Shear Bond Strength of Repaired Ceramic-Metal Restorations Using Different Bonding Agents with Different Surface Treatments
Background: Fracture of ceramic-metal restorations is a major problem facing the dentists and the patients. There are several bonding systems currently available in the market to repair the fractured ceramic-metal restorations inside or outside the oral cavity. Purpose: The purpose of this study was to test the efficiency of repairing of metal-ceramic restorations using different bonding systems with different surface treatments. This efficiency was tested through the conduction of shear bond strength of the composite bonded to the porcelain and to nickel-chromium alloy using three different bonding agents (Excite, AdheSE, and Prompt L-Pop) with four different surface treatments (sandblasting and enchant, diamond stone roughening, sandblasting and hydrofluoric acid etching, or without surface treatment). Materials and Methods: A total of 120 specimens were prepared, 60 specimens from porcelain and 60 specimens from nickel-chromium alloy. Each group was divided into three equal subgroups, 20 specimens each, corresponding to the 3 bonding agents used. Each subgroup was further subdivided into four subgroups, 5 specimens each, corresponding to the surface treatment procedures. Bonding agents applied over all specimens and cured, followed by application of a micro-hybrid light-cured composite resin (Tetric Ceram). Thermal cycling was done for all specimens between 5°C and 55°C for 1000 cycles with a 10-second dwell time. Shear bond strength test was conducted using a universal testing machine ata cross-head speed of 0.5 mm/min. Results: The highest shear bond strength value recorded for the porcelain specimens bonded with Excite bonding agent with surface treatment sandblasting and hydrofluoric acid etching. In metal groups, the AdheSE bonding agent showed the highest shear bond strength value with the same surface treatment of the porcelain specimens. It was observed that sandblasting followed by hydrofluoric acid etching produced the most effective treatment method for porcelain and metal surfaces. Conclusion: The most effective technique for repairing metal ceramic restoration was sandblasting with hydrofluoric acid etching as surface treatment together with AdheSE or Excite bonding agents.