International Journal of Periodontics & Restorative Dentistry, 01/2000

This study evaluated the soft tissue stability around 10 single-tooth implants. All cases were treated following the same protocol, which included guided bone regeneration and connective tissue grafting. One year after prothesis insertion the soft tissue shrinkage on the buccal side of the implant crown was 0.6 mm on average. The soft tissue volume in the papilla area increased on average by 0.375 mm, and none of the papillae lost volume.

This study evaluated a bovine-derived bone xenograft (Bio-Oss) in the treatment of human periodontal osseous defects. Four patients with at least one tooth that had been recommended for extraction because of interproximal advanced periodontal disease volunteered to participate. The surgical procedure consisted of flap reflection, soft tissue debridement, placing a notch in calculus as a histologic reference point, root planing, placement of the bovine-derived xenograft and a bioresorbable physical barrier, and flap closure. Patients were seen every 2 weeks for plaque control and any necessary adjunctive treatment. At 4 to 6 months postsurgery, 6 teeth, along with the adjacent graft site, were removed en bloc. Histologic observations demonstrated new bone, new cementum, and new periodontal ligament coronal to the reference notch in 3 of the 4 specimens. This study indicates that periodontal regeneration is possible following grafting with a bovine-derived xenograft.

This work describes the therapeutic protocol of combined orthodontic-periodontal treatment and evaluates the effectiveness of surgical and nonsurgical periodontal therapy in the maintenance of a healthy periodontal status after the orthodontic treatment. Surgical periodontal treatment was performed in 267 patients affected by severe periodontal disease, and 128 patients had nonsurgical treatment. For each patient the mean value of probing depth (mPPD) and the rate of positive bleeding on probing (%BoP) of the teeth involved in the orthodontic movement were registered before the start of the periodontal treatment, at the end of the orthodontic treatment, and 2, 4 ,6, 10, and 12 years after the end of the orthodontic treatment. Comparison between pretreatment and posttreatment values and between pretreatment and follow-up values showed a decrease in mPPD and %BoP that was of statistical significance. The difference between posttreatment and follow-up values was not statistically significant. These results suggest that orthodontic treatment is no longer a contraindication in the therapy of severe adult periodontitis. In these cases orthodontics improve the possibilities of saving and restoring a deteriorated dentition.

Extraction socket defects or alveolar ridge defects may limit or restrict placement of implants. The present study assessed the efficacy of inducing bone formation with demineralized freeze-dried bone (DFDB), osteoconduction with hydroxyapatite (HA), and guided bone regeneration with expanded polytetrafluoroethylene (e-PTFE) in bone defects adjacent to endosseous implants in an animal model. Twenty-four implants were placed in the long bones of 3 pigs. After preparation of 24 cylindric acute defects adjacent to the coronal 5 mm of each implant, 18 of the defects were treated by DFDB, HA, or e-PTFE. The 6 remaining defects healed spontaneously with no treatment (controls). In each pig, one tibia received 4 commercially pure titanium screw implants (3.75 mm 3 15 mm), while the contralateral tibia received 4 HA-coated cylindric implants (3.25 mm 3 15 mm). Bone formation in response to the 3 treatments and control cases was evaluated using computer-assisted densitometric image analysis. The results showed that a higher density of tissue formed under e-PTFE membranes. A significantly greater increase in bone density was noticed in bone defects treated with an e-PTFE membrane vs DFDB (P = 0.04), in e-PTFE vs control sites (P = 0.04), and in defects treated with HA vs DFDB (P = 0.04) in HA-coated implants. In titanium implants the differences observed were not significant. It was also observed that bone regeneration in defects treated with HA differs with the type of implant used (titanium vs HA-coated implants), but such differences were not significant.

Obtaining root coverage has become an important part of periodontal therapy. In this study, 2 surgical root coverage procedures were examined. The control group was treated with a coronally positioned pedicle graft combined with a connective tissue graft. The test group was treated with a coronally positioned pedicle graft combined with an acellular dermal matrix. There was no statistically significant difference in the mean root coverage obtained (96.2% control vs 95.8% test). There was a statistically significant reduction in probing depth (1.2 mm control vs 0.7 mm test) and increase in keratinized tissue (2.0 mm control vs 1.2 mm test) in both groups. The connective tissue graft produced a greater mean probing reduction and mean keratinized tissue increase than the acellular dermal matrix. However, this did not appear to be clinically significant. The results of both procedures were esthetically acceptable to the patients and clinically acceptable in all cases. In this study, the acellular dermal matrix and the connective tissue graft resulted in similar amounts of root coverage.

In an effort to improve regenerative capacity and establish higher levels of predictability, the use of a new graft material was investigated in baboon infrabony periodontal defects. A graft matrix composed of human demineralized freeze-dried bone combined with human connective tissue glycoprotein was implanted in 20 defects in 9 baboons. Control, debrided-only sites in the same animal served as a comparison. Grafted sites achieved a 1.8-mm greater reduction in probing depth and attachment gain compared to controls. In addition, 25.3% greater defect fill was found in grafted sites. Histologic analyses provided evidence of bone induction by the graft matrix and regeneration of new cementum, periodontal ligament, and bone in the grafted sites.

Classical guidelines for osseointegration include a long healing time, during which functional load should be avoided. However, the long healing period might impose an intolerable situation on some patients, especially in the completely edentulous situation. Studies on immediately loaded implant-supported prostheses in completely edentulous patients have been reported, exhibiting high success rates comparable to conventionally loaded implants. This article describes the surgical and prosthodontic procedure for the immediately loaded mandibular implant bar overdenture as well as its clinical rationale.

In the visible dental region in particular, implant-prosthetic restorations filling single-tooth gaps make exacting demands on function and esthetics. One crucial factor influencing the esthetic outcome is the emergence profile of the restoration. The introduction of aluminum oxide or zirconium oxide abutments, which can be milled to meet individual requirements, provides new opportunities for reconstruction adapted to anatomic findings. Tooth-matched coloring combined with customized preparation and dimensioning make for optimal mucogingival esthetics in implant-supported single-tooth restorations. The aim of the present article is to give a general survey and to illustrate the use of ceramic abutments with clinical case reports.

The purpose of the present microbiologic and case-controlled clinical study was to examine the colonization of 2 different resorbable barrier membranes by sulfate-reducing bacteria (SRB). The barrier membranes tested were Guidor matrix barrier and Resolut regenerative material. Ten patients exhibiting 3 Class II furcation defects and 7 intrabony defects were included in the study. The probing depth and the clinical attachment level at 4 surfaces per tooth were taken at the beginning of the study. Microbiologic samples were taken from the experimental sites and from the approximal sites of the adjacent teeth. Both types of resorbable membranes were positive for SRB colonization. The detection of SRB in 2 of 7 intrabony defects and in all defects with furcation involvement before the membrane placement indicated that these organisms are a common inhabitant of sites showing periodontal destruction and are associated with guided tissue regeneration (GTR). According to the clinical criteria for healing tendencies used in this study, the GTR procedures were less successful in the presence of SRB. There were no significant clinical effects of different resorbable membrane materials or membrane layout on attachment level changes for either the intrabony defect or furcation groups after 18 months. There were no statistical differences for sites that became exposed to SRB when compared to sites that remained unexposed after 18 months. The numeric significance of SRB in relation to the total microbial count needs to be determined to gain insight into the ecologic role of membrane resorption rates.