title: The effect of disinfecting solutions on bending properties and weight changes of Co-Cr and Ti-6Al-7Nb alloys for dentures.
abstract: We aimed to evaluate the effect of a denture cleanser and NaOCl 5.25% solution on the modulus of elasticity, the ultimate stress, and the weight changes of Co-Cr and Ti-6Al-7Nb alloys. To evaluate the modulus of elasticity and ultimate stress, 24 Co-Cr and 24 Ti-6Al-7Nb castings were fabricated, immersed in Corega Extradent, NaOCl 5.25%, or water in subgroups of six each. Thirty-six castings were produced to evaluate weight changes, 18 Co-Cr and 18 Ti-6Al-7Nb, and immersed in Corega Extradent, NaOCl 5.25%, or water in subgroups of six each. Changes in the modulus of elasticity, ultimate stress, and weight were calculated before and after immersion in the cleanser or NaOCl 5.25% solution for 45 cycles of 10 min each. Two-way analysis of variance ANOVA and Tukey's test at α = 0.05 were used to analyze the data. The modulus of elasticity and the ultimate stress of Co-Cr decreased after immersion in the solutions. The same properties of Ti-6Al-7Nb decreased in NaOCl 5.25% and increased in the other solutions. Weight loss was observed in Co-Cr alloy in both Corega Extradent and NaOCl 5.25%. A weight increase was observed in Co-Cr in water. An increase was observed in Ti-6Al-7Nb in Corega Extradent, NaOCl 5.25%, and water. The highest decrease (P = 0.05) in the modulus of elasticity and ultimate stress in Co-Cr were observed in NaOCl 5.25%, whereas no statistically significant differences (P > 0.05) were observed in Ti-6Al-7Nb in any of the solutions. A statistically significant weight loss (P < 0.05) was observed when Co-Cr was immersed in NaOCl 5.25%, and a statistically significant weight increase (P > 0.05) was observed when Ti-6Al-7Nb was immersed in Corega Extradent. The Co-Cr alloy bending properties after immersion fulfilled ADA Specification No. 14 for satisfactory clinical performance.
authors.affiliation: Department of Biomaterials, Dental School, University of Athens, 2 Thivon Str, 115 27, Athens, Greece. trpapad@dent.uoa.gr.
authors.forename: Triantafillos
authors.initials: T
authors.lastname: Papadopoulos
authors.affiliation: Division of Removable Prosthodontics, Dental School, University of Athens, Athens, Greece.
authors.forename: Gregory
authors.initials: G
authors.lastname: Polyzois
authors.affiliation: Private practice, Kalamata, Greece.
authors.forename: Athena
authors.initials: A
authors.lastname: Tapanli
authors.affiliation: Private practice, Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Frangou
mesh_terms: D002858:Chromium Alloys; D003035:Cobalt; D003722:Dental Alloys / Q000737:chemistry; D019551:Dental Disinfectants; D003799:Dental Stress Analysis; D003820:Denture Cleansers; D003778:Dentures; D055119:Elastic Modulus; D007101:Immersion; D008422:Materials Testing; D018583:Pliability; D012973:Sodium Hypochlorite; D014025:Titanium
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D019551:Dental Disinfectants; D003820:Denture Cleansers; C070282:Ti-6Al-7Nb alloy; D003035:Cobalt; C075333:Extradent; D014025:Titanium; D012973:Sodium Hypochlorite