Statistical modeling of tooth mobility after treating adult periodontitis

Abstract.

The healing process following periodontal surgery for advanced adult periodontitis is described. Of the various indicators, tooth mobility (TM) is considered, and its relation to surgical treatment and the time lapse from the flap surgery is quantitatively modeled by non-parametric regression. Mobility is measured by an electronic apparatus, which also automatically performs the modeling. A new statistical method for TM prediction is demonstrated, and its quality is estimated. We show that the quality at the first step of prediction is approximately 0.7. This indicates that the prediction method is able to model the effect of surgery on the healing process, although the random scattering of TM data recorded in the examined group is relatively large. The influence of periodontal surgery on TM, alone and in combination with systemic metronidazole, is quantitatively characterized in two groups of 12 patients each. In the test group, which received metronidazole, TM decreased significantly 1 week postoperatively, compared to the control group without the antibiotic. The gingival fluid flow rate (GFFR) and the percentage of spirochete morphotypes detected by darkfield microscopy exhibited a similar dependence. Significant differences in TM, GFFR and the percentage of spirochetes between the two groups were observed over a period of several weeks. Probing depths (PD) in both groups at 2 and 12 months after surgery did not reveal any category with pockets deeper than 4 mm. A gain of clinical attachment level of more than 2 mm (CAL) was observed at measurements of 16.7% and 10.6% on the test and control groups, respectively, 1 year after surgery.