The effect of periodontal therapy on lymphocyte blastogenesis to plaque associated microorganisms.

The effect of clinical treatment on the in vitro lymphocyte blastogenic response to a panel of dental plaque-associated microorganisms, as well as non-oral antigens, was assessed longitudinally in a group of twenty-three patients during treatment for periodontitis. The patients' blastogenic response to the non-oral antigens remained constant, without significant change, throughout the three year study. Following scaling, root planning, and ora! hygiene instruction {hygiene phase), an increased blastogenic response to the plaque-associated stimulants {except B. gingivalis) was observed. Responses measured after periodontal surgery and one year following the hygiene phase (first maintenance year) were lower than pretreatment values. Between the first and second yearly maintenance phase evaluations there was a significant increase in the blastogenic response to A. viscosus. B. gingivalis. and F. nucleatum. Thus, periodontal therapy initially resulted in a reduction of plaque antigen-induced lymphocyte blastogenesis. However, the responses increased again with time in the absence of deteriorating clinical parameters,