PHOSPHATE AND THIOPHOSPHATE PRIMERS FOR BONDING PROSTHODONTIC LUTING MATERIALS TO TITANIUM

Statement of problem. When resin-bonded prostheses are constructed wit h titanium, they must be strongly bonded with luting materials for the prostheses to withstand the oral environment over the long term. Howe ver, limited information is available about the bond durability betwee n luting materials and titanium.Purpose. This study determined whether a phosphate and two thiophosphate primers increase bond strength and durability between a commercially available pure titanium and four lut ing agents. Material and methods. Three primers and four luting agents were divided into three groups according to the type of acidic monome rs: carboxylic acid derivatives (4-META, 4-AET, and MAC10), a phosphor ic acid derivative (MDP), and a thiophosphoric acid derivative (MEPS). Disk specimens were bonded with 16 combinations of 3 primers and 4 lu ting agents, including 4 controls. Shear bond strengths were determine d after 1-day immersion in water and after thermocycling for 100,000 c ycles. Results. Bond strengths were influenced by thermocycling, prime r, luting agent, and their combinations. After thermocycling, the grou ps that demonstrated the highest bond strengths were six combinations of two primers (Cesead Opaque Primer and Metal Primer II) and three lu ting agents (Imperva Dual, Panavia 21, and Super-Bond C&B).