Cytotoxicity of Various Endodontic Materials on Stem Cells of Human Apical Papilla

Comparative evaluation of the effects of three hydraulic calcium silicate cements on odontoblastic differentiation of human dental pulp stem cells: an in vitro study

OBJECTIVE

The study aimed to compare the response of human dental pulp stem cells (hDPSCs) towards three hydraulic calcium silicate cements (HCSCs) by measuring cytotoxicity and expression of dentinogenic genes.

METHODOLOGY

Dental pulps of five impacted mandibular third molars were extirpated as a source for hDPSCs. Next to culturing, hDPSCs were subjected to fluorescence-activated cell sorting after the third passage to validate stemness of the cells. Human DPSCs were exposed to diluted supernatants of OrthoMTA (OMTA), Biodentine (BD) and Calcium-Enriched Mixture (CEM) at concentrations 10, 25, 50 and 100% at the first, third and fifth day of culture. Then, cells were exposed to 10% concentrations supernatant of HCSCs to determine DSPP and DMP1 gene expression, using a quantitative polymerase-chain reaction. Data were analyzed using one-way and three-way ANOVA, followed by Tukey post hoc statistical tests.

RESULTS

Optimal cell proliferation was observed in all groups, regardless of concentration and time-point. HCSC supernatants were non-cytotoxic to hDPSCs at all three time-points, except for 100% Biodentine on day five. On day seven, OMTA group significantly upregulated the expression of DSPP and DMP1 genes. On day 14, expression of DMP1 and DSPP genes were significantly higher in BD and OMTA groups, respectively.

CONCLUSION

Biodentine significantly upregulated DMP1 gene expression over 14 days, whereas CEM was associated with only minimal expression of DSPP and DMP1 .

Assessment of Cytotoxicity and Odontogenic/Osteogenic Differentiation Potential of Nano-Dentine Cement Against Stem Cells from Apical Papilla

OBJECTIVE

Assessment of the cytotoxicity of novel calcium silicate-based cement is imperative in endodontics. This experimental study aimed to assess the cytotoxicity and odontogenic/osteogenic differentiation potential of a new calcium silicate/pectin cement called Nano-dentine against stem cells from the apical papilla (SCAPs).

MATERIALS AND METHODS

In this experimental study, the cement powder was synthesized by the sol-gel technique. Zirconium oxide was added as opacifier and Pectin, a plant-based polymer, and calcium chloride as the liquid to prepare the nano-based dental cement. Thirty-six root canal dentin blocks of human extracted single-canal premolars with 2 mm height, flared with #1, 2 and 3 Gates-Glidden drills were used to prepare the cement specimens. The cement, namely mineral trioxide aggregate (MTA), Biodentine, and the Nano-dentine were mixed according to the manufacturers' instructions and applied to the roots of canal dentin blocks. The cytotoxicity and odontogenic/osteogenic potential of the cement were evaluated by using SCAPs.

RESULTS

SCAPs were characterized by the expression of routine mesenchymal cell markers and differentiation potential to adipocytes, osteoblasts, and chondrocytes. Cement displayed no significant differences in cytotoxicity or calcified nodules formation. Gene expression analysis showed that all three types of cement induced significant down- regulation of COLA1; however, the new cement induced significant up-regulation of RUNX2 and SPP1 compared to the control group and MTA. The new cement also induced significant up-regulation of TGFB1 and inducible nitric oxide synthase (iNOS) compared with Biodentine and MTA.

CONCLUSION

The new Nano-dentin cement has higher odontogenic/osteogenic potential compared to Biodentine and MTA for differentiation of SCAPs to adipocytes, osteoblasts, and chondrocytes.

Evaluation of the Cytotoxicity of Two Types of Triple Antibiotic Paste on Human Permanent Dental Apical Papilla Stem Cells: an in vitroin vitro Study

Statement of the Problem

The use of a new antimicrobial combination in the regenerative endodontic treatment of immature teeth pulp necrosis is a well-known method. Concerns have been raised about the destructive effect of this combination on the stem cells from the apical papilla of permanent human teeth, and there is a study gap.

Purpose

The main objective of the present study was to investigate the cytotoxic effect of modified triple antibiotic paste (mTAP) on stem cells from the apical papilla (SCAPs) of permanent human teeth.

