dental materials 22 ( 2 0 0 6 ) 1024–1028 available at www.sciencedirect.com journal homepage: www.intl.elsevierhealth.com/journals/dema Effect of temperature on the silane coupling agents when bonding core resin to quartz fiber posts Francesca Monticelli a,* , Manuel Toledano b , Raquel Osorio b , Marco Ferrari a a Department of Restorative Dentistry and Dental Materials, University of Siena, Policlinico Le Scotte, Viale Bracci, 53100 Siena, Italy b Department of Dental Materials, School of Dentistry, University of Granada, Spain article info Article history: Received 21 June 2005 Received in revised form 1 September 2005 Accepted 4 November 2005 Keywords: Fiber posts Core build-up Silane coupling Air-drying Solvent evaporation abstract Objectives. To evaluate the effect of different silane agents and air-drying temperatures on bond strength of translucent quartz fibre posts to composite resin. Methods. The post surface was etched with 10 vol% hydrogen peroxide for 20 min. A two- liquid coupling agent containing 4-methacryolxyethyl trimellitate anhydride (4-META) and -trimethoxysilyil propyl methacrylate (-MPTS) and two pre-hydrolyzed single component silanes containing 3-methacryloxypropyltrimethoxysilane (3-MPS) and glycid-oxi-propyl- trimetil-oxi-silane (GPS), respectively, were used for treating the fiber posts. Two different post-silanization drying temperatures were applied (21 and 38 ◦ C). A dual-cure composite resin (Core Paste XP) was selected to build-up the core around posts, obtaining cylindrical specimens that were serially cut in beams and subsequently loaded in tension (TBS) at a cross-head speed of 1 mm/min until failure. Bond strength data were statistically analyzed by two-way ANOVA and Student–Newman–Keuls tests (˛ = 0.05). Results. Warm air-drying determined significantly higher bond strengths (p < 0.001) for glycid- oxi-propyl-trimetil-oxi-silane (11.6MPa) and 4-methacryolxyethyl trimellitate anhydride/- trimethoxysilyil propyl methacrylate silane (11.7MPa). These two systems exhibited lower bond strengths (6.9 and 8.8MPa, respectively) than 3-methacryloxypropyltrimethoxysilane (11.0 MPa) when dried at 21 ◦ C. No statistical differences were recorded for 3- methacryloxypropyltrimethoxysilane when drying at 21 or 38 ◦ C. Significance. The composition of the silane coupling agent in terms of acidic content, solvent rate or degree of hydrolysis may influence resin/post bond strength when dried at 21 ◦ C. Drying at 38 ◦ C most likely facilitates the evaporation of solvents present in the silane agent, resulting in increased bond strength of the composite resin to the fiber post. © 2005 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. 1. Introduction Several studies suggested the use of silane coupling agents in coating applications to promote adhesion between inorganic surfaces and polymeric molecules [1,2]. Organosilanes have the formula R ′ -Si-(OR) 3 with an organic functional group (R ′ ) and three alkoxy groups (R): the chemi- ∗ Corresponding author. Tel.: +39 0338 4623264; fax: +39 0577233117. E-mail address: francescamonti@hotmail.it (F. Monticelli). cal reaction begins with the hydrolysis of the alkoxide groups (R) into silanols (SiOH) that may condense forming siloxane bonds [2,3]. Many factors (pH, presence of solvents, molecule size, etc.) may exert an influence in the way silane molecules can absorb, condense or interact with the substrate, influencing coupling effectiveness [4,5]. 0109-5641/$ – see front matter © 2005 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.dental.2005.11.024