TY - JOUR
T1 - Monomer conversion, microhardness, internal marginal adaptation, and shrinkage stress of bulk-fill resin composites
AU - Fronza, Bruna Marin
AU - Rueggeberg, Frederick Allen
AU - Braga, Roberto Ruggiero
AU - Mogilevych, Borys
AU - Soares, Luis Eduardo Silva
AU - Martin, Airton Abrahão
AU - Ambrosano, Gláucia
AU - Giannini, Marcelo
N1 - Funding Information:
This study was supported by The State of São Paulo Research Foundation (FAPESP) (No. 2013/05247-4 ). The authors are in debt to Dr. Francisco André Ossamu Tanaka (NAP/MEPA—ESALQ/USP) for scanning electron microscopy support, and to Mr. Marcos Blanco Cangiani for his technical assistance.
Publisher Copyright:
© 2015 Academy of Dental Materials.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - Objective To evaluate degree of conversion (DC), Knoop microhardness (KHN), internal marginal adaptation (IA), and polymerization shrinkage stress (PS) of one conventional and four bulk-fill composites. Methods Bulk-fill composites tested were Surefil SDR (SDR), Filtek Bulk-Fill (FBF), Tetric EvoCeram Bulk-Fill (TEC), and EverX Posterior (EXP). The conventional composite Herculite Classic (HER) was tested using both incremental and bulk-fill insertion techniques. Standardized Class I preparations (4-mm-depth) were made in extracted molars and restored with each product system (N = 5). After 1-week wet storage, restorations were cross-sectioned and DC and KHN were evaluated at four depths (1, 2, 3, and 4 mm) using confocal Raman spectroscopy and KHN techniques, respectively. Epoxy resin replicas of restorations were evaluated using scanning electron microscopy for IA. PS was determined using composite bonded to acrylic rods attached to a universal testing machine (N = 5). Results Within bulk-fill products, only SDR and FBF demonstrated similar DC at all depths, and KHN values did not statistically differ among depths, except for TEC. Neither placement method nor depth affected KHN or DC, except the DC of HER bulk-fill at 4 mm. Incrementally layered HER, and bulk-fills SDR and TEC demonstrated the lowest proportion of internal gaps. Highest and lowest PS values were measured for EXP and TEC, respectively. Significance DC with depth was not uniform among all bulk-fill materials, although no difference in KHN was found. Higher PS correlated positively with higher proportion of interfacial gaps. The incremental technique using conventional composite showed reduced gap formation.
AB - Objective To evaluate degree of conversion (DC), Knoop microhardness (KHN), internal marginal adaptation (IA), and polymerization shrinkage stress (PS) of one conventional and four bulk-fill composites. Methods Bulk-fill composites tested were Surefil SDR (SDR), Filtek Bulk-Fill (FBF), Tetric EvoCeram Bulk-Fill (TEC), and EverX Posterior (EXP). The conventional composite Herculite Classic (HER) was tested using both incremental and bulk-fill insertion techniques. Standardized Class I preparations (4-mm-depth) were made in extracted molars and restored with each product system (N = 5). After 1-week wet storage, restorations were cross-sectioned and DC and KHN were evaluated at four depths (1, 2, 3, and 4 mm) using confocal Raman spectroscopy and KHN techniques, respectively. Epoxy resin replicas of restorations were evaluated using scanning electron microscopy for IA. PS was determined using composite bonded to acrylic rods attached to a universal testing machine (N = 5). Results Within bulk-fill products, only SDR and FBF demonstrated similar DC at all depths, and KHN values did not statistically differ among depths, except for TEC. Neither placement method nor depth affected KHN or DC, except the DC of HER bulk-fill at 4 mm. Incrementally layered HER, and bulk-fills SDR and TEC demonstrated the lowest proportion of internal gaps. Highest and lowest PS values were measured for EXP and TEC, respectively. Significance DC with depth was not uniform among all bulk-fill materials, although no difference in KHN was found. Higher PS correlated positively with higher proportion of interfacial gaps. The incremental technique using conventional composite showed reduced gap formation.
KW - Composite resin
KW - Dental restoration
KW - Gap formation
KW - Hardness
KW - Methacrylate
KW - Polymerization
KW - Stress
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U2 - 10.1016/j.dental.2015.10.001
DO - 10.1016/j.dental.2015.10.001
M3 - Article
C2 - 26608118
AN - SCOPUS:84947578872
SN - 0109-5641
VL - 31
SP - 1542
EP - 1551
JO - Dental Materials
JF - Dental Materials
IS - 12
ER -