Clinical, microbiological and immunological features of subjects with refractory periodontal diseases.

27 subjects with active destructive periodontal diseases were treated by modified Widman flap surgery and systemic tetracycline and divided into 4 groups based on pre- and post-therapy hazard rates (% of sites losing greater than 3 mm of attachment in 1 year). Pre- and post-therapy hazard rates were respectively: group I (3 subjects) less than 4 and less than 4; group II (8 subjects) greater than 4 and less than 4; group III (3 subjects) less than 4 and greater than 4; group IV (refractory group of 13 subjects) greater than 4 and greater than 4. Baseline mean pocket depths and attachment loss of groups I and II subjects were less than groups III and IV subjects and exhibited less suppuration. 6 group IV subjects lost a total of 38 teeth after therapy, in contrast to no tooth loss in subjects in the other 3 groups. Redness, bleeding on probing, plaque levels and age did not differ among groups. Subjects in the 4 groups differed in the subgingival species to which they showed elevated serum antibody responses. Group IV subjects showed elevated responses to a select range of gram-negative species, including A. actinomycetemcomitans strains Y4 or ATCC 29523, F. nucleatum and B. intermedius. No subject in any of the other groups exhibited an elevated response to B. intermedius. The mean % of each species in all sampled sites, both before and after therapy, was computed for each subject. Subjects in groups III and IV (high post-therapy hazard rates) exhibited elevated mean levels of B. forsythus, F. nucleatum, S. intermedius, E. corrodens, and B. gingivalis.(ABSTRACT TRUNCATED AT 250 WORDS)