Disease progression in periodontally treated and untreated patients--a retrospective study.

BACKGROUND, AIMS: The aim of this retrospective study was to assess the effect of regular supportive periodontal treatment on disease progression in patients with moderate to advanced periodontitis.
METHOD: We compared radiographic change of interdental bone level and number of teeth at 2 time points in 3 patient groups (mean age 46 years): group A, periodontally untreated patients (n= 14) who dropped out during initial therapy; group B, non-compliant patients (n=26), who discontinued supportive periodontal therapy after ca. 2 years of maintenance; group C, compliant patients (n=27), who regularly attended the maintenance program for 7 years. Periodontal treatment was performed as scaling and root planing or flap surgery in groups B and C. All 3 groups were re-examined ca. 7 years after the initial examination.
RESULTS: Patients in group A lost 3.8 teeth (0.5 teeth/year), those in group B 3.2 (0.4 teeth/year), and in group C, patients lost 2.0 teeth (0.2 teeth/year). About half of the patients lost no teeth (group A 43%, B 42%, C 55%), and only 17 subjects lost more than 3. At the 2nd examination, an increase in interdental bone was found only in group C (+0.13 mm), while groups A and B lost 0.57 mm and 0.31 mm of alveolar bone level, respectively (p<0.05 group C versus A and B).
CONCLUSIONS: Systematic periodontal treatment stops interdental bone loss and decreases the rate of tooth loss in most cases. Periodontal surgery without regular follow-up care cannot prevent further periodontal destruction, but it can delay it.