Fracture Resistance of Anterior Endocrown vs. Post Crown Restoration an In-vitro Study
Objective: The purpose of this study is to study the fracture resistance of anterior endocrown versus post crown restoration.
Materials and methods: Thirty caries free of extracted human maxillary canine with complete root formation were selected for this study. Also two types of ceramics were used: IPS Emax press and Celtra Press. Thirty samples were fabricated and divided into 2 groups (15 samples each) according to the type of ceramic used. Then each subgroup was subdivided into 3 subgroups (5 samples each) according to the type of restorations: Endocrown 6 mm, Endocrown 10 mm, post+core+crown. All specimens were subjected to a thermocycling procedure in automated thermocycling machine. Samples were thermocycled for 5000 cycles, between 5°C-55°C with a dwell time 15 seconds. All samples were individually mounted on a computer controlled materials testing machine for a fracture resistance test. After fracture resistance test, all specimens in the test groups were viewed using a USB digital-microscope, magnification × 35, and the images were captured and transferred to a IBM personal computer equipped with the Image-tool software (Image J 1.43 U, National Institute of Health, USA) to determine failure mode pattern according to the following categorization.
Results: Regarding the fracture resistance testing, the results of the present study revealed that there was no statistically significant difference between mean fracture resistance values of IPS Emax press (235.54 N) and Celtra press; (244.98 N) where both showed statistically non-significant highest mean fracture resistance.
Conclusion: The results obtained in this study revealed a non-significant difference between the endocrown restorations and the post and core and crown. Although endocrown showed higher fracture resistance values compared to the post and core and crown. Also the results showed non-significant difference between the endocrown restorations with different designs. Although endocrown (10 mm) showed higher fracture resistance values than endocrown (6 mm) which may be due to an increase in surface area.