title: Diametral tensile strength and Vickers hardness of a composite after storage in different solutions.
abstract: This study evaluated the Vickers hardness (VHN) and diametral tensile strength (DTS) of the composite Z100 (3M ESPE) cured with: Quartz-Tungsten-Halogen light curing unit (QTH) (700mW/cm2- 40 s) and Argon laser (1,000mW/cm2- 10 s). Specimens of 2 mm depth and 8 mm diameter were immersed for 30 days at 37 degrees C in different storage means: water, alcohol, acetic acid, propionic acid and dry (control). The DTS (n = 8) was determined with a crosshead speed of 0.5 mm/min. The VHN (n = 8) test was carried out using a 50 g load for 60 s. Statistical analysis was performed by two-way ANOVA and Tukey's test (alpha = 0.05). The relationship between VHN and DTS was observed by Pearson correlation. The light source was not significant in both tests (VHN: P < 0.18; DTS: P < 0.92), but the factor storage showed significance (P < .001). Mechanical properties of the control group were statistically superior to those of the other storage groups (VHN = 102.2; DTS = 42.3 MPa). The alcohol group showed the lowest VHN (93.3) and DTS (33.8 MPa) values, which were similar to values for propionic (VHN = 97.5; DTS = 35.9 MPa) and acetic acids (VHN = 97.8; DTS = 36.1 MPa), but different from that of water (VHN = 102.2; DTS = 42.3 MPa). The relationship between VHN and DTS values presented a positive correlation (r2 = 0.90; P < 0.01).
authors.affiliation: Department of Dental Materials, School of Dentistry, University of São Paulo, São Paulo, Brazil. igorsm@usp.br <igorsm@usp.br>
authors.forename: Igor S
authors.initials: IS
authors.lastname: Medeiros
authors.forename: Maurício N
authors.initials: MN
authors.lastname: Gomes
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Loguercio
authors.forename: Leonardo E R
authors.initials: LE
authors.lastname: Filho
mesh_terms: D019342:Acetic Acid; D000704:Analysis of Variance; D003188:Composite Resins / Q000528:radiation effects; D003799:Dental Stress Analysis; D004356:Drug Storage; D000431:Ethanol; D006219:Halogens; D006244:Hardness; D054020:Lasers, Gas; D008027:Light; D008422:Materials Testing; D044367:Phase Transition; D011422:Propionates; D012044:Regression Analysis; D012822:Silicon Dioxide / Q000528:radiation effects; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D014867:Water; D015040:Zirconium / Q000528:radiation effects
chemical_list: D003188:Composite Resins; D006219:Halogens; D011422:Propionates; C083568:Z100 composite resin; D014867:Water; D000431:Ethanol; D012822:Silicon Dioxide; D015040:Zirconium; C029658:propionic acid; D019342:Acetic Acid