Evaluation of the whitening and remineralization effects of a mixture of amorphous calcium phosphate, hydroxyapatite and tetrasodium pyrophosphate on bovine enamel

Abstract

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives:The purpose of the present study was to evaluate the whitening effect, morphological and structural changes, and remineralization of the enamel induced by 3 combined agents: amorphous calcium phosphate (ACP), hydroxyapatite (HA), and tetrasodium pyrophosphate (TSP). Methods: The study was performed on 90 bovine enamel slabs, which were divided into the 6 groups: negative control-distilled water (Group 1); positive control-opalescence F (Group 2); 10% mixed agent (Group 3); 25% mixed agent (Group 4); 50% mixed agent (Group 5); and 100% mixed agent (Group 6). Changes in the shade of the enamel slabs were evaluated using Shade Eye-NCC. Morphological changes were assessed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) was used to determine the remineralizing effect of the three agents on enamel slabs. Results: The change in shade of the enamel (ad*) was noted to increase significantly with increase in whitening frequency in all groups. The value of Δn* was significantly greater in all groups except for the negative control group (P<0.001). SEM revealed that the control group, Group 5, and Group 6 had similar morphologies. The fluorescence lesion areas in the 4 mixture-treated group were significantly smaller than those in the positive control group (P<0.001). Conclusions: These results showed that the mixture of ACP, HA, and TSP was highly effective for bovine enamel whitening and acted by inducing the remineralization of enamel. Clinical significance: We evaluated the applicability of a new mixture containing ACP, HA, and TSP. This mixture would be highly useful in aesthetic dentistry because of its whitening efficiency, which does not compromise the enamel's integrity.

The Use of Calcium Phosphates in Cosmetics, State of the Art and Future Perspectives

“…Therefore, there is the need of innovative whitening agents to overcome the limitations of current materials. CaPs can fill this role, and several research works have already proved this [107][108][109][110][111][112][113][114][115][116][117][118]. CaPs as whitening agents have been proposed as innovative abrasive agents, as carrier of peroxides, or as adjuvant of bleaching agents.…”

“…In this regard, the distinction of CaPs between cosmetic ingredients and therapeutic ingredients is labile because CaPs have a two-fold whitening action: (i) as an abrasive, to remove the stains by mechanical friction, and (ii) as a remineralizing ingredient, to restore the enamel structure and improve light scattering and absorption, leading to teeth brightness and whiteness [109,112,116]. In addition, it was demonstrated that the remineralization action of CaPs makes the enamel surface smoother and less prone to staining [113,116]. The whitening effect of CaPs has been studied in vitro [116], ex vivo [109][110][111][112][113][114][115], and in vivo [107,108,115,116].…”

“…In addition, it was demonstrated that the remineralization action of CaPs makes the enamel surface smoother and less prone to staining [113,116]. The whitening effect of CaPs has been studied in vitro [116], ex vivo [109][110][111][112][113][114][115], and in vivo [107,108,115,116]. The majority of the works employ HA as CaP phase [107][108][109][110][111][112][113][114][115][116], as HA is the natural mineral phase of the teeth, while some other works also investigated the effect of TCP [109,111], or mixtures of HA, ACP, and pyrophosphates [113].…”

“…The whitening effect of CaPs has been studied in vitro [116], ex vivo [109][110][111][112][113][114][115], and in vivo [107,108,115,116]. The majority of the works employ HA as CaP phase [107][108][109][110][111][112][113][114][115][116], as HA is the natural mineral phase of the teeth, while some other works also investigated the effect of TCP [109,111], or mixtures of HA, ACP, and pyrophosphates [113]. However, based on the published papers, it is not possible to assess whether a CaP phase is more efficient than another as a whitening agent.…”

“…However, based on the published papers, it is not possible to assess whether a CaP phase is more efficient than another as a whitening agent. In addition, these works have studied the whitening effect of CaPs as a raw material [109,110,113,115], as a prototype gel or toothpaste formulation [112,116], or as a commercial product [107,108,111,114], making it very difficult to discriminate the influence of HA on the whitening effect from other ingredients. Furthermore, the analysis of tooth color is problematic because in vivo assessment is subjective and made by comparison with a color scale, while ex vivo is strongly dependent on the variability of the tested teeth [119].…”