Mineral loss and color change of enamel after bleaching and staining solutions combination

Abstract

Abstract. Pigments of food and beverages could affect dental bleaching efficacy. The aim of this investigation was to evaluate color change and mineral loss of tooth enamel as well as the influence of staining solutions normally used by adolescent patients undergoing home bleaching. Initial hardness and baseline color were measured on enamel blocks. Specimens were divided into five groups (n ¼ 5): G1 (control) specimens were kept in artificial saliva throughout the experiment (3 weeks); G2 enamel was exposed to 10% carbamide peroxide for 6 h daily, and after this period, the teeth were cleaned and stored in artificial saliva until the next bleaching session; and G3, G4, and G5 received the same treatments as G2, but after bleaching, they were stored for 1 h in cola soft drink, melted chocolate, or red wine, respectively. Mineral loss was obtained by the percentage of hardness reduction, and color change was determined by the difference between the data obtained before and after treatments. Data were subjected to analysis of variance and Fisher's test (α ¼ 0.05). G3 and G5 showed higher mineral loss (92.96 AE 5.50 and 94.46 AE 1.00, respectively) compared to the other groups (p ≤ 0.05). G5 showed high-color change (9.34 AE 2.90), whereas G1 presented lower color change (2.22 AE 0.44) (p ≤ 0.05). Acidic drinks cause mineral loss of the enamel, which could modify the surface and reduce staining resistance after bleaching.

Susceptibility to Coffee Staining during Enamel Remineralization Following the In‐Office Bleaching Technique: An In Situ Assessment

“…This difference was justified by the fact that wine is a highly acidic beverage, which is capable of intensifying the demineralization of the enamel surface and increase its vulnerability to staining . This theory is supported by a recent in vitro study, in which high enamel mineral loss, resulting from exposure to very acidic drinks between bleaching sessions, has resulted in increased staining susceptibility due to superficial alterations …”

“…Many authors have related the susceptibility to staining after bleaching to alterations caused by the bleaching agents to the dental enamel structure . These agents, often of acid nature, can dissolve the mineral content of the enamel, thus leading to loss of calcium and phosphate, and resulting in reduced crystal size and increased intercrystalline spaces within enamel .…”

“…3,4 Many authors have related the susceptibility to staining after bleaching to alterations caused by the bleaching agents to the dental enamel structure. [5][6][7][8][9][10][11] These agents, often of acid nature, can dissolve the mineral content of the enamel, thus leading to loss of calcium and phosphate, and resulting in reduced crystal size and increased intercrystalline spaces within enamel. 12 During the dissolution process, the carbonate present in the structure of enamel may also be lost and expose the delicate protein structure surrounding the crystals.…”

Evaluation of the effect of different enamel surface treatments and waiting times on the staining prevention after bleaching

“…Specimens of G5 showed the highest color alteration while G1 the lowest. Staining food and beverages of acid pH can induce mineral loss on enamel, modify the surface and reduce the resistance to staining after bleaching (12). …”

“…The surface roughness increases with pure 35% hydrogen peroxide but not with a mixture of sodium bicarbonate (NaHCO3) and 30% hydrogen peroxide, which was attributed to the bigger pH of the mixture, compared to the more acid pH of 35% hydrogen peroxide (11). Colourant beverages with acid pH may cause enamel mineral loss, modify the surface and reduce the resistance to staining after bleaching (12). …”