Effects of application method on shrinkage vectors and volumetric shrinkage of bulk-fill composites in class-II restorations

Kaisarly, Dalia; Langenegger, Ruth; Litzenburger, Friederike; Heck, Katrin; El Gezawi, Moataz; Roesch, Peter und Kunzelmann, Karl-Heinz (2022): Effects of application method on shrinkage vectors and volumetric shrinkage of bulk-fill composites in class-II restorations. In: Dental Materials, Bd. 38, Nr. 1: S. 79-93

Abstract

Objectives: Upon initial proximal wall construction, the favorable C-factor of class-II cavities may become unfavorable. This study investigated the application method on bulk-fill resin composite polymerization shrinkage. Methods: Occluso-proximal class-II cavities were prepared in 40 molars and bonded with a self-etch adhesive (Adhese Universal). The study groups varied according to the resin composite application: group-1: bulk application, Tetric EvoCeram Bulk Fill (TBF);group-2: proximal wall construction (TBF) and occlusal cavity filling (TBF);group-3: thin flowable liner layer, Tetric EvoFlow Bulk Fill (TEF) and bulk filling (TBF);group-4: flowable liner (TEF), proximal wall (TBF), occlusal cavity (TBF);and group-5: bulk application, SDR (3 mm) and capping layer (TBF, 1 mm). Each resin composite increment was scanned twice using micro-CT (uncured, cured 40 s) at a resolution of 16 mu m. Shrinkage vectors and volumetric polymerization shrinkage were evaluated and statistically analyzed (one-way ANOVA). SEM images were used to investigate the tooth-restoration interface. Results: Shrinkage vectors differed significantly among the groups and were greatest in gp5-fl/SDR (47.6 mu m), followed by gp1-TBF (23.8 mu m) and least in gp5-fl/SDR+TBF (11.1 mu m). Volumetric shrinkage varied significantly with the use of SDR (gp5-fl/SDR: 2.6%) and TEF (gp4-fl/TEF: 2.5%) to TBF (gp4-fl/TEF+wl/TBF: 0.6%) in the incremental application. Significance: Building a proximal resin composite wall yielded smaller shrinkage vectors than the bulk application. Applying a thin flowable liner decreased the shrinkage vectors, even more when building a proximal wall. A thin flowable liner is recommended when building a proximal resin composite wall. (c) 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0109-5641
• Sprache: Englisch