Effect of alumina abrasion for bonding between Ti-6Al-7Nb alloy and an indirect composite

Hidenori Sugawara, DDS,(a) Hiroaki Yanagida, DDS, PhD,(b) Naomi Tanoue, DDS, PhD,(c) Yoshikazu Koishi, DDS, PhD,(d) Kiyoshi Nagano, DT,(a) Mitsuru Atsuta, DDS, PhD,(a) and Hideo Matsumura, DDS, PhD(e)

(a)Division of Fixed Prosthodontics and Oral Rehabilitation, Nagasaki University Graduate School of Biomedical Sciences, (b)Department of General Dentistry, and (c)Department of Specialized Dentistry, Nagasaki University Hospital of Medicine and Dentistry, Nagasaki, (d)Department of Dental Materials Science, Nihon University School of Dentistry at Matsudo, Matsudo, and (e)Department of Crown and Bridge Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan

Purpose: The current study aimed to examine the influence of air-pressure and alumina grain size in air-abrasion on bonding between an indirect prosthodontic composite material and a titanium alloy.
Materials and Methods: Disk specimens were cast from a titanium-aluminum-niobium alloy (Ti-6Al-7Nb, T-Alloy Tough) and air-abraded with eight different air-pressures (0.00-0.40 MPa) and four different sizes of alumina particles (50-250 μm). The disks were bonded with a composite material (Estenia) and 24-hour shear bond strengths were determined.
Results: Among the eight air-pressure conditions employed for abrading 50 μm alumina, the greatest bond strengths (33.7-38.7 MPa) were recorded with air-pressures of 0.30, 0.35, and 0.40 MPa (p<0.05). When the alloy was air-abraded with 0.35 MPa pressure using four different sized alumina, the group abraded with 50 μm alumina showed the highest bond strength (38.7 MPa, p<0.05).
Conclusion: Within the study’s limitations, the use of 50 μm particle sized alumina in combination with the air-pressure of 0.35 MPa is recommended for bonding the Estenia composite material to Ti-6Al-7Nb alloy.
(Int Chin J Dent 2004; 4: 8-14.)

Clinical Significance
: Air-pressure and alumina grain size in air-borne particle abrasion influence the bonding characteristics between an indirect composite and a titanium alloy.
Key Words: air-abrasion, alumina, bonding, niobium, Ti-6Al-7Nb alloy, titanium.