Effects of tobacco smoking on plaque development and gingivitis.

A study was undertaken to test the hypothesis that patients who smoke tobacco have a more rapid rate of plaque deposition and development of gingivitis than those patients who do not smoke tobacco. Twenty subjects participated in this study, their age range was 17 to 30 years. Ten were smokers and 10 were nonsmokers. After an initial thorough removal of all deposits, oral hygiene measures were stopped for 10 days. On days 3, 7 and 10, plaque levels were evaluated using the Plaque Index and the gingival status was evaluated using the Gingival Index. Samples of plaque were stained by the Gram technique and examined microscopically. Plaque levels appeared to be higher in smokers than nonsmokers but the differences were not statistically significant. No consistent differences were evident in the gingival status of the two groups. Microbiological analysis showed a statistically significant increase in the percentage of Gram-positive bacteria to Gram-negative bacteria in the smokers as compared to the nonsmokers on day 3, however these differences were not maintained in the plaque samples taken after the 3rd day.