Cytotoxicity and proinflammatory cytokine expression induced by interim resin materials in primary cultured human dental pulp cells.
BACKGROUND
Acrylic resin materials for interim restoration may adversely affect pulp tissue during the polymerization phase.


OBJECTIVE
The purpose of this in vitro study was to determine the cytotoxic and proinflammatory cytokine production effects induced by interim resin materials in primary cultured human dental pulp cells (hDPCs).


METHODS
Five interim resin materials were evaluated: 3 types of chemically activated products, 1 light-activated product, and 1 computer-aided design and computer-aided manufacturing (CAD-CAM) product. After obtaining eluates from interim resin materials that either were in the process of polymerizing or were already polymerized, these extracts were cocultured with hDPCs under serially diluted conditions (50%, 25%, 12.5%, 6.25%, and 3.125%) for 24 hours with positive (1% phenol) and negative (distilled water) controls. A cell viability assay with tetrazolium was used to evaluate toxic effects on the cells, and images of both live and dead cells were captured using confocal microscopy. Proinflammatory cytokine levels were measured using cytokine antibody arrays. All experiments were independently repeated 3 times, and data were analyzed using 1-way ANOVA and post hoc Tukey honest significant differences test (α=.05).


RESULTS
Cell viabilities less than 70% were observed from the eluates of the 3 chemically activated products under the 50% conditions. Among the chemically activated products, the adverse effects were significantly greater with eluates derived from the polymerizing phase compared than those that had already polymerized, as shown by confocal microscopy images of live and dead cells. However, the light-activated and CAD-CAM-fabricated products did not adversely affect the hDPCs. Significantly increased levels of proinflammatory cytokines were not detected in 12.5% of extract from polymerizing compared with distilled water control.


CONCLUSIONS
The 50% eluates derived from chemically activated interim resin during the polymerizing phase were cytotoxic to hDPCs and may adversely affect pulp tissue. Recommendations such as excess washing are necessary during fabrication.
Researcher, Institute of Tissue Regeneration Engineering, Dankook University, Cheonan, Republic of Korea.
Jung-Hwan
JH
Lee
Graduate student, Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
Soo-Kyung
SK
Jun
Assistant Professor, Department of Conservative Dentistry, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
Ho-Jin
HJ
Moon
Professor, Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, Republic of Korea. Electronic address: haelee@dku.edu.
Hae-Hyoung
HH
Lee
D000180:Acrylic Resins / Q000494:pharmacology / Q000633:toxicity*; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D003764:Dental Materials / Q000494:pharmacology / Q000633:toxicity*; D003782:Dental Pulp / Q000166:cytology* / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007249:Inflammation / Q000139:chemically induced*
D000180:Acrylic Resins; D016207:Cytokines; D003764:Dental Materials