Objective

To measure the effect of simulated human salivary esterases (SHSE) and metalloproteinases (MMP) inhibition on the integrity of restoration–tooth interfaces made from traditional or polyacid-modified resin composites bonded to human dentin by either total-etch or self-etch adhesives.

Methods

Resin–dentin specimens, made from traditional (Z250) or polyacid-modified (Dyract-eXtra) composites were bonded to human dentin using total-etch (TE-Scotchbond) or self-etch (SE-EasyBond) adhesives. TE was applied with or without the MMP inhibitor galardin. Specimens were incubated in phosphate-buffer or SHSE (37 °C/pH = 7.0) for up to 180 days, then suspended in a continuous flow biofilm fermenter cultivating biofilms of Streptococcus mutans UA159. Interfacial bacterial penetration, biofilm biomass and viability were measured by confocal laser scanning microscopy and biomarker dyes and used as interfacial biodegradation markers.

Results

All specimens showed increased biofilm penetration and biomass with time regardless of incubation condition. SHSE increased bacterial penetration in all experimental samples after 180 days (p < 0.05). Galardin reduced interfacial bacterial ingress and bacterial biomass vs. non-MMP-inhibited TE-bonded specimens (p < 0.05). TE interfaces showed lower interfacial bacterial biomass vs. SE after 90-day and 180-day (p < 0.05). Dyract-eXtra specimens showed lower bacterial cell viability within the interface vs. Z250 (p < 0.05).

Significance

The biodegradation of resin–tooth interfaces is accelerated by esterases, modulated by MMP inhibition and is dependent on the material’s chemistry and mode of adhesion. The in vitro bacterial growth model used in this study facilitates the elucidation of differences in interfacial integrity and biostability between different materials and techniques and is suitable for assessment of their performance prior to clinical evaluation.

中文翻译：

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树脂-牙本质界面的生物降解取决于修复材料，粘附方式，酯酶或MMP抑制

客观的

要测量模拟的人类唾液酯酶（SHSE）和金属蛋白酶（MMP）抑制对修复体完整性的影响，该修复体是由通过全蚀刻或自蚀刻粘合剂与人牙本质粘合的传统或多元酸改性树脂复合材料制成的。

方法

使用全蚀刻（TE-Scotchbond）或自蚀刻（SE-EasyBond）粘合剂将由传统（Z250）或多元酸改性（Dyract-eXtra）复合材料制成的树脂-牙本质标本粘合到人牙本质上。在有或没有MMP抑制剂加拉丁的情况下使用TE。将标本在磷酸盐缓冲液或SHSE（37°C / pH = 7.0）中孵育长达180天，然后将其悬浮在连续流生物膜发酵罐中，以培养变形链球菌UA159的生物膜。通过共聚焦激光扫描显微镜和生物标记染料测量界面细菌的渗透，生物膜生物量和生存力，并用作界面生物降解标记。

结果

无论孵育条件如何，所有标本均显示生物膜渗透性和生物量随时间增加。180天后，SHSE在所有实验样品中均增加了细菌渗透（p <0.05）。相对于非MMP抑制的TE结合标本，加拉丁可减少界面细菌的进入和细菌生物量（p <0.05）。在90天和180天后，TE界面显示出比SE更低的界面细菌生物量（p <0.05）。与Z250相比， Dyract-eXtra标本显示界面内细菌细胞活力较低（p <0.05）。

意义

树脂-牙齿界面的生物降解通过酯酶加速，受MMP抑制调节，并取决于材料的化学性质和粘附方式。本研究中使用的体外细菌生长模型有助于阐明不同材料和技术之间界面完整性和生物稳定性的差异，并适合在临床评估之前评估其性能。