Effect of the bonding strategy on the tensile retention of full-contour zirconia crowns

• Autor(a) principal: Feitosa, Sabrina A. [UNESP]
• Data de Publicação: 2018
• Outros Autores: Campos, Fernanda [UNESP], Yoshito, Walter Kenji, Lazar, Dolores R.R., Ussui, Valter, Valandro, Luiz Felipe [UNESP], Bottino, Marco A. [UNESP], Bottino, Marco C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.ijadhadh.2018.06.006; http://hdl.handle.net/11449/171094
• topic: Adhesion; MDP; Properties; Retention strength; Surface conditioning; Yttria-stabilized tetragonal zirconia polycrystals; Zirconia

This study evaluated the effect of distinct bonding strategies on the retention of full-contour zirconia ceramic (Y-TZP, FCZ) crowns, and it characterized some physicochemical and mechanical properties of FCZ ceramic and its corresponding glazing system. To evaluate retention strength, dies were made with a dentin-analogue material to simulate a prepared tooth. FCZ crowns were manufactured using CAD-CAM technology and allocated into groups according to the bonding strategy: no ceramic treatment (PF – Panavia F cementation), glaze (GL), tribochemical silica coating (CJ), CJ + GL, and piranha solution followed by glaze (PS + GL). The specimens were subjected to thermocycling and storage in distilled water for 100 days before the retention tests. FCZ presented a porosity volume fraction of 0.2%, an apparent density of 6.06 g/cm3, Vickers hardness of 12.4 ± 0.07 GPa, and fracture toughness of 5.54 ± 0.24 MPa m1/2. SEM revealed a homogeneous microstructure composed of submicron-sized grains. XRD identified mainly zirconia's tetragonal phase. Glaze powder morphology was observed to be irregular, with a nanometric particle size, and a diffraction pattern characteristic of an amorphous material with several peaks of leucite. The PF and GL groups had higher retention values. The majority of the groups presented pre-test bonding failures, and two catastrophic failures of the FCZ-crown (GL and PF groups) were noted. The use of an MDP-containing resin cement or glaze application might improve retention of the FCZ crowns.