Can the combination of proanthocyanidin and vitamin E or palm oil effectively protect enamel against in vitro erosive and abrasive challenges?

OBJECTIVES: This study aimed to assess the effect of proanthocyanidin, palm oil and vitamin E against erosive and erosive+abrasive challenges in vitro after enamel pellicle formation in situ. METHODOLOGY: Bovine enamel blocks (n=84) were obtained and divided into the following treatment groups: negative control (NC) - deionized water; positive control (PC) - SnCl2/NaF/AmF-containing solution; palm oil (PO); 2% proanthocyanidin (P2); vitamin E (VitE); 2% proanthocyanidin+palm oil (P2PO); and 2% proanthocyanidin+vitamin E (P2VitE). For 5 days, one half of the sample from each group was subjected to erosion and the other half was subjected to erosion+abrasion. The acquired enamel pellicle (AEP) was pre-formed in situ for 30 minutes. The specimens were then treated in vitro with solutions (500 µl, 30s for each group). Subsequently, the blocks were left in the oral cavity for another hour to obtain the modified AEP. The blocks were immersed in 0.5% citric acid (pH=2.5) for 90s, 4×/day. AEP formation and treatment were carried out before the first and third erosive challenges, and after these challenges, abrasive cycles (15s) were performed on half of the samples. Enamel wear was quantified by profilometry and data were analyzed by two-way ANOVA and Tukey's test (p<0.05). RESULTS: All groups showed higher wear when exposed to erosion+abrasion than when exposed to erosion alone (p=0.0001). PO, P2VitE, P2, and P2PO showed enamel wear similar to the PC group, but only PC, PO and P2VitE differed from the NC group. The other groups behaved similarly to NC. CONCLUSION: It was concluded that the combination of proanthocyanidin and vitamin E was effective in reducing wear in the face of in vitro erosive and erosive+abrasive challenges.

Effect of a Toothpaste Containing Surface Pre-Reacted Glass-Ionomer Filler on the Remineralization of Artificial Carious Enamel Lesions in situ.

This study evaluated the remineralizing effect of a toothpaste containing surface pre-reacted glass-ionomer (S-PRG) filler on demineralized enamel in situ. For this, 180 bovine enamel samples were demineralized by using a microcosm biofilm model for 3 days. Thereafter, the samples were randomly signed to 15 healthy volunteers and to 3 cross-over in situ phases corresponding to the following treatments: (1) toothpaste containing 1,500 ppm F as NaMFP (positive control, Colgate®Cavity Protection), (2) toothpaste containing 5% S-PRG filler (Shofu®), and (3) placebo toothpaste (negative control prepared by Shofu®). Four demineralized enamel blocks were fixed into each palatal appliance per phase. The volunteers wore the appliances for 5 days and were trained to brush their teeth 2 times for 2 min a day, while one drop of the toothpaste's slurry (1:3) was dripped on each sample for the same period. The surface hardness and TMR analyses were done and analyzed by ANOVA/Tukey and t test (p < 0.05). S-PRG filler and Colgate® toothpastes were equally able to improve 2-2.5× enamel remineralization by the analysis of % surface hardness recovery. However, S-PRG toothpaste was the only one able to significantly improve ΔΔZ (the integrated mineral loss recovery: 1,489 ± 503 %vol.µm) compared to placebo (1,050 ± 467 %vol.µm), while Colgate® did not differ from placebo. No differences were seen between the groups with respect to ΔLD. S-PRG filler and Colgate® toothpastes show similar potential to remineralize the lesion surface. However, S-PRG toothpaste is better to recover mineral loss at the subsurface area.