Impact of Experimental Nano-HAP Pastes on Bovine Enamel and Dentin Submitted to a pH Cycling Model

Abstract

This in vitro study evaluated the preventive potential of experimental pastes containing 10% and 20% hydroxyapatite nanoparticles (Nano-HAP), with or without fluoride, on dental demineralization. Bovine enamel (n=15) and root dentin (n=15) specimens were divided into 9 groups according to their surface hardness: control (without treatment), 20 Nanop paste (20% HAP), 20 Nanop paste plus (20% HAP + 0.2% NaF), 10 Nanop paste (10% HAP), 10 Nanop paste plus (10% HAP + 0.2% NaF), placebo paste (without fluoride and HAP), fluoride paste (0.2% NaF), MI paste (CPP-ACP, casein phosphopeptide-amorphous calcium phosphate), and MI paste plus (CPP-ACP + 0.2% NaF). Both MI pastes were included as commercial control products containing calcium phosphate. The specimens were treated with the pastes twice a day (1 min), before and after demineralization. The specimens were subjected to a pH-cycling model (demineralization-6-8 h/ remineralization-16-18 h a day) for 7 days. The dental subsurface demineralization was analyzed using cross-sectional hardness (kgf/mm 2 , depth 10-220 µm). Data were tested using repeated-measures two-way ANOVA and Bonferroni's test (p<0.05). The only treatment able to reduce the loss of enamel and dentin subsurface hardness was fluoride paste (0.2% NaF), which differed significantly from the control at 30-and 50-µm depth (p<0.0001). The other treatments were not different from each other or compared with the control. The experimental Nanop pastes, regardless of the addition of fluoride, were unable to reduce dental demineralization in vitro.

Caries-preventive effect of anti-erosive and nano-hydroxyapatite-containing toothpastes in vitro

“…In situ, again, no significant difference in mineral gain has been shown by a nHA (10 wt%) and a sodium fluoride toothpaste (1100 ppm F − ) [5]. However, analyzing nHA being incorporated in experimental pastes, more negative results have been observed [6]. For the experimental pastes containing 10 % as well as 20 % nHA, no significant difference could be observed for enamel subsurface demineralization compared both to no treatment and to placebo (paste without nHA and F − ) [6].…”

“…However, analyzing nHA being incorporated in experimental pastes, more negative results have been observed [6]. For the experimental pastes containing 10 % as well as 20 % nHA, no significant difference could be observed for enamel subsurface demineralization compared both to no treatment and to placebo (paste without nHA and F − ) [6]. Only when fluoride (0.2 % NaF) was combined to a nHAcontaining (10 %) paste, a significant improvement of enamel remineralization could be observed, in situ.…”

Alteração Da Microdureza Superficial Do Esmalte Dentário Expostos a Chás Industrializados

“…Logo, os achados desta pesquisa devem ser interpretados levando-se em conta as limitações da abordagem experimental adotada, uma vez que o estudo in vitro não reproduz todos os aspectos da dinâmica bucal, que inclui o processo de desmineralização e remineralização, a lavagem e neutralização proporcionada pela saliva e as outras estruturas orgânicas que estão presentes na cavidade bucal (BUZALAF et al, 2010;COMAR et al, 2013). No entanto, este tipo de estudo possibilita menor variabilidade intrínseca e melhor controle científico (BUZALAF et al, 2010) e, por isso, pode ser utilizado para aumentar a conscientização sobre a erosão dentária e elaboração de bons conselhos, direcionados à prevenção.…”

Treatment Protocol for Dentin Hypersensitivity

“…[12][13][14][15] Nowadays, many doubts still exist in relation to the different desensitizing protocols and about the best agent that obliterates the dentinal tubules and protects the exposed dentin in the presence of intrinsic acids and extrinsic challenges. Therefore, we propose a DH treatment protocol using new desensitizing agents availed in the market, i.e., replicable in research groups as well as by dental practices.…”