Subgingival restorations may be associated with periodontal plaque inflammation

Abstract

Subjects. Subject data were derived from a subset of longitudinal study of the initiation and progression of periodontal disease in human beings. Conducted between 1969 and 1995, 7 surveys were made during that period in 160 subjects. At the initial visit, there were 159 control cohorts and 69 test cohorts; 26 years later (1995), data were obtained from 53 control and 28 test cohorts. Exposure. The progression of periodontal status as influenced by the placement of subgingival margins in a patient population receiving regular dental care was examined. Main Outcome Measure. The main outcome measures were attachment levels, gingival health (PlI, GI), and restoration indices. Main Results. The PlI increased significantly (P < .05) for the test sites between the first and second surveys and reached averages of PlI =1.57-1.77, whereas the PlI for the control sites remained fairly constant (PlI = 1.43-1.54). The GI was significantly greater (P < .005) in the test sites at all observation periods (GI = 1.03-1.38) compared to the control sites (GI = 0.47-0.88). No difference in the mean loss of attachment was evident between the test and control groups until year 4. Between years 4 and 19, greater attachment level loss was present in the test group (P < .05). However, this difference was no longer significant at year 26.