Objective

This study tested the effects of small leucine-rich proteoglycan (SLRP) proteins on phosphoric acid (PA)-treated dentin bonding overtime and the role of such SLRPs in the remineralization potential of demineralized dentin collagen.

Methods

Coronal dentin sections of human molars were used. SLRPs were either decorin (DCN) or biglycan (BGN) in core or proteoglycan form (with glycosaminoglycans, GAGs). Groups were: No treatment (control), DCN core, DCN + GAGs, BGN core, BGN + GAGs. Samples were etched with PA for 15 s and prior to application of Adper Single Bond Plus and composite buildup an aliquot of the specific SLRPs was applied over dentin. Twenty-four hours or 6 months after the bonding procedure, samples were tested for microtensile bond strength (MTBS). Debonded beams were analyzed by scanning electron microscopy (SEM). For remineralization studies, dentin blocks were fully demineralized, infused with the SLRPs, placed in artificial saliva for 2 weeks, and evaluated by transmission electron microscopy (TEM).

Results

MTBS test presented a mean of 51.4 ± 9.1 MPa in control with no statistically significant difference to DCN core (47.6 ± 8.3) and BGN core (48.3 ± 6.5). The full proteoglycan groups DCN + GAGs (27.4 ± 4.5) and BGN + GAGs (36.4 ± 13.6) showed decreased MTBS compared to control (p < 0.001). At 6 months, control or core-treated samples did not have a statistically significant difference in MTBS. However, SLRPs with GAGs showed statistically significant improvement of bonding (62.5 ± 6.0 for DCN and 52.8 ± 8.1 for BGN, p < 0.001) compared to their baseline values. SEM showed that GAGs seem to favor water retention but overtime help remineralization. TEM of demineralized dentin indicated a larger collagen fibril diameter pattern of samples treated with core proteins compared to control and a smaller diameter with DCN + GAGs in water with evidence of mineralization with DCN + GAGS, BGN core and BGN + GAGs.

Significance

: In conclusion, core proteins seem not to affect dentin adhesion significantly but the presence of GAGs can be detrimental to immediate bonding. However, after ageing of samples, full proteoglycans, particularly DCN, can significantly improve bonding overtime while promoting remineralization which can prove to be clinically beneficial.

中文翻译：

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注入蛋白多糖的牙本质底物的稳定性和再矿化

客观的

本研究测试了富含亮氨酸的小蛋白聚糖 (SLRP) 蛋白对磷酸 (PA) 处理的牙本质粘合超时的影响，以及此类 SLRP 在脱矿质牙本质胶原再矿化潜力中的作用。

方法

使用人臼齿的冠状牙本质切片。SLRP 是核心或蛋白聚糖形式的核心蛋白聚糖 (DCN) 或双糖链蛋白聚糖 (BGN)（带有糖胺聚糖、GAG）。组是：无治疗（对照）、DCN 核心、DCN + GAG、BGN 核心、BGN + GAG。样品用 PA 蚀刻 15 秒，在应用 Adper Single Bond Plus 和复合材料之前，将等分试样的特定 SLRP 应用在牙本质上。粘合程序后 24 小时或 6 个月，测试样品的微拉伸粘合强度 (MTBS)。通过扫描电子显微镜 (SEM) 分析剥离的光束。对于再矿化研究，牙本质块完全脱矿，注入 SLRP，置于人工唾液中 2 周，并通过透射电子显微镜 (TEM) 进行评估。

结果

MTBS 测试在控制中呈现 51.4 ± 9.1 MPa 的平均值，与 DCN 核心 (47.6 ± 8.3) 和 BGN 核心 (48.3 ± 6.5) 没有统计学上的显着差异。与对照相比，全蛋白多糖组 DCN + GAG (27.4 ± 4.5) 和 BGN + GAG (36.4 ± 13.6) 显示 MTBS 降低 (p < 0.001)。在 6 个月时，对照或核心处理的样本在 MTBS 方面没有统计学上的显着差异。然而，与基线值相比，具有 GAG 的 SLRP 显示出具有统计学意义的粘合改善（DCN 为 62.5 ± 6.0，BGN 为 52.8 ± 8.1，p < 0.001）。SEM 表明 GAG 似乎有利于保水，但加班有助于再矿化。

意义

: 总之，核心蛋白似乎不会显着影响牙本质粘附，但 GAG 的存在可能不利于立即粘合。然而，在样品老化后，全蛋白多糖，特别是 DCN，可以显着改善结合时间，同时促进再矿化，这在临床上是有益的。