The Effect of Different Remineralizing Agents on Laser Bleached Enamel

Abstract

One of the most required esthetic measures for patients with teeth discoloration or those who strive to have a beautiful smile and appearance is bleaching. The objective of this study is to analyze enamel morphological changes, chemical composition and microhardness following the application of 35% hydrogen peroxide, utilizing two various protocols for laser activation and the application of 4 different remineralizing agents. Materials and methods:In this study, 40 extracted human lateral and central incisors were chosen where the researcher categorized teeth into 2 groups consisting of 20 incisors, using two different laser-activated bleaching protocols. The researcher then subdivided each group into 4 subsets consisting each of 5 incisors where 4 remineralizing agents were applied to each bleached subset. Enamel surface morphology was studied by ESEM. Calcium and Phosphorus content were measured by EDAX and microhardness Vicker's test was performed to study the alteration in enamel hardness. Pre-and post-demineralization (bleaching) investigations were conducted and then they were repeated following remineralization.Results: ESEM revealed the improvement of enamel surface morphology in the remineralized groups except in (HD) and (LD) groups. After remineralization, all groups had a higher weight percent of calcium (Ca) and phosphorus (P) levels than its levels after demineralization except in groups (HD) and Vicker's hardness number in all groups showed significant increase except (HD) and (LD). Conclusion:The use of remineralizing agents containing casein phosphopeptide-amorphous calcium phosphate, fluoride or hydroxyapatite nanoparticles could improve the enamel morphology, microhardness and chemical composition of laser bleached enamel.

THE EFFECT OF MISWAK & ITS PROTOCOL OF PLACEMENT, ON THE STRUCTURE, MINERAL CONTENT OF CHEMICAL AND LASER ASSISTED BLEACHED WHITE SPOT

“…This might be attributed to the fulldepth action of the laser-activated bleaching agent, in judgement to the undefined effect of non Laser bleaching on the surface and depth. The efficacy of bleaching also grows (less heat), which is another benefit for this technique with low post whitening sensitivity (16) .…”

“…The granular pattern of minerals was less observable. Enamel surface showing moderate irregularities with depressions and erosions (16) (fig. 4).…”

The micro‐shear bond strength of resin cements to aged laser bleached enamel after using different desensitizing agents

“…Considering the earlier mentioned facts, in addition to the postoperative hypersensitivity, the application of a desensitizing agent with remineralizing potentials after bleaching has become a known protocol that is recommended by manufacturers, though, this process would leave us with an altered enamel surface. It has been reported that CPP‐ACP application, after in‐office bleaching, is capable to avert negative changes of roughness and hardness to enamel (Ata, 2019; Gama Cunha et al, 2012; Shadman et al, 2015) and increase the calcium levels of enamel (Llena et al, 2019; Samaha & Gomaa, 2020). Its action depends on maintaining high concentration of calcium and phosphate ions and localizing ACP at the tooth surface (Coceska et al, 2016; de Carvalho et al, 2014) which interact with carbonates to block surface defects with hydroxyapatite crystals (HA; Moule et al, 2007), increasing the density of HA crystals on the surface (Khoroushi et al, 2011).…”

“…that CPP-ACP application, after in-office bleaching, is capable to avert negative changes of roughness and hardness to enamel (Ata, 2019;Gama Cunha et al, 2012;Shadman et al, 2015) and increase the calcium levels of enamel (Llena et al, 2019;Samaha & Gomaa, 2020). Its action depends on maintaining high concentration of calcium and phosphate ions and localizing ACP at the tooth surface (Coceska et al, 2016;de Carvalho et al, 2014) which interact with carbonates to block surface defects with hydroxyapatite crystals (HA; Moule et al, 2007), increasing the density of HA crystals on the surface (Khoroushi et al, 2011).…”

“…Trying to overcome the sensitivity post operatively, several desensitizing agents have been introduced for use before or after bleaching or in association with bleaching gels (Nanjundasetty & Ashrafulla, 2016). Moreover, such desensitizing agents can reduce the morphological changes (Coceska et al, 2016) and the loss of mineral content (Sasaki, 2015) in the enamel and regain its dropped microhardness (Samaha & Gomaa, 2020) after bleaching. New technologies are being introduced in this field such as the casein phosphopeptide‐amorphous calcium phosphate (CPP‐ACP) which provides a calcium and phosphate reservoir that can bind to enamel surface (Lata et al, 2010) to avoid the negative changes of bleaching to enamel.…”