Remineralization potential of a novel varnish: an in vitro comparative evaluation

Despite fluoride's widespread use in preventing dental caries, it remains a significant oral disease with some drawbacks. Consequently, new preventative agents have emerged that can function independently of fluoride. Our aim is to demonstrate the efficacy of newly developed varnishes, 3% Rennou (theobromine calcium and phosphate) and 1% Rennou, in remineralizing initial caries. In our experiment, 40 human enamel samples were randomly allocated into four groups of 10 samples each as: Group 1 (G1): 5% NaF (Colgate PreviDent®), Group 2 (G2): 1% Rennou®, Group 3 (G3): 3% Rennou® and Group 4 (G4): Casein Phosphopeptide-Amorphous Calcium Phosphate + Fluoride (MI Varnish^TM GC). To produce an artificial carious lesion in the enamel, the samples were kept in a demineralizing solution for 72 hours. Samples underwent pH cycling for 6 days in order to induce remineralization. The means of the three measurements were compared, and the percentage of Surface Microhardness Recovery in (SMHR%) was calculated. Scanning Electron Microscopy (SEM) was used for qualitative assessment of surface changes. G1 had the highest SMHR% value, followed by G3, G2 and G4. The One-way ANOVA (Analysis of Variance) showed significant differences in the SMHR% values among the groups after six days of cycling (p < 0.001). In pairwise comparisons, groups did not show differences in means of SMHR% except for G1 and G4 (p = 0.006). In the SEM Images, after treatment within the NaF group, many flaky sediments were found on the enamel surface. Similarly, the maximum mineral gain was seen in the NaF and Rennou groups. SEM images of both varnish surfaces revealed a uniform layer interspersed with shapeless precipitates. All varnishes treated artificial enamel lesions to varying degrees. However, both concentrations of Rennou showed remineralization potential comparable to 5% NaF in acceptable statistical measurements. Thus, it could be used as a potentially effective preventive measure for pediatric patients.