Gene expression analysis of conventional and interactive human gingival cell systems exposed to dental composites.
OBJECTIVE
The aim of this study was the detection of putative gene expression-related effects of dental composites in conventional and interactive gingival cell systems.


METHODS
Conventional monoculture (MC) and interactive cell systems (ICS) comprising human gingival fibroblast (HGF) and immortalized human gingival keratinocytes (IHGK) were exposed for 24h and 7 days according to ISO10993-12:2012 manufactured eluates of different composites (Ceram X(®), Filtek™ Supreme XT, Filtek™ Silorane, Fusio™ Liquid Dentin, and Vertise™ Flow). qRT-PCR-based mRNA analysis for biomarkers indicating cell proliferation, differentiation, apoptosis, inflammation, and adhesion was performed. Apoptotic cells were quantified by annexin-V labeling.


RESULTS
Due to low RNA amounts, qPCR could not be performed for Vertise™ Flow and Fusio™ Liquid Dentin at day 7. At 24h, flowables yielded increased transcription for biomarkers of inflammation and apoptosis in IHGK, irrespective of the cell system. HGF cultures displayed lower transcription for cell adhesion markers in both cell systems. Filtek™ Supreme XT showed increased differentiation by elevated filaggrin gene expression in both cell systems for IHGK at day 7, while Filtek™ Silorane and Ceram X(®) yielded elevation of inflammation biomarkers in both cell types. Annexin-V labeling revealed high apoptosis rates for both flowables and Filtek™ Supreme XT for IHGK, while low rates were detected for Filtek™ Silorane and Ceram X(®).


CONCLUSIONS
Among the composites evaluated, exposition of IHGK and HGF in conventional and interactive cell systems demonstrated most pronounced gene expression alterations in response to flowables, coinciding with elevated levels of apoptosis.
Department of Oral Biotechnology, University Medical Center Freiburg, Center of Dental Medicine, Freiburg, Germany.
Simon Daniel
SD
Schulz
Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Center of Dental Medicine, Hugstetter Straße 55, 79106 Freiburg, Germany.
Christopher
C
Rüppell
Department of Oral Biotechnology, University Medical Center Freiburg, Center of Dental Medicine, Freiburg, Germany.
Pascal
P
Tomakidi
Department of Oral Biotechnology, University Medical Center Freiburg, Center of Dental Medicine, Freiburg, Germany.
Thorsten
T
Steinberg
Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Munich, Germany.
Franz-Xaver
FX
Reichl
Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Center of Dental Medicine, Hugstetter Straße 55, 79106 Freiburg, Germany.
Elmar
E
Hellwig
Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Center of Dental Medicine, Hugstetter Straße 55, 79106 Freiburg, Germany. Electronic address: olga.polydorou@uniklinik-freiburg.de.
Olga
O
Polydorou
D017209:Apoptosis; D017220:Dentin-Bonding Agents / Q000633:toxicity*; D005347:Fibroblasts / Q000378:metabolism; D000091344:Filaggrin Proteins; D015870:Gene Expression; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism; D012313:RNA; D062047:Silorane Resins / Q000633:toxicity*
D017220:Dentin-Bonding Agents; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D062047:Silorane Resins; D012313:RNA
Apoptosis; Biocompatibility; Cell morphology; Cell proliferation; Cell viability; Composite; Gene expression