Effect of Nanohydroxyapatite Incorporation in Hydrogen Peroxide Bleaching Agent on Minerals Content of Dental Enamel

Background: Current study was assessed to evaluate the effect ofnanoydroxyapatite (nHAp) incorporation in hydrogen peroxide(HP) bleaching agent on selected minerals content of dentalenamel. Material and Methods: 30 sound upper first premolarteeth were used in this study. Enamel blocks (7mm× 5mm×3mm)were obtained from the middle third of buccal surfaces of theteeth. Each dental block was embedded in self-cure acrylic resinwith exposed exterior enamel surface. Enamel samples weredivided into three groups (n=10): deionized water (DW) ascontrol group, HP bleached group, and hydrogen peroxidemodified by nanohydroxyapatite (HP-nHAp) bleached group.Energy Dispersive X-Ray Spectroscopy (EDS) was used toevaluate the elemental composition changes of each samplebefore and after treatment. Result: Findings of the current studyrevealed reduction of each of enamel calcium (Ca) andphosphorous (P) minerals content after treatment compared withbaseline data for all groups, with statistically significantdifference for HP group only. The percentage of Ca and P weightloss of enamel subjected to HP bleaching was the highest,followed by HP-nHAp treated group, while the control group wasthe least one with statistically significant difference between eachof (HP and HP-nHAp) groups, and (HP and control) groups. Nosignificant reductions were observed after treatment in Ca/P ratioin all groups. Conclusion: Adding of nHAp material to HPbleaching agent could decrease its adverse effects on dentalenamel surface.