Evaluation of 2 methods to assess gingival bleeding in smokers and non-smokers in natural and experimental gingivitis

The purpose of the present study was to compare the bleeding tendency as elicited by probing the marginal gingiva (BOMP) and probing to the bottom of the pocket (BOPP) in smokers and non-smokers in natural gingivitis and during experimental gingivitis. 11 smokers (sm) and 14 non-smokers (nsm) were recruited. When they had less than 20% approximal bleeding sites, they entered a 14-day trial period of 'experimental gingivitis'. Subjects returned 30 days later, after resuming normal oral hygiene procedures, for a final gingival assessment. A split-mouth design was chosen using 2 contra-lateral quadrants for each index (being either BOMP or BOPP). A consistently higher bleeding score of approximately 10% was observed by probing to the bottom of the pocket. At day 14 with both indices, a significant difference between smokers and non-smokers was detected (BOMP: sm=15%, nsm=30%; BOPP: sm=27%, nsm=44%). The increment between gingival health and experimental gingivitis was significantly higher in non-smokers than in smokers but comparable for both indices (BOMP: sm=8%, nsm=23%; BOPP: sm=9%, nsm=26%). Probing to the bottom of the pocket results in significantly more bleeding in gingival health and gingivitis as compared to probing of the marginal gingiva. This shows that evaluation of the gingival condition with BOMP, the method of choice with respect to gingivitis, can be used as a parameter for inflammation when comparing smokers and non-smokers. The suppressed inflammatory response to plaque accumulation, as observed in smokers, indicates that they should be identified as a separate group when they participate as panelists in (experimentally induced) gingivitis studies.