Combining structural-thermal coupled field FE analysis and the Taguchi method to evaluate the relative contributions of multi-factors in a premolar adhesive MOD restoration.
OBJECTIVE
The aim of this study was to determine the relative contribution of changes in restorative material, cavity dimensions, adhesive layer adaptation, and load conditions on the biomechanical response of an adhesive Class II MOD restoration during oral temperature changes.


METHODS
A validated finite-element (FE) model was used to perform the structural-thermal coupled field analyses and the Taguchi method was employed to identify the significance of each design factor in controlling the stress.


RESULTS
The results indicated that thermal expansion in restorative material amplified the thermal effect and dominated the tooth stress value (69%) at high temperatures. The percentage contributions of the load conditions, cavity depth, and cement modulus increased the effect on tooth stress values 46%, 32%, and 14%, respectively, when the tooth temperature was returned to 37 degrees C. Load conditions were also the main factor influencing the resin cement stress values, irrespective of temperature changes. Increased stress values occurred with composite resin, lateral force, a deeper cavity, and a higher luting cement modulus.


CONCLUSIONS
The combined use of FE analysis and the Taguchi method efficiently identified that a deeper cavity might increase the risk of a restored tooth fracture, as well as a ceramic inlay with a lower thermal expansion, attaining a proper occlusal adjustment to reduce the lateral occlusal force and low modulus luting material application to obtain a better force-transmission mechanism are recommended.
Lin
Chun-Li
CL
Department of Mechanical Engineering, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan. cllin@mail.cgu.edu.tw
Chang
Yen-Hsiang
YH
Lin
Yi-Feng
YF
D001641:Bicuspid / Q000473:pathology* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D001831:Body Temperature / Q000502:physiology; D003188:Composite Resins / Q000737:chemistry; D003198:Computer Simulation; D017076:Computer-Aided Design; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000145:classification* / Q000379:methods; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature; D013814:Thermal Conductivity; D013816:Thermodynamics
D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements