The influence of horizontal glass fiber posts on fracture strength and fracture pattern of endodontically treated teeth: A systematic review and meta‐analysis of in vitro studies

Abstract

Purpose This systematic review and meta‐analysis aimed to summarize available evidence regarding the effect of horizontal glass fiber posts (HGFPs) on fracture strength and fracture pattern of endodontically treated teeth (ETT) compared to controls without HGFP. The review protocol was registered on the OSF registries. Methods Literature searches were conducted in MEDLINE/PubMed, Scopus, Web of Science, Embase, Google Scholar, and ProQuest for all relevant studies published up to February 2022. All in vitro studies that assessed the influence of HGFPs on fracture strength and fracture pattern of ETT whether mesio‐occluso‐distal or mesio‐occlusal or DO cavities were considered eligible. Review Manager (RevMan) was used for the meta‐analysis. Subgroup and funnel plot analyses were also performed. Quality assessment was conducted by two independent reviewers. Results A total of 12 articles met the inclusion criteria, and 10 studies underwent quantitative evaluation. The pooled effect showed that fracture resistance of molar teeth restored with HGFP was significantly higher than teeth without HGFP (standardized mean difference [SMD]: 1.61, 95% confidence interval [CI]: 0.14, 3.09, p = 0.03), whereas marginally significant for premolars (SMD: 1.36, 95% CI: −0.00, 2.73, p = 0.05). Regarding fracture patterns, the presence of an HGFP significantly increased the occurrence of restorable fracture patterns for premolars (odds ratios [OR]: 4.15, 95% CI: 1.60, 10.82, p = 0.004) compared to controls, whereas the difference was not significant for molars (OR: 1.09, 95% CI: 0.43, 2.77, p = 0.85). Moderate risk of bias was identified in 9/12 studies; one study showed a high risk of bias and two studies showed a low risk of bias. Conclusions Within the limitations of this study, there is evidence from in vitro studies that the use of HGFP increases the fracture resistance of the ETT when compared to teeth without HGFP and also reduces the occurrence of non‐restorable fractures for premolars. However, well‐conducted in vitro and prospective clinical studies are warranted to validate this finding.

Effect of Long Glass Fiber Orientations or a Short-Fiber-Reinforced Composite on the Fracture Resistance of Endodontically Treated Premolars

“…Since the materials and preparation techniques used are different, no study directly compares to the results of this study. However, these findings are consistent with a recent systematic review and meta-analysis by Abdulrab et al [31], which investigated the effect of horizontal glass fiber posts on fracture strength.…”

“…The transfixed technique is described as creating grooves in the buccal and palatal/lingual cusps to horizontally insert the post [30], which has also been labeled as the transcoronal [17] or the horizontal fiber post [31] technique. In the studies where this technique was used with different materials, such as polyethylene fibers [17], a glass fiber post [32], or a zirconia post [30], it was found that this technique increased the fracture resistance of teeth.…”