Analysis of Anticaries Potential of Pit and Fissures Sealants Containing Amorphous Calcium Phosphate Using Synchrotron Microtomography

Abstract

The aim of this study was to analyze the anticaries potential of pit and fissure sealants containing amorphous calcium phosphate (ACP) by synchrotron microtomography. Bovine enamel blocks (4×4 mm; n=50) were selected through surface hardness (Knoop) analysis. Slabs were obtained through cross-sections taken 1 mm from the border of the enamel. Five indentations, spaced 100 μm apart, were made 300 μm from the border. Ten specimens were prepared for each tested material (Ultraseal XT plus TM, Aegis, Embrace, Vitremer and Experimental Sealant). The materials were randomly attached to the sectioned surfaces of the enamel blocks and fixed with sticky wax. The specimens were submitted to pH cycling. After that, the surface hardness (SH1) was determined, and the blocks were submitted to synchrotron microcomputed tomography analysis to calculate the mineral concentration (ΔgHAp cm(-3)) at different areas of the enamel. The comparison between the SH1 and ΔgHAp cm(-3) showed a correlation for all groups (r=0.840; p<0.001). The fluoride groups presented positive values of ΔgHAp cm(-3), indicating a mineral gain that was observed mainly in the outer part of the enamel. The ACP showed mineral loss in the outer enamel compared with fluoride groups, although it inhibited the demineralization in the deeper areas of enamel. The combination of two remineralizing agents (fluoride and ACP) was highly effective in preventing demineralization.

Effectiveness of Pit and Fissure Sealants Containing Amorphous Calcium Phosphate (ACP) and Fluoridein the Prevention of Demineralization of Adjacent Enamel: In-Vitro Study

“…Fluoride groups showed a positive rate of mineral gain, which was clearly visible in the outer layer of the enamel. The ACP group showed a loss of demineralization in the outer layer compared to the fluoride group, although it inhibition demineralization in the deep areas of the enamel, while the combination between (ACP and F) was highly effective in preventing demineralization [10].…”

“…The results of the Delben [10] study showed that ACP inhibited the demineralization in the deep areas of the enamel, while fluoride products had a greater effect in the surface areas of the enamel, while the combination of ACP and F remineralization factors was more effective In the prevention of demineralization. They evaluated the discontinuity probability of caries of ACPcontaining sealant using (SMG) synchrotron microtomography.…”

“…Recently some studies have been indicated that both amorphous calcium phosphate and fluoride-containing sealants have a role in protecting the adjacent enamel against demineralization. However, there are limited studies on the potential remineralization efficacy of ACP-containing sealants on the adjacent enamel [3,4,10].…”

Estudo in vitro sobre a remineralização de lesões cariosas com o uso de materiais resinosos contendo partículas de fosfato dicálcico dihidratado funcionalizadas com TEGDMA

“…promissora para a recuperação mineral da dentina e da camada híbrida na interface dentina-compósito, o que justifica a intensa atividade de pesquisa observada sobre este tema. contendo flúor e um cimento de ionômero de vidro modificado com resina)(99).Uma vez que a adição de partículas de CaP no compósito diminui sua resistência mecânica, diversas estratégias foram avaliadas para contornar este problema e permitir que estes compósitos possam ser utilizados em restaurações com elevada solicitação oclusal. Por exemplo, a associação de CaP com partículas 4.1 -Difractogramas das nanopartículas de DCPD sintetizadas Figura 4.2 -Imagens de microscopia eletrônica de transmissão mostrando as nanopartículas de DCPD funcionalizadas com TEGDMA (A) e não funcionalizadas (B) Figura 4.3 -Imagens de microscopia eletrônica de varredura mostrando os aglomerados de nanopartículas de DCPD funcionalizadas com TEGDMA (A) e não funcionalizadas (B).…”