The Effect of Remineralizing Toothpastes on Enamel Surface Roughness after Hybrid Laser Bleaching (An In vitro Study)


Background: one of the complications of power bleaching is surface roughness of enamel which increases thepossibility of post bleaching teeth discoloration. The aim of the present study is to evaluate the effect of toothpastecontaining nano hydroxyapatite, NovaMin and kin sense fluoride on surface roughness of human tooth enamel afterlaser bleaching with 35% hydrogen peroxide bleaching gel.Materials and Methods: Twenty human enamel incisors were cleaned and their labial surface polished up to #1200,then categorized into four equal groups; first group kept without bleaching as a control group, while the remainingthree experimental groups were bleached with 35% hydrogen peroxide, and each group treated with a restorepaste containing one of the following: nano hydroxyapatite, NovaMin, and Kin fluoride. Bleaching was done withlaser hybrid system (DMC Whitening Lase II, Sao Paulo, Brazil). Enamel roughness values assessed by an atomic forcemicroscopy (AA3000, Bosten, USA) before and after treatment with restore tooth paste.Results: Paired t-test used to compare the mean roughness values before and after treatment with each restorepaste. One-way analysis of variance and Duncan post hoc tests used to determine the differences between meanroughness values of the groups. A p-value of 0.05 or less considered a significant. The results showed a highlysignificant statistical differences of remineralization of all types of restore tooth pastes.Conclusions: Nano hydroxyapatite past exhibiting a higher ability to reduce the surface roughness after laserbleaching than other tested pastes.