Culture of gingival fibroblasts on bioabsorbable regenerative materials in vitro.

BACKGROUND: The use of membranes in guided tissue regeneration (GTR) can limit the apical migration of gingival cells and favor the establishment of new attachment by periodontal ligament fibroblasts. However, gingival recession during healing following GTR has been described as a frequent complication. The purpose of this study was to determine if gingival fibroblasts are affected by the composition of the bioabsorbable membranes used in mucogingival surgery. METHODS: Two type of bioabsorbable regenerative materials were used as cell carriers. Wistar rat gingival fibroblasts (RGF) were obtained from attached gingiva, cut into small fragments, and placed in culture dishes. When confluent, cells were detached using trypsin and identified as "first transferred cells" (P1). At the third passage (P3), cell count, trypan blue exclusion test, acid phosphatase activity, DNA synthesis, phase contrast microscopy, and scanning electron microscopy were performed. The cells were then placed in wells containing the membranes and incubated for 72 hours. RESULTS: When examined under microscopy, the control wells (without membranes) showed one cell type with the elongated appearance characteristic of fibroblasts. The wells with membranes showed an altered cell morphology with a high proportion of cell fragments regardless of the type of membrane used. CONCLUSIONS: These results suggest that cell carrier membranes could affect RGF morphology and thus alter gingival tissue healing following GTR.

Clinical and microbial findings on osseo-integrated implants; comparisons between partially dentate and edentulous subjects.

Clinical and microbiological parameters in partially dentate and edentulous patients treated with oral implants were compared in this study. Twenty-four subjects including 9 males and 15 females, aged 33 to 70 were treated with 98 Brånemark fixtures. Plaque index, gingival index, pocket depth, implant mobility and crevicular fluid flow rate were measured. Latex agglutination tests identified the presence of Actinobacillus Actinomycetem-comitans, Porphyromonas gingivalis and Prevotella intermedia. Partially dentate patients accumulated more plaque than edentulous patients (P = 0.05), whereas crevicular fluid flow rate was significantly higher (P < 0.001) in the partially dentate population. Porphyromonas gingivalis and Prevotella intermedia were more frequently detected (P < 0.01) in partially dentate patients. These results indicate that the presence of natural teeth alter clinical and microbiological parameters which could in turn affect the long term success rate of implants.