International Journal of Periodontics & Restorative Dentistry, 03/1995

Although ostectomy has been proven in numerous studies to be and effective means of reducing pocket depth, some clinicians still question its merits. To determine the efficacy of ostectomy for the treatment of periodontitis, 870 pairs of presurgical and postsurgical radiographs of sites treated by ostectomy were examined. The postsurgical radiographs, taken 5 to 30 years postoperatively, revealed distinct lamina dura and demonstrated that ostectomy is an effective and predictable technique for intercepting the progressive loss of attachment in selected sites with periodontitis.

Clinical success of resin-bonded fixed partial dentures is primarily dependent on their long-term retention. Retention rates of resin-bonded prostheses placed in 66 patients treated by three dentists in private practice were evaluated in the present study. seventy-seven resin-bonded fixed partial denture were followed over a period of 1 year to 11 years. Thirty (39%) became dislodged, but nine were successfully rebonded; thus there were 21 failures (27%). Prosthesis location and operaator expertise minimally influenced the longetivity of these restorations, but the luting agents tested in this sample had a profound impacet on retention. Debonding rates were excessive for some materials tested, whereas other agents proved to by predictable. Modifications in preparation design that enhance resistnce form were also likely contributors to improved retention rates.

An area of deep, long-standing recession on a mandibular first premolar was treated for root coverage in a 40-year-old woman. The recession was 6.0mm deep with a probing depth of 2.0 mm, and there was no attached gingiva. A thick (1.5-mm) free autogenous epithelium and connective tissue graft from the palate was placed to the cementoenamel junction of the tooth after instrumentation and tetracycline conditioning of the root surface. The tooth and facial soft tissues were removed in block section 10.5 months later. At the time of extraction, there had been a gain of 5.0 mm of root coverage, and there was 5.0 mm of keratinized gingiva on the facial aspect. The probing depth was 1 mm. Histologic measurement showed 4.4 mm of new attached and 4.0 mm of new bone growth. The coronal extend of the new attachment and new bone were in an area previously exposed by recession.

Recent studies have reported the successful use of guided tissue regenertion procedures with nonresorbable barrier membranes to treat buccal recession in humans. Nonresorbable membranes, however, require a reentry procedure for removal, disturbing the delicate healing process. Resorbable membranes were used in a guided tissue regenertion procedure in nine patients with one site of buccal recession each. The resorbable barrier yielded satisfactory clincal results, providing significant gains in probing attachment and root coverage. However, both the surgical technique and the design of the barrier used require improvement for applicaton at sites of buccal recession.

Periapical, panoramic, linear tomographic, and computerized tomographic radiographs were made of a partially dentate human mandible with four implants in place. Measurements taken from the radiographs and computer-generated images were compared to measurements made directly on the cross-sectioned test specimen. Periapical radiographs produced the most accurate measurements. Computerized and linear tomographic images produced the unique advantage of cross-sectional views of anatomic structures, but image blurring inherent to linear tomography and volume-averaging error inherent to computerized tomography affected the accuracy of measurements made from these images. The use of a dense dimensional reference object helped to compensate for radiographic distortion and is appropriate when projection radiographic techniques are used. The CT reference scale provided the most accurate method for interpreting measurements made from the computerized tomogram. The use of a dense dimensional reference object is inappropriate with CT because of its volume-averaging error.

This article presents two methods of guided tissue regenertion with polytetrafluoroethylene membranes that promote extensive regeration of periodontal supporting tissue around several adjacent teeth. These techniques are effective in patients with profound marginal periodontitis and advanced horizontal and vertical bony defects affecting large areas of the mouth. In method A, the goal of regeneration is reached by covering the defect with a row of seveal ovelapping membranes. However,the favorable results obtained with this method had to be weighed against various problems concerning the surgical procedure and wound healing. These unsolved difficulties prompted the development of method B, in which only one large membrane is used. After appropriate relieving incisions are made in the membrane, it is placed into the interdental space and thus able to cover and extensive periodontal defect. during the last 4 years, favorable results have been obtained with both new methods of guide tissue regeneration.

A new flap design, the coronally positioned palatal sliding flap, was used to cover barrier membrane placed over implants in one patient, and to provide localized ridge augmentation around implants in another patient. The method is a valid surgical approach because of the favorable risk-benefit ratio. The surgical technique is easy to perform, and it is possible to obtain a sufficient positio nof the palatal tissue. This new palatal flap design may indicated for a variety of implant surgery.