Ai Tokue1, Tohru Hayakawa, Chikahiro Ohkubo. 1. Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Japan. tokue-ai@tsurumi-u.ac.jp
Abstract
PURPOSE: The fatigue failure of denture clasps has often been observed in removable partial denture rehabilitation. To increase their fatigue strength, shot peening was evaluated as a surface treatment. In this study, we evaluated the fatigue resistance and retention of cast clasps by using a shot peening treatment. METHODS: A cobalt-chromium (Co-Cr) alloy, commercial pure titanium (CP Ti), silver-palladium-gold (Ag-Pd-Au), and a gold-platinum (Au-Pt) alloy were cast and then treated with shot peening. The retentive forces of the clasps were measured up to a repetition of 10,000insertion/removal cycles in distilled water at 37°C. A fatigue test was also performed using a 15-mm cantilever. Specimens were loaded with a constant deflection of 2.0mm with 20Hz. A shot peening treatment indicated a better stability of retentive forces than that without shot peening. The retentive force of Co-Cr clasps without shot peening was remarkably decreased at 500 cycles of insertion/removal repetition. RESULTS: The clasps with a shot peening treatment provided approximately 1.4-3.6 times higher fatigue strengths than those without a shot peening treatment. CONCLUSION: To prevent the fatigue failure of the denture clasps and use the dentures for long term, a shot peening treatment would be recommended.
PURPOSE: The fatigue failure of denture clasps has often been observed in removable partial denture rehabilitation. To increase their fatigue strength, shot peening was evaluated as a surface treatment. In this study, we evaluated the fatigue resistance and retention of cast clasps by using a shot peening treatment. METHODS: A cobalt-chromium (Co-Cr) alloy, commercial pure titanium (CP Ti), silver-palladium-gold (Ag-Pd-Au), and a gold-platinum (Au-Pt) alloy were cast and then treated with shot peening. The retentive forces of the clasps were measured up to a repetition of 10,000insertion/removal cycles in distilled water at 37°C. A fatigue test was also performed using a 15-mm cantilever. Specimens were loaded with a constant deflection of 2.0mm with 20Hz. A shot peening treatment indicated a better stability of retentive forces than that without shot peening. The retentive force of Co-Cr clasps without shot peening was remarkably decreased at 500 cycles of insertion/removal repetition. RESULTS: The clasps with a shot peening treatment provided approximately 1.4-3.6 times higher fatigue strengths than those without a shot peening treatment. CONCLUSION: To prevent the fatigue failure of the denture clasps and use the dentures for long term, a shot peening treatment would be recommended.
Authors: Maria R Reslan; Essam Osman; Lucette Segaan; Mohammad Rayyan; Christelle Joukhadar; Mohamed Fattouh Journal: J Int Soc Prev Community Dent Date: 2021-01-30
Authors: Javier Nino-Barrera; Jose Sanchez-Aleman; Manuel Acosta-Humanez; Luis Gamboa-Martinez; Carlos Cortes-Rodriguez Journal: Sci Rep Date: 2021-06-21 Impact factor: 4.379