Effect of reinforcement with resin composite on fracture strength of structurally compromised roots

Abstract

This study was aimed at evaluating the fracture resistance of structurally compromised roots restored with four different post and core systems. Thirty-two bovine roots were uniformly shaped to simulate human mandibular premolar roots. The roots were divided into four groups based on the type of restoration: cemented cast post and core (Group MC), resin composite build-up (Group CR), resin composite and prefabricated glass fiber post build-up (Group FRC), and thick-layer dual-cured resin composite-reinforced smalldiameter tapered cast post and core (Group CRM). After a static loading test, the failure mode and fracture resistance were recorded. Group CRM (719.38±196.73 N) exhibited a significantly high fracture resistance compared with the other groups (Group MC: 429.56±82.43 N; Group CR: 349.56±66.21 N; Group FRC: 398.94±112.71 N; p<0.05). In conclusion, Group CRM exhibited better mechanical properties for structurally compromised roots with no ferrules, although all types of restorations showed non-restorable fracture modes.

Influence of Different Post-Core Systems on Impact Stress: a Pilot Study

“…However, some studies have reported that there is a high risk of root fracture, even with a Fiber-Resin PC [4, 29]. Further study is needed to clarify the effect of different post-core systems on fracture resistance and mode of failure.…”

Photoelastic stress analysis of endodontically treated teeth restored with different post systems: normal and alveolar bone resorption cases

“…Regardless of type of post, diameter was 1/3 of that of the root width 11,17) , but two kinds of post lengths in the root were adopted: one was 2/3 of the length of the root; the other was 1/3 of the length of the root. The upper part of the post was parallel; the lower part had a taper 18) angle of 3° and the apex was designed as a semicircle. Two different levels of alveolar bone were assumed.…”

Influence of post and core materials on distortion around 4-unit zirconia bridge margins

“…For this reason, in this study, the abutment roots were made of resin composite in order to ensure uniformity in the traits and the conditions of the roots. In addition, the Young's modulus of resin composite is similar to that of dentin 30,32) . Moreover, to simulate the clinical situation more accurately, the abutment roots were placed with a certain amount of inclination 23) and with specific distances 23) between them, the values of which were calculated from anatomical measurements.…”

“…Our results support the hypothesis that 4-unit zirconia FPD which abutment was restored by cast post and core restrain the surface strain compared to which abutment was restored by resin composite with glass fiber posts. The elastic moduli of resin composite (12 GPa) 29) and glass fiber post (28 GPa) 30) are not close to that of Y-TZP; on the other hand, the modulus of gold alloy (95 GPa) 42) is much closer. Assif et al 43) and Suzuki et al 20) reported that forces were concentrated between a rigid and a less rigid material, especially lateral forces.…”

“…In our previous studies, we used extracted human or bovine teeth for abutment roots 19,[29][30][31] . However, it is possible that the results could have been influenced by the morphological traits and the conditions of the extracted teeth.…”