Histologic and histomorphometric evaluation of two bone substitute materials for bone regeneration: an experimental study in sheep.

INTRODUCTION: In the past decade, there has been an increase focus on regeneration approaches as related to periodontics and implant therapies. The main objective of the present study is the evaluation of quality, density, and thickness of the newly formed bone in experimental defects treated with deproteinized bovine bone mineral (DBBM) and bioapatite-collagen. MATERIALS: Fifteen identical cuboidal defects were prepared in the alveolar edentulous mandibular ridges in 10 male sheep. Defects were randomly assigned to be treated either with DBBM, Bioapatite-collagen or remained unfilled as the control group. Defects of these 3 groups were histologically examined after 6 months. RESULTS: The mean percentages of bone regeneration with DBBM, Bioapatite-collagen, and control group were 51.40% +/- 3.57%, 27.66% +/- 4.18%, and 19% +/- 1%, respectively (P < 0.05). Defects filled with Bio-Oss and control defects did not show foreign body reaction, whereas Biostite particles had a reaction in 40% of the specimens. Trabecular thickness and type of new regenerated bone were also significantly different between Bio-Oss and Biostite (P < 0.05) and control group (P < 0.05). CONCLUSION: The results of the present study suggest that using of DBBM particles can promote bone regeneration more effectively than Bioapatite-collagen, and both materials were more promising than the control group.

An alternative sinus floor elevation procedure: trephine osteotomy.

Today, the sinus floor elevation procedure is not only being used on a routine basis, but clinicians are reporting high success rates. The sinus floor graft has become an important option in the treatment of the edentulous posterior maxilla, where vertical bone height is less than ideal. A review of maxillary sinus floor elevation as an integral part of restoring the posterior maxillary is discussed. The related anatomy of the area and current osteotomy techniques are reviewed. This article describes a trephine osteotomy, which is an alternative technique to the existing lateral antrostomy approach currently being used.

Analysis of aspartate aminotransferase and alkaline phosphatase in crevicular fluid from implants with and without peri-implantitis.

PURPOSE: The aim of this investigation was to determine the presence of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in crevicular fluid collected from implants with and without clinical and radiographic signs of peri-implantitis. MATERIALS AND METHODS: There were 17 implants with symptoms of peri-implantitis in 12 subjects, including 4 females and 8 males, compared to 17 implants in 13 subjects, including 5 females and 8 males, with healthy peri-implant tissues. Filter paper strips were used to collect peri-implant crevicular fluid for 30 seconds in the base of the crevice/pocket. SPSS statistical software (SPSS, Inc., Chicago, IL) was used to determine AST and ALP activity. RESULTS: The results showed that there was a significant difference in the activity of AST and ALP between the 2 study groups (P < 0.0001). AST activity was significantly associated with the amount of bleeding on probing (P = 0.02), but no statistical correlation was found between ALP activity and increased amount of bleeding on probing (P = 0.05). CONCLUSIONS: Within the limits of this study, our results may suggest that peri-implant crevicular fluid analysis could be further investigated in longitudinal studies as a suitable diagnostic strategy in the evaluation of dental implants.

Alveolar vertical distraction osteogenesis: historical and biologic review and case presentation.

Dental rehabilitation of partially or totally edentulous patients with dental implants has become common practice in the last few decades, with reliable long-term results. However, local conditions of edentulous alveolar ridges may be unfavorable for implant placement. Vertically deficient alveolar ridges, in particular, may have insufficient bone volume to hold implants of adequate dimensions, making implant placement difficult or impossible. To correct this situation, a variety of surgical procedures have been proposed, including onlay bone grafts, vertical guided bone regeneration, and alveolar distraction osteogenesis. Distraction osteogenesis is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. This process is initiated when a traction force is applied to the bone segments and continues as long as the callus tissues are stretched. This traction force, in turn, generates tension within the tissues that connect the bone segments, which stimulates new bone formation parallel to the vector of distraction. The aim of this article is to provide clinicians with the historical background of and biologic basis for the concept of distraction osteogenesis, which can be traced back to the 1800s. Finally, a clinical case is presented to demonstrate a step-by-step application of alveolar distraction osteogenesis as a treatment protocol in a partially edentulous ridge for improvement of esthetics.

Indirect impression technique for multiple cast dowel and cores facilitated with three putty indexes.

Fabrication of multiple direct cast dowel-and-core patterns is time-consuming and difficult because the clinician must assess the adequacy of the reduction of the final restoration and the path of insertion for the patterns. This article describes a technique for making impressions of multiple endodontically treated teeth for the indirect fabrication of cast dowel and cores, which are waxed up via three putty indexes obtained from the diagnostic waxup. This enables clinicians and technicians to communicate in a manner that facilitates predictable and consistent prosthetic therapy.

The use of three different matrices to ensure proper spatial dimension in fabricating definitive implant-supported prostheses.

Implant concepts continue to evolve not only in terms of materials, surfaces, and designs but also in clinical experience and technical management. This article presents a clinical and laboratory procedure describing how to plan, ensure, and achieve proper spatial dimension in fabricating definitive implant-supported prostheses with the use of 3 different matrices. This will in turn aid in restoring the patient with a predictable outcome from the outset of the treatment.

Transforming an existing fixed provisional prosthesis into an implant-supported fixed provisional prosthesis with the use of healing abutments.

Maintaining a fixed provisional prosthesis through all phases of complex implant prosthodontic therapy for a soon-to-be completely edentulous arch is a difficult task. This article focuses on the treatment phase in which teeth and/or transitional implants supporting a provisional fixed partial denture are removed. The described technique makes use of healing abutments to support a modified provisional fixed partial denture. This protocol ensures patient comfort and allows proper soft tissue healing before definitive implant abutment selection. It also eliminates the placement of interim implant abutments.