Finite element analysis of maxillary central incisor porcelain veneer by orthogonal experiment

Objective With consideration of the major load factors,the finite element analysis of the mechanics characteristics of maxillary central incisor was conducted by the method of orthogonal experiment,and then a relatively reasonable design plan of porcelain veneer was obtained.Methods Window,butt-joint and overlapped maxillary central incisor porcelain veneer complex which are 0.5㎜、0.7㎜、0.9㎜ respectively were made and the finite element model was established after spiral computed tomography scan.Followed by the finite element which was based on orthogonal experiment,the optimal combination of factor parameters under the circumstance of optimal stress distribution was found.Results Loading station had the greatest influence on the stress,followed by the thickness of porcelain veneer and loading angle;incisal design type has the least influence;the smallest influence on the stress was found under the circumstance of 0°(loading angle),central 1/3(loading station)and 0.9mm(thickness).The stress of all the positions of window and butt-joint porcelain veneer were greater than the overlapped one.A relatively large stress concentration area is located in the position of dental neck.Conclusion Patients who have normal over bite are the perfect ones for the porcelain veneer restoration;the thickness of porcelain veneer has relatively large influence on the stress distribution of veneer complex;incisal design type is the least important one,however,the overlapped one is the most clinically preferable one;the degree of inclination of labial surface has relatively small influence on the stress distribution of porcelain veneer;power which is transmitted along the long axis is the most powerful ones.