open access

https://doi.org/10.14943/doctoral.k15497

https://hdl.handle.net/2115/89897

ユニバーサルアドヒーシブの接着に対する疎水性ボンディング材の影響

英語

nanoleakage

2023-03-23

Hokkaido University

51p

Purpose: To determine the effect of an extra hydrophobic resin layer (EHL) onthebond strength and durability of three different pH one-step universal adhesives (UAs). Materials and methods: One hundred and nineteen extracted non-carious humanmolars were used in this study. The flat dentin surfaces were exposed and dividedinto7 groups and 14 subgroups. Three one-step UAs with different pH, G-Premio Bond(GPB), Scotchbond Universal (SBU), All-Bond Universal (ABU) were used inthis study, while the bonding agent of Clearfil SE Bond 2 (SE2) was selected as an EHLtoGPB, SBU and ABU. The six experimental groups were: GPB, GPB+EHL, SBU, SBU+EHL, ABU, ABU+EHL, and SE2 was used as a control group. The adhesives were applied to flat dentin surfaces according to each manufacturer’s instructions, while for the EHL groups, dentin surfaces were treated with one of these adhesives followed by the application of EHL prior to light cure. The microtensile bond strength(μTBS) was evaluated after 24 h water storage or after 15,000 thermal cycling (TC). The fracture modes, interfacial structures were analyzed using SEM, whilenanoleakage (NL) was analyzed using SEM under backscattered mode. Elasticmodulus (EM) and hardness (H) of the adhesive layer were evaluated byananoindenter. The data of μTBS were analyzed by three-way ANOVAto determinethe effects of adhesive, EHL and TC and the interaction effect of these three factors, and the multiple comparisons were performed using one-way ANOVA, followedbyGames-Howell test. As for the data of EM and H, two-way ANOVA was employed to determine the effects of adhesive and EHL as well as the interaction of these twoparameters, multiple comparisons between groups were performed using one-wayANOVA, followed by Tukey’s test (α=0.05). Results: Significantly higher μTBS was achieved in GPB+EHL group compared withGPB group both at 24 h and after 15,000 TC (p<0.05). The additional use of EHLdidnot significantly improve the μTBS of SBU and ABU groups both at 24 h and after 15,000 TC (p>0.05). After 15,000 TC, the bond strength of GPB+EHL, SBU, SBU+EHL, ABU+EHL and SE2 group significantly decreased compared with the 24h groups, while no significant difference was found within GPB and ABUgroups (p>0.05). Many bubbles were found in GPB group both at 24 h and after 15,000TC, while the bubble formation was rare in other groups. GPB group showed higher NLthan SE2 both at 24 h and after 15,000 TC, while GPB+EHL group demonstratedlower NL than GPB group. The mean EM and H of adhesive layer in GPB+EHLgroup was significantly decreased compared with GPB group (p<0.05). Conclusions: The results indicated that the bond strength and durability of lowpHone-step UA (GPB) were significantly improved by additional application of EHLboth at 24 h and after 15,000 TC, while no significant improving effect for ultra-mildone-step UAs (SBU and ABU), GPB works well as a primer in a two-step bondingsystem while SBU, ABU does not work well.

2023-03-23

甲第15497号

博士(歯学)

(主査) 教授 佐野 英彦, 教授 井上 哲, 教授 吉田 靖弘

歯学院（口腔医学専攻）

博士論文

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