Discussion
erosion, enamel lesions, mineral loss, human dentitions, erosive, dentitions, aprismatic, tooth
EROSION, HYDROXYAPATITE
The present study aimed to provide a minimally invasive available clinical solution to intercept erosion and its consequences by testing Bioactive Glass 45S5 (BAG45S5) on both human primary and permanent dentitions. To overcome the lack of reliability in the use of bovine teeth instead of human ones, teeth were used from both human dentitions instead of bovine teeth for more favourable clinically applicable results. In a review of literature conducted by Yassen et al. [Dissolution of the enamel usually occurs when it is exposed to undersaturated solutions at a pH less than the critical pH, which is thought to be 5.5 [BAG45S5 has been widely studied for its effectiveness on enamel remineralization. It improved the microhardness of the subsurface-eroded enamel surface [Changes in surface roughness commonly occur after the interaction of acidic solutions with tooth structures. While the effect of erosive solutions on the surface roughness depends on the thickness of the aprismatic layer, the non-treated permanent enamel with its thin aprismatic surface layer demonstrated a notable roughness after exposure to the erosive acid, whereas the non-treated primary enamel with its generally uniform and thicker aprismatic layer presenting a more stable surface texture was not as affected by the erosive agent [Moreover, the results of the current study revealed that both human dentitions were showing significant loss of calcium and phosphate ions post the erosive challenge. The dissolution was expected to occur due to the weak constitution of the calcium-deficient carbonated hydroxyapatite crystals present in the enamel layer causing a distorted lattice conformation that is more soluble in acidic environments. The primary dentition presented greater mineral loss and surface distortion, because of the higher number of carbonate molecules in the hydroxyapatite crystals in the primary enamel as well as the presence of copious organic content specific to primary enamel [On the contrary, enamel surface that was pre-treated by BAG45S5 before the erosive challenge showed decreased rates of carbon ions when compared to the baseline. Moreover, there was no significant change in calcium or phosphate content after erosion also compared to baseline. The effect of BAG45S5 on enamel lessened the effect of erosion on either primary or permanent enamel compared to enamel of erosion-only surfaces. BAG45S5 was suggested to be able to restore early erosive enamel lesions with complete loss of hydroxyapatite crystal content [On demineralized enamel surface, BAG45S5 acted in some way differently as suggested by several studies. Abbassy et al. [Throughout the comparison between both dentitions, the permanent dentition which received BAG45S5 showed slightly better response following exposure to induced erosive challenge. Permanent enamel has better consolidation with particles of BAG45S5 due to the intrinsically higher inorganic content as well as morphological differences, indicating that the permanent enamel allows better integration of Bioactive Glass with the inherent calcium and phosphate ions to form more hydroxycarbonate apatite crystals [