ABSTRACT
Objective: This study aimed to assess the destructive effects of citric acid, lactic acid and acetic acid produced from the fermentation of foods on primary teeth enamel
Methods: This in vitro, experimental study was conducted on 24 sound primary teeth. The teeth were polished with a fine abrasive paper under running water. Tooth pieces measuring 3×4×3mm were cut out of the teeth and stored in 100% humidity until the experiment. The specimens were divided into 3 groups [n=8] and immersed in acetic acid, citric acid and lactic acid, respectively. The enamel microhardness of specimens was measured by Vickers microhardness tester at baseline and 5 and 30min after immersion in the freshly prepared acid solutions
Results: Repeated measures ANOVA showed that the effect of immersion time on microhardness was significant [p<0.001]. Pairwise comparison among 0, 5 and 30 minutes time points using Bonferroni adjustment showed significant differences in microhardness at different time points [p<0.001]. Evaluation of the effect of type of acid on microhardness revealed that the microhardness was not significantly different in the three groups of acids [p=0.915]. Among the three understudy acids, only the reduction in microhardness from time 0 to 30 minutes was significantly different between lactic acid and acetic acid [p=0.042]
Conclusion: Citric acid, lactic acid and acetic acid were all capable of demineralization and reduction of enamel microhardness. A significant difference existed in the demineralization potential of acids [the highest for lactic acid]. However, this effect was more significant early after exposure
ABSTRACT
Statement of the Problem: Dental caries is the most common disease of childhood. Using probiotics has recently been introduced to reduce the incidence of dental caries. It consists of live microbial food supplements that beneficially affect the host, and hence are considered an alternative way to eradicate the infections.
Purpose: The aim of this study is to evaluate the effect of consumption of probiotic yogurt on the children's salivary cariogenic microflora.
Materials and Method: A double-blind randomized study was performed recruiting 2 parallel groups; 24 healthy children in the case and 25 children in the control group. All healthy children were followed- up over 4 periods. Periods 1 and 3 were wash-out periods with duration of 1 and 2 weeks, respectively. During periods 2 and 4 [2weeks duration each], the case group consumed 200g yogurt containing Bifidobacterium lactis [1×10[6] per gram] once daily and the control group consumed normal yogurt. Salivary Streptococci mutans and Lactobacilli were enumerated before and after the yogurt consumption periods. Pre- and post-treatment values within and between regimens were compared using the t-test and paired samples
Results: There was a reduction in Streptococcus mutans and Lactobacillus counts in the control group, but for Streptococcus mutans, the count reduction between phases 1 and 4 was statistically significant [p= 0.009]. In the case group, neither the Streptococcus mutans count nor the Lactobacilli count was significantly reduced
Conclusion: Based on the findings of this study, short-term daily consumption of probiotic yogurt containing Bifidobacterium lactis could not reduce the levels of salivary Streptococcus mutans and Lactobacilli in 6 to 12 year-old children, while normal yogurt could reduce the Streptococcus mutans counts significantly