title: Evaluation of hardness and color stability in the soft lining materials after thermocycling and chemical polishing.
abstract: The aim of this study was to evaluate the Shore A hardness and color stability of two soft lining materials after thermocycling and when chemical polishing was used or omitted. Two acrylic-based soft lining materials were tested: Coe-Soft and Soft Confort, 14 specimens were made for each material. They were distributed in four groups according to the treatment performed. The specimens were thermocycled (1000 cycles) and half of the group submitted to chemical polishing (methyl methacrylate). Shore A hardness was determined and color stability was calculated by means of Commission International de l'Eclairage Lab uniform color scale using a spectrophotometer, the measurements were made immediately after deflasked, chemical polishing and thermocycling. Analysis of variance (ANOVA) and Tukey's tests were performed at p < 0.01. Color changes (deltaE) were observed after thermocycling in both soft lining materials: Soft Confort (10.60) showed significantly higher values than Coe-Soft (4.57). Coe-Soft (26.42) showed higher Shore A hardness values than Soft Confort (19.42). Chemical polishing did not influence in the color stability of both materials; however, influenced in the hardness values of Coe-Soft.
authors: Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University, Brazil. goiato@foa.unesp.br
authors: Marcelo Coelho
authors: MC
authors: Goiato
authors: Rosse Mary
authors: RM
authors: Falcón-Antenucci
authors: Daniela Micheline dos
authors: DM
authors: Santos
authors: Eduardo Piza
authors: EP
authors: Pellizzer
mesh_terms: D003116:Color; D003775:Dental Polishing; D003799:Dental Stress Analysis; D003822:Denture Liners; D006244:Hardness; D006358:Hot Temperature; D008689:Methacrylates
chemical_list: D008689:Methacrylates; C069457:Coe-Soft denture lining material