Periodontal probing depth and subgingival temperature in smokers and non-smokers.

The aim of this study was to investigate the difference in subgingival temperature between smokers and non-smokers at different probing depths, and the effect of probing depth on subgingival temperature for smokers and non-smokers. 20 smokers and 20 non-smokers, with adult periodontitis, and retained upper anterior teeth were included. Initially sublingual temperatures were recorded, followed by subgingival temperature, pocket probing depth, and bleeding upon probing measurements at 3 buccal points at probing depths of 2, 3, 4, 5, and 6 mm for each of the anterior teeth. Sublingual temperatures were consistently higher than subgingival temperatures. The subgingival temperature measurements of pockets which bled upon probing, were subtracted from the sublingual temperature to produce temperature differentials (delta T), independent of individual body temperature, that were compared between smokers and non-smokers. The relationship between probing depth and delta T was examined in, and between, smokers and non-smokers for bleeding sites. delta T was found to decrease linearly with the increase of probing depth, suggesting a subsequent increase of subgingival temperature. Smokers were found to have significantly increased delta T(suggesting lower subgingival temperatures) compared to non-smokers, at probing depths of 2, 3, 4, and 5 mm. The differences in delta T for sites 6 mm in depth were not statistically significant between the 2 groups. It is concluded that for maxillary buccal anterior sites, there is a decrease of temperature differentials with an increase of probing depth at bleeding sites for both smokers and non-smokers. Smokers had higher temperature differentials compared to non-smokers, at probing depths of 2, 3, 4 and 5 mm.