The International Journal of Oral & Maxillofacial Implants, 01/1990

The biologic principle of guided tissue regeneration was applied to regenerate alveolar bone in conjunction with the placement of titanium dental implants. In one case, complete osseointegration of an implant was achieved by the placement of a Teflon membrane over an implant that had been inserted into an alveolus immediately following tooth extraction. In a second case, the same biologic principle was used to increase the volume (height and width) of a resorbed, edentulous alveolar ridge to provide adequate bone dimensions for implant installation. In both cases, the membranes appear to have prevented the repopulation of the wound area by cells other than those derived from surrounding bone tissue. These two different applications of the principle of guided tissue regeneration open new avenues for reconstructive osseous surgery. Keywords: bone regeneration, guided tissue regeneration, osteogenesis, subtraction radiography, titanium implant, wound healing

In severely atrophic or osteoporotic mandibles, the location of the inferior alveolar nerve may vary considerably, both superoinferiorly and mediolaterally. A clinician's ability to reliably locate this nerve within the mandible would permit the surgical planning of implant placement in the posterior edentulous mandible. Eight edentulous cadaver mandibles were studied. A technique that precisely locates the inferior alveolar nerve within the mandible is described. The technique will aid the surgeon in planning a surgical approach to the posterior mandible with reduced risk of injury to the inferior alveolar nerve. Keywords: buccolingual position, inferior alveolar nerve, posterior mandibular dental implants

An analysis of implant placement in the posterior region of eight edentulous cadaver mandibles was performed. The results demonstrated that the radiographic technique developed can be employed to safely place implants adjacent to the inferior alveolar nerve in the posterior mandible by using radiographic laminography and a specially designed intraoral reference splint. Keywords: buccolingual position, inferior alveolar nerve, posterior mandibular dental implants

Clinical and DNA probe analysis were used to evaluate 36 failing implant sites in 13 patients. Failing implants showed evidence of increased mobility and a high incidence of peri-implant radiolucencies in radiographs. The probing depth was greater than 6 mm in 58% of the sites measured. Moderate levels of Actinobacillus actinomycetemcomitans, Bacteroides intennedius, and Bacteroides gingivalis were detected with DNA probe analysis. Keywords: DNA probe, mobility, probing depth, target bacteria radiographic radiolucencies

Where fixture placement and inclination had not been optimal from a restorative perspective, angulated abutments were used to overcome compromised esthetic and functional results in situations of complicated anatomy. The angulated abutment is a treatment adjunct that provides flexibility for ensuring successful treatment when a variety of reconstruction problems are confronted. Keywords: angulated abutments, complicated anatomy, malaligned implants

The purpose of this investigation was to determine the comparative surface roughness produced by various oral hygiene instruments and materials on titanium implant abutments. Ten Brånemark titanium abutment cylinders were used, with one serving as an untreated control. One abutment was used to evaluate each of nine oral hygiene instrumentation methods used for specified lengths of time or instrument strokes. Each abutment was sonically cleaned, air dried, and viewed with a scanning electron microscope. Polaroid photomicrographs were made of abutment surfaces at predetermined magnifications. They were analyzed by three investigators, who compared individual test parameters in terms of time application or stroke number. The resulting abutment surface roughness was also evaluated. The rubber cup with flour of pumice created a smoother surface than the control; the interdental brush, soft nylon toothbrush, plastic scaler, Eva® plastic tip, rubber cup, and Cavi jet® left a surface comparable to the control; the metal scalers and the Cavitron® created a severely roughened surface. Keywords: maintenance, surface roughness, titanium abutments

This report presents the clinical outcome of 47 consecutively placed Core-Vent® implants inserted in 35 patients followed for 2 to 4 years by clinical and 3 to 48 months by radiographic examination. The implants were used in mandibles and maxillae to support single crowns, overdentures, and fixed prostheses splinted to natural teeth as recommended by the manufacturer. Of the 47 implants, 43 could be examined. A total of 11 implants was removed, nine because of progressive vertical bone loss and two because of fractures. The vertical bone loss was calculated for the 32 remaining implants. Twenty-eight implants demonstrated a bone loss of more than 2 mm and 16 showed a loss of more than one-third of the implant height. According to the criteria proposed by Schnitman and Shulman in 1979, the total success rate was 37.2%. When using the criteria suggested by Albrektsson et al in 1986, the total success rate was calculated to be 9.3%. Keywords: bone resorption, clinical examinations, dental implants, radiographs

This longitudinal study of 39 patients who underwent treatment involving osseointegrated implants examined problems Keywords: body image, motives for implants, neuroticism, patient expectations, patient satisfaction, patient support, psychological impact, postoperative problems

Naturally occurring closing and chewing forces were measured in dentitions with mandibular fixture-supported bilateral distal two-unit cantilever fixed prostheses occluding with complete dentures, and the vertical bending stress in the cantilever joint of the preferred chewing side was assessed. Occlusal forces were measured using eight miniature strain gauge transducers bilaterally and symmetrically mounted in complete dentures. Occlusal forces over the entire prosthesis were registered in basic (habitual) occlusion and with a 100-µm-high premature occlusal contact on the second cantilever unit. Closing and chewing forces increased distally. The premature occlusal contact did not significantly influence the total forces over the entire dentition but increased the local forces over the second cantilever unit. The group mean maximal vertical bending stress for closing forces reached the fatigue limit for unhardened type III dental gold alloy in basic occlusion. Although the interfered occlusion resulted in a significant redistribution of forces and significantly altered the stress contributions from each cantilever unit, maximal vertical bending stress in the cantilever joint was not significantly influenced. During chewing, the fatigue limit was not reached in basic or in interfered occlusion. Keywords: complete dentures, implants, occlusal interference, vertical bending stress

Focal areas of gingival hyperplasia surrounding the transmucosal portions of titanium implants have been attributed to poor hygiene, lack of attached gingival tissues, and titanium allergy. Following mandibular vestibuloplasty and placement of a split-thickness skin graft, two of five patients developed persistent proliferation of the epithelial tissue surrounding endosseous CP titanium dental implants. In both circumstances, traditional gingivectomy procedures, chemotherapeutic agents, and aggressive oral hygiene measures failed to adequately control the hyperplastic response. Following replacement of the titanium abutments with custom-fabricated gold abutments, the epithelial condition appeared to return to normal. Keywords: dental implant, gold, hyperplastic tissue, titanium