Saliva substitute in combination with high-concentrated fluoride toothpaste: Effects on demineralised dentin in vitro

Abstract

Objectives The aim of this in vitro study was to assess the effects of saliva substitutes (modified with respect to calcium, phosphates, and fluorides) in combination with a high-concentrated fluoride toothpaste on demineralised dentin. Methods Before and after demineralisation of bovine dentin specimens (subsurface lesions; 37 °C, pH 5.0, 5 d), one-quarter of each specimen's surface was covered with nail varnish (control of sound/demineralised tissue). Subsequently, specimens were exposed to original Saliva natura (saturation with respect to octacalciumphosphate [ S OCP]: 0.03; SN 0), or to three lab-produced Saliva natura modifications ( S OCP: 1, 2, and 3; SN 1–3) for 2 and 5 weeks (37 °C). An aqueous solution ( S OCP: 2.5) served as positive control (PC). Two times daily (2 min each), Duraphat toothpaste (5000 ppm F −; Colgate)/saliva substitute slurry (ratio 1:3) was applied gently. Differences in mineral losses (ΔΔ Z) and lesion depths (ΔLD) between values before and after exposure were microradiographically evaluated. Results After both treatment periods specimens immersed in SN 0 revealed significantly higher mineral losses (lower ΔΔ Z values) and lesion depths (lower ΔLD) compared to PC ( p < 0.05; ANOVA). After 5 weeks, specimens stored in SN 1 and 2 showed significantly higher mineral losses compared to PC ( p < 0.05), while those stored in SN 3 showed similar results ( p > 0.05). No differences in mineral loss could be observed between SN 2 and 3 ( p > 0.05). Conclusions Under the conditions of this limited protocol, the combination of Saliva natura solutions slightly saturated with respect to OCP in combination with a high-concentrated fluoride toothpaste enabled remineralisation of dentin in vitro.