engleski

Effect of cigarette smoking on calcium fluoride uptake by enamel: an in vitro study

Introduction: Main role in caries-preventive mechanism of topical fluoridation has loosely bound fluoride (CaF2) which acts as a potential “reservoir” of fluoride, enhancing remineralization and retarding demineralization processes. The amount of CaF2 formed is known to depend on several factors such as fluoride concentration, the time of exposure, the pH of the solution, phosphate and calcium concentration. The source of calcium may be enamel, saliva, plaque and calculus. It has been showed that presence of saliva, even in small amounts, is important for success of topical fluoride treatment, presumably because of its calcium content. There are some indications that heavy smokers have higher salivary calcium concentration than their non-smokers counterparts. The aim of this study was to assess the difference in alkali-soluble (KOH-soluble) fluoride uptake by enamel between smokers and nonsmokers who use fluoridated toothpaste, assuming the difference in salivary calcium concentration. Materials and methods: Four enamel slabs were cut from each of 14 impacted third molars and randomly assigned into 4 groups. The slabs were mounted in dental wax, which covered all surfaces but enamel surface. Unstimulated saliva was collected from two volunteers by having them expectorate for 15 minutes into a sterile container at the same time in the morning, which was then stored on 4°C. Both subjects were healthy young males with good oral hygiene. One of the subjects was smoker, smoking 30 cigarettes a day for past 5 years, and other subject was non-smoker. Calcium concentration and pH of saliva was measured after saliva collection. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the determination of calcium concentration in saliva. Two groups (A and B) were shaken in saliva (A in smokers' saliva, B in nonsmokers' saliva) for 5 min and than shaked for 3 min in a toothpaste slurry (toothpaste/deionized water slurry (1:3 w/w) ; Elmex ®, GABA International AG, Münchenstein, Switzerland - silica based toothpaste, 1400 ppm F-, Amine fluoride (Olaflur), pH=4.6). One of the groups (group C) had no saliva treatment and was only shaked in toothpaste slurry for 3 min. The treatment was repeated after 6-hour period. One of the groups (D) served as control group with no treatment. The fluoride concentrations were determined by an ion selective electrode by method of Caslavska et al. (1975.) and the amount KOH-soluble fluoride was calculated as described by Dijkman et al. (1983.). Results: Calcium concentration in smokers’ saliva was higher (52.68 mg/L) than in nonsmokers’ saliva (23.95 mg/L). The enamel uptake of KOH-soluble fluoride (μg/cm2 ± SD) in the group A was significantly higher (1.43 ± 0.48) than those of other two treatment groups: B (0.76 ± 0.26) and C (0.96±0.27), P<0.015. The enamel uptake of KOH-soluble fluoride in all 3 groups was statistically different to those in control group. Only difference which was not significant was observed when comparing the uptake of KOH-soluble fluoride between groups B and C, P>0.015. Conclusion: The results showed that saliva collected from heavy smoker, which had higher salivary calcium concentration, enhanced enamel uptake of alkali-soluble fluoride.

smoking ; calcium fluoride ; enamel uptake

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