In previous papers we have reported longitudinal results of periodontal treatment based on mean values for all treated teeth,1,2 and analysis based on mean values from the half mouths of patients.3 These methods of analysis, however, did not reveal specifically what happened over time to pockets of various depth and attachment levels.

The purpose of this study was to determine the influence of furcation involvement (FI) and mobility (MO) on change in probing periodontal attachment level (AL) on molar teeth. Twenty-four patients were selected from The University of Michigan longitudinal periodontal clinical trial. The patients who met the entry criteria received a baseline examination and were treated by periodontal scaling and root planing followed by different periodontal surgical approaches in a split-mouth design. Patients were placed on a 3-month interval for maintenance prophylaxis and had yearly periodontal scorings for a period of 8 years. The scorings included determination of AL, FI, MO, and tooth loss (TL). Data for molar teeth from three different time periods (at entry (A) and at 1 (B) and 8 (C) years) were analyzed. The results demonstrated that teeth with FI were 2.54 times more likely to be lost when compared to teeth without FI during the maintenance period. By using paired t test approach to the probing attachment level data, molars with FI had significantly more loss between times B and C but not between A and B or A and C. Teeth with increased MO demonstrated significantly more AL between times A and C and B and C. When the interaction between MO and FI was analyzed, teeth with both FI and MO had significantly more attachment loss during the maintenance period (B to C). No statistically significant difference was found among the three different therapeutic approaches (pocket elimination, curettage, and modified Widman flap) during any of the time periods.(ABSTRACT TRUNCATED AT 250 WORDS)

CONVINCING EVIDENCE of new connective tissue 1 and epithelial attachment 2 following periodontal therapy has revived the interest in therapeutic methods aimed at reattachment. Although new attachment has been re ported following several modalities of treatment, 3-5 there is a remarkable lack of data from controlled clinical trials to indicate the short and long term potential for gain or loss of periodontal attachment following treat ment.

The role of personal plaque control in periodontal maintenance care was studied in 78 patients who had undergone periodontal therapy and were on 3-month recall for prophylaxis over 8 years. Variations in pocket depth and attachment levels were related to individuals with plaque scores above and below the median. The results also were analyzed by comparing the 25% of the sample having the lowest plaque scores with the 25% having the highest scores over 7 years of maintenance care. Students t test was used. It was found that personal oral hygiene as expressed in plaque scores was not critical for maintenance of post-treatment pocket depth and attachment levels in patients with professional tooth cleaning every 3 months. The initial post-treatment reductions in pocket depth and variations in attachment levels were more favorable in patients with good than with poor oral hygiene, but, these differences were not significant after 3 to 4 years of maintenance care.

Data collected as part of an 8-year longitudinal study on periodontal therapy involving 82 patients and 1974 teeth were analyzed to determine if tooth mobility influenced the result of treatment. For each patient, pocket depth, attachment level and tooth mobility were scored clinically at the initial appointment, and once a year for 8 years following periodontal therapy. The treatment consisted of scaling, oral hygiene instruction, occlusal adjustment, periodontal surgery (curettage, modified Widman or pocket elimination), followed by recall prophylaxes every 3 months. Tooth mobility data on a scale of 0--3 were related to changes in attachment levels for three grades of severity of periodontal disease, based on initial pocket depth (1--3 mm, 4--6 mm, and 7 + mm). Mean patient attachment changes were calculated from teeth in the same severity category for each patient. The data were analyzed by one-way analysis of variance and Scheffe's multiple comparison procedure to test the hypothesis of equal effects of tooth mobility on the results of the treatment for the three severity groups over 8 years. The results indicate that there is a statistically significant relationship between original tooth mobility and the change in level of attachment following treatment. Pockets of clinically mobile teeth do not respond as well to periodontal treatment as do those of firm teeth exhibiting the same initial disease severity.