In Vitro Effect of Strontium-Doped 45S5 Bioglass and Nd:YAG Laser on Microhardness of Demineralized Enamel

This study aimed to assess the effect of strontium-doped 45S5 bioglass (BG) and Nd:YAG laser on the microhardness of demineralized enamel.

In this in vitro, experimental study, 65 sound enamel samples were prepared of human premolars and polished, and then immersed in a demineralizing solution for 10 weeks. The samples were randomly divided into 5 groups of control, BG, laser, laser plus BG, and BG plus laser. Two samples of each group underwent assessment of surface morphology under a scanning electron microscope. Finally, the microhardness of samples was measured using a Vickers hardness tester, and data were analyzed by ANOVA.

The mean microhardness of the BG group was significantly higher than that of other groups (P<0.05). The lowest microhardness was noted in the control group. The difference in microhardness was significant between laser and laser plus BG groups (P<0.05). Further, the BG plus laser group had a significant difference in microhardness with BG and control groups (P<0.05). The difference between laser plus BG and control groups was also significant in this respect (P<0.05). Eventually, maximum morphological changes were observed in the BG group.

Overall, BG seems to be effective for the treatment of incipient enamel caries. It effectively increases enamel microhardness and decreases mineral loss while preserving the integrity of the enamel surface.