Scanning electron microscope study of the junction between restorations and gingival cavosurface margins.

This study demonstrates a definite interfacial void between the cervical margins of the tooth preparation and gold inlay, composite resin, and amalgam restorations. In addition, these marginal defects permit plaque formation within them. Furthermore, microleakage may be a complicating factor in this lack of fit. Restorations which may be "clinically acceptable" may not, in fact, be ideal because of the properties of the restorative materials. It would seem desirable, therefore, to encourage the development of new restorative materials that will bond to the tooth surface.

Effects of scleral collagen upon the healing of experimental osseous wounds.

Standardized wounds were created in the femurs of 13 female white New Zealand rabbits and implanted with autogenous scleral connective tissue, Achilles bovine tendon collagen chips and cores of cancellous autogenous bone and marrow. A blood-filed wound served as a control. The dynamics of the healing of these wounds over periods of time ranging from 12 days to 3 months was studied by routine histology, fluorescent microscopy and by radiography. Rapid healing of the control and bone implant wounds occurred but was retarded by the implantation of sclera. Collagen chips provoked an active lymphocytic response and severely impeded the healing of the experimental wounds. These experiments were discussed in light of the current interest in allogenic scleral implants in periodontal therapy.