Biomechanical In Vitro Study on the Stability of Patient-Specific CAD/CAM Mandibular Reconstruction Plates: A Comparison Between Selective Laser Melted, Milled, and Hand-Bent Plates

Abstract

Study Design: An experimental in vitro study. Objective: Plate fractures are a recurrent problem in alloplastic mandibular reconstruction. Hypothetically it can be assumed that computer-aided design (CAD)/computer-aided manufacturing (CAM) reconstruction plates have a higher stability than conventional hand-bent plates. The aim of the study was to compare additive and subtractive fabricated CAD/CAM mandibular reconstruction plates as well as conventional plates with regard to their biomechanical properties. Methods: In a chewing simulator, plates of 2 conventional locking plate systems and 2 CAD/CAM-fabricated plate systems were compared. The plates were loaded in a fatigue test. The maximum number of cycles until plate fracture and the plate stiffness were compared. Results: While all conventional plates fractured at a maximum load between 150 and 210 N (Newton) after a number of cycles between 40 000 and 643 000, none of the CAD/CAM plates broke despite a nearly doubled load of 330 N and 2 million cycles. Both CAD/CAM systems proved to be significantly superior to the hand-bent plates. There was no difference between the 2 CAD/CAM systems. Conclusions: Concerning the risk of plate fracture, patient-specific CAD/CAM reconstruction plates appear to have a significant advantage over conventional hand-bent plates in alloplastic mandibular reconstruction.