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Microcomputed Tomography Evaluation of Volumetric Shrinkage of Bulk‐Fill Composites in Class II Cavities
Author(s) -
Algamaiah Hamad,
Sampaio Camila S.,
Rigo Lindiane C.,
Janal Malvin N.,
Giannini Marcelo,
Bonfante Estevam A.,
Coelho Paulo G.,
Reis Andre F.,
Hirata Ronaldo
Publication year - 2016
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/jerd.12275
Subject(s) - shrinkage , materials science , molar , composite material , composite number , resin composite , adhesive , polymerization , curing (chemistry) , significant difference , dentistry , layer (electronics) , medicine , polymer
Purpose This study aimed to quantify polymerization shrinkage of one conventional and three bulk‐fill composites, under bonded and unbonded conditions, in Class II preparations using 3D microcomputed tomography (μCT) and report its location. Materials and Methods Preparations (2.5 mm occlusal depth × 4 mm wide × 4 mm mesial box and 1 mm beyond the CEJ distal box depth) were made in 48 human extracted molars ( n = 6). Four composites were tested, one regular (Vitalescence/VIT) and three bulk‐fill: SureFil SDR Flow (SDR), Tetric EvoCeram Bulk Fill (TET), and Filtek flowable Bulk Fill (FIL). Teeth were divided into four groups according to restorative material used and subdivided into two subgroups, according to the presence of an adhesive system (XP Bond) application (bonded [‐B]) or its absence (unbonded [‐U]). Each tooth was scanned three times: (1) after cavity preparation, (2) before and (3) after composite light‐curing. Acquired μCT images were imported into 2D and 3D software for analysis. Results Significantly different volumetric shrinkage between bonded and unbonded conditions was observed only for TET group ( p < 0.05), unbonded presenting significantly higher volumetric shrinkage. Among the bonded groups, TET‐B presented significantly lower shrinkage than both SDR‐B and FIL‐B but not significantly different from VIT‐B. Generally, shrinkage occurred at occlusal and distal surfaces. Conclusions When applied to bonded Class II cavities, TET exhibited significantly lower volumetric shrinkage compared to the other bulk‐fill composites. However, it also exhibited the highest difference of volumetric shrinkage values between unbonded and bonded cavities. Clinical Significance Volumetric polymerization shrinkage occurred with all composites tested, regardless of material type (conventional or bulk‐fill) or presence or absence of bonding. However, volumetric shrinkage has been reduced or at least maintained when bulk‐fill composites were used compared to a conventional composite resin, which makes them a potential time saving alternative for clinicians. (J Esthet Restor Dent 29:118–127, 2017)