USE OF COLLAGEN MATRICES IN ORAL TISSUE REGENERATION.

OBJECTIVES: The present study wanted to investigate the influence of the biomaterials used in GBR procedures for the treatment of horizontal bone defects in dogs. Different healing times (4 days, 2 weeks, 6 weeks, 3 months) were considered to analyze the variations in tissue composition at different time points. A multivariate/multilevel analysis was used to answer the question whether factors other than the treatment group and the healing time can be correlated to the GBR treatment outcomes. MATERIALS AND METHODS In this in vivo experimental study three horizontal defects were shaped in each lower hemi-mandible of eighteen beagle dogs. After 3 months of healing, the atrophic ridges were laterally augmented through the use of a bone xenogeneic graft (T1), a collagen membrane (T2) or a combination of both biomaterials (T3). After the scheduled healing time points, dissected blocks were processed for qualitative and quantitative analysis. RESULTS. All animals experienced uneventful healing during the whole study period. A statistically significant correlation was found between greater augmented volume and the combined treatment group (T3), whereas T2 presented the higher percentage of mineralized tissue within the augmented area. The percentage of mineralized tissue was also correlated with longer healing time points. In all groups the treatment outcome were statistically influenced by the ridge morphology (horizontal ridge width and defect depth, p<0,01). CONCLUSIONS Bone regeneration in non-contained horizontal bone defects may be achieved by means of the three selected treatment strategies, although several factors seems to be involved in the final outcome of the procedure.