Fracture Resistance comparison of Chamfer and Shoulder Finish lines in All Ceramic posterior restorations: An in vitro study

Dr. K. Sayed Akber Pasha

Volume : VIII, Issue : IV, April - 2018

Fracture Resistance comparison of Chamfer and Shoulder Finish lines in All Ceramic posterior restorations: An in vitro study

Dr. K. Sayed Akber Pasha

Abstract :

Introduction

The fracture of all ceramic restorations due to the occlusal and lateral forces is one of the major problems these days.This problem arises mainly due to high intensity of masticatory forces in the molar and premolar area along with the ittle nature of ceramic restorations.The aim of this present in–vitro study is to compare the fracture resistance of chamfer and shoulder margins under a cyclic load of Inceram crowns.

Material and methods

First maxillary premolar without any cracks and caries extracted for orthodontic purposes were included in the present study.Using appropriate burs, 50 in. chamfer and 90 in. shoulder margins were formed on the tooth. Using polyvinylsiloxane, impressions were made and 10 epoxy resin dies were faicated.Using a universal testing machine called Instron, mechanical testing was carried out.

Results

The mean ± standard deviation for the resistance of fracture came out to be 610.28±58.56 for chamfer margin and 502.54±105.45 for that of shoulder margin. The difference between the two groups was statistically significant as revealed by Student’s t–test (p = 0.011).

Discussion

Fracture caused by the occlusal and lateral masticatory forces seems to be one of the main problems of all ceramic restorations. These restorations can sometimes lead to unesthetic appearance and many biologic problems because of the metal present in these restorations.

Conclusion

The results of the present study suggested that the chamfer margin is better as compared to the shoulder margin in case of all ceramic posterior restorations in terms of fracture resistance against the vertical and lateral masticatory forces.