Evaluation of Tissue Reaction to Some Denture Base Materials

Objectives: There are still controversies about denture base materials. One of the methods to evaluate the materials biocompatibility is animal study. The purpose of this study was to evaluate of dog's mouth vestibular tissue reaction to Co-Cr, heat cure acrylic resin, and acrylic resin mixed with aluminum oxide with control group with histopathologic method. Methods:Twelve disk shape samples (2mmx8mm), in four groups of Co-Cr, acrylic resin, acrylic resin mixed with 20% weight ratio aluminum oxide and control group (Teflon) were fabricated. In one stage surgery two samples of each material (8 samples) was implanted in buccal vestibule of each dog (n=6), subcutaneously. After 45 and 90 days samples were excised with peripheral tissues (in each time half of the samples). Tissue inflammation was assessed by grading from 0 to 3 and presence of fibrotic capsule by histological observations. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests.

Results:Tissue reaction between Co-Cr and control group was significant(P=0.02); but it was not significant between other groups.There was no significant difference between 45 and 90 days. The formation of fibrotic capsule groups was significant (P=0.01). It was significant between Co-Cr and Acrylic resin groups (P=0.01) and Acrylic resin and control groups (P=0.01).

Conclusion:The Co-Cr group was more toxic than other groups. The inflammation increased during time. The inflammation in two acrylic groups was more than control and less than Co-Cr group. The formation of fibro tic capsule, except in Al2O3 group was increased during time.