Periodontitis stage and grade modifies the benefit of regular supportive periodontal care in terms of need for retreatment and mean cumulative cost.

The risk of relapse in the maintenance population may be correlated with higher stage and grade, patient compliance, modifiable risk factors and the nature of the treatment provided during APT. The total cost of treatment of recurrences was lower for compliers in Stage III/IV and Grade B/C compared with erratic compliers with the same severity and risk.