ABSTRACT
Microbial plaque is the main etiologic factor which causes disease in soft tissue around dental implants. The purpose of this study was to evaluate the effect of plaque on health indicies of soft tissue around dental Implants. 45 patients with 211 dental implants were examined clinically for four years after prosthodontic treatment. Plaque index and health indices of soft tissue including pocket depth, attachment level, bleeding index, and gingival index were measured. The results were compared in two groups of zero and non zero plaque. The repeated measured ANOVA and Friedman test were used for statistical data analysis. The results of this study showed that in the first group, in which the plaque index was zero, probing pocket depth, probing attachment level, bleeding index, and gingival index were lower than in the second group. According to the results of this study, aggregation and increase of plaque around dental implants decreases the health level of soft tissue around dental implants and its continuation may cause disease in protective tissues of the implant