d e n t a l m a t e r i a l s 2 8 ( 2 0 1 2 ) 783–791 Available online at www.sciencedirect.com jo u rn al hom epa ge : www.intl.elsevierhealth.com/journals/dema Setting characteristics of vinyl-polysiloxane interocclusal recording materials Panayiota Hatzi a,∗ , Michail Tzakis b , George Eliades c a Department of Prosthodontics, School of Dentistry, University of Athens, Greece b Department of Orofacial Pain, School of Dentistry, University of Athens, Greece c Department of Biomaterials, School of Dentistry, University of Athens, Greece a r t i c l e i n f o Article history: Received 15 October 2011 Received in revised form 7 March 2012 Accepted 11 April 2012 Keywords: Interocclusal recording materials Vinyl-polysiloxanes Hardness Composition Setting shrinkage Curing efficiency a b s t r a c t Objectives. To investigate the elemental and molecular composition, curing efficiency, setting shrinkage strain and hardness of vinyl-polysiloxane interocclusal recording materials. Methods. The materials tested were Blu-Mousse Classic/BMC, Exabite II NDS/EXB, Futar Scan/FTS, O-Bite/OBT, Occlufast Rock/OFR, R-Si-Line Metalbite/RMB and Stone Bite/STB. Composition was examined by SEM/EDX and micro-ATR FTIR. Curing efficiency (n: 7) was evaluated by micro-ATR FTIR on unset materials and following 3, 5, and 10 min after mixing. Setting shrinkage strain (%S, n: 7) was evaluated by the bonded-disk method as a function of time up to 10 min after mixing and Shore-D hardness measurements (n: 7) were performed at setting time and after 72 h storage at room temperature. Statistical analysis was performed by one-way ANOVA and paired t-tests (a: 0.05). Results. All materials were particle-filled vinyl-polysiloxane composites with different ele- mental composition. C, O and Si were found at highest concentration in all products, whereas Al, Na, Mg, Ti and Ca were additionally detected. Curing efficiency measure- ments ranked the products in three statistically homogeneous groups (OFR, EXB, OBT > FTS, RMB > BMC, STB) at all time intervals, except OFR which at 5 and 10 min was ranked in the second group. In all products, a statistically significant increase in %S max values was found in comparison with %S at setting time. Strain saturation was reached by all materials at dif- ferent time intervals, except from BMC and OBT. Hardness differences were detected among materials for the same time interval and between time intervals per material. Significance. Differences among materials were detected regarding the properties tested, which may imply variations in their clinical performance. © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. 1. Introduction Interocclusal registrations used for mounting models on articulators are partly responsible for the occlusal quality and precision of the final prosthetic restorations. Accurate ∗ Corresponding author at: Department of Prosthodontics, School of Dentistry, University of Athens, 2, Thivon St., 115 27 Athens, Greece. Tel.: +30 6945497740. E-mail address: phatzi@dent.uoa.gr (P. Hatzi). mountings can lead to restorations that require minimal occlusal modifications intraorally and consequent reduction of chairside clinical time [1]. A wide range of materials has been used for interocclusal recordings; from wax to the most current elastomeric materials like vinyl-polysiloxanes. The latter are produced from impression materials by the addition 0109-5641/$ – see front matter © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.dental.2012.04.001