Materials and Method

In this in vitro study, stem cells were removed from the immature teeth. After cultivation and third passage, metronidazole, ciprofloxacin, minocycline, and clindamycin were placed in the cell culture medium alone , paired, and in combinations as triple antibiotic paste (TAP) (metronidazole, ciprofloxacin, and minocycline) and mTAP (metronidazole, ciprofloxacin, clindamycin) with doses of 25, 50, 100, 200, 400μg/ml. After 1 and 3 days, cell viability in the culture medium was assessed using the MTT method ([4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). SPSS software version 24, descriptive statistics methods, and statistical tests such as Kruskal-Wallis and Mann-Whitney tests were adopted to analyze the data.

Results

Analysis of MTT findings indicated that the use of mTAP at 100μg/ml and TAP at 200μg/ml had no adverse cytotoxic effect on stem cells in the first 24 hours, compared to the control group. The cell viability decreased at higher concentrations, although it was not statistically significant. After 72 hours, the toxicity of concentrations higher than 100μg/ml of mTAP and 400 μg/ml of TAP significantly mitigated the percentage of viable cells.

Conclusion

The obtained results demonstrated that the concentration of 100 μg/ml of mTAP could replace TAP in regenerative endodontic treatments at the studied time intervals without worrying about the toxicity.

Cytotoxic Effect of Nano Fast Cement and ProRoot Mineral Trioxide Aggregate on L-929 Fibroblast Cells: an in vitro Study

Statement of the Problem:

Endodontic materials that are placed in direct contact with living tissues should be biocompatible. The cytotoxicity of Nano Fast Cement (NFC) compared to ProRoot Mineral Trioxide Aggregate (ProRoot MTA) must be evaluated.

Purpose:

This In vitro study aimed to assess the cytotoxic effects of NFC in comparison to ProRoot MTA on L-929 mouse fibroblast cells.

Materials and Method:

In this animal study, L-929 mouse fibroblast cells were grown in Dulbecco's Modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS) in an atmosphere of 5% co₂/95% air at 37 C̊. A total of 10⁴ cells from the fourth collection were plated in each well of a 96-well micro-titer plate. Materials were mixed according to the manufacturer’s instruction and placed into the related plastic molds with 5 mm diameter and 3 mm height. After 24 hours and a complete setting, the extracts of the tested materials were produced at six different concentrations and placed in the related wells. Cells in DMEM served as the negative control group. DMEM alone was used as the positive control group. Methyl-thiazoltetrazolium (MTT) colorimetric assay was conducted after 24, 48, and 72 hours. The absorbance values were measured by ELISA plate reader at 540 nm wavelength. Three-way analysis of variance, post-hoc Tukey, LSD, and independent t-test were used for the statistical analyses using SPSS software, version 16.0.

Results:

There was no statically significant difference between MTA and NFC in cell viability values at different concentrations and different time intervals (p= 0.649). Viability values were significantly decreased after 72 hours, but there was no significant difference between the first and second MTT assays (p= 0.987). Cytotoxicity significantly increased at concentrations higher than 6.25 µɡ/ml.

Conclusion:

Cytotoxicity depends on time, concentration, and cement composition. There was no statistically significant difference between NFC and MTA concerning their cytotoxic effects on L-929 mouse fibroblast cells.

Effect of biodentine coated with emdogain on proliferation and differentiation of human stem cells from the apical papilla

BACKGROUND

This study assessed the effect of Biodentine coated with Emdogain (Biodentine/Emdogain) on proliferation and differentiation of human stem cells from the apical papilla (SCAPs). METHODS AND RESULTS: In this in vitro, experimental study, SCAPs were isolated from two immature impacted third molars and cultured. After ensuring the stemness of the cells by assessing the cell surface markers, they were exposed to Biodentine, Emdogain, and Biodentine/Emdogain for 24 and 72 h. The control cells did not receive any intervention. Cell viability was evaluated by the methyl thiazolyl tetrazolium assay. Expression of odontogenic differentiation genes was analyzed by the quantitative reverse transcription polymerase chain reaction. Alkaline phosphatase (ALP) activity was quantified by the respective kit. Data were analyzed by one-way ANOVA, t-test, and Mann-Whitney test (α = 0.05). Cell viability did not change after 24 h of exposure to biomaterials. At 72 h, the viability of the cells exposed to Biodentine and Biodentine/Emdogain decreased compared with the control group. The expression of dentin sialophosphoprotein, dentin matrix protein 1, and bone sialoprotein genes, and ALP activity significantly increased in all three experimental groups, compared with the control group at both 24 and 72 h; this increase was significantly greater in Biodentine/Emdogain group. The number of mineralized nodules significantly increased in all groups after 72 h with a greater rate in Biodentine/Emdogain group.

