Investigation of Remineralization effect of F-CaSiO4 incorporated Chitosan-Modified Persian gum hydrogels

Abstract

Background: Regarding the high prevalence of dental caries all over the world, the control and prevention of this issue in the first steps have attracted a lot of attention. Dental caries initiate from the outer most layer of tooth, called enamel. Various materials have been introduced in the previous studies that can prevent mineral loss(Demineralization) and cause to the precipitation of minerals within the enamel(Remineralization). Chitosan and F-CaSiO4 are two of the mentioned materials. The aim of the present study is the investigation of the remineralization of F-CaSiO4 reinforced chitosan/modified Persian gum hydrogel.

Methods: Eightteen Molar or Premolar extracted teethes were used in the current study. The crown of prepared teethes were divided into two parts in the mesiodistal direction. The obtained enamel blocks were classified into six groups in a way that each group was possess six samples. The initial hardness of samples were examined through the Vickers microhardness test by making three indentations in each sample. The surface of samples were coated by two layers of acid-resistant varnish. Meanwhile, the F-CaSiO4-filled hydrogel based on chitosan/modified Persian gum was prepared by the freeze-drying method. The first, second and third groups were not have any treating chemicals. The fourth, fifth, and sixth groups were treated using chitosan, F-CaSiO4, and CaSiO4-filled chitosan/Persian gum hydrogel, respectively. The treating chemical was put on the surface of each sample using a little brush. Thereafter, the samples were plunged into the demineralization solution as the first step of the pH cycle. After 3 h, the samples were withdrawn and immersed for 21 h in the remineralization solution. The explained cycle repeated for 5 days. Then, three different new indentations were created on the surface of each sample and the hardness of the samples were investigated by the Vickers microhardness test.The hardness difference before and after pH cycles is representative of lost minerals. The amount of lost phosphate in each group was calculated through Gas-Chromatography Mass technique. The morphological aspects of a sample of sixth group and the type of formed elements on its surface was evaluated by SEM and EDX techniques. Data comparison was done using ANCOVA test and SPSS software27. P<0.05 was considered significant.

Results: The difference of microhardness values in group six before and after treatment (42.6±5.3) was lower than that of the control group (208.1±31.3 & 231.3±27.7), group four (142.1±24.1), and group five (113.6±19.5). There was a significant difference among microhardness values of group six and other groups (pvalue<0.05). Moreover, the loss of phosphate was lower in group six compared to other groups. The obtained FESEM images and EDX analysis also confirmed the presence of hydroxyapatite crystals on the surface of group six.

Conclusions: According to the obtained results, it can be claimed that Persian gum modified chitosan with F-CaSiO4 additive can reduce the demineralization of tooth enamel. In addition, this hydrogel acts more effectively compared to neat Persian gum-modified chitosan hydrogel and neat F-CaSiO4 in reducing minerals’ loss from enamel.