Dental bleaching agents with calcium and their effects on enamel microhardness and morphology

Abstract

Aim: To evaluate enamel microhardness and morphology after bleaching with hydrogen peroxide containing calcium in different concentrations. Methods: One hundred specimens of human teeth were ground and polished and had the initial microhardness evaluated. The specimens were randomly assigned into five groups (n=20): Group 1 -Control group (no treatment); Group 2 -Home Peroxide 6% (without calcium); Group 3 -Home Peroxide 7.5% (without calcium); Group 4 -White Class 6% (with calcium); Group 5 -White Class 7.5% (with calcium). For each group, the bleaching was performed according to the manufacturer's specifications. The specimens were bleached once a day for 5 days and subjected to pH cycling. Microhardness and scanning electron microscopy (SEM) analysis were performed before and after bleaching. Results: The results showed that groups submitted to bleaching treatment presented hardness loss compared to the control group. The group of 7.5% hydrogen peroxide with calcium showed a lower percentage of hardness loss in relation to other groups. Conclusion: Calcium in association with a higher hydrogen peroxide concentration may decrease microhardness changes on enamel.

In vitro comparison of impact of different bleaching Agents on the microhardness of Enamel

“…Although no statistical significant results are seen in the present study (p > 0.005), some alterations do occur in the microstructure of enamel after bleaching agents. Pizani et al, 19 following their study on bleaching agents with and without calcium on enamel microstructure, showed that in association with higher concentration of HP, calcium may decrease the MH and structural changes on enamel. Calcium was introduced in the bleaching system to decrease and minimize the enamel structure alterations and loss of minerals.…”

The effect of different biomimetic materials as a remineralization protocol on microhardness and ultramorphology of bleached enamel

“…Additionally, it has been shown that bleaching with 35-38% hydrogen peroxides may change enamel morphology and alter mineral content (3,4,(8)(9)(10) . Thus, efforts have been made to achieve a protocol capable of remineralizing bleached enamel, recovering microhardness loss and surface alterations (11)(12)(13)(14)(15) . This study was designed to assess and compare the effect of two remineralizing protocol using innovative biomimetic materials (Nano-BG and Nano-HA) on the structural integrity of bleached enamel surface, manifested by microharness and morphological changes in enamel surface.…”

“…All of these factors contribute to the difficulty of repairing dental enamel tissue. (8,10) In order to minimize such demineralization after contact with bleaching agents, some ingredients such as fluoride (11)(12)(13) , calcium (14) or amorphous calcium phosphate (11) are added into the bleaching gel by manufacturers. Some biomimetic materials such as nano hydroxyapatite and nano structured bioactive glass have been advocated as new techniques for enamel reconstruction that have been a challenging topic of research in material sciences and dentistry .…”

An Analysis of Dental Enamel after Bleaching using 35% Hydrogen Peroxide with Energy-dispersive X-ray Spectroscopy

“…The thickness and density affect the surface of the tooth crown. The composition of ORIGINAL RESEARCH 1,3,4 Department of Oral Biology, Faculty of Dentistry, University of Hasanuddin, Makassar, Indonesia elements of tooth enamel is composed of cells, organic matrix, and inorganic matrix; these cells control the initial production of tissue minerals. 1 Tooth enamel consist of consist of 96% inorganic material, 4% water, organic matter, and fibrous tissue.…”

“…The salts comprise of materials such as keratin (pseudokeratin), collagen, peptone, glycoproteins, polysaccharides, fats, and acids amino. 2,3 Enamel consists of the outer and inner enamel, which are enamel surface and subsurface enamel. Surface enamel contains more fluorine and a little carbonate so that the surface enamel is harder, less porous, insoluble, and more radiopaque.…”