Tooth loss impairs oral function. The aim of the present review was to evaluate the causal association between smoking and tooth loss on the basis of high-quality studies.

Objective. The association between gingival pigmentation and active smoking has been established. This investigation is the first to address the relationship between gingival pigmentation in children and passive smoking.Methods. A case-control study was performed involving 59 nonsmoking children who were selected from patient records of a dental clinic in a rural town in Japan. The number of subjects was based on a power calculation. Two calibrated examiners independently observed labial gingiva via oral photographs.Results. An interview determined that 61% of children had at least 1 smoking parent. Gingival pigmentation was observed in 71% to 78% of children. Interexaminer agreement was satisfactory (κ = 0.73). Percentage of smoking parents was higher in children with gingival pigmentation (70–71%) than in those who lacked pigmentation (35%). Odds ratios of parental smoking adjusted by age and gender were 5.6 (95% confidence interval: 1.5–20.0) and 5.4 (1.4–21.2) for the 2 examiners.Conclusion. These findings suggest that excessive pigmentation in the gingiva of children is associated with passive smoking. The visible pigmentation effect in gingiva of children could be useful in terms of parental education.

This review evaluated evidence of the relationship between secondhand smoke (SHS) and dental caries in children in epidemiological studies. Relevant literature was searched and screened, and the methodological quality was assessed. The search yielded 42 citations. High-quality studies including one cohort format and 14 case-control format studies were selected. Early childhood caries was examined in 11 studies. The independent association of SHS was significant in 10 studies, and the strength was mostly weak to moderate. One study did not select SHS as a significant variable. Three studies reported decreases in the risk of previous exposure, and the association was not significant. Dose-response relationships were evident in five studies. Permanent teeth were examined in seven studies. Five studies reported significant associations, which were mostly weak. The risk of previous exposure remained similar to that of current exposure, and a dose-response relationship was not evident in one study. The overall evidence for the causal association in early childhood caries is possible regarding epidemiological studies, and the evidence of permanent teeth and the effect of maternal smoking during pregnancy were insufficient. The results warrant further studies of deciduous teeth using a cohort format and basic studies regarding the underlying mechanism.

Resolution of dysbiosis following treatment for periodontal disease and tobacco dependence has been reported in longitudinal intervention studies. In the present report, we evaluated the biological findings regarding the effect of smoking on the periodontal microbiome. A standardized electronic search was conducted using MEDLINE; overall, 1099 papers were extracted. Studies that addressed the relationship between tobacco and periodontal pathogens were included. Finally, 42 papers were deemed appropriate for the present review. Functional changes in periodontal pathogens exposed to nicotine and cigarette smoke extract support the clinical findings regarding dysbiosis of the subgingival microbiome. Dysbiosis of the periodontal microbiome was presented in smokers regardless of their periodontal condition (healthy, gingivitis, or periodontitis) and remained significant only in smokers even after the resolution of experimentally-induced gingivitis and following reduction of clinical signs of periodontitis with non-surgical periodontal treatment and over 3 months post-therapy. Based on these findings, smoking cessation in periodontitis patients is beneficial for promoting a health-compatible subgingival microbial community. To maximize the benefits of these interventions in dental settings, further studies on periodontal microbiome are needed to elucidate the impact of tobacco intervention on preventing recurrence of periodontal destruction in the susceptible subjects.