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

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 degrees 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 degrees C). An aqueous solution (S(OCP): 2.5) served as positive control (PC). Two times daily (2min each), Duraphat toothpaste (5000ppmF(-); Colgate)/saliva substitute slurry (ratio 1:3) was applied gently. Differences in mineral losses (DeltaDeltaZ) and lesion depths (DeltaLD) 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 DeltaDeltaZ values) and lesion depths (lower DeltaLD) 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. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.