Masako Fujioka-Kobayashi1, Richard J Miron2, Adrian Lussi3, Reinhard Gruber4, Nicoleta Ilie5, Richard Bengt Price6, Gottfried Schmalz7. 1. Department of Cranio-Maxillofacial Surgery, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, Bern, 3010, Switzerland. 2. Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern, 3010, Switzerland. 3. Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern, 3010, Switzerland. 4. Department of Oral Biology, Dental School, Medical University of Vienna, Sensengasse 2a, Vienna, 1090, Austria. 5. Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr 70, Munich, 80336, Germany. 6. Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, 5981 University Ave., Halifax, Nova Scotia, B3H 4R2, Canada. 7. Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern, 3010, Switzerland; Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, University of Regensburg, Regensburg, 93042, Germany. Electronic address: Gottfried.Schmalz@klinik.uni-regensburg.de.
Abstract
OBJECTIVE: This study investigated the influence of the degree of conversion (DC), resin-based composites (RBC) composition, and the effect of additional violet light from one light curing unit (LCU) on cell attachment/growth, eluate cytotoxicity, and gene expression. METHODS: The effect of different DC of RBCs on human gingival fibroblasts (HGFs) when cultured directly onto cured RBCs, and when exposed afterwards to eluates in cell culture medium was examined. Venus® (RBC-V; Bis-GMA-based) and Venus Pearl® (RBC-P; TCD-DI-HEA and UDMA-based) were cured using a single emission peak (blue) light, Translux Wave®; TW and a dual emission peak (blue-violet) light, Translux 2 Wave®; T2W. To determine the value of the additional violet light from the T2W, exposure times and distances were adjusted to deliver similar radiant exposures (RE) from the blue region of both lights at five different RE levels from 1.5 J/cm² to 28.9 J/cm². RESULTS: Both RBCs light-cured with the T2W at higher REs resulted in higher DC, increased cell adhesion and decreased eluate cytotoxicity. RBC-V induced greater cell adhesion, lower mRNA levels of pro-inflammatory markers, and higher mRNA levels of a proliferation marker than RBC-P. Wettability was the same for both RBCs. Toxicity decreased with increasing number of elution cycles. The initial eluates from RBC-P had a lower toxicity than from RBC-V. SIGNIFICANCE: RBCs cured with T2W (delivering both blue and violet light) at higher RE had greater DCs. The greatest DC and the least cell reactions were observed when the RE was >25 J/cm².
OBJECTIVE: This study investigated the influence of the degree of conversion (DC), resin-based composites (RBC) composition, and the effect of additional violet light from one light curing unit (LCU) on cell attachment/growth, eluate cytotoxicity, and gene expression. METHODS: The effect of different DC of RBCs on human gingival fibroblasts (HGFs) when cultured directly onto cured RBCs, and when exposed afterwards to eluates in cell culture medium was examined. Venus® (RBC-V; Bis-GMA-based) and Venus Pearl® (RBC-P; TCD-DI-HEA and UDMA-based) were cured using a single emission peak (blue) light, Translux Wave®; TW and a dual emission peak (blue-violet) light, Translux 2 Wave®; T2W. To determine the value of the additional violet light from the T2W, exposure times and distances were adjusted to deliver similar radiant exposures (RE) from the blue region of both lights at five different RE levels from 1.5 J/cm² to 28.9 J/cm². RESULTS: Both RBCs light-cured with the T2W at higher REs resulted in higher DC, increased cell adhesion and decreased eluate cytotoxicity. RBC-V induced greater cell adhesion, lower mRNA levels of pro-inflammatory markers, and higher mRNA levels of a proliferation marker than RBC-P. Wettability was the same for both RBCs. Toxicity decreased with increasing number of elution cycles. The initial eluates from RBC-P had a lower toxicity than from RBC-V. SIGNIFICANCE: RBCs cured with T2W (delivering both blue and violet light) at higher RE had greater DCs. The greatest DC and the least cell reactions were observed when the RE was >25 J/cm².