Fatigue behaviour of recasted removable partial denture alloys

Background: Clasps undergo fatigue fracture under repeated flexures caused by denture insertion, removal and mastication. Aims & Objectives: The aim of this study was to compare the fatigue behaviour of different generations and different proportions of as cast and recasted alloys used for removable partial denture. Material Methods: A total of 210 specimens were casted and divided into 21 groups each 10 specimens for four different alloy groups. The alloys studied were low gold alloy, medium gold alloy, and palladium alloy and cobalt chromium alloy group. Different proportions used were 100%, 50%, 75% new alloy and alloys were studied up to three generations. One way deflection fatigue test was used. The number of cycles required to fracture each specimen was recorded and subjected to statistical analysis [95% confidence level]. Results: Results revealed invariably decreased fatigue resistance for the alloy groups studied for the second and third generation. Also it is decreasing if the new alloy percentage used was less than 100%. Conclusion; Recasting apart from compromising the biocompatibility, fatigue resistance is also compromised. Key Words: Deflection fatigue test; Noble alloys; Recasting