Adhesive luting of orthodontic devices to silica-based ceramic crowns—comparison of shear bond strength and surface properties

Objectives: The aim of this study was to analyse the impact of different clinical conditioning approaches and an ammonium polyfluoride- and trimethoxysilylpropyl methacrylate-based experimental primer for intraoral luting of buccal tubes on silica-based ceramic surfaces. Materials and methods: A total of 60 leucite-reinforced glass ceramic molar crowns were conditioned using different methods (n = 10): I-roughening, hydrofluoric acid, silane; II-roughening, silane; III-roughening, experimental coupling agent; IV-experimental coupling agent; V-roughening; VI-no treatment. A buccal tube was adhesively luted to the ceramic surface. Subsequently, water storage, thermocycling and chewing simulation were carried out. The shear bond strength (SBS) was determined, and changes in the surface were assessed. Results: All tubes of the control group (group VI) debonded after incubation. The conditioning methods using coupling agents revealed mean values for SBS of 61.56 MPa (group I), 45.53 MPa (group III), 41.65 MPa (group II), and 23.14 MPa (group IV). In groups I–III, both composite residues and cracks/tear-outs were detected. Conclusions: The conditioning of silicate ceramic surfaces with a suitable coupling agent system appears to allow sufficient adhesive luting of buccal tubes. The intraoral luting of fixed appliance elements on silicate ceramic surfaces using an ammonium polyfluoride- and trimethoxysilylpropyl methacrylate-based ceramic primer can withstand orthodontic forces. Clinical relevance: Ammonium polyfluoride- and trimethoxysilylpropyl methacrylate-based ceramic primers revealed promising results for the intraoral adhesive luting of orthodontic devices to silica-based ceramic crowns.