Abstract
This study was designed to clinically investigate the influence of bruxism on molar furcation involve-ment. In the first examination, forty-five patients with furcation involvement were selected and examined for the extent of this involvement, the severity of periodontitis, and the grade of bruxism. In the second examination, 37 patients who had received periodontal maintenance therapy for twenty-two months after the first examination were selected. They were classified into two groups at the time of re-examination : one group wore oc-clusal splints for more than one year; the other wore splints for a limited time period. The obser-vations included the examination of furcation involvement, and ratio of total bacterial number, Porphromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans using an in-direct immunofluorescence technique.
The results showed the furcation involvement to be more severe in strong bruxers. Furcation involvement in the first group improved consider-ably as compared to that of the second group. However, there was no difference in bacterial ratio between the two groups. We speculate that improvement of furcation involvement was due to reduction of occlusal trauma achieved by using occlusal splints and that bacterial flora had little influence on the result.
Therefore, it was suggested that nocturnal brux-ism influences the progression of molar furcation involvement.
