Background and aims. Lysozyme and lactoferrin are salivary proteins which play an important role in innate defense mechanisms against bacteria. This study investigated the association of salivary lysozyme and lactoferrin concentrations with early childhood caries (ECC).Materials and methods. This study was carried out on 42 healthy children (age range, 36 to 71 months), of whom 21 were caries free (CF) and 21 had ECC. Disposable needle-less syringes were used to collect unstimulated saliva from buccal and labial vestibules. Fifteen children who had ECC were treated completely and their saliva was collected in the same way for the second time, three months after treatment. Lysozyme and lactoferrin concentrations were measured and recorded by the ELISA method. The intergroup comparisons were carried out using chi-square, Student’s t-test and Wilcoxon signed ranked test. A P-value less than 0.05 was considered as statistically significant.Results. The mean concentration of lysozyme was significantly higher in CF group compared with that of ECC group (P = 0.04). Although the mean concentration of lactoferrin in ECC group was higher in comparison with ECC group, the difference was not statistically significant (P = 0.06). After dental treatment, the mean concentrations of lysozyme and lactoferrin did not change in comparison with their concentrations before treatment.Conclusion. ECC may have a relationship with lower concentrations of unstimulated salivary lactoferrin and lysozyme and reduced amounts of these two salivary proteins may be a risk factor for dental caries in children.

Background Remineralization of incipient caries is one of the goals in dental health care ,especially in pediatric dentistry. The present study aimed at comparing the effects of MI varnish (3M (United states)) , Nano paste( FGM(Brezil) ), 5% sodium fluoride varnish) DuraphatColgate (united states) ) on remineralization of enamel lesions. Material and Methods In this in-vitro study, 60 intact human pre-molars, were randomly allocated to four groups of 15. Baseline surface microhardness in three points in the center of the polished area was measured. After two days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 under-went treatment with MI varnish, nano paste, 5% sodium fluoride varnish and then again microhardness was measured. The results were analyzed by one-way analysis of variance (ANOVA), repeated measures ANOVA, and Bonfreni table was used. Results Duraphat varnish in comparison with control group, significantly increased surface microhardness and in comparison with Nano and MI paste varnish groups significant differences was shown between groups. ( P < 0.05). MI paste varnish and Nano paste similary showed more increases in surface microhardness in comparison with Duraphat varnish and control groups (P≈1). Conclusions According to the results of this study, all three varnishes, Duraphat , MI paste and Nano paste increase the enamel surface microhardness and remineralization of incipient caries. MI paste and Nano paste compared to Duraphat Varnish, significantly showed more increases in enamel surface microhardness but Nano paste and MI paste were almost the same. Key words: CPP-ACP, Nano varnish, fluoride varnish, microhardness, demineralization, remineralization.

Introduction: Tooth decay as the most common infectious-nutritional disease in the world. The current work aims to investigate the antibacterial effect of thymol-loaded chitosan nanocomposite (TLCN) against Streptococcus mutans and Actinomyces viscosus as the main cariogenic bacteria. Methods: Antibacterial activity of TLCN was assessed on S. mutans and A. viscosus. The effects on protein leakage in the tested bacteria, as well as its cytotoxicity, were studied by Bradford’s method and cell viability assay, respectively. Results: The size of the nanocomposite varied from 100 to 600 nm. The best minimum inhibitory concentration (MIC) related to nanocomposite + chlorhexidine was reported 2.66 for both bacteria. TLCN dose-dependently increased the protein leakage (P < 0.05). The 50% cytotoxic concentration (CC50) of nanocomposite against on normal (HGF1-PI1) and cancer (KB) cells were 149.6 and 68.4 μg/mL, respectively. Conclusion: TLCN, especially in combination with chlorhexidine, displayed potent antibacterial effects against the main cariogenic bacterial causes. Nevertheless, other examinations are required to illuminate the precise mechanisms and its toxicity mainly in clinical settings.

Background The efficacy of fluoride varnish in preventing dental caries has been well documented. The objective of this study was to compare the impact of four different fluoride varnish brands containing 5% sodium fluoride on the sound enamel of permanent teeth. Methods In this experimental study, 40 sound human premolar teeth were randomly assigned to four groups (Fluorilaq®, FluoroDose®, Preventa®, Kimia®; N = 10). Each tooth was sectioned into buccal and lingual halves, corresponding to the control and the experimental subgroups, respectively. In the experimental halves, a semi-circular shaped area of the enamel was treated with the designated fluoride varnish. All specimens underwent Acid Etch Enamel Biopsy. Fluoride and Calcium concentrations were measured using a Potentiometer and Inductively Coupled Plasma optical emission spectrometer, respectively. The collected data were analyzed using paired t-test and one-way ANOVA at P < 0.05. Results There was a significant difference between the enamel fluoride content of experimental and control halves in all groups (P < 0.05). Preventa® Fluoride varnish caused the highest Fluoride uptake, followed by FluoroDose®, Fluorilaq®, and Kimia®. All pair comparisons were statistically significant (P < 0.05), except for Preventa® vs. FluoroDose® (P = 0.36). Conclusions Since all examined Fluoride varnishes increased the Fluoride content of the tooth enamel, they potentially qualify for caries prevention. Furthermore, Preventa® could be considered a good domestic alternative for other brands investigated in this research, in terms of enamel fluoride uptake.