市販の各種ホワイトニング剤がエナメル質の微小硬度，表面粗さ，色調およびせん断接着強さに及ぼす影響．

Effects of Different Over - the - Counter Whitening Products on the Microhardness, Surface Roughness, Color and Shear Bond Strength of Enamel.

抄録

研究目的:

本研究の目的は，4種類の市販ホワイトニング剤がヒトエナメル質の微小硬度，表面粗さ，色，せん断接着強さ（SBS）および表面性状に及ぼす影響を，歯科医師指導のホームホワイトニングに使用する製品と比較して評価することであった．

Objective: The purpose of this study was to evaluate the effects of four over-the-counter (OTC) whitening products on the microhardness, surface roughness, color, shear bond strength (SBS) and surface charecteristics of human enamel compared with a product used for dentist-supervised home whitening.

材料と方法:

Materials and methods: Seventy eight enamel specimens allocated into 6 groups (n=13): 1-Opalescence PF 10% (OP) dentist prescribed home whitening product, 2-Opalescence Go prefilled tray (PT), 3-Opalescence Whitening Toothpaste (WT), 4-Listerine Healthy White whitening mouth rinse (WMR), 5-Cavex Bite&White whitening pen (WP) and 6- no treatment (Con). The microhardness (VHN), surface roughness (Ra) and color of the specimens were measured (T). The specimens were then subjected to whitening protocols for 14 days (T.) followed by artificial saliva storage for 14 days (T). The measurements were repeated at T and T. The SBS test was done after the application of 35% phosphoric acid (Scotchbond Universal Etchant), followed by a universal adhesive (G-Premio Bond) and a micro hybrid/universal resin composite (Essentia) into a Teflon tube attached to the enamel surface (p<0.05). Surface morphologies of the enamel surfaces were examined by SEM. p value was set at 0.05.

結果:

OP，PT，WPはエナメル質試料の微小硬度を低下させたが（p＜0.05），WTとWMRで処理したエナメル質試料の微小硬度には有意な変化が見られなかった（p＞0.05）．エナメル質試料のRa値は，OP，PTおよびWTの塗布により増加した（p＜0.05）のに対し，WMRおよびWPの塗布では変化が認められなかった（p＞0.05）．OP，PT，WMR，WPは，エナメル質の色調を変化させた（p＜0.05）．OPを塗布したエナメル質を除き，SBS群間に有意差は認められなかった．OPはSBSの値が最も小さくなった(p=0.001)．SEM観察により、エナメル質表面は平滑であることが確認された。

Results: Application of OP, PT and WP decrased the microhardness of enamel specimens (p<0.05) whereas, no significant changes were seen in the microhardness of enamel specimens treated with WT and WMR (p>0.05). Ra values of enamel specimens increased with the application of OP, PT and WT (p<0.05); whereas no changes were observed after the applications of WMR and WP (p>0.05). OP, PT, WMR, and WP changed the color of the enamel(p<0.05). There were not any significant differences among the SBSs groups, apart from OP applied enamel specimens. OP showed the least SBS values (p=0.001). SEM observations revealed smooth enamel surfaces.

結論:

ホワイトニング製品は，エナメル質の微小硬度，表面粗さ，色調にそれぞれ異なる影響を及ぼした．OPのみがエナメル質のSBSを減少させた．

Conclusions: The whitening products affected the microhardness, surface roughness, color of enamel differently. Only OP decreased the SBS of the enamel.