Effect of Full Coverage, Endocrowns, Onlays, Inlays Restorations on Fracture Resistance of Endodontically Treated Molars
Correspondence Address :
Fixed Prosthodontic Department
Faculty of Dentistry
MSA University, Egypt
Received on: September 29, 2015, Accepted on: October 29, 2015, Published on: November 09, 2015
Citation: Ahmed Hamdy (2015). Effect of Full Coverage, Endocrowns, Onlays, Inlays Restorations on Fracture Resistance of Endodontically Treated
Copyright: 2015 Sato T, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Purpose: This in vitro study compared the fracture resistance of endodontically treated first maxillary molars restored with fiber posts (FRC Postec Plus-Ivoclar Vivadent) and lithium disilicate ceramic (IPS e. Max Press/ Ivoclar Vivadent) full crowns, endocrowns, onlays and inlays with respect to the observed failure modes.
Materials and Methods: Fifty sound human maxillary first molars were selected, prepared and divided into five groups. Group 1 was left intact (control), all other groups were endodontically treated, group 2 was restored with lithium disilicate full crown. Group 3: Endocrown restorations. Group 4: Onlay restorations. Group 5: Inlay restorations. All restorations were fabricated from lithium disilicate according to manufacturer instructions. Fracture resistance (N) was measured using a universal testing machine parallel to the long axis of tooth till failure. Fractures were divided into 2 groups restorable and non-restorable. The mean loads of failure of each group were statistically compared using ANOVA p<0.001. Chi-square tests were used to compare frequencies of favorable and unfavorable failure among groups.
Results: Mean failure loads were :group 1:985 N, group 2:1076 N, group 3:989 N, group 4:908 N and group 5:638 N respectively. As regard mode of failure: group 1:40% restorable, group 2:90% restorable, group 3:80% restorable, group 4:80% restorable and group 5:30% restorable.
Conclusions: 1-Full coverage, intact teeth and endocrowns showed the highest fracture resistance respectively with no significant difference. 2-Onlays then inlays showed the least fracture resistance resistance. 3-Full coverage group showed the best mode of failure and inlay showed the worst.