The purpose of this in vitro study was to evaluate the effects of four over-the-counter (OTC) whitening products on the microhardness, surface roughness, color, shear bond strength (SBS) and surface charecteristics of human enamel compared with a product used for dentist-supervised home whitening. Seventy eight enamel specimens allocated into 6 groups (n=13): 1-Opalescence PF 10% (OP) dentist prescribed home whitening product, 2-Opalescence Go prefilled tray (PT), 3-Opalescence Whitening Toothpaste (WT), 4-Listerine Healthy White whitening mouth rinse (WMR), 5-Cavex Bite&White whitening pen (WP) and 6- no treatment (Con). The microhardness (VHN), surface roughness (Ra) and color of the specimens were measured (T₀). The specimens were then subjected to whitening protocols for 14 days (T₁.) followed by artificial saliva storage for 14 days (T₂). The measurements were repeated at T₁ and T₂. The SBS test was done after the application of 35% phosphoric acid (Scotchbond Universal Etchant), followed by a universal adhesive (G-Premio Bond) and a micro hybrid/universal resin composite (Essentia) into a Teflon tube attached to the enamel surface (p<0.05). Surface morphologies of the enamel surfaces were examined by SEM. p value was set at 0.05 Application of OP, PT and WP decrased the microhardness of enamel specimens (p0.05). Ra values of enamel specimens increased with the application of OP, PT and WT (p0.05). OP, PT, WMR, and WP changed the color of the enamel(p<0.05). There were not any significant differences among the SBSs groups, apart from OP applied enamel specimens. OP showed the least SBS values (p=0.001). SEM observations revealed smooth enamel surfaces. The whitening products affected the microhardness, surface roughness, color of enamel differently. Only OP decreased the SBS of the enamel.

SUMMARY: Objective: This clinical study aimed to assess the efficacies of mineral trioxide aggregate (MTA) and calcium hydroxide [Ca(OH)2] in the treatment of deep carious lesions by the direct complete caries removal technique. Methods and Materials: A total of 100 permanent molar/premolar teeth were capped with either Ca(OH)2 (n=49) or MTA (n=51) and restored with composite resin in 73 patients. Periapical radiographs were acquired prior to the treatment as well as at six, 12, and 24 months posttreatment. Two calibrated examiners performed the clinical and radiographic assessment of the periapical pathology and pulpal symptoms. Intergroup comparisons of the observed values were performed using the Fisher exact test. Significance was predetermined at α = 0.05. Results: The recall rates were 100% at six and 12 months posttreatment and 98.6% at 24 months posttreatment. Four teeth capped with Ca(OH)2 (two each at six and 12 months posttreatment) and two capped with MTA (one each at 12 and 24 months posttreatment) received endodontic emergency treatment because of symptoms of irreversible pulpitis, which were clinically and/or radiographically established. There were no significant differences in pulp vitality between the two pulp-capping agents at six, 12, or 24 months posttreatment (p=0.238, p=0.606, and p=0.427, respectively). Conclusions: Both pulp-capping materials were found to be clinically acceptable at 24 months posttreatment.