Effect of Preheating of Resin Luting Materials on Push-Out Bond Strength of Fiber Posts to Intraradicular Dentin

TL;DR

This study found that preheating certain dental materials improves their bond strength and hardness when attaching fiber posts to teeth.

Contribution

The novel finding is that preheated fiber-reinforced flowable composites outperform traditional dual-cure resin cements in bond strength and microhardness.

Findings

Preheated EverX Flow showed significantly higher push-out bond strength and microhardness than LinkForce.

G-aenial Injectable had the lowest bond strength and microhardness values.

Bond strength decreased from the coronal to the apical region within each material.

Abstract

This study aimed to evaluate the effect of preheating on the push-out bond strength (PBS) and microhardness (HV) of fiber-reinforced flowable and injectable composites and to compare them with dual-cure resin–cement for post cementation. Fifty premolars were endodontically treated, and post spaces were prepared. Specimens were divided into five groups (n = 10) based on the resin luting material. After adhesive application, fiber posts were luted with dual-cure resin–cement (LinkForce), fiber-reinforced flowable composites (EverX Flow; non-heated/preheated), and injectable composites (G-aenial Universal Injectable; non-heated/preheated). After 24 h, roots were sectioned (coronal, middle, apical) for PBS testing (Instron). For HV, 10 specimens per resin luting material were prepared, and top/bottom microhardness was measured to assess the depth of cure. Data were analyzed with two-way ANOVA and post hoc Tukey tests (p < 0.05). Both types of resin luting material and preheating significantly affected PBS and HV (p = 0.0001). Preheated EverX Flow showed significantly higher PBS and HV than LinkForce, while G-aenial Injectable exhibited the lowest values (p < 0.05). Within each resin luting material, PBS significantly decreased from the coronal to the apical region (p = 0.0001). Preheated fiber-reinforced flowable composites demonstrate improved microhardness and adhesion, offering a reliable alternative to the dual-cure resin–cements for fiber post cementation.

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