International Journal of Periodontics & Restorative Dentistry, 05/1995

Developments in biomaterials in the field of adhesion have made possible a less invasive dentistry. Improvements in adhesive polymers along with the analysis of certain failures in resin-bonded prostheses have suggested the micropreparation of abutment teeth. A long-term study of resin-bonded prostheses and splints was undertaken. The success rate of this protocol is presented for a study period of 10 years (1984 to 1993). These results indicated that the resin-bonded prosthesis is a viable option in patients who ar missing one or two teeth. Of 145 prostheses, 11 failed, resulting in an overall survival rate of 83% (Kaplan-Meier test). Furthermore, the study confirmed that, for splints, preparation is important to counter the major stresses related to tooth mobilityin patients with periodontal disease.

The surgical procedure of using a titanium in combination with a mandibular bone graft for a single-tooth reconstructon is presented. The donor bone was taken from the vestibular base, close to the symphysis of the mandible. Patients whowere missing a maxillary incisor or canine tooth, and exhibiting a loss of supporting bone in the area, were found suitable for the technique.

Although nonbiodegradable barrier membranes have been proven partially successful in achieving regeneration of lost periodontium through the principles of guided tissue regeneration, their use requires a second surgical procedure for their removal. The results of a study, in which a biodegradable collagen membrane was used to treat dehiscence defects in dogs, are presented. The membrane was an effective barrier to the downgrowth of gingival epithelium during the early stages of healing and tended to increase the regeneration of new cementum and connective tissue attachment. It was also biocompatable and biodegradable.

A new technique, the modified coronally positioned flap precedure, is described for treatment of Class 2 and 3 molar furcation defects in conjunction with barrier membranes. This technique is designed to minimize barrier exposure during the healing phase and to cover and protect the newly formed granulation tissue following barrier removal. Examples are presented and discussed, and modifications for varying situations are described. The modified coronally positioned flap technique is applicable for use with nonresorbable and resorbable membranes.

The surgical repositioning of the inferior alveolar nerve facilitates the placement of implants in the posterior mandible. The entire height of the posterior mandible is made available and enable implant to be anchored in two cortical plates,improving the primary fixation and increasing the area of bone-implant interface. The posterior mandible can thus be predictable treated with implants in those cases where posterior support is considered important for occlusal stability and masticatory effciency. The rapid and total recovery of sensation to the lip following nerve repositioning renders the procedure more acceptable to both the patient and the clinician.

Most microfilled composite resins are relatively resistant to generalized wear; however, they commonly exhibit poor resistance to localized wear becaues of debonding of prepolymerized particles from the resin matrix. A copolymerized new composite resin, in which the filler particle trimethylolpropane-trimethacrylate is chemically bonded to the resin matrix, is evaluated. Epic-TMPT was subjected to both generalized and localized wear tests that revealed that its wear resistance was higher than that of other composite resin systems. Epic-TMPT in posterior occlusal cavities showed less than 8 um of wear for each restoration, 1 year after placement. Placement of Epci-TMPT into large anterior abfraction lesions withour mechanical retention, with surface etching, and subject to severe traumatic occlusion resulted in 87% retention 1 year after plaement. In vivo usage biocompatibility tests demonstrated nopulpal irritation or inflammation when Epic-TMPT was placed on vital dentin of crown preparations with complete enamel removal.

This study was undertaken to examine histologically the healing response of alveolar bone following removal of granulation and/or connective tissues from interproximal craters by manuel curettage or ablation by carbondioxide laser. The time required to complete each type of degranualtion procedure was also compared. Four interproximal treatment sites in each quadrant of two dogs were randomly assigned to each treatment modality. Neither treatment modality was totally effective in removing all suprabony connective tissue. Healing was clinically uneventfula and histologically similar for both treatment groups at all time intervals. Lasr-treatedspecimines exhibited little of no inflammatory cell infiltrate, areas of heat-induced tissue necrosis, accumulations of Carbonized debirs that initially was surroundex by macrophages and eventually phagocytized by multinucleated giant cells, and spiceles of nonvital boe that exhibited a surface layer of osteoid. Although manual curettage was found to be statistically significantly faster, the difference between mean times was roughly 55 seconds and therfore unlikely to be clinically significant.