Impact of Artificial Saliva's Mucin on Erosive De and Remineralization

Objectives: The aim of this study was to evaluate the effect of mucin on artificial saliva when compared to human saliva in situ, on the remineralization of erosion lesions and on the inhibition of erosive demineralization.
Methods: For the remineralization phase (RE) bovine enamel blocks were subjected to short-term acidic exposure by immersion in citric acid 0.05 M (pH 2.5) for 15 s. Superficial hardness test was performed, enamel blocks were selected (n=60) and randomly divided into the studied groups. For the demineralization phase (DE) sound enamel blocks were selected by microhardness, randomly divided into the studied groups, subjected to salivas for 2h than immersed into citric acid. The studied groups were (n=15 per group for each DE and RE): G/Mucin- artificial saliva given by Klimek et al. (0.33 g KH₂PO₄, 0.34 g Na₂HPO₄, 1.27 g KCl, 0.16 g NaSCN, 0.58 g NaCl, 0.17 g CaCl₂, 0.16 g NH₄Cl, 0.2 g urea, 0.03 g glucose, 0.002 g ascorbic acid and 2.7 g mucin in 1,000 mL distilled water/pH7); G/No mucin- artificial saliva given by Klimek et al. without mucin; G/Human saliva- in situ and G/Control- deionized water. The protocols for the groups consisted in the immersion of the blocks in G/mucin, G/no mucin or G/Control for 2 h. On the G/Human saliva volunteers wore palatal appliances for 2h. Enamel remineralization and demineralizationa were measured by superficial microhardness test (% hardness recovery and % hardness change, respectively). The data were analyzed using one-way ANOVA and Tukey’s test.
Results: All studied saliva were able to promote enamel remineralization and no differences were found among them (p<0.05). For DE, artificial saliva with mucin and human saliva (in situ) presented lower hardness loss, with no differences between them (p>0.05).
Conclusions: All artificial and human saliva were able to remineralize initial enamel erosion lesion and to protect the enamel against demineralization. In addition, in in vitro erosion studies, the saliva with mucin could be a good substitute for human saliva due to it’s similarly protection against demineralization.