title: Effect of Pre-heating on Microtensile Bond Strength of Composite Resin to Dentin.
abstract: OBJECTIVE
  Direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. The purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures.
  
  
  METHODS
  Occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon carbide papers to obtain flat dentin surfaces. The dentin was etched with 37% phosphoric acid and bonded with Adper Single Bond 2 according to the manufacturer's instructions. The specimens were randomly divided into two groups (n=22) according to the composite resin applied: FiltekP60 and Filtek Z250. Each group included three subgroups of composite resin pre-curing temperatures (4°C, 23°C and 37°C). Composite resins were applied to the dentin surfaces in a plastic mold (8mm in diameter and 4mm in length) incrementally and cured. Twenty-two composite-to-dentin hour-glass sticks with one mm(2) cross-sectional area per group were prepared. Microtensile bond strength measurements were made using a universal testing machine at a crosshead speed of one mm/min. For statistical analysis, t-test, one-way and two-way ANOVA were used. The level of significance was set at P<0.05.
  
  
  RESULTS
  Filtek P60 pre-heated at 37ºC had significantly higher microtensile bond strength than Filtek Z250 under the same condition. The microtensile bond strengths were not significantly different at 4ºC, 23ºC and 37ºC subgroups of each composite resin group.
  
  
  CONCLUSIONS
  Filtek P60 and Filtek Z250 did not have significantly different microtensile bond strengths at 4ºC and 23ºC but Filtek P60 had significantly higher microtensile bond strength at 37 ºC. Composite and temperature interactions had significant effects on the bond strength.
authors: Associate Professor, Department of Operative Dentistry, Member of Social Determinants of Oral Health Research Center, Dental School, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Abdolrahim
authors: A
authors: Davari
authors: Associate Professor, Department of Operative Dentistry, Member of Social Determinants of Oral Health Research Center, Dental School, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Alireza
authors: A
authors: Daneshkazemi
authors: Postgraduate Student of Operative Dentistry, Department of Operative Dentistry, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Behnaz
authors: B
authors: Behniafar
authors: Postgraduate Student of Operative Dentistry, Department of Operative Dentistry, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Mahsan
authors: M
authors: Sheshmani
keywords: Composite resin; Filtek P60; Filtek Z250; Microtensile bond strength; Temperatures
references: J Dent Res. 1999 Aug;78(8):1469-76
references: 10439035
references: Dent Mater. 2001 Nov;17 (6):504-11
references: 11567688
references: J Dent Res. 2006 Jan;85(1):38-43
references: 16373678
references: J Prosthodont. 2008 Oct;17(7):550-4
references: 18761576
references: Oper Dent. 2007 Jul-Aug;32(4):363-71
references: 17695609
references: Dent Mater. 2011 Apr;27(4):e51-9
references: 21145580
references: J Esthet Restor Dent. 2006;18(6):340-50; discussion 351
references: 17083439
references: Dent Mater. 2004 Oct;20(8):766-77
references: 15302457
references: Dent Mater. 2004 Jul;20(6):543-53
references: 15134942
references: Braz Dent J. 2009;20(3):205-10
references: 19784465
references: Dent Mater. 2003 Jun;19(4):298-307
references: 12686294
references: J Appl Oral Sci. 2012 May-Jun;20(3):323-8
references: 22858698
references: Dent Mater. 2010 Sep;26(9):908-14
references: 20557926
references: Dent Mater. 2006 Jun;22(6):515-26
references: 16171856
references: Angle Orthod. 2003 Dec;73(6):692-6
references: 14719734
references: Dent Mater. 2003 May;19(3):206-11
references: 12628432
references: J Appl Oral Sci. 2005 Dec;13(4):393-8
references: 20865226
references: J Dent Res. 1988 Jun;67(6):932-7
references: 3170905
references: J Dent Res. 2005 Jul;84(7):663-7
references: 15972598
references: J Biomed Mater Res. 1986 Jan;20(1):121-31
references: 3949822
references: Dent Mater. 1993 Sep;9(5):325-31
references: 7995485
references: Scand J Dent Res. 1982 Dec;90(6):484-9
references: 6218603
references: Braz Dent J. 2006;17(3):186-90
references: 17262122
references: Dent Mater J. 2011;30(3):350-7
references: 21597213