International Journal of Periodontics & Restorative Dentistry, 05/1993

This study evaluated the use of guided tissue regeneration in preventing and treating bone loss after surgical removal of horizontally impacted mandibular third molars. A test group of 10 patients who were treated with expanded polytetrafluoroethylene membranes was compared with a control group of 10 patients who did not receive membranes. Patients were evaluated preoperatively and 3,6,9 and 12 months postoperatively for changes in gingival inflammation, clinical probing depth, probing attachment level, and recession. Within the limits of this study, the use of expanded polytetrafluoroethylene membranes greatly improved the clinical results.

The development and testing of a new restorative system for ITI dental implants is presented in this paper. Design characteristics as well as test procedures and results regarding mechanical strength of the different interfaces to different loads and load directions, resistance to rotational forces, transfer accuracy, and marginal fidelity of the final restorations are described. The results obtained demonstrate the mechanical stability of the system, which favors biologically sound and esthetic restorations while maintaining the simplicity of the procedures.

Recent research has increased understanding of periodontal tissue reactions to orthodontic treatment. However, little is known about the response to intrusive tooth movement. This report describes clinical and radiographic changes of a periodontally compromised and malpositioned maxillary incisor during combined periodontal and orthodontic treatment by intrusion.

This study examined naturally occuring cementum anomalies in the area of the dentogingival junction in 12 adult human cadaver jaws. Jaws were sectioned mesiodistally along the long axis of the teeth, and the remaining facial and lingual portions were sectioned buccolingually. This technique provided two to four nondecalcified ground sections for each tooth surface (n=171 surfaces) for staining and analysis. The cementum thickness was measured histomorphometrically at three random sites per tooth to determine a mean cementum thickness for each tooth. Cementum anamolies were found on 18 (11.5%) of the 171 surfaces. Of the cementum anomalies observed, nine (5.3%) were classified as small, two (1.2%) as medium, and seven (4.1%) as large. Also 25% of the specimens had at least one area of increased cementum thickness that was considered a variation from normal. Of the aberrations in the cementum thickness 94.4% were found on interproximal surfaces; aberrations were predominantly located at the insertion of the transeptal fibers. Loss of attachment can expose the cementum anomalies, making them an important anatomic consideration during periodontal and restorative therapy.

This paper classifies treatment procedures for areas where implants cannot be placed because of lack of sufficient bone, or where additional bone is needed to enhance the results and prognosis of implant placement and restoration. Treatment classification is based on timing to tooth extraction in relation to implant placement and guided tissue regeneration. Treatment types and their techniques, their advantages and disadvantages, and indications for their use are discussed.

Over the years, dentists have had difficulty in correctly relating margin placement to the periodontal apparatus. Especially in the prosthetic treatment of the demanding, advanced, periodontal-prosthetic case, many failures (of periodontal health or or esthetics), have been due to the incorrect prosthetic management of the periodontal soft and hard tissues. These failures frequently have been blamed on poor oral hygiene and poor cooperation by the patient, but this is not always true. This paper, through the presentation of a literature review and clinical examples, discusses the important, correct relationship of the biologic width to the placement of the restorative margin. This relationship is vital to the achievement of long-lasting periodontal health.