A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers

Abstract

Objectives To evaluate the biological and physicochemical features of bioactive root canal sealers. Materials and methods Human periodontal ligament fibroblasts (hPDLF) and human osteoblasts (hOB) were exposed to eluates of three bioactive root canal sealers, GuttaFlow® bioseal (GF), BioRoot™ RCS (BR), and TotalFill® BC Sealer (TF), and the epoxy resin–based sealer AH plus® (AH). Cytotoxicity and cellular inflammatory response were evaluated. The osteogenic potential was examined using human mesenchymal stem cells (hMSC). Film thickness, flowability, and pH were assessed. Root canal treatment was performed on human extracted teeth to evaluate the sealers’ tightness towards bacterial penetration. The antibacterial activity against common pathogens in primary root canal infections was tested. Results AH was severely cytotoxic to hPDLF and hOB (p < 0.001). The bioactive sealers were generally less cytotoxic. IL-6 levels in hPDLF were elevated in the presence of AH (p < 0.05). AH and GF suppressed IL-6 production in hOB (p < 0.05). AH and BR stimulated the PGE2 production in hPDLF and hOB (p < 0.05). BR was the only sealer that led to calcium deposits in hMSC (p < 0.05). TF and AH showed the lowest film thickness and the highest flowability. Bacterial tightness was best in teeth filled with AH and BR. All sealers showed similar antimicrobial activity, but the overall antimicrobial efficacy was moderate as the bacteria were reduced by just one log scale (p < 0.05). Conclusions This study revealed favorable in vitro results regarding the biocompatibility of the bioactive root canal sealers. Clinical relevance Bioactive root canal sealers may be a useful alternative to epoxy resin–based sealers.

Cytotoxicity and Mineralization Activity of Calcium Silicate-Based Root Canal Sealers Compared to Conventional Resin-Based Sealer in Human Gingival Fibroblast Cells

“…Correct root canal treatment of teeth with apical periodontitis is done following the complete removal of infected pulp, while root canal preparation is followed by the establishment of apical and coronal seals [ 1 ]. The purpose of root canal obturation as the last stage of endodontic treatment is to create a gap-free environment throughout the entire root canal system to prevent recurrent infection and any communication between the internal space of the root canal and the periapical tissues [ 2 ].…”

“…Still, several drawbacks regarding the biocompatibility of these sealers have been reported, including cytotoxic effects on fibroblasts, potential mutagenic activity, and the induction of severe inflammatory response in bone tissue. Concerns have also been raised that AH may exhibit adverse effects on the adjacent host tissues and delay the periapical healing of teeth with apical periodontitis [ 1 ].…”

Premixed calcium silicate-based root canal sealers have better biological properties than AH Plus: A systematic review and meta-analysis of in vivo animal studies and in vitro laboratory studies

“…[ 13 39 49 ] Forty-one studies included in this systematic review investigated only cell viability. [ 1 2 3 9 10 11 12 14 15 27 28 29 30 31 32 33 34 35 37 38 40 41 43 44 45 46 47 48 50 51 52 53 55 56 57 60 61 62 63 65 ] In addition, four studies that investigated genotoxicity also analyzed cell viability[ 4 54 58 64 ] and one study investigated only genotoxicity. [ 66 ]…”

“…Adequate contact between test materials and cells is essential in biological analyses and can occur in three forms: direct, indirect, and via extracts. [ 67 ] Most studies use extracts for cell viability evaluation,[ 1 2 4 9 10 12 13 14 15 27 29 30 31 32 34 35 36 37 38 39 40 44 45 46 48 49 50 51 52 53 54 56 57 58 60 61 62 63 64 65 ] whereas few employ indirect contact (sealers on insert)[ 3 33 ] or direct contact. [ 11 28 41 43 47 55 ] Monolayer cell cultures are satisfactory for cell viability tests of endodontic materials.…”

“…[ 3 54 ] The divergence among the studies that analyzed cell viability may be explained by the diversity of cells from different sources, as the type of cell can affect the result of the analyses. [ 67 ] Stem cells from the human periodontal ligament are the most frequently used,[ 9 15 37 46 48 52 60 61 64 ] followed by human gingival fibroblasts,[ 2 43 45 53 54 ] fibroblasts from the human periodontal ligament,[ 4 12 14 28 29 ] and rat fibroblasts. [ 34 36 39 63 ]…”