ABSTRACT
This study aims to investigate the mechanical properties, composition and surface preparation for adhesive bonding of the recently introduced zirconia-reinforced lithium silicate (ZLS) glass-ceramic. One single block of ZLS was used to prepare the specimens (n=14). The fracture toughness (Ft) and the Vickers hardness (HV) were measured on specimens partially crystallized (PCs) (n=4) and fully crystallized (FCs) at 840°C for 8 min (n=4). The surface treatment was done using hydrofluoric-acid gel (HF) at different concentrations and times of action on FCs specimens (n=4). SEM-EDX was used to test elemental composition and crystalline phases (n=2). The new ZLS glass-ceramic showed significantly higher values of HV and Ft for FCs, PCs showed a brittle behavior. The surface etching should be made using HF at 4.9% for 20 s.
Subject(s)
Dental Porcelain , Lithium , Acid Etching, Dental , Ceramics , Dental Bonding , Dental Stress Analysis , Hydrofluoric Acid , Materials Testing , Silicates , Stress, Mechanical , Surface PropertiesABSTRACT
A fixed prosthesis, supported by implants, was fabricated prior to surgery and cemented with passive fit immediately after placement of 14 implants in the mandible. The prosthesis was constructed before implant surgery on a plaster cast that precisely reproduced the patient's hard and soft tissues. The cast was built using a method that allowed the transfer of hard and soft tissue anatomy from computerized tomograms. A rigid surgical stent, cast in gold, was used to place the implants into prosthetically ideal positions under three-dimensional control. The prosthesis was placed immediately after implant placement, using an occlusion-driven method, which avoided the need for occlusal adjustments to the prosthesis.
