Porcelain-titanium bonding with a newly introduced, commercially available system.

STATEMENT OF PROBLEM

Titanium is widely used in implant dentistry because of its high strength, toughness, biocompatibility, and low cost. The fabrication of complex substructures is now possible with a number of automated systems. One major obstacle to broad clinical acceptance of porcelain-titanium prostheses is the poor ceramic-metal bonding.

PURPOSE

The purpose of this study was to compare titanium bonding with a traditional bonder and a newly introduced titanium bonding system. Bonding was characterized by the delamination crack initiation stress per ISO 9693:2009.

MATERIAL AND METHODS

Grade 4 titanium strips were laser machined to meet ISO 9693:2009 standards. Bonding and firing of opaque porcelain was accomplished by using a traditional titanium ceramic system and a newly introduced bonding system. Variables tested besides the bonding system included the length of the porcelain block (7 mm, 8 mm, 9 mm); the thickness of the block (1.0 mm, 1.6 mm); testing the specimens 1 mm off-center; and reusing the strips. Crack initiation stresses were calculated and compared by ANOVA and the Duncan test (α=.05).

RESULTS

The newly introduced commercially available system gave the strongest bond (41.82 ±5.7 MPa), followed by the 9 mm specimens (32.2 ±3.9 MPa), then a statistically similar group of the 8 mm, 7 mm, and 1.6 mm thick specimens with new Ti (approximately 23 MPa), and last a similar group with 7 mm, 8 mm, and 1 mm offset loading on reused Ti (approximately 16 MPa). The lower limit under ISO 9693:2009 was 23 MPa.

CONCLUSIONS

The newly introduced commercially available system achieved much higher bond strengths than traditional titanium systems, even better than those for many high-gold alloys.