title: Fatigue resistance of titanium-nickel alloy cast clasps.
abstract: In this study fatigue resistance of experimentally prepared titanium-nickel (50.8% nickel and 49.2% titanium) cast clasps was evaluated in a simulated clinical situation. The change in force required to remove the titanium-nickel clasps was recorded under a repeated placement-and-removal test on steel model abutment teeth. Commercially-pure titanium, cobalt-chromium alloy, and gold-silver-palladium-copper alloy clasps were also tested for comparison. The tips of the clasps were located in the 0.25- and 0.50-mm undercut areas of the abutments. No significant changes in the retentive force were found in titanium-nickel clasps in the 1,010 repeated cycles, whereas the other three types of clasp revealed a significant decrease in the force required for removal during the test procedures (repeated analysis of variance P < 0.001). The results suggest that the cast titanium-nickel clasp may be suitable in removable prosthodontic constructions because of its significantly less permanent deformation during service. This report also discusses clinical applicability and some current problems with this new application.
authors.affiliation: First Department of Prosthodontics, Faculty of Dentistry, Tokyo Medical and Dental University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kotake
authors.forename: N
authors.initials: N
authors.lastname: Wakabayashi
authors.forename: M
authors.initials: M
authors.lastname: Ai
authors.forename: T
authors.initials: T
authors.lastname: Yoneyama
authors.forename: H
authors.initials: H
authors.lastname: Hamanaka
mesh_terms: D000704:Analysis of Variance; D003442:Crowns; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry*; D003735:Dental Casting Technique; D016734:Dental Clasps / Q000706:statistics & numerical data; D003799:Dental Stress Analysis / Q000379:methods / Q000706:statistics & numerical data; D019544:Equipment Failure Analysis / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D009532:Nickel / Q000737:chemistry*; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium