pH の異なるオフィスホワイトニング材がウシエナメル質の表面形状に及ぼす影響

The effect of in-office bleaching materials with different pH on the surface topography of bovine enamel.

抄録

本研究では，オフィスホワイトニング剤のpHの違いによるウシエナメル質の表面形状変化を評価した．pH5.5，7.0，8.5の23％HOを牛歯標本（n=10）に塗布し，10分間光照射を行った．漂白処理を3回繰り返し，ベースライン時と3回連続塗布後の試料について，線表面粗さ（Ra）およびビッカース硬度試験（VHN）を行った．また，3回目の漂白の前後で，形態学的変化を観察した．データは，二元配置分散分析およびTukey's HSDにより解析した．漂白剤のpHはRaおよびVHNに有意に影響した（p<0.05）．低 pH では Ra が有意に増加し，VHN が減少した．また，すべての群に形態学的変化が認められ，pH5.5 の群に顕著な影響が認められた．以上より，漂白剤のpHはRa，VHNおよび表面形態に影響を与えることが示唆された．

This study evaluated the alterations of surface topography of the bovine enamel caused by different pH of in-office bleaching agents. 23% HO with pH 5.5, 7.0 and 8.5 were applied on the bovine tooth specimens (n=10) and photo-irradiated for 10 min. The bleaching procedure was repeated three times and specimens were subjected to linear surface roughness (Ra) and Vickers microhardness test (VHN) at baseline and after three consecutive applications. The morphological alterations were observed before and after third bleaching application. Data were analyzed by two-way ANOVA followed by Tukey's HSD. The pH of the bleaching agent significantly affects the Ra and VHN (p<0.05). Low pH yielded a significant increase in Ra and decrease in VHN. All the groups showed morphological alterations and profound effect was found in pH 5.5 group. It was concluded that the pH of the bleaching agent can affect Ra, VHN and surface morphology.