Objective: The aim of this study is to assess the effectiveness of a very brief structured counseling for tobacco cessation in dentistry clinics.

Method: A cluster randomized trial was conducted in Sweden in 2012-2013.

Twenty-seven dentistry clinics in two Swedish counties were randomized to provide either a structured brief advice based on the 5 A's model or usual care. Participants were 467 patients currently using tobacco daily (225 in the intervention group and 242 in usual care), of which 97% were retained at follow-up, six months after enrolment. Study outcomes were: 7-day abstinence (primary outcome); 3-month sustained abstinence; 50% reduction of the amount tobacco used; quit attempts lasting at least 24 h.

Results: Compared to usual care, brief counseling was not associated to statistically significant increase in the proportion abstinent from tobacco use after 6. months. However, there was a statistically significant association with reduction of tobacco consumption (OR = 2.07 95% CI 1.28-3.35). Changes in the expected direction for all outcomes were more frequent in the intervention than in the usual care group, and larger among exclusive snus users than among smokers.

Conclusions: Very brief and structured counseling in dentistry may achieve positive behavioral modifications among tobacco users, with significant reduction of tobacco consumption, particularly among smokeless tobacco users.