International Journal of Periodontics & Restorative Dentistry, 05/2008

Early implant placement is one treatment option for implant therapy following single-tooth extraction in the anterior maxilla. The surgical technique presented here is characterized by tooth extraction without flap elevation, a 4- to 8-week soft tissue healing period, implant placement in a correct three-dimensional position, simultaneous contour augmentation on the facial aspect with guided bone regeneration using a bioabsorbable collagen membrane combined with autogenous bone chips and a low-substitution bone filler, and tension-free primary wound closure. The surgical step-by-step procedure is presented with a case report. In addition, the biologic rationale is discussed.

The aim of this randomized controlled clinical trial was to compare the efficacy of implants placed with a flapless procedure and restored immediately (test group) or early (6 weeks) (control group) in partially edentulous patients up to 1 year after loading. Both groups were nonocclusally loaded. Ten patients were included in each group. No patients dropped out and no failures were recorded. Two complications occurred in the early loading group, but both were resolved. It can be concluded that the use of a flapless technique for placing implants in conjunction with nonocclusal immediate loading in select patients can provide excellent clinical results. These preliminary findings should be confirmed by larger randomized clinical trials.

Cultured gingival dermal substitute (CGDS), composed of gingival fibroblasts and matrix and fabricated using tissue-engineering techniques, has been used for root coverage procedures. Fourteen sites from four patients with >= 2 mm of Miller Class I or II facial gingival tissue recession were treated. The autologous CGDS sheet, prepared prior to surgical treatment, was grafted over the teeth with gingival recession and then covered with a coronally positioned flap. Vertical and horizontal recession was measured at baseline (prior to the surgical procedure) and 13 to 40 weeks (average: 30.7 ± 9.6 weeks) after surgery. The average vertical and horizontal root coverage after surgery was 79.1% ± 25.7% and 75.2% ± 31.4%, respectively. Moreover, there was a significant increase of keratinized and attached gingival tissue at the final clinical evaluation compared with preoperative measurements (P .05). These results demonstrate CGDS as a promising grafting material for use with root coverage procedures in periodontal therapy.

The aim of this investigation was to assess the possibility of preserving the buccal and lingual plates of a postextraction socket from resorption using bone filler after tooth extraction. In 10 patients, 10 single extraction sites in the posterior area received a bone substitute. The osteoconductive material was covered by a collagen membrane in all cases. Contour changes of the alveolar process were evaluated intraorally using a surgical caliper over a 4-month period. Four months after extraction, a specimen was harvested from the area previously augmented with bone filler, and histologic analysis was performed. The results demonstrated that it was possible to preserve about 85% of the initial ridge dimensions, allowing for correct implant placement. From a histologic point of view, new bone formation was detected in all sites, with a 25% average residual presence of the graft particles. This investigation confirms the benefit of augmenting an extraction socket with bone substitutes.

This case series reports on the use of nonsilica-based high-strength full ceramics for different prosthetic indications. Fifty-two consecutive patients received toothor implant-supported zirconia reconstructions during a 2-year period. The observation period for reexamination was 12 to 30 months. The most frequent indications were single crowns and short-span fixed partial dentures. A few implant superstructures were screw-retained, whereas all remaining restorations were cemented on natural teeth or zirconia implant abutments. Clinical examination included biologic (probing depths, bleeding on probing) and esthetic (Papilla Index) parameters, as well as technical complications. No implant was lost or caused any problems, but two teeth were lost after horizontal fracture. Overall, the periodontal parameters were favorable. Fractures of frameworks or implant abutments were not observed. Abutment-screw loosening occurred once for one premolar single crown. Furthermore, five implant crowns in the posterior region exhibited chipping of the porcelain veneering material. With regard to esthetics, no reconstructions were considered unacceptable, but three crowns were remade shortly after delivery. In this short-term study, it was observed that biologic, esthetic, and mechanical properties of zirconia were favorable, and the material could be used in various prosthetic indications on teeth or implants.

Implant relocation is a new surgical technique for correcting the alignment of malpositioned implants by mobilizing them with the surrounding bone until the desired position is achieved. In this case report, a 25-year-old woman was treated for the malposition of an implant in the maxillary left canine site. The use of a piezoelectric scalpel permits narrow, precise, and safe osteotomies, thus preventing involvement of the soft tissue and producing better healing potential compared to burs or saws. The results suggest that inadequately axially inclined implants can be successfully reconfigured using segmental piezoelectric osteotomies.

The aim of this clinical study was to evaluate the coverage of gingival recession defects with enamel matrix derivatives (EMD) with or without a connective tissue graft (CTG). Twenty-five patients (16 female, 9 male) from 16 to 58 years of age (mean: 32.2; SD: 11.2) with 92 gingival recessions (Miller Class I and II) and with at least 4.0 mm of clinical attachment loss were treated with a modified surgical technique for root coverage by CTG with EMD (45 recession defects) or EMD only (47 recession defects). Vertical recession depth, probing depth, clinical attachment level, dehiscence depth, width of keratinized gingiva (vertical), and recession coverage were recorded before surgery (baseline) and at 12 and 24 months. The average presurgical recession depth was 4.4 mm (SD: 1.3) with EMD and CTG versus 3.2 mm (SD: 1.1) with EMD only. Both treatment modalities led to a significant decrease in recession and a gain in attachment. Mean root coverage 12 months postoperatively was 92.7% (SD: 13.5) (EMD and CTG) versus 96.3% (SD: 11.5) (EMD only). Compared to the mean root coverage of recession after 24 months, the change was not significant. The results confirmed that the applied modified surgical techniques are safe and predictable, with better clinical outcomes at the donor and recipient sites.

The most significant local factors for successful implant placement are the quality and quantity of bone present. Bone loss occurs on a predictable basis following loss of the natural dentition, provided no interceptive therapies are carried out. Restoration of considerable hard tissue defects can be achieved using a variety of techniques, including autogenous blocks and newer methods such as corticocancellous allograft blocks. This report demonstrates successful ridge augmentation using an iliac crest monocortical allograft. Nine patients in need of ridge augmentation for the placement of 16 dental implants were included in this series. Histology from one case after the 6-month healing period demonstrated newly formed woven bone with vascular ingrowth, suggestive of osteoconduction. All grafted sites appeared integrated with clinically visible bleeding following removal of the fixation screw. The mean gain of ridge augmentation at the 6-month reentry was 3.0, 3.2, 3.1, and 3.0 mm, respectively, at the crest and 1, 3, and 5 mm apical to the crest, with individual gains up to 7 mm. Implants were successfully placed in all sites. This method represents an alternative source of block allograft bone for significant alveolar ridge augmentation.

The successful esthetic integration of a prosthesis is dependent on the anatomic site in which the restoration is inserted. Edentulous site enhancement is a regenerative approach based on the following: (1) anatomic evidence that the morphology of soft tissues is dependent on the underlying support (bone, roots, implants) but also significantly influenced by overlying structures (fixed or removable prostheses); (2) histologic evidence of the remarkable regenerative capacity of the newly formed tissue that develops during healing by secondary intention; (3) clinical evidence that it is possible to guide the formation of this new regenerative tissue by creating a support with proper morphology and a highly polished surface; (4) observations that positive pressure exerted by alimentary bolus and negative pressure produced by deglutition affect the growth of this tissue healing by second intention; and (5) the application of appropriate oral hygiene techniques to guide tissue healing and maintain its integrity. The edentulous site enhancement approach is simple, practical, and predictable and offers minimal postoperative complications. This paper describes the edentulous site enhancement approach as applied in the pontic areas.