Recurrence of destructive periodontal disease after treatment. A long term study

This study demonstrates the difficulties which arise in statistical analysis derived from data of observations in post-treatment healing and recurrence of periodontal disease. Ten individuals received an initial phase of treatment followed by surgical pocket elimination utilizing replaced flap surgery. Clinical measurements of recession and pocketing were taken pre-operatively and 6 monthly thereafter for a period of four years after treatment. The results have shown that surgical treatment is least benefit in cases of mild pocketing, and of most benefit in cases of severe pocketing. A tendency for reduction in recession levels after two years was observed. Pocketing and attachment levels showed a tendency toward relapse as early as 6 months postoperatively. However, this simple observation masks a complex pattern of tissue remodeling in which some sites remain stable, others improve, while others relapse with time. Improvement may occur concurrently in different sites. Continued improvement in the clinical parameters of pocketing and attachment levels was observable in some sites for up to 2 years after surgery, after which the tendency for recurrent disease became more noticeable. Analyses of changes in attachment levels may be misleading, because they may mask the divergent or convergent trends of recession and pocketing, which may be occurring simultaneously. As bursts of healing as well as bursts of destruction could be observed concurrently over the period of 4 years after treatment, it is suggested that a state of "dynamic equilibrium" is established, in which continued tissue remodeling over a protracted period of time, may give rise to the clinical misconception that little or no changes are occurring in the majority of sites with time.