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Stem cell-based therapy ( SC- BT) is emerging as an alternative for endodontic therapies. The interaction between stem cells and scaffolds plays a crucial role in the generation of a 'friendly cell' microenvironment. The aim of this systematic review was to explore techniques applied to regenerate the pulp-dentine complex tissue using SC- BT. An electronic search into the SciVerse Scopus ( SS), ISI Web Science ( IWS) and Entrez PubMed ( EP) using specific keywords was performed. Specific inclusion and exclusion criteria were predetermined. The search yielded papers, out of which full-text papers were included in the final analyses. Data extraction pooled the results in four main topics: (a) influence of the chemical properties of the scaffolds over cell behaviour; (b) influence of the physical characteristics of scaffolds over cell behaviour; (c) strategies applied to improve the stem cell/scaffold interface; and (d) influence of cue microenvironment on stem cell differentiation towards odontoblast-like cells and pulp-like tissue formation. The relationship between the scaffolds, the environment and the growth factors released from dentine are critical for de novo pulp tissue regeneration. The preconditioning of dentine walls with ethylenediaminetetraacetic acid ( EDTA) was imperative for successful pulp-dentine complex regeneration. An analyses of the grouped results revealed that pulp regeneration was an attainable goal. [ABSTRACT FROM AUTHOR]

Conde MCM, Nedel F, Campos VF, Smith AJ, Nör JE, Demarco FF, Tarquinio SB. Odontoblast RNA stability in different temperature-based protocols for tooth storage. International Endodontic Journal, 45, 266-272, 2012. Abstract Aim To evaluate the effect of four tooth storage temperature-based methods on quality of RNA obtained from cells retrieved from human dental pulps and human pre-dentine. Methodology RNA was isolated from dental pulp tissue and from cells retrieved by scraping the pre-dentine of freshly extracted human third molars ( n = 15) using TRIzol® reagent. Teeth were randomly assigned to the following temperature conditions: immediate RNA isolation after tooth extraction, liquid nitrogen (24 h), −80 °C (24 h), 20 °C (24 h) and 4 °C (6 h). RNA integrity was checked by the density of 28S and 18S ribosomal RNA. RT-PCR was used to analyse the expression of odontoblast makers (DSPP, DMP1 and MEPE) and the housekeeping gene GAPDH. Results All experimental conditions evaluated preserved RNA integrity. The three odontoblastic markers were amplified from the pulp tissue and from the cells associated with pre-dentine. Conclusion The four storage options allowed RNA isolation for RT-PCR analysis. These findings may facilitate the use of clinically derived human dental pulp and odontoblasts for endodontic research. [ABSTRACT FROM AUTHOR]

Aim, To compare and contrast two colorimetric assays used for the measurement of proliferation using two dental pulp cell types: dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF). Methodology, Dental pulp stem cells or HDPF were seeded at 0.25 · 104 cells per well in 96-well plates. Cell proliferation was evaluated after 24–72 h. At the end of the experimental period, the sulforhodamine B (SRB) assay or a water-soluble tetrazolium salt (WST-1) assay was performed. Optical densities were determined in a microplatereader (Genius; TECAN). Data were analysed by Student’s t-test (comparison between cell types) and one-way anova followed by Tukey test (time-point intervals). Pearson’ correlation tests were performed to compare the two assays for each cell line. Results, Both assays showed that DPSC had higher proliferation rates than HDPF. A positive significant correlation between the two colorimetric assays tested for both cell types DPSC (Pearson’s correlation coefficient = 0.847; P < 0.05) and HDPF (Pearson’s correlation coefficient = 0.775; P < 0.05). Conclusion, Both tests demonstrated similar trends of cell proliferation, and thus are both appropriate for the evaluation of DPSC and HDPF. The choice of assay is therefore one of the practical applications. SRB stained plates can be dried and stored so may have utility in laboratories where data may require review or when access to analytical equipment is limited. WST-1 assays have the benefit of both ease and speed and may have utility in laboratories requiring either high throughput or rapid analyses. [ABSTRACT FROM AUTHOR]

Aim To investigate the hypothesis that different haemostatic agents could impair the histological response of human pulps capped with calcium hydroxide. Methodology Forty-five third molars scheduled for extraction were selected. Class I cavities with pulp exposures were prepared. Three agents were used to control bleeding: 0.9% saline solution (control, n = 14), 5.25% sodium hypochlorite ( n = 16) and 2% chlorhexidine digluconate ( n = 15). The pulps were dressed with hard-setting calcium hydroxide cement. After 7, 30 or 90 days, teeth were extracted, formalin-fixed and prepared for histochemical techniques. The biological response was categorized using the following criteria: inflammatory response, soft tissue organization, reactionary dentine and reparative dentine. Data were submitted to statistical analysis, using nonparametric Kruskal–Wallis one-way analysis of variance on ranks. Differences amongst groups were detected using Dunn's method. Results The statistical analysis disclosed that whilst inflammatory response decreased over time, reactionary dentine deposition and reparative dentine formation increased in the latter periods of evaluation ( P < 0.05). The three agents had similar performances for all criteria evaluated. The conventional pulp response to calcium hydroxide was observed over time, and complete pulp healing was observed in 88% of the specimens after 90 days. Conclusion The three haemostatic agents did not impair the healing process following pulp exposure and capping with calcium hydroxide at different time intervals investigated. [ABSTRACT FROM AUTHOR]