In vitro dentine remineralization with a potential salivary phosphoprotein homologue

• Potential of casein as an in vitro salivary phosphoprotein homologue was tested.
• Casein inhibited surface precipitation but allowed dentine lesion remineralization.
• Lower casein concentrations resulted in greater mineral gain over time.
• Casein can be a salivary protein homologue for dentine remineralization studies.

ObjectiveAdvantages of introducing a salivary phosphoprotein homologue under standardized in vitro conditions to simulate the mineral-stabilizing properties of saliva have been proposed. This study longitudinally investigates the effects of casein, incorporated as a potential salivary phosphoprotein homologue in artificial saliva (AS) solutions with/without fluoride (F) on in vitro dentine lesion remineralization.DesignThin sections of bovine root dentine were demineralized and allocated randomly into 6 groups (n = 18) having equivalent mineral loss (ΔZ) after transverse microradiography (TMR). The specimens were remineralized using AS solutions containing casein 0 μg/ml, F 0 ppm (C0–F0); casein 0 μg/ml, F 1 ppm (C0–F1); casein 10 μg/ml, F 0 ppm (C10–F0); casein 10 μg/ml, F 1 ppm (C10–F1); casein 100 μg/ml, F 0 ppm (C100–F0) or casein 100 μg/ml, F 1 ppm (C100–F1) for 28 days with TMR taken every 7 days.ResultsSurface mineral precipitation, evident in group C0–F1, was apparently inhibited in groups with casein incorporation. Repeated measures ANOVA with Bonferroni correction revealed higher ΔZ for non-F and non-casein groups than for their counterparts (p < 0.001). Subsequent multiple comparisons showed that mineral gain was higher (p < 0.001) with 10 μg/ml casein than with 100 μg/ml when F was present in the earlier stages of remineralization, with both groups achieving almost complete remineralization after 28 days.ConclusionCasein is a potential salivary phosphoprotein homologue that could be employed for in vitro dentine remineralization studies. Concentration related effects may be clinically significant and thus must be further examined.