Histologic analysis of the osseointegration of endosseous implants in simulated extraction sockets with and without e-PTFE barriers. Part II: Histomorphometric findings.

This investigation constitutes a pilot study of osseous changes around hydroxylapatite-coated implants analyzed histologically nine weeks following their placement into stimulated mongrel dog extraction sites either with or without e-PTFE barriers. An image analysis system was utilized for the assessment of undecalcified sections for the following parameters: (1) crestal alveolar bone height, (2) distance to the most coronal bone in residual defects, (3) distance to the most lateral bone in residual defects, and (4) area of bone regenerated in standardized 1 mm x 3 mm portions of original defects. Two-way ANOVA demonstrated that there were significant differences among the barrier, non-barrier, and control sites for all parameters except crestal bone height (p < 0.05). When one animal which displayed premature clinical exposure of e-PTFE was excluded from the analysis, crestal change showed a significant improvement (P < 0.05) for barrier vs. non-barrier sites. Therefore, the proper application of e-PTFE barriers was usually associated with crestal bone apposition rather than resorption and a greater osseous fill of the original crestal defect when compared with sites where no barrier had been placed.