Preventive Effect of Polymer-based Desensitizerswith NaF on Root Dentindemineralization

Objectives: The aim of this study was to evaluate the effect of a polymer-based desensitizer with NaF and oxalic acid on prevention of root demineralization using micro-CT.
Methods: Two commercially available dentin desensitizers; MS Coat One [MS0(+)] (Sun Medical, Japan) containing both methacrylate-co-p-styren sulfonic acid polymer (MS) and oxalic acid (+), and MS Coat F [MS3000(+)] (Sun Medical, Japan) additionally containing 3000 ppmF NaF (3000), and four experimental polymer-based desensitizers: MS0(-), MS3000(-), MS7000(-), and MS7000 (+). Fluor Jelly (Bee Brand, Japan) containing 9000 ppmF NaF was used as a positive control (NaF9000). Bovine root dentin surface were treated with one of the desensitizers for 30 s. The specimens were then immersed in demineralizing solution (pH 4.5, 10h). They were scanned using micro-CT and analyzed by using a 3D image software. Mean mineral loss (ML) after demineralization were calculated from the mineral density profiles. The specimens were observed under the SEM. The collected ML data were statistically analyzed using Mann Whitney U test with Bonferroni correction.
Results: The mean ML values (vol%.μm) were: Control (19.0±2.4), MS0(+) (17.4±3.5), MS3000(+) (10.3±3.3), MS7000(+) (7.3±3.1), MS0(-) (21.9±3.5), MS3000(-) (13.2±2.4), MS7000(-) (9.5±4.0), NaF9000 (7.8±2.0). Under SEM observation, a membrane structure created on dentin surface was observed in the group of MS polymer and fluoride. Moreover, dentinal tubules were occluded after demineralization with the desensitizer with the presence of oxalic acid.
Conclusions: The MS polymer-based desensitizer with oxalic acid and high concentration of fluoride was effective to prevent root dentin demineralization.