Influence of fatigue testing and cementation mode on the load-bearing capability of bovine incisors restored with crowns and FRC posts

Abstract

The aim of the study was to evaluate the influence of fatigue and cementation mode on the fracture behaviour of endodontically treated bovine incisors restored with fiber-reinforced-composite (FRC) posts and crowns. Forty-eight endodontically treated incisors were restored with FRC posts, composite build-ups, and cast crowns. In 16 teeth, each of the posts were cemented conventionally with KetacCem (3M Espe) or adhesively with Panavia F (Kuraray) or RelyXUniCem (3M Espe). One-half of the specimens in each group were subjected to thermal cycling with 10,000 cycles at 5-55°C and mechanical aging, loading the specimens in 1,200,000 cycles with 50 N. Fracture resistance was determined by loading the specimens until fracture at an angle of 45°. The loading test showed that cementation mode and fatigue testing had an influence on the load bearing capability. Before fatigue testing no statistically significant differences between the different cementation modes could be detected. After fatigue testing, conventionally cemented FRC posts lead to statistically significant higher fracture loads compared to adhesively luted posts. Most specimens fractured in a favourable way, independent from the type of cementation.

Mechanical resistance evaluation of a novel anatomical short glass fiber reinforced post in artificial endodontically treated premolar under rotational/lateral fracture fatigue testing

“…The load frequency 6 Hz set in the fatigue test was suggested by a study by Nie et al 19) , who indicated that the 6 Hz test frequency was reasonable when the fiber post was exposed in an air environment to perform fatigue test. The endurance limitation at 1.2×10 6 cycles was 66.81 N for the anatomical SGFR fiber post and 67.77 N for the X-Posts, falling into the reasonable area in previous work ranging from 50-127.4 N 16,28,29) . All failure modes were found in the artificial dentin but not the post itself indicating that post fit adaption in root canal was not a key issue in the lateral resistance test.…”

Osteo-odonto-keratoprosthesis (OOKP) and the testing of three different adhesives for bonding bovine teeth with optical poly-(methyl methacrylate) (PMMA) cylinder

“…They found no difference between conventional cementation (Ketac Cem) and adhesive luting (RelyX) with regard to fatigue of FRC posts. Only after inducing fatigue by thermal cycling and chewing simulation was a significant difference in specimen fracture force found in favour of conventional cementation (371 N and 494 N for RelyX and Ketac Cem, respectively) 7. In our study, a favourable outcome for the adhesive luting agent was found.…”

Fracture resistance of cementum-extended composite fillings in severely damaged deciduous incisors: An in vitro study

“…[ 10 ] Despite the proper fit of the cast posts and cores, their application has been limited due to their solely frictional intracanal retention and their relatively high fracture rate as a factor of their stiffness. [ 11 ] Therefore, there has been a shift toward application of resin-based posts, which offers a closer modulus of elasticity to the root and an adhesive along with mechanical retention, leading to superior stress distribution under functional loads. [ 12 ] The flared root in ECC patients lacks sufficient coronal and apical dentin to gain proper fitness for the prefabricated posts.…”