The Effect of Ferrule Design on Fracture Resistance and Failure Modes of Indirect Composite Endocrowns



Payaminiya L¹ ; Mohseni M² ; Ghorbani E²
Source: International Journal of Dentistry and Oral Science Published:2021

Abstract

Objective: The effect of ferrule design on fracture resistance of endocrowns is still unknown. Material and Methods: Thirty extracted human mandibular third molars were randomly distributed into 2 groups (n=15). In the first group, ferrule was not considered and the margins were prepared butt-joint. Second group received a circumferential 2 mm ferrule around the teeth. Conventional impressions were made. Endocrowns were fabricated of indirect composite, and then lutedwith resin cement. Then, all of the specimens were subjected to fracture resistance in a universal testing machine. Failure loads were recorded. Failure mode analysis was accomplished by 25x magnification optical microscope.The data were analyzed using Mann-Whitney U test, and Chi-square test (P < 0.05). Results: Endocrowns with no ferrule showed a greater mean failure load (2019.69 N) than ferrule containing endocrowns (836.89 N). However, statistical analysis showed no significant difference between these two groups (P=0.349). Fractography analysis showed that only 4 out of 30 endocrowns exhibited catastrophic failure, and 73.3% of the failures were adhesive. And no significant difference was found between failure modes of the groups (P =0.242). Conclusions: Ferrule design had no significant effect on failure loads and failure modes of endocrowns. © Leila Payaminiya 2021.