Statement of problem

An intraradicular retainer formed by multiple independent glass fiber filaments was developed aiming to allow better adaptation in flattened root canals; however, the performance of the new posts is unclear.

Purpose

The purpose of this in vitro study was to compare the bond strength (BS) and adhesive interface quality achieved in flattened root canals restored with conventional glass fiber posts (CFPs) and multifilament glass fiber posts (MFPs).

Material and methods

The distal roots of mandibular molars with long oval root canals were endodontically treated, and the obturation material was removed and assigned to 2 groups (n=11) according to the type of retainer used: CFP (WhitePostDC#0.5; FGM) or MFP (CometTail#4; Synca). The posts were cemented with self-adhesive resin cement. The specimens were sectioned (2 slices per third). The most cervical slice in each third was used to evaluate the BS, while the adhesive interface in the apical slices was analyzed by scanning electron microscopy. BS data were analyzed by using a multilevel generalized linear model, and adhesive interface SEM data were analyzed by using a multilevel ordinal logistic regression model (α=.05).

Results

Multilevel regression showed a statistically significant difference for the “type of retainer” factor (P=.001; CFP 2.61 ±1.30>MFP 1.59 ±1.54). No statistically significant differences were found for the “root thirds” factor (P=.346) or for the interaction of both factors (P=.114). The failure pattern was predominantly mixed or adhesive for CFP and adhesive to dentin for MFP. A better adaptation of the restorative material was observed in the cervical third for CFP and in the apical third for MFP (P<.001).

Conclusions

MFP resulted in lower BS values than CFP, with a higher prevalence of adhesive failures to dentin and better adaptation of the adhesive interface in the apical third.

中文翻译：

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生物力学制备后，将多丝玻璃纤维桩的粘结强度和粘结界面质量吸引到扁平椭圆形的根管上，而不会增加牙本质的磨损。

问题陈述

为了使扁平根管更好地适应，开发了由多个独立的玻璃纤维细丝形成的放射内固定器。但是，新职位的表现尚不清楚。

目的

这项体外研究的目的是比较用常规玻璃纤维桩（CFP）和复丝玻璃纤维桩（MFP）修复的扁平根管的粘合强度（BS）和粘合界面质量。

材料与方法

对具有长椭圆形根管的下颌磨牙的远侧根进行牙髓治疗，并根据所使用的固定器类型将闭塞材料去除并分为2组（n = 11）：CFP（WhitePostDC＃0.5; FGM）或MFP（ CometTail＃4； Synca）。桩用自粘树脂胶粘剂粘结。将标本切成薄片（每秒钟2片）。每三分之二的宫颈切片最多用于评估BS，而根尖切片中的粘合剂界面通过扫描电子显微镜分析。使用多级广义线性模型分析BS数据，并使用多级序数Logistic回归模型（α= .05）分析粘合界面SEM数据。

结果

多级回归显示“保留类型”因子在统计学上有显着差异（P = .001； CFP 2.61±1.30> MFP 1.59±1.54）。没有统计学显著差异被发现为“根三分之二”因子（P = 0.346）或两个因素（相互作用P = 0.114）。失效模式主要是CFP混合或粘合，MFP粘合到牙本质。在CFP的颈椎三分之一和MFP的牙根三分之一中观察到修复材料的适应性更好（P <.001）。

结论

MFP导致的BS值低于CFP，其对牙本质的粘接失败率更高，并且在顶端的第三者中粘接界面的适应性更好。