Using a chewing simulator for fatigue testing of metal ceramic crowns.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Dental Materials

Background:

• Dynamic loading is crucial for predicting the clinical longevity of ceramic crowns.
• Traditional dynamic loading machines are expensive and have limited testing capacity.
• A cost-effective alternative is needed to assess the fatigue resistance of metal ceramic crowns.

Purpose of the Study:

• To evaluate the SD Mechatronik Chewing Simulator as a cost-effective tool for assessing the fatigue resistance of metal ceramic crowns.
• To compare the fatigue resistance of four different metal ceramic materials under dynamic loading.
• To investigate the influence of thermal expansion mismatch on fatigue resistance using finite element method (FEM) simulations.

Main Methods:

• Four metal ceramic materials were tested on lower first molar crowns subjected to dynamic loading (200,000 cycles) with simultaneous thermocycling.
• The SD Mechatronik Chewing Simulator was used, with forces verified by a 3D force sensor.
• Statistical analyses (exponential, Weibull, lognormal models) and FEM simulations were performed to determine fatigue resistance and stress distribution.

Main Results:

• The SD Mechatronik Chewing Simulator accurately reflected applied forces.
• Failure modes included cracks and chippings, with no significant differences between materials at 250N.
• Estimated fatigue resistance varied by material, with IPS InLine showing the highest (105N) and GC Initial the lowest (68N) using the Weibull model.

Conclusions:

• The SD Mechatronik Chewing Simulator is a suitable and economical option for testing the fatigue resistance of layered PFM crowns.
• The employed testing methodology is adaptable for evaluating ceramic-on-metal, ceramic-on-zirconia, and monolithic ceramic materials.
• This simulator provides a valuable tool for material development and quality control in dental prosthetics.