International Journal of Periodontics & Restorative Dentistry, 06/1993

Five patients with buccal gingival recession (4 to 6 mm) underwent surgical treatment consisting of a guided tissue regeneration procedure associated with a free gingival graft. The graft was used to cover the newly formed tissue on the root surface at the reentry. Root coverage was complete in three patients, while 1 mm of recession remained in the other two patients. The free gingival graft reconstructed the keratinized tissue, which had been lost because of recession. Moreover, it allowed the mucogingival junction, which had been displaced coronally during the first surgery, to be realigned, therefore preventing a shallowing of the vestibule.

Among the goals of orthodontic therapy is the establishment of optimal facial form, occlusal function, and dental esthetics. Orthodontic treatment of patients with congenitally missing teeth, especially maxillary lateral incisors, can be accomplished best by positioning the remaining natural dentition in the anatomically correct location and closely coordinating therapy with the osseointegration team members. Special divergence of adjacent root tips is essential to provide space for the implant. The Brånemark system of implant therapy is the treatment of choice for the permanent replacement of congenitally missing teeth.

The placement of one-stage endosseous dental implants and the achievement of success rates greater than or equal to two-stage implants present a unique challenge for combining regeneration and implant placement. This report describes the evolution of a technique in which membrane barrier technology is combined with implant placement. This allows healing to occur with minimal inflammation around the one-stage implant and provides an extended, complication-free healing period for both osseous regeneration and implant integration. Present membrane technology requires a second surgical procedure to remove the membrane, but future resorbable membranes, when available, should make regeneration around one-stage implants a relatively simple clinical procedure.

Three periodontal probes - a manual probe and two computerized, pressure-sensitive probes - were studied to determine their relative recording accuracy. In the first part of the study, replicate probing measurements were taken with the three probes at shallow (less than 5 mm) and deeper (greater than or equal to 5 mm) periodontal sites. In the second part of the study, probing depths were determined on all teeth except third molars by the three probing techniques at a single appointment. Mean values between replicate probings for each instrument did not differ statistically, except for duplicate measurements with one of the electronic probes in pockets with depths greater than 5 mm. All three probes demonstrated higher standard deviations with increasing depth, which indicates decreased reproducibility of probing depth measurements. Results of this study suggest that an electronic, pressure-sensitive probe yields more reproducible probing depth measurements than a conventional manual periodontal probe.

A case report is presented to introduce a simple, predictable technique to restore implants in ceramometal on milled custom abutments. The new component discussed in this paper was created to fabricate prosthetic posts for cement-retained ceramometal prostheses. It is available for most major implant systems and is applicable to nearly any ceramometal implant restorative situation, with the rare exception of extremely short intraocclusal distance or extreme lingual placement or angulation of the implant fixture.

This study used photoelastic stress analysis to compare the location and magnitude of periradicular stresses created by load application directed through two anatomically different natural teeth and three different implant designs. Also studied was the contribution made by the periodontal ligament in the transfer of these stresses. Within the limits of this study, results suggest that the abutment structures with the greatest amount of periodontal support tend to distribute stresses in the most favorable manner. Also, the conical shape of the tooth root, with its large cervical area, has a distinctly positive effect on stress distribution.

Closed fenestration wounds in four mongrel dogs were used to study the source of fibroblast proliferation and extracellular matrix production during healing; the arrangement and attachment of newly formed collagenous fibers; and the cementogenesis and osteogenesis at healing sites. Fenestration wounds were made through the alveolar bone, periodontal ligament, cementum, and dentin, and citric acid, tetracycline, or sterile water was applied to the dentinal walls for 3 minutes. Nonresorbable membranes were randomly placed over half of the defects. Animals were killed at 1, 3, 7, or 21 days and routine histologic examinations with hematoxylin and eosin staining followed. Results of this pilot study suggest that the periodontal ligament and/or alveolar bone are the main source of fibroblast proliferation and migration as well as extracellular matrix formation at the initial stages of healing, and that at 21 days, citric acid stimulated more cementogenesis than tetracycline or sterile water. Also, while the tetracycline influenced the maximal deposition of alveolar bone, no differences in healing were found between the citric acid, tetracycline, and sterile water with and without the use of membrane barriers.