Evaluation of the effect of toothpastes with different ingredients on the surface microhardness and surface properties of artificial incipient caries, in vitro

In the present study, the aim was to evaluate and compare the effect of toothpaste with different fluoride concentrations and kinds of toothpaste with alternative remineralization agents on the surface microhardness and surface properties of artificial incipient caries, in vitro. Enamel samples from bovine incisors were divided into 5 groups as 4 study groups (N-HAP, BioC, 1450F, and 1000F) and 1 control group (n=13). Baseline surface microhardness (SMH) values were measured for all samples and they were kept in a demineralization solution at 37°C for 72 hours, after which the artificial incipient caries lesions were created. Post-demineralization (PD) SMH values and post-treatment (PT) SMH values with tubes of toothpaste in the study groups were measured following a 14-day pH cycle. Baseline, PD, and PT surface properties of the samples were evaluated using a Scanning Electron Microscope (SEM) (n=3). The crystal phases that occurred on the enamel surfaces were determined by X-Ray Diffraction (XRD) (n=3). Statistical analyses were done using one-way analysis of variance, Newman Keuls, Tukey, Kruskal Wallis, and Dunn's tests. The findings were evaluated at a significance level of p<0.05. There were statistically significant differences between all groups in terms of mean PT SMH values (p=0.0001). The highest mean SMH among the study groups was observed with 1450 F, and the lowest was observed with N-HAP. PT SMH values were higher than PD SMH values but lower than baseline across all study groups. SEM examinations revealed mineral gains on enamel surfaces after treatment across study groups. XRD analysis revealed calcium phosphide and calcium phosphate carbonate on enamel surfaces after demineralization and the predominant presence of HAP and FAP in the 1000F and 1450F groups, HAP in the N-HAP group, and calcium silicate in the BioC group after treatment. In conclusion, it can be suggested that fluoride toothpaste remains the best choice for preventing dental caries, and toothpaste with bioactive glass and N-HAP could be alternatives to fluoride toothpaste.