ผลของสารป้ายทดลองนาโนไฮดรอกซีอะพาไทต์ต่อการคืนแร่ธาตุบนผิวเคลือบฟันซึ่งสูญเสียแร่ธาตุระยะแรก

Abstract

Objective: To evaluate the remineralization efiects of nano-hydroxyapatite containing paste on early demineralized enamel under simulated pH cyeling model compare with fluoride and CPP-ACP containing paste. Methods: Enamel specimens were obtained from human premolars and embedded in acrylic resin blocks. All specimens were ground flat and polished and demineralized 7 days to create artificial caries lesion prior cut perpendicular to surface for measuring mineral loss. Eighty specimens were selected from mean of mineral loss and randomly allocated to five groups (n=16): control (without treatment), nano-hydroxyapatite paste (10% HAP), nano-hydroxyapatite with fluoride paste (10% HAP + 1000 ppm NaF), fluoride paste (1000 ppm NaF) and CPP-ACP paste. Demineralized mineral loss and lesion depth were analyzed using micro-computed tomography and cross-sectional hardness and elastic modulus were measured by mean of nanoindenter. The specimens were evaluated after assigned treatment and simulated pH cycling model for 7 and 14 days. Within experimental group, the micro-computed tomography and naoindenter were evaluated at the period of 7 and 14 days. All collected data were calculated to changes in variables and analyzed between experimental groups and times. All statistical test was performed at a 5% level of significance. Results: The nano-hydroxyapatite paste and fluoride paste exhibited the ability to diminish mineral loss and lesion depth significantly after treated for 14 days. Cross sectional hardness and elastic modulus also increased but noticed at the different depth of lesion. On the other hand, the CPP-ACP group showed progressing in mineral loss and lesion depth after a period of 7 and 14 days, in which there were no significant difference compared to those of the control group. Conclusion: The use of nano-hydroxyapatite paste under the condition of pH-cycling for 14 days promotes remineralization on early demineralized enamel in the same way as using fluoride paste. However, the different characteristic of remineralization has been observed.