FACTORS ASSOCIATED WITH DIFFERENT RESPONSES TO PERIODONTAL THERAPY

In a study of the efficacy of modified Widman flap surgery and scaling and root planing accompanied by I of 4 systemic adjunctive agents, Au gmentin, tetracyline, ibuprofen or placebo, it was observed that subje cts differed in their response to therapy. The difference was only par tially accounted for by the adjunctive agent employed. The purpose of the present investigation was to examine clinical and microbiological features in subjects who showed different levels of attachment change post-therapy. 40 subjects were subset into 3 groups based on mean atta chment level change post-therapy. 10 poor response subjects showed mea n attachment loss; 19 moderate response subjects showed mean attachmen t gain between 0.02-0.5 mm and 1I good response subjects showed a mean gain of attachment >0.5 mm. Clinical parameters were measured at 6 si tes per tooth both pre- and post-therapy. Microbiological samples were taken from the mesial aspect of each tooth and evaluated individually for their content of 14 subgingival taxa using a colony lift method a nd DNA probes. % of sites colonized by each species was computed for e ach subject both pre- and post-therapy. Significant differences were o bserved among treatment response groups for mean probing pocket depth, attachment level and % of sites with plaque pre-therapy. The poor res ponse subjects had the lowest mean probing pocket depth and attachment level, but the highest plaque levels. Post-therapy, the poor response group exhibited the greatest degree of gingival inflammation as asses sed by gingival redness and bleeding on probing. Subjects in the good response group showed decreases in the % of sites colonized for 9 of 1 4 test species, while subjects in the poor response group showed an in crease in % of sites colonized for 12 species. The differences in chan ge in % of sites colonized among groups were significant for B. forsyt hus and P. gingivalis. The majority of attachment loss in poor respons e subjects occurred at sites with pre-therapy probing pocket depths <4 mm. Subjects with moderate or good treatment responses had fewer shal low or moderate sites showing attachment loss and a large proportion o f sites in all probing pocket depth categories showing attachment gain . Sites that lost attachment greater than or equal to 2 mm post-therap y showed a significant increase in counts of P. intermediate, B, forsy thus and A. actinomycetemcomitans b, while sites that gained attachmen t showed a decrease in these species. The data indicated that subjects who showed a good treatment response exhibited a decrease in the leve l of gingival inflammation and a marked reduction in the % of sites co lonized by suspected periodontal pathogens. In subjects showing a poor treatment response, the level of gingival inflammation was not decrea sed and levels of periodontal pathogens increased.