CAD/CAM Polymer vs Direct Composite Resin Core Buildups for Endodontically Treated Molars Without Ferrule

Abstract

Semidirect core buildup made from high-performance polymer enhanced the performance of all-ceramic leucite-reinforced glass ceramic crowns compared with direct light-curing composite resin buildups. The use of a fiber-reinforced post system did not influence the fatigue strength of all-ceramic crowns.

Current options concerning the endodontically-treated teeth restoration with the adhesive approach

“…With the improvement of adhesive dentistry, a paradigm shift to postless approaches in restoring endodontically treated teeth with ferrule is in progress. 8,15,16,20,38,39,40 Teeth with a minimum of 2 mm of ferrule have been restored without posts in combination of a resin composite core build-up. 15,16,35 This technique seems to mimic more closely the structure and biomechanical behavior of a natural tooth, in contrast to the concept of post-and-core build-ups.…”

“…15 Other techniques could be used to improve bond strength and tooth resistance, such as IDS 41 and indirect composite resin. 40 All aspects of the restoration (crown, adhesive interface, build-up, and tooth) seem to form a cohesive assembly which ideally mimics the properties of the dentin-enamel junction. Modern approaches for posterior and anterior ETT with ferrule have been investigated and proved to be efficient even without the use of a post, as the retention of the crown is granted by the bonding to the ferrule-retained core build-up.…”

“…20,87 It was concluded that the post did not increase the fatigue resistance of the endodontically treated molars, but caused more root fractures. 20,40 Hence, the use of a post can be questioned due to the higher number of catastrophic failures. 13,20 In vitro studies, in spite of being less relevant than clinical trials, have the ability to isolate and investigate a particular variable of interest under strictly standardized conditions.…”

In vitro methods to evaluate the mechanical behavior of teeth restored with post and core: a structured review

“…Data of survival percentage vs. load levels are then plotted on a graph and a log-rank test is normally used to compare the groups. Güth et al 15 (2016) used this methodology to investigate the restoration of broken--down endodontically treated molars without ferrule effect using glass ceramic crowns on different composite resin core buildups. A cyclic load was applied at a frequency of 5 Hz, starting with a load of 200 N for 5000 cycles, followed by stages of 400, 600, 800, 1000, 1200 and 1400 N at a maximum of 30,000 cycles each.…”

“…This type of loading may be used to estimate the survival probability of a treatment 15,44 ; to evaluate the fatigue strength 112 ; and to promote aging, all of which try to simulate the oral environment.…”