Effect of carboxymethylcellulose-based saliva substitutes on predemineralised dentin evaluated by microradiography

This study investigated the effect of six lab-produced saliva substitutes based on carboxymethylcellulose (CMC) differing in octacalciumphosphate saturations (OCP-s) on mineralisation of bovine dentin in vitro.

Dentin specimens were prepared (n=234); prior to and after demineralisation (37 degrees C; pH 5.0; 7 d), one-third of each specimen surface was covered with nail varnish (control of sound dentin). Subsequently, specimens (n=13) were exposed to either one of the six CMC-based solutions (OCP-s: 0, 0.5, 1, 2, 4, and 8) at pH 6.5 or to Glandosane for 5 and 10 weeks (37 degrees C). Two aqueous solutions (OCP-s: 0 and 1) served as controls. After storage, thin sections were prepared and mineral loss was calculated by transversal microradiography.

After both storage periods specimens immersed in Glandosane revealed a significantly increased mineral loss compared to all other solutions (p<0.05; Bonferroni post hoc test). Control solution with OCP-s=1 induced a significant remineralisation (p<0.05; adjusted paired t-test). Only after 5 weeks exposure to the CMC-based solution with an OCP-s=2 a significant remineralisation compared to baseline (p<0.05) as well as a significantly increased mineral gain of the surface area compared to higher saturated solutions (p<0.05; Bonferroni post hoc test) could be observed.

CMC seems to hamper dentin remineralisation, although after 5 weeks a mineral gain could be induced with slightly supersaturated CMC-solutions with respect to OCP.