Kunam Divya, Sampath Vidhya, Manimaran Sujatha, Sekar Mahalaxmi
Department of Conservative Dentistry and Endodontics, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India.
Department of Conservative Dentistry and Endodontics, SRM Dental College, Chennai, Tamil Nadu, India.
Contemp Clin Dent. 2019 Jul-Sep;10(3):489-493. doi: 10.4103/ccd.ccd_810_18.
The objective was to evaluate the effect of nano-hydroxyapatite (nHA) derived from chicken eggshell on bleached human enamel in comparison with commercial casein phophopeptide-amorphous calcium phosphate (CPP-ACP) paste using Vickers microhardness test.
nHA powder was prepared from chicken eggshell using combustion method. nHA slurry was prepared by mixing 1.8 g of nHA powder with 0.3 ml of distilled water. Forty intact maxillary anterior teeth were collected and decoronated, and the crowns were embedded in acrylic mold with the labial enamel surfaces exposed. Baseline microhardness evaluation was done (T). The specimens were randomly divided into the following four groups ( = 10) based on the surface treatment of enamel: Group 1: no bleaching treatment; Group 2: bleaching with 30% hydrogen peroxide (HP) solution; Group 3: bleaching followed by the application of CPP-ACP; and Group 4: bleaching followed by the application of nHA. The specimens were stored in artificial saliva at 37°C for 2 weeks, after which they were subjected to Vickers microhardness test (T). One-way ANOVA and Tukey's multiple comparison tests were used for statistical analysis ( < 0.05).
Bleaching with HP significantly decreased the enamel microhardness. CPP-ACP and nHA derived from chicken eggshell increased the enamel microhardness significantly. There was no significant difference in microhardness values among the CPP-ACP and nHA groups.
Nano-hydroxyapatite sourced from chicken eggshell was as effective as CPP-ACP in remineralizing and restoring the lost microhardness of bleached enamel.
采用维氏显微硬度测试法，评估源自鸡蛋壳的纳米羟基磷灰石（nHA）与市售酪蛋白磷酸肽 - 无定形磷酸钙（CPP - ACP）糊剂相比，对漂白后人牙釉质的影响。
采用燃烧法从鸡蛋壳制备nHA粉末。将1.8 g nHA粉末与0.3 ml蒸馏水混合制备nHA浆液。收集40颗完整的上颌前牙并去除牙冠，将牙冠嵌入丙烯酸模具中，使唇面釉质表面暴露。进行基线显微硬度评估（T）。根据釉质表面处理情况将标本随机分为以下四组（每组 = 10）：第1组：未进行漂白处理；第2组：用30%过氧化氢（HP）溶液漂白；第3组：漂白后应用CPP - ACP；第4组：漂白后应用nHA。将标本在37°C的人工唾液中保存2周，之后进行维氏显微硬度测试（T）。采用单因素方差分析和Tukey多重比较检验进行统计分析（P < 0.05）。
用HP漂白显著降低了釉质显微硬度。CPP - ACP和源自鸡蛋壳的nHA显著提高了釉质显微硬度。CPP - ACP组和nHA组之间的显微硬度值无显著差异。
源自鸡蛋壳的纳米羟基磷灰石在再矿化和恢复漂白釉质丧失的显微硬度方面与CPP - ACP同样有效。
