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

Robin Kasper; Karsten Winter; Sebastian Pietzka; Alexander Schramm; Frank Wilde

doi:10.1177/1943387520952684

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

Craniomaxillofac Trauma Reconstr. 2021 Jun;14(2):135-143. doi: 10.1177/1943387520952684. Epub 2020 Aug 28.

Authors

Robin Kasper¹, Karsten Winter², Sebastian Pietzka^{1

3}, Alexander Schramm^{1

3}, Frank Wilde^{1

3}

Affiliations

¹ Department of Oral and Maxillofacial Surgery, University Hospital Ulm, Ulm, Germany.
² Institute of Anatomy, Medical Faculty, Leipzig University, Leipzig, Germany.
³ Department of Oral and Plastic Maxillofacial Surgery, Military Hospital Ulm, Ulm, Germany.

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.

Keywords: CAD-CAM; biomechanics; mandibular reconstruction; patient-specific implants.