Objectives

The purpose of the study was to evaluate the integrity of dentine type I collagen after self-etching (SE) treatments with strong and mild universal adhesives.

Methods

Coronal dentine specimens (n = 10/product) were imaged by optical microscopy and analyzed by ATR-FTIR spectroscopy before and after treatment with 32% phosphoric acid gel (PA-negative control), 17% neutral EDTA (ED-positive control) conditioners and Adhese Universal (AD), Clearfil Universal Bond Quick (CQ), G-Premio Bond (GP), Prelude One (PR) and Scotchbond Universal (SB) adhesives. From the spectroscopic analysis the following parameters were determined: a) Extent of dentine demineralization (DM%) and b) percentage area of the Amide I curve-fitted components of β-turns, 3₁₀-helix/β-turns, α-helix, random coils, β-sheets and collagen maturation (R) index. Statistical analysis was performed by one-way ANOVA (DM%), paired t-test/Wilcoxon test (Amide I components) and Spearman correlation coefficient (DM% vs Amide I components) at an a = 0.05 level.

Results

PA, ED and GP removed the smear-layer and opened tubule orifices, whereas all other treatments removed only the intratubular smear-layer fraction. The ranking of the statistically significant differences in DM% was PA > GP > ED > AD, SB, CQ, PR, with AD being significantly different from PR. Regarding the Amide I components, PA demonstrated a significant reduction in β-turns, α-helices and an increase in β-sheets, GP a reduction in β-turns, AD an increase in β-turns and random coils, and CQ an increase in β-turns. PR, SB and ED showed insignificant differences in all the Amide I components. Significant correlations were found between DM%-random coils and DM%-R.

Significance

The universal adhesives used in the SE mode induced none to minimal changes in dentine collagen structure, without evidence of the destabilization pattern observed after conventional phosphoric acid treatments.

中文翻译：

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通用粘合剂对牙本质胶原蛋白的影响

目标

该研究的目的是评估使用强力和温和通用粘合剂进行自酸蚀 (SE) 处理后牙本质 I 型胶原蛋白的完整性。

方法

在用 32% 磷酸凝胶（PA 阴性对照）、17% 中性 EDTA（ED 阳性对照）调理剂处理前后，通过光学显微镜对冠状牙本质标本（n  =  10/产品）进行成像并通过 ATR-FTIR 光谱分析和 Adhese Universal (AD)、Clearfil Universal Bond Quick (CQ)、G-Premio Bond (GP)、Prelude One (PR) 和 Scotchbond Universal (SB) 粘合剂。从光谱分析中确定了以下参数：a) 牙本质脱矿的程度 (DM%) 和 b) β-转角、3 _10-螺旋/β-转角、α-螺旋的酰胺 I 曲线拟合组分的百分比面积、无规卷曲、β-折叠和胶原成熟 (R) 指数。通过单向方差分析 (DM%) 进行统计分析，配对t-test/Wilcoxon 检验（酰胺 I 成分）和 Spearman 相关系数（DM% 对酰胺 I 成分）在 a  =  0.05 水平。

结果

PA、ED 和 GP 去除了涂片层并打开了小管孔，而所有其他处理仅去除了管内涂片层部分。DM% 的统计学显着差异排序为 PA  >  GP  >  ED  >  AD、SB、CQ、PR，其中 AD 与 PR 有显着差异。关于酰胺 I 组分，PA 表现出β-转角、α-螺旋和β-折叠的显着减少，GP β-转角减少，AD β-转角和无规卷曲增加，CQ 增加在β-转角。PR、SB 和 ED 在所有酰胺 I 组分中显示出微不足道的差异。在 DM%-随机线圈和 DM%-R 之间发现了显着的相关性。

意义

SE 模式中使用的通用粘合剂不会引起牙本质胶原结构的最小变化，也没有在常规磷酸处理后观察到的不稳定模式的证据。