Relining effects on the push-out shear bond strength of glass fiber posts

Adriana Rosado Valente Andrioli,Andréa Araújo De Vasconcellos,Milton Edson Miranda,Margareth Coutinho

doi:10.1590/1807-2577.14815

Abstract

Abstract Introduction The correct use of glass fiber posts in endodontically treated teeth is essential for the clinical success of restorative treatment. Objective This study evaluated the push-out shear bond strength of relined (R) or non-relined (NR) glass fiber posts, cemented with self-adhesive resin cement [RelyXTM U100 (U100)] and conventional resin cement [RelyXTM ARC (ARC)]. Material and method Sixty human single-rooted teeth were endodontically treated and divided into ARC-NR; U100-NR; ARC-R; U100-R groups. The teeth were sectioned into cervical, middle and apical thirds, and subjected to the push-out test. Bond strength was analyzed by the Friedman test; cement and post types were compared by the Mann Whitney test. The pattern of failures was evaluated with digital camera through images at 200x magnification, and was classified as adhesive (at the cement/dentin or cement/post interface), cohesive (cement or post), and mixed failures. Result In ARC-NR, bond strength values were higher in the cervical third; in U100-NR and ARC-R they were similar between the thirds. In U100-R, in the cervical and middle thirds the bond strength values were similar, and there was lower value in the apical third. For non-relined glass fiber posts, the highest mean bond strength values were observed with self-adhesive resin cement. Whereas, relined posts cemented with conventional resin cement had stronger cement layer in comparison with non-relined fiber posts. Conclusion The post relining technique was efficient in ARC-R. ARC-NR and U100-R showed improved bond strength in the cervical region of canal walls. The main failures were adhesive at the cement-post interface.

Highlights

The correct use of glass fiber posts in endodontically treated teeth is essential for the clinical success of restorative treatment
Studies on the adhesive capacity of cement systems that have investigated the presence, location and thickness of the hybrid layer in root dentin have suggested that the clinical success of post bonding is associated with frictional rather than micromechanical retention or chemical bond to dentin[5,7,8]
Cement thickness is not measured accurately, but D’Arcangelo et al.[11] found high bond strength values when using an appropriate oversized post space produced with a thickness of 0.1-0.3 mm

Summary

Introduction

The correct use of glass fiber posts in endodontically treated teeth is essential for the clinical success of restorative treatment. Objective: This study evaluated the push-out shear bond strength of relined (R) or non‐relined (NR) glass fiber posts, cemented with self-adhesive resin cement [RelyXTM U100 (U100)] and conventional resin cement [RelyXTM ARC (ARC)]. For non-relined glass fiber posts, the highest mean bond strength values were observed with self-adhesive resin cement. The application of intraradicular fiber posts is an alternative procedure for restoring endodontically treated teeth. These posts exhibit the following advantages: thy have esthetic properties; and are: resistant to corrosion; easy to remove if necessary; implanted in one or two visits[1]; flexible and compatible with adhesive cement systems[2]. Cement thickness is not measured accurately, but D’Arcangelo et al.[11] found high bond strength values when using an appropriate oversized post space produced with a thickness of 0.1-0.3 mm

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