Statement of problem

Light transmitted deep into the root canal is an important parameter to increase bonding of the cement to the post and dentin. Glass fiber posts seem to be an option to increase transmitted light, but literature on the light transmittance profile and power transmission to deep canal regions is lacking.

Purpose

The purpose of this in vitro study was to evaluate light delivered by 2 types of fiberglass posts submitted to different surface treatments and to evaluate the bond strength.

Material and methods

Whiteposts and Superposts were allocated to 4 groups: no surface treatment, surface treatment with 24% hydrogen peroxide, surface treatment with silane, and surface treatment with 24% hydrogen peroxide plus silane. The total light transmitted by the posts was measured by using an integrating sphere to collect the diffuse light. The light profile that was laterally delivered to the post was measured with a power detector equipped with an optical fiber probe. The bond strength was measured with the push-out test. Scanning electron microscopy was used to evaluate the surface treatments. The light transmission data were analyzed by using a generalized linear model and the Bonferroni test and the bond strength values were evaluated by using ANOVA and the Tukey test (α=.05).

Results

The cervical third presented the highest transmission (74.1% for Whiteposts and 74.6% for Superposts), followed by the middle (20.9% for Whiteposts and 20.4% for Superposts) and apical (5.0% for both Whiteposts and Superposts) thirds. Superposts led to higher bond strength than Whiteposts (9.73 ±5.89 and 8.48 ±4.99 MPa, respectively). Surface treatment with silane and hydrogen peroxide plus silane afforded similar bond strength (11.4 ±6.4 and 10.7 ±5.6 MPa, respectively), which was higher as compared with the bond strength obtained after surface treatment with hydrogen peroxide. For both post types, the bond strength decreased from the cervical (12.2 ±6.0 MPa) to the middle (9.7 ±5.0 MPa) and apical (6.5 ±3.6 MPa) thirds.

Conclusions

Light transmission and bond strength decreased from the cervical to the apical third. Surface treatment impacted bond strength; light transmission through Whiteposts was slightly higher than light transmission through Superposts.

中文翻译：

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玻璃纤维桩经过不同表面处理后的透光率和粘结强度

问题陈述

透射到根管深处的光是增加水泥与桩和牙本质的粘结的重要参数。玻璃纤维桩似乎是增加透射光的一种选择，但是缺乏有关光透射率分布和向深管区域传输功率的文献。

目的

这项体外研究的目的是评估通过两种类型的玻璃纤维桩进行不同表面处理后发出的光，并评估其粘结强度。

材料与方法

Whiteposts和Superposts分为4组：无表面处理，用24％过氧化氢进行表面处理，用硅烷进行表面处理以及用24％过氧化氢加硅烷进行表面处理。柱子透射的总光通过使用积分球进行测量，以收集散射光。用配备有光纤探针的功率检测器测量横向传递到柱子的光分布。结合强度通过推出试验来测量。扫描电子显微镜用于评估表面处理。使用广义线性模型和Bonferroni检验分析透光数据，并使用ANOVA和Tukey检验（α= .05）评估粘合强度值。

结果

颈椎第三者的传播率最高（Whiteposts为74.1％，Superposts为74.6％），其次是中间（Whiteposts为20.9％，Superposts为20.4％）和心尖（Whiteposts和Superposts均为5.0％）。与白柱相比，超级柱的粘结强度更高（分别为9.73±5.89和8.48±4.99 MPa）。用硅烷和过氧化氢加硅烷进行表面处理可得到相似的粘结强度（分别为11.4±6.4和10.7±5.6 MPa），这比用过氧化氢进行表面处理后得到的粘结强度要高。对于两种桩柱类型，粘结强度均从颈椎（12.2±6.0 MPa）降低至中间（9.7±5.0 MPa）和心尖（6.5±3.6 MPa）的三分之二。

结论

透光率和粘结强度从子宫颈降低到顶端的三分之一。表面处理影响粘结强度；Whiteposts的透光率略高于Superposts的透光率。