft and hard tissues, and processed for histologic evaluation; a gain of clinical attachment was found in all cases. Healing in all three defects treated with EMD + BG was mainly characterized by new cementum with inserting collagen fibers and new periodontal ligament; most graft particles were surrounded by bone-like tissue, indicating ongoing mineralization. Treatment with BG resulted in epithelial downgrowth and connective tissue encapsulation of the graft material in all three specimens. Reformation of cementum and periodontal ligament was observed in one of the specimens, limited to the most apical part of the defect. Formation of bone-like tissue around the graft particles was observed in only one of the three specimens treated with BG. Direct contact between the BG particles and root surface (cementum or dentin) was not observed in any of the six specimens. BG alone has low potential to facilitate periodontal regeneration. However, EMD + BG resulted in formation of new cementum with an associated periodontal ligament, as well as enhanced mineralization around the BG particles.

Achieving functional and esthetic implant-supported single-tooth restorations in the anterior region of the maxilla can be particularly challenging. Insufficient hard tissue can preclude proper implant positioning, while inadequately treated soft tissue will not exhibit a gingival appearance similar to that of the adjacent teeth. The aims of this article are to analyze the different clinical possibilities (standard and compromised situations) for implant-supported single-tooth restorations in the anterior zone and highlight the importance of knowing the biologic, anatomic, surgical, and prosthetic concepts, particularly the interproximal bone height of adjacent teeth, in the prognosis and predictability of achieving an esthetic result.

The present study performed an SEM evaluation of the efficiency of the following detergents on smear layer removal on the root surface: sodium lauryl sulphate, Plax, castor oil, and EDTA 24%. Sodium lauryl sulphate did not remove the smear layer and showed the worst results of all detergents tested. Plax and castor-oil detergents showed similar results represented by partial removal of the smear layer; these results were better than those obtained in the control (physiologic serum) and sodium lauryl sulphate groups. Neutral EDTA 24% was the most efficient detergent for smear layer removal.

Narrow dentoalveolar ridges remain a serious challenge for the successful placement of endosseous implants. This case series describes a modification of previous ridge-splitting techniques using a microsaw blade. The approach enables treatment of ridges as thin as 2.5 mm at the alveolar crest and simultaneous placement of dental implants. In one extreme case reported here, where the crest width was less than 2.5 mm, a two-stage approach was used; implants were placed about 1 month after ridge expansion. In the 10 patients treated in this series, 27 dental implants were placed and achieved successful integration.

This study investigated the relationship between root trunk length and prognosis for molars with furcation involvement. Molars with furcation involvement were obtained from 169 patients affected with periodontitis. The test group consisted of 174 hopeless molars screened from a total of 441 molars with Class III involvement; the remaining 267 molars formed the control group. Both arches showed a significantly higher missing rate for teeth with a long root trunk length (type C) in second molars (41.3% and 32.4% in the maxilla and mandible, respectively), with a high degree of Class III furcation involvement for the test group (extracted hopeless or poor prognosis), compared to first molars (9.9% and 0.9% in the maxilla and mandible, respectively). Both arches had a significantly higher prevalence of long root trunk lengths in the second molars compared to first molars, irrespective of furcation site. Although first molars had an early and higher prevalence of Class III furcation involvement than second molars, the latter reached a significantly higher missing rate. Molars with longer root trunk lengths had a higher risk for poor prognosis than shorter root trunks when teeth were affected by Class III furcation involvement. For extracted furcation-involved maxillary second molars that failed to respond to periodontal therapy, long root trunk length (C) accounted for the greatest prevalence at the mesial furcation site (41.8%), followed by the distal (33.0%) and buccal sites (25.2%); the greatest prevalence of root trunk length C was found at the lingual (47.9%) and buccal furcation sites (45.1%) of mandibular second molars. When a molar with root trunk type C has a Class III involvement, the prognosis is poor; for the disease to reach that level, greater amounts of attachment must be destroyed.

When maximum precision is required in performing surgery to satisfy particular esthetic demands, a surgical microscope that enhances complete visualization of the operative field may represent a useful tool. Twenty-four cases of gingival recession (depth 2 to 5 mm) were treated by different mucogingival surgical techniques in 24 patients: 12 procedures were performed with the aid of a surgical microscope (test group), whereas the other 12 patients were treated without the microscope (control group). Recession depth, probing depth, periodontal attachment loss, and keratinized gingival tissue width were recorded at baseline and 12 months following surgery. Three examiners separately evaluated pictures of the final cases on a scale from 1 to 3, focusing on three esthetic parameters (scarring, gingival margin, and papillae appearance). All parameters significantly improved from baseline to 12 months in both groups, except for probing depth, which did not significantly change. Although the outcomes of the test group always showed a major improvement over the controls, no significant differences could be detected between test and control groups. Mean defect coverage at 12 months was 86% and 78% for test and control groups, respectively; complete coverage was achieved in 58.3% and 33.4% of cases, respectively. Qualitative esthetic evaluation showed: (1) high concurrence among examiners; (2) significantly better scarring and marginal profile in the test group; and (3) no significant difference in papillae appearance. The application of magnification in mucogingival surgery accomplished better results in terms of success and predictability compared to conventional techniques and might help achieve excellent esthetic outcomes.