The fracture characteristics of glass fiber post and core on using different types of core resin materials

Statement of problem: Glass fiber post is one of recent developments to accommodate esthetic restoration for endodontically treated teeth. This has many advantages over conventional post system in physical properties, esthetic factor, risk of root and restoration fracture, adhesion to core, radiopacity, removal and retrievabilty, biocompatibility and chemical stability. Purpose: This in vitro study was to evaluate the most suitable type of resin core for the glass fiber post through surveying the fracture modes and the maximum load that fractures the tooth. Material and methods: 50 sound maxillary premolars restored with glass fiber posts(ParaPost. Fiber White) and different types of resin cores(ParaCore, Z100TM, Rebilda. and Admira.) were prepared and loaded to faiure in a universal test machine. The maximum fracture load and fracture mode were investigated in the specimens that were restored with resin and those of metal cast and core. With the data, Wilcoxon rank sum test was used to validate the significance between the test groups, and Tukey’s studentized range test was used to check if there is any significant statistical difference between each test group. Every analysis was approved with 95% reliance. Results: measuring the maximum fracture load of teeth specimens, there was a significant difference between the maximum fracture loads of the tooth specimens. ParaCore showed the highest mean maximum fracture load followed by Z100TM. And, the distribution of fracture mode of tooth specimens showed generally Type D, the three parted fracture of the core around the post was mostly seen(62.5%), and specifically, ParaCore showed 90% and Z100TM showed 100% Type D fracture. Conclusion: Referring to the values of maximum fracture load and mean compressive fracture load, ParaCore and Z100TM had high values and are recommended as tooth colored resin core material for glass fiber post. CLINICAL IMPLICATIONS. This study was carried out intending to be of aid in selecting the appropriate resin core for the glass fiber post. The dual cure type composite resin ParaCore and light cure type composite resin Z100TM have good properties and are recommended as tooth colored resin core material for glass fiber post.ope