Confocal Time Lapse Imaging as an Efficient Method for the Cytocompatibility Evaluation of Dental Composites

Abstract

It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The objective of this study was to use 3D CLSM time lapse confocal imaging to assess the in vitro biocompatibility of dental composites. This method provides an accurate and sensitive indication of viable cell rate in contact with dental composite extracts. The ELS extra low shrinkage, a dental composite used for direct restoration, has been taken as example. In vitro assessment was performed on cultured primary human gingival fibroblast cells using Live/Dead staining. Images were obtained with the FV10i confocal biological inverted system and analyzed with the FV10-ASW 3.1 Software. Image analysis showed a very slight cytotoxicity in the presence of the tested composite after 5 hours of time lapse. A slight decrease of cell viability was shown in contact with the tested composite extracts compared to control cells. The findings highlighted the use of 3D CLSM time lapse imaging as a sensitive method to qualitatively and quantitatively evaluate the biocompatibility behavior of dental composites.

Gingival epithelium attachment to well- or partially cured resin composites

“…Cytotoxicity caused by components of resin composite has been researched extensively in the past (Englemann et al, 2001;Geurtsen and Leyhausen, 2001;Goldberg, 2008;Lefebvre et al, 1996;Yoshii, 1997). The extent of the cytotoxic effect is material-, dose-and cell-type dependent (Attik et al, 2013;Geurtsen and Leyhausen, 2001;Quinlan et al, 2002;Salehi et al, 2015;Shafiei et al, 2014). Various components of resin composite can lead to cell-death, as shown in previous studies (Attik et al, 2013;Geurtsen and Leyhausen, 2001;Quinlan et al, 2002;Salehi et al, 2015;Shafiei et al, 2014).…”

“…The use of SEM and confocal microscopy yielded comparable results, indicating that either microscope can be used to assess cell attachment. As suggested by Attik et al (2014), the use of microscopy is an efficient method to evaluate the cyto-compatibility of dental composites. In the current study, the SEM images showed attachment of cells to the surface of resincomposite specimens.…”

“…Beside its toxic effects, TEGDMA also affects the cells' viability (Engelmann et al, 2002;Stanislawski et al, 2003;Stanislawski et al, 2000). Furthermore, studies have shown that epithelial cell attachment to resin composites is significantly reduced, compared to various materials used as controls (Abdulmajeed et al, 2014;Al-Hiyasat et al, 2012;Camp et al, 2003;Hakki et al, 2012;Huang et al, 2002). Increased production of pro-inflammatory cytokines has also been shown for various cells when in contact with different (co-)monomers (Borzangy et al, 2013;Longo et al, 2016;Schmalz et al, 2000).…”

Trends in Tissue Regeneration: Bio-Nanomaterials

“…Confocal imaging is a very useful to imaging technique in biomedical research, offering the ability to visualize different cell structures and their interaction with nanomaterials by using fluorescent dyes, as well allowing the creation of Z-stacks to recreate the three-dimensional architecture. Confocal imaging has been used to analyze the safety of dental nanostructured materials made from methacrylate monomers [37]. Another approach of engineered tissues has been the generation of oral soft and non-soft tissue.…”

Time resolved 3D live-cell imaging on implants

“…A good soft-tissue-implant interface, which is initiated by gingival fibroblasts, is required to form a barrier against bacterial penetration and parallel inhibition of epithelial downgrowth [ 9 , 17 ]. Therefore, many studies in the field of dental implant testing have been conducted using gingival fibroblasts [ 5 – 9 , 17 – 19 ].…”