Sub gingival temperature (II). Relation to future periodontal attachment loss

The purpose of the present investigation was to determine whether sub gingival temperature was a risk indicator of periodontal attachment loss (detected in the following 2 months) in a subject or at a site. 29 subjects were measured at 6 sites per tooth for clinical parameters as well as sub gingival temperature using a periodontal temperature probe (Periotemp TM , ABIO‐DENT SM , Danvers, MA). The same instrument was used to measure sublingual temperature in order to compute differences between sub gingival and sublingual temperature. Clinical and temperature parameters were measured at 2‐month intervals. A total of 49 subject visits which had both baseline temperature and subsequent attachment level change measurements were available for analysis. Attachment level loss >2.5 mm occurred at 1 or more sites at 16 of 49 subject visits. Elevated mean sub gingival temperature was related to subsequent attachment loss particularly in individuals who exhibited more than 1 progressing site. The odds ratios of a subject exhibiting new attachment loss at 1 or more sites or at 2 or more sites were 14.5 and 64.0 if the subject's mean sub gingival temperature exceeded 35.5°C. Subjects with high mean sub gingival temperatures and widespread periodontal destruction appeared to be at greatest risk for new attachment loss. Discriminant analysis using % of sites with suppuration, redness and attachment level > 3 mm and mean site temperature correctly “predicted” disease activity with a sensitivity, specificity and overall agreement of 0.75, 0.76 and 0.82 respectively. Of 7243 sites, 43 (0.59%) and 160 (2.2%) showed attachment loss of either 2.5 mm or more or 2 mm or more respectively. Unchanging sites exhibited lower mean site temperature and higher deviations from sublingual than sites which lost or “gained” attachment. % of sites showing new attachment loss increased with increasing site temperature, decreasing site temperature deviation and a change in the indicator value from green to yellow to red. For example, % of sites exhibiting loss of attachment of 2.5 mm or more was 0.23 at <34°C, 0.36 at 34–35°C, 0.82 at 35–36°C and 1.04 at >36°C. This pattern was observed for subsets of sites with pocket depths < 4 mm and 4–6 mm, but was weaker for pockets > 6 mm. Most striking was the high risk (8.9% of sites) of new attachment loss at sites with shallow pockets (<4 mm), which bled on probing and had red temperature indicator values compared with the lower risk (1.4%) at shallow, non‐bleeding sites with green indicator values. The findings of the present investigation suggest that knowledge of the sub gingival temperature will be useful in identifying subjects and sites at risk for new attachment loss.