Gingival epithelium attachment to well- or partially cured resin composites

Abstract

Ideal restoration material for caries would allow attachment of gingival epithelia. The attachment of epithelial cells to specimens of the 4 most commercially used well- or partially-cured resin composites, with and without TEGDMA, was assessed. Effects of resin composite on the Ca9-22 gingival epithelial cell-line were assessed by measuring the cytotoxicity, viability and gene expression for attachment, apoptosis, ROS-production, pro-inflammatory cytokines, and matrix metalloproteinases. As controls, cells on tissue culture plastic or bovine tooth enamel specimens were used. Significantly less cell attachment was measured on freshly made resin-composite specimens. Concomitantly, significantly higher cytotoxicity was measured in the presence of freshly made resin-composite specimens. However, after 8 d of leakage, the cell attachment to and cytotoxicity of the resin composite was comparable to bovine tooth enamel. Significantly higher expressions of IL6, MMP2, BCL6 and ITGA4 were measured in cells attached to resin-composite surfaces than controls. There were no significant differences between the results using different conditions of resin composite, with or without TEGDMA and well or partially cured. Less cell attachment and presence of more inflammatory markers were observed on all freshly-made resin-composite surfaces. However, after a leakage period attachment of cells to the resin composite improved to the level of natural tooth materials such as enamel. This indicated that the negative effects of resin composites on epithelial cells might be transient.

<i>In vitro</i> biocompatibility testing of different base materials used for elevation of proximal subgingival margins using human gingival epithelial cells

“…A total of 112 specimens (28 specimens of each restorative material) were prepared in a specially designed mold (6.0 mm diameter × 1.5 mm depth). The specimens were prepared by a standardized method in which the material was pressed into the mold between two glass slides covered with Mylar strips (SS White, Lakewood, NJ, USA) [2]. All the materials were mixed and dispensed in accordance with the manufacturers' instructions.…”

“…Proximal posterior cavities extending below the cement-enamel junction (CEJ) and cavity margins located beneath gingival tissues represent a very common clinical situation [1]. Besides the challenges encountered during restoration of such defects and bonding to dentin/cementum margins [1], the restorative material employed is in direct contact with gingival epithelial tissues, which may result in direct or indirect interactions [2]. In a normal healthy situation, junctional epithelial cells are attached to tooth structure by hemi-desmosomes and form a tight seal between the gingiva and the tooth surface [2,3].…”

“…Besides the challenges encountered during restoration of such defects and bonding to dentin/cementum margins [1], the restorative material employed is in direct contact with gingival epithelial tissues, which may result in direct or indirect interactions [2]. In a normal healthy situation, junctional epithelial cells are attached to tooth structure by hemi-desmosomes and form a tight seal between the gingiva and the tooth surface [2,3]. Consequently, in clinical situations, attachment of gingival epithelial cells to restorative materials placed below the gingiva is desirable for restoring the same seal [2], otherwise, bacterial invasion and colonization may occur, leading to periodontal problems [3].…”

“…In a normal healthy situation, junctional epithelial cells are attached to tooth structure by hemi-desmosomes and form a tight seal between the gingiva and the tooth surface [2,3]. Consequently, in clinical situations, attachment of gingival epithelial cells to restorative materials placed below the gingiva is desirable for restoring the same seal [2], otherwise, bacterial invasion and colonization may occur, leading to periodontal problems [3].…”

“…Therefore, this study evaluated and compared the viability of oral gingival epithelial cells after being in direct contact with four different base materials used for elevation of proximal subgingival margins. The null hypotheses were: (1) the type of material would not significantly affect the viability of oral gingival epithelial cells; (2) there would be no significant difference between the viability of gingival epithelial cells incubated on each material for different periods.…”