Dental Caries Area of Rat Molar Expanded by Cigarette Smoke Exposure

Abstract

Objectives: Passive smoking is the involuntary inhalation of cigarette smoke (CS) and has an adverse impact on oral health. We examined the effect of CS exposure on caries risk and experimental dental caries. Methods: Experimental dental caries was induced in rat maxillary molars which were inoculated orally with Streptococcus mutans MT8148 and maintained on a cariogenic diet (diet 2000) and high sucrose water during the experimental period. CS-exposed rats were intermittently housed in an animal chamber with whole-body exposure to CS until killed. Whole saliva was collected before CS exposure (day 0) and for 30 days after the start of CS exposure. Saliva secretion was stimulated by administration of isoproterenol and pilocarpine after anesthesia. Maxillary molars were harvested on day 31. Results: The increase in body weight of the CS-exposed rats was less than that of the control rats. Salivary flow rate, concentration of S. mutans in the stimulated saliva and caries activity score did not significantly differ between 0 and 30 days after the start of CS exposure. Histological examination of the caries-affected area on maxillary molars 30 days after CS exposure showed expansion compared to control rats. In the electron probe microanalysis, no differences were observed between the mineral components of the CS-exposed teeth and the control teeth. Conclusion: These results suggest that CS exposure expands the caries-affected area in the maxillary molars of the rat.

Association between exposure to household smoking and dental caries in preschool children: a cross-sectional study

“…Nicotine also increases extracellular polysaccharides, which can attract other microorganisms, such as Candida albicans , onto the dental plaque [21]. In fact, in vivo, the caries-affected area on the molars was more expanded in cigarette smoke-exposed rats than in control rats [22]. In humans, tobacco smoking was associated with elevated levels of Streptococcus mutans and Lactobacilli [23, 24].…”

Daily smoking and 4‐year caries increment in Finnish adults

“…Researchers have only started to unravel some of the potential effects of tobacco smoking on the biology associated with caries development, including alterations in saliva and dental plaque . A recent experiment has also shown that exposure to cigarette smoke expanded the caries‐affected area in maxillary molars of rats . Further research is needed to assess the above pathways as explanations for the link between smoking and caries.…”

The role of tobacco use on dental care and oral disease severity within community dental clinics in Japan

“…In other studies that controlled for possible confounders, however, dental caries were significantly and independently associated with smoking [21-25]. A cohort study design may allow the inference of causality [21], and the effects of exposure to tobacco contents on the growth and metabolism of Streptococcus mutans [26] and on the expansion of the dental caries area [27] may suggest biological plausibility. A mechanism which acts via this cariogenic microorganism is conceivable, since the effects of tobacco use on periodontal microorganisms [28,29] has been recently added to the list of potential causal pathways [30].…”