PMID- 35227045 OWN - Quintessence Publishing Company, Ltd. CI - Copyright Quintessence Publishing Company, Ltd. OCI - Copyright Quintessence Publishing Company, Ltd. TA - J Adhes Dent JT - The Journal of Adhesive Dentistry IS - 1757-9988 (Electronic) IP - 1 VI - 24 PST - epublish DP - 2022 PG - 39-48 LA - en TI - Effect of Grinding and Regenerative Heat Treatment on the Fracture Resistance of a Zirconia/Porcelain Veneer Interface LID - 10.3290/j.jad.b2701695 [doi] FAU - Candido, Lucas Miguel AU - Candido L FAU - Ferreira, Eduardo Bellini AU - Ferreira E FAU - Pinelli, Lígia Antunes Pereira AU - Pinelli L CN - OT - zirconia OT - dental prosthesis OT - x-ray diffraction OT - surface properties OT - heat treatment AB - Purpose: To experimentally assess the effect of regenerative heat treatment (HT) on yttria-stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP) to guarantee veneer adhesion strength. Materials and Methods: One surface of bar-shaped Y-TZP specimens was ground (G) with a diamond stone, while the control samples (C) were not. Groups C900 and G900 were submitted to HT at 900°C for 60 min, whereas groups C1000 and G1000 were submitted to HT at 1000°C for 30 min. The treated surfaces were characterized by x-ray diffractometry (XRD), scanning electron microscopy (SEM), and optical and mechanical profilometry. The energy release rate through interface fracture was determined by a four-point bending test on notched Y-TZP veneered specimens. XRD was refined by the Rietveld method, mean roughness (Ra) and energy release rate were submitted to two-way ANOVA (α = 0.05), and the images were analyzed descriptively. Results: The monoclinic phase (vol%), means of Ra (µm), and the energy release rate (J/m2) were, respectively: C = 1.2/0.17/6.8, C900 = 0.0/0.18/6.6, C1000 = 0.0/0.18/7.6, G = 2.6/1.16/8.3, G900 = 0.0/1.07/8.0, and G1000 = 0.0/1.01/5.7. The surface fraction of monoclinic zirconia increased by grinding and decreased by HT. Ra also increased after grinding (p < 0.005) but remained unaltered after HT (p = 0.22). Increased irregularity was observed in the G groups and a subtle smoothing of the surface after HT. After the fracture of the bilayers, a residual amount of porcelain could be seen on the zirconia surface in all groups. The energy release rate was statistically equal among all groups (p > 0.05). Conclusion: Heat treatment after grinding completely restored the tetragonal phase of zirconia without altering the energy release rate during interfacial fracture. AID - 2701695