International Journal of Periodontics & Restorative Dentistry, 03/1999

The purpose of this study was to evaluate whether regeneration is possible in human furcation defects. Three molars with Class II furcation involvement were included in this study. A notch was placed in calculus in the furcation to serve as a reference point for histologic evaluation. The defects were treated with a demineralized freeze-dried bone allograft combined with a bioabsorbable membrane. At 6 months postoperative, the teeth were extracted with a small piece of tissue from the furcation area. The samples were then processed for histologic evaluation. Regeneration was found in 2 of the 3 samples. This study demonstrated that regeneration is possible in human furcation defects.

Selecting the appropriate abutment can be both complex and confusing with the ever-increasing number of implant choices and transepithelial abutments available. Many restorative dentists resort to fabricating costly custom abutments to avoid the selection process. Although custom abutments are at times necessary, prefabricated abutments are usually more desirable. This article will describe the various abutments available and how to select the correct abutment for a given clinical situation in an organized, systematic fashion. Criteria discussed include implant position, angulation, soft tissue height, and interocclusal space. The latest modifications and developments in implant abutments are reviewed along with an indirect method of selecting abutments in a laboratory setting.

Following endodontic treatment, a large periapical lesion (9.0 mm 3 9.0 mm) at a maxillary central incisor was treated with demineralized freeze-dried bone allograft (DFDBA) using the principles of guided tissue regeneration (GTR). The physical barrier was removed 6 months postsurgical. The cortical alveolar plate was observed to be completely reconstructed. Histologic evaluation demonstrated lamellar bone surrounding DFDBA particles. Radiographic follow-up 1 year posttreatment demonstrated complete resolution of the periapical radiolucency.

The purpose of this study was to document mean, standard deviation, and range of furcation depth and interroot separation dimensions of 5 multirooted tooth types. A total of 412 extracted teeth were examined and classified as: maxillary first molar, maxillary second molar, maxillary first premolar, mandibular first molar, and mandibular second molar. The furcation depth was measured at the level of the furcation dome and 3 and 5 mm apical to the dome. Interroot separation was measured 3 and 5 mm apical to the furcation dome. Mean furcation depth at the dome was 7.48 mm buccally and 6.67 mm mesiodistally for maxillary first molars; 6.69 mm buccally and 5.94 mm mesiodistally for maxillary second molars; 3.54 mm mesiodistally for maxillary first premolars; 7.96 mm buccolingually for mandibular first molars; and 7.46 mm buccolingually for mandibular second molars. Interroot separation dimensions 3 mm apical to the dome were: 2.58 mm buccally, 4.17 mm mesially, and 4.48 mm distally for maxillary first molars; 1.92 mm buccally, 3.89 mm mesially, and 4.04 mm distally for maxillary second molars; 2.47 mm mesially and 2.58 mm distally for maxillary first premolars; 3.15 mm buccally and 2.95 mm lingually for mandibular first molars; and 2.54 mm buccally and 2.75 mm lingually for mandibular second molars.

This study evaluated new bone formation in 3 types of osseous defects following treatment with demineralized freeze-dried bone allografts (DFDBA) and cell-occlusive membranes. For 8 patients electing to receive implant treatment, a distinction was made among 3 clinical situations: (1) existing alveolar ridge defects; (2) extraction sockets with lost buccal plate; and (3) extraction sockets with an intact alveolus. Implants were placed a mean of 6 months after the regenerative procedure. Clinical examination of bone width and height at the time of implant placement showed sufficient augmentation or preservation, and implants were inserted without incident. Histologic examination of hard tissue biopsies obtained from the implant sites revealed no discernible differences among the 3 types of defects. Specifically, all sites demonstrated DFDBA particles surrounded by woven or lamellar bone. No fibrous encapsulation of DFDBA or inflammatory reaction was observed. Osteoblasts were found lining marrow spaces. Howeship's lacunae, with and without resident osteoclasts, were clearly seen in several DFDBA particles; this finding supports the belief that DFDBA undergoes osteoclasis in vivo. These results demonstrate that commercially available DFDBA has osteoconductive properties that lead to appositional new bone growth in both self-contained and non-self contained osseous defects.

The edentulous ridge expansion (ERE) technique is a partial-thickness flap procedure for implant surgery that was developed in 1986. The ERE technique permits the use of osseointegrated implants at sites whose minimal orofacial dimensions are insufficient for traditional implant surgery. The present work is a histologic and ultrastructural study of hard tissue repair modalities at edentulous sites that were treated with the ERE technique in 20 humans. Biopsies were obtained from the tissue regenerating within the surgically created bone gap between the mobile buccal and nonmobile lingual or palatal bone-periosteum plates ('bone flaps') on days 40, 90, 120, 150, and 480 (day 0 = day of implant insertion). The results suggest that osteoblasts differentiate from preexisting mesenchymal cells located on the original fissure walls, with consequent deposition of new bone in the surgically created intrabony defect.

This article describes a new and simplified surgical approach to harvest subepithelial connective tissue grafts from the palate. For this procedure, only a single incision parallel to the gingival margin is used to access the donor site for graft preparation and harvesting. Grafts of variable size and thickness can be obtained. Since no band of epithelium is removed with the connective tissue graft the palatal donor site can heal with primary intention. No stents or hemostatic agents are necessary to cover the donor area postoperatively, and suturing can be reduced to a minimum. The harvesting technique is illustrated step by step, and the clinical application of connective tissue grafts harvested with the proposed method is demonstrated with the coverage of a gingival recession.

The success of endosseous dental implants is enhanced when sufficient bone is present to stabilize the implant. If adequate bone for full coverage of the implant is not possible, then the use of guided bone regeneration to regenerate the missing bone has been shown to be a predictable solution. Defect size can often limit the amount of soft tissue available for coverage of the membrane, which is essential in obtaining an optimal result when using regenerative and osseointegrative principles. The treatment philosophy demonstrated in this case report uses controlled subperiosteal tissue expansion to facilitate the incorporation of guided bone regeneration with the subsequent placement of endosseous dental implants. This treatment modality provided a successful treatment for an otherwise compromised case.

The lateral periodontal cyst is a relatively rare cyst of the jaw (0.8%) of unproven origin. It is most commonly found in the mandible between the roots of canines and premolars. This article reports a case of a lateral periodontal cyst in a 73-year-old woman, documents its diagnosis and treatment, and also presents a 1-year reentry. No grafting or barrier techniques were used. The result was complete bony regeneration of the defect after 1 year.