Bruna Marin Fronza1, Frederick Allen Rueggeberg2, Roberto Ruggiero Braga3, Borys Mogilevych4, Luis Eduardo Silva Soares5, Airton Abrahão Martin6, Gláucia Ambrosano7, Marcelo Giannini8. 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.
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.
Authors: Bruna Marin Fronza; Steven Lewis; Parag K Shah; Matthew D Barros; Marcelo Giannini; Jeffrey W Stansbury Journal: Dent Mater Date: 2019-04-16 Impact factor: 5.304
Authors: Márcia de Almeida Durão; Ana Karina Maciel de Andrade; Maria do Carmo Moreira da Silva Santos; Marcos Antônio Japiassú Resende Montes; Gabriela Queiroz de Melo Monteiro Journal: Eur J Dent Date: 2020-11-26