Expression of Mineralization Markers during Pulp Response to Biodentine and Mineral Trioxide Aggregate

Axin2-expressing cells differentiate into reparative odontoblasts via autocrine Wnt/β-catenin signaling in response to tooth damage

In non-growing teeth, such as mouse and human molars, primary odontoblasts are long-lived post-mitotic cells that secrete dentine throughout the life of the tooth. New odontoblast-like cells are only produced in response to a damage or trauma. Little is known about the molecular events that initiate mesenchymal stem cells to proliferate and differentiate into odontoblast-like cells in response to dentine damage. The reparative and regenerative capacity of multiple mammalian tissues depends on the activation of Wnt/β-catenin signaling pathway. In this study, we investigated the molecular role of Wnt/β-catenin signaling pathway in reparative dentinogenesis using an in vivo mouse tooth damage model. We found that Axin2 is rapidly upregulated in response to tooth damage and that these Axin2-expressing cells differentiate into new odontoblast-like cells that secrete reparative dentine. In addition, the Axin2-expressing cells produce a source of Wnt that acts in an autocrine manner to modulate reparative dentinogenesis.

Furcation Perforation: Periradicular Tissue Response to Biodentine as a Repair Material by Histopathologic and Indirect Immunofluorescence Analyses

INTRODUCTION

The purpose of this study was to evaluate the in vivo response of periradicular tissues after sealing of furcation perforations with Biodentine, mineral trioxide aggregate (MTA), and gutta-percha by means of histopathologic and indirect immunofluorescence analyses.

METHODS

Thirty teeth of 3 dogs were divided into 3 groups: Biodentine (n = 14 teeth), MTA (negative control, n = 10 teeth), and gutta-percha (positive control, n = 6 teeth). After endodontic treatment, perforations were made on the center of the pulp chamber floor and filled with the materials. After 120 days, the animals were killed, and blocks containing the teeth and periradicular tissues were processed histotechnically for histopathologic semiquantitative (new mineralized tissue formation and bone resorption at the perforation site) and quantitative (thickness and area of newly formed mineralized tissue and number of inflammatory cells) analyses and RUNX2 immunofluorescence assay. Data were analyzed by χ², Fisher exact test, Mann-Whitney test, one-way analysis of variance, Kruskal-Wallis test, and Dunn posttest (α = 0.05).

RESULTS

MTA and Biodentine induced the formation of significantly more new mineralized tissue (P < .0001) than gutta-percha, which did not induce the formation of mineralized tissue in any case. Complete sealing of the perforations was more frequent with MTA, which formed mineralized tissue with greater thickness and area. Biodentine and MTA exhibited no bone resorption in the furcation region, fewer inflammatory cells, and greater RUNX2 immunostaining intensity than gutta-percha.

CONCLUSIONS

Although MTA presented higher frequency of complete sealing and greater thickness and area of newly formed mineralized tissue, Biodentine also had good histopathologic results and can be considered as an adequate furcation perforation repair material.

Cytotoxicity and Initial Biocompatibility of Endodontic Biomaterials (MTA and Biodentine™) Used as Root-End Filling Materials

Objective. The aim of this study was to evaluate the cytotoxicity and cellular adhesion of Mineral Trioxide Aggregate (MTA) and Biodentine (BD) on periodontal ligament fibroblasts (PDL). Methods. PDL cells were obtained from nonerupted third molars and cultured; MTS cellular profusion test was carried out in two groups: MTA and BD, with respective controls at different time periods. Also, the LIVE/DEAD assay was performed at 24 h. For evaluation of cellular adhesion, immunocytochemistry was conducted to discern the expression of Integrin β1 and Vinculin at 12 h and 24 h. Statistical analysis was performed by the Kruskal-Wallis and Mann-Whitney U tests. Results. MTA and BD exhibited living cells up to 7 days. More expressions of Integrin β1 and Vinculin were demonstrated in the control group, followed by BD and MTA, which also showed cellular loss and morphological changes. There was a significant difference in the experimental groups cultured for 5 and 7 days compared with the control, but there was no significant statistical difference between both cements. Conclusions. Neither material was cytotoxic during the time evaluated. There was an increase of cell adhesion through the expression of focal contacts observed in the case of BD, followed by MTA, but not significantly.

Comparative evaluation of calcium silicate-based dentin substitute (Biodentine®) and calcium hydroxide (pulpdent) in the formation of reactive dentin bridge in regenerative pulpotomy of vital primary teeth: Triple blind, randomized clinical trial

Background:

Considering the biological concerns of calcium hydroxide (CH) as a pulpotomy agent, an alternative silicate based dentin substitute i.e. Biodentine (Ca₃SiO₅) was evaluated clinically and radiographically.

Aims:

To evaluate the effectiveness of dentin substitute (Biodentine) in regenerative pulpotomy of vital primary teeth that would giv a biological base to its use in forming reactive dentin bridge and overcoming the drawbacks of calcium hydroxide.

Material and Methods:

Randomised clinical trial on 40 bilateral carious primary molars in 20 participant children (aged 5-10 years) was carried out by same operator using Ca₃SiO₅(group-1) and CH (group-2) as vital pulpotomy agents. Blinded clinical and radiographic outcomes were observed at 3, 6 and 12 months interval.

Results:

Clinical outcomes of both protocols were analysed using Pearson's chi-square test applied at P < 0.05. Descriptive statistics were expressed as mean increase in dentin bridge formation in mms from two reference points in standardized radiographs using paired ‘t’- test at baseline and 12 months and found to be statistically significant (P < 0.05) in group-1 when compared with group-2.

Conclusion:

Group-1 revealed statistically favourable regenerative potential along with clinical success compared to group 2 thereby sharing both indications and mode of action with CH, but without its drawbacks of physical and clinical properties.