Format

Send to

Choose Destination
Dent Mater. 2015 Dec;31(12):1542-51. doi: 10.1016/j.dental.2015.10.001. Epub 2015 Nov 20.

Monomer conversion, microhardness, internal marginal adaptation, and shrinkage stress of bulk-fill resin composites.

Author information

1
Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901, Piracicaba 13414-903, SP, Brazil. Electronic address: bruna.fronza@hotmail.com.
2
Department of Oral Rehabilitation, College of Dental Medicine, Georgia Regents University, 1430 John Wesley Gilbert Dr, Augusta, GA 30912, USA. Electronic address: frueggeb@gru.edu.
3
Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, Av. Professor Lineu Prestes, 2227, São Paulo 05508-000, SP, Brazil. Electronic address: rrbraga@usp.br.
4
Institute of Research and Development, University of Paraíba Valley, Av. Shishima Hifumi, 2911, São José dos Campos 12244-000, SP, Brazil. Electronic address: borysmog@gmail.com.
5
Institute of Research and Development, University of Paraíba Valley, Av. Shishima Hifumi, 2911, São José dos Campos 12244-000, SP, Brazil. Electronic address: lesoares@univap.br.
6
Institute of Research and Development, University of Paraíba Valley, Av. Shishima Hifumi, 2911, São José dos Campos 12244-000, SP, Brazil. Electronic address: amartin@univap.br.
7
Department of Statistics, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901, Piracicaba 13414-903, SP, Brazil. Electronic address: glaucia@fop.unicamp.br.
8
Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901, Piracicaba 13414-903, SP, Brazil. Electronic address: giannini@fop.unicamp.br.

Abstract

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 4mm) 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 4mm. 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.

KEYWORDS:

Composite resin; Dental restoration; Gap formation; Hardness; Methacrylate; Polymerization; Stress

PMID:
26608118
DOI:
10.1016/j.dental.2015.10.001
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center