In vitro analysis of the cytotoxicity and the antimicrobial effect of four endodontic sealers

<p>Abstract</p> <p>Introduction</p> <p>The aim of this study was to investigate <it>in vitro </it>the cytotoxicity and antibacterial properties of four different endodontic sealers using human periodontal ligament fibroblast cell proliferation and visual analysis of growth inhibition.</p> <p>Methods</p> <p>A silicone (GuttaFlow), silicate (EndoSequence BC), zinc oxide eugenol (Pulp Canal Sealer EWT) and epoxy resin (AH Plus Jet) based sealer were incubated with PDL fibroblasts (10⁴cells/ml, n = 6) up to 96 h. Cell proliferation (RFU) was determined by means of the Alamar Blue assay. Cell growth and morphology was visualized by means of fluorescent dyes. Possible antibacterial properties of the different sealers were visualized by means of SEM (<it>Enterococcus faecalis; Parvimonas micra</it>).</p> <p>Results</p> <p>Fibroblast proliferation depended on sealer and cultivation time. After 72 and 96 h GuttaFlow and EndoSequence BC showed relatively non-cytotoxic reactions, while Pulp Canal Sealer EWT and AH Plus Jet caused a significant decrease of cell proliferation (p < 0.001). Visualization of cell growth and morphology with various fluorescent dyes supplemented the results. No antibacterial effect of EndoSequence BC to <it>P. micra </it>was found, whereas GuttaFlow showed a weak, Pulp Canal Sealer EWT and AH Plus Jet extensive growth inhibition. Also, no antibacterial effect of GuttaFlow, EndoSequence BC or AH Plus Jet to <it>E. faecalis </it>could be detected.</p> <p>Conclusions</p> <p>These <it>in vitro </it>findings reveal that GuttaFlow and EndoSequence BC can be considered as biocompatible sealing materials. However, prior to their clinical employment, studies regarding their sealing properties also need to be considered.</p

Experimental comparative study of the histotoxicity of poly(lactic-co-glycolic acid) copolymer and poly(lactic-co-glycolic acid)-poly(isoprene) blend

Current treatments of craniosynostosis rely on the application of metal springs for cranial bone deviation. However, those metal springs demand a second surgical procedure for their removal. An attractive alternative would be the substitution of metal for bioresorbable polymers in the composition of the springs. The addition of poly(isoprene), PI, to poly(lactic-co-glycolic acid), PLGA, produces a polymeric blend with partial miscibility and distinct mechanical behavior that may benefit the patient recover. It is necessary to compare the histotoxicity of PLGA/PI to that presented by PLGA. In order to verify the histological behavior of the blend, 46 male Wistar rats (Rattus norvegicus, albino strain) underwent implantation of PLGA or PLGA/PI in the skull and were allocated into subgroups by timing of euthanasia (15, 30, 60, or 90 days). After euthanasia, the skull was removed and the histotoxicity was assessed histopathologically. The PLGA/PI blend showed greater histotoxicity in animals euthanized at 60 days, although in this period the histotoxicity of the PLGA/PI blend was similar to that of the PLGA copolymer at 15 days. Despite the instability of histological response, presented in different periods of observation, the results obtained in long-term show that the material has high potential for studies in craniosynostosis treatment

Evaluation of root canal morphology of human primary mandibular second molars by using cone beam computed tomography

Objectives: The aim of the present study was to investigate the root canal configurations of primary mandibular second molars (PMSMs) using Vertucci classification. Materials and Methods: The root canal types of 228 PMSMs (228 mesial and 228 distal roots) were evaluated. In addition, the relationship between external root morphology and Vertucci classification was investigated. The Chi‑square test or Fisher Exact Chi‑square test was used for the evaluations, and P &lt; 0.05 was considered statistically significant for all tests. Results: The most commonly observed root canal type, which was observed in 228 roots (50%), was Type 4 followed by Type 8 (15.79%), Type 5 (14.47%), Type 1 (9.21%), and Type 3 (6.57%). In 150 mesial roots, the root canal Type 4 was observed whereas the same type was observed in 78 distal roots, and the difference was significant (P &lt; 0.001). In flat roots (82.9%), the most frequently observed root canal type was Type 4 (50.8%) (P &lt; 0.001).Conclusion: Various root canal types were observed in both mesial and distal roots although Type 4 was the most commonly observed. Root canal types showed a  consistent relationship with separated and conical root shapes whereas the flat roots showed different root canal types.Keywords: Primary teeth, root canal, Vertucci classificatio