2026/07/01 by Pedro Molinero-Mourelle, Pedro Molinero‐Mourelle, Mustafa Borga Donmez +7
Dentistry · Engineering · #Dental materials and restorations #Bone Tissue Engineering Materials #Endodontics and Root Canal Treatments
paper · doi:10.1016/j.prosdent.2026.06.034
STATEMENT OF PROBLEM: Additive manufacturing has emerged as an alternative for fabricating implant-supported zirconia restorations. However, knowledge regarding the effect of restoration height on the mechanical behavior of such restorations remains limited. PURPOSE: The purpose of this in vitro study was to compare the load-bearing capacity of additively and subtractively manufactured screw-retained zirconia crown-abutment complexes of different heights following cyclic loading. MATERIAL AND METHODS: A mandibular model with an implant placed in the right first molar region was digitized to design implant-supported screw-retained crowns with heights of 10 or 15 mm. These designs were used to fabricate 10- or 15-mm 3 mol% zirconia crowns by additive or subtractive manufacturing (n=5). All crowns were cemented onto identical titanium-base abutments using an autopolymerizing dental luting composite resin and subjected to cyclic loading (1.7 Hz, 98 N, 1.2 million cycles). After cyclic loading, all specimens were subjected to load-to-failure testing. The maximum loads recorded at the point of crown-abutment complex failure were analyzed using a 2-way analysis of variance, with manufacturing method and crown height as main factors, including their interaction (α=.05). RESULTS: No crown failure occurred during cyclic loading. During load-to-failure testing, abutments exhibited plastic deformation before crown fracture, irrespective of manufacturing method or crown height. Accordingly, the recorded maximum loads reflected the load-bearing capacity of the crown-abutment complex, and no statistically significant effects were found for manufacturing method, crown height, or their interaction (P≥.405). Mean maximum loads ranged from 3292 N to 3810 N, with individual values between 1552 N and 5335 N. CONCLUSIONS: All additively and subtractively manufactured implant-supported screw-retained zirconia crown-abutment complexes remained intact during cyclic loading, with maximum loads exceeding previously reported masticatory forces in the molar region.