CONCLUSIONS

All biomaterials increased the differentiation of SCAPs, expression of odontogenic genes, and ALP activity, but Biodentine/Emdogain was significantly more effective for this purpose.

Conservative Management of Periapical Cementoblastoma: A Case Report

As a rare ectomesenchymal neoplasm, benign cementoblastoma comprises less than 6% of all odontogenic tumors. The typical treatment plan involves surgical excision and extraction of the affected tooth. Limited evidence, however, suggests the conservative management of this condition as the best treatment. This article discusses the case of a 32-year-old man who had benign cementoblastoma and underwent conservative treatment. The diagnosis was established based on clinical and radiological features analyses. Root canal therapy was performed on the tooth, followed by enucleation, curettage, apicoectomy, and guided bone regeneration (GBR) 30 days later. After a year of follow-up, there was no recurrence, and the tooth was in healthy conditions. These findings demonstrated that the tooth affected by cementoblastoma can be saved. It was treated conservatively to preserve the patient's oral health and masticatory function.

Regenerative Endodontics Success Factors and their Overall Effectiveness: An Umbrella Review

Introduction

Regenerative endodontics is a developing field of dentistry and aims to recover the physiological and anatomical functions of the tooth for cases of severe dental caries, pulpal pathologies and dental trauma.

Materials and Methods

This umbrella review seeks to discover the scientific evidence on the effectiveness and the factors result in successful regenerative endodontic therapies in teeth with necrotic pulps and with incomplete root development. The study was conducted following the PRISMA Guidelines. There were no restrictions regarding search period. A comprehensive literature search was carried out in EMBASE, LILACS, PubMed, Cochrane, Scopus, and Google Scholar. A quality evaluation was conducted by using AMSTAR-2. A descriptive analysis of the included systematic reviews and meta-analysis were conducted.

Results

Thirteen descriptive systematic reviews and 7 meta-analyses were included. Three articles evidenced low methodological quality according to AMSTAR-2 tool. Overall success rates for the endodontic regeneration procedures ranged from 50% to 98% and the survival rates were between 94% and 100%. Pulp regeneration had a high success rate, evidenced by factors such as the resolution of symptoms, healing, increased root length, dentin thickening and recovery of sensitivity. Follow-up varied from 1 to 48 months for the original studies included in the systematic reviews and meta-analyses.

Conclusions

Endodontic practice offers the clinician a good treatment option in case of necrotic pulp with immature roots such as the endodontic regeneration, that is supported by high and moderate quality scientific literature.

Human Treated Dentin Matrix Hydrogel as a Drug Delivery Scaffold for Regenerative Endodontics

Introduction

The objective of the current study was to develop a human treated dentin matrix (hTDM) hydrogel for use as a scaffold to allow the controlled release of an antimicrobial agent for regenerative endodontics.

Materials and Methods

Human extracted teeth were treated via chemical demineralization using ethylene diamine tetra-acetic acid solution to produce hTDM powder. Fourier transform infrared spectroscopy (FTIR) was conducted to determine the functional groups of hTDM, scanning electron microscopy (SEM) was used to define the morphology/particle size of hTDM, and energy dispersive X-ray analysis was performed to identify the superficial apatite groups. Prepared hTDM powder was added to the amoxicillin-clavulanate mixture with a mass ratio of 1:1. Then, the combination was dripped into a 5% (w/v) calcium chloride solution. Antibiotic release profiles were evaluated for 14 days via high performance liquid chromatography (HPLC). Hydrogel degradation properties were studied for 14 days using 10 mL of phosphate buffered saline (PBS). Encapsulation efficiency was determined by HPLC, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of amoxicillin-clavulanate were determined against Enterococcus faecalis (E. faecalis). The antibacterial activity of amoxicillin-clavulanate against E. faecalis was investigated for 14 days via agar diffusion test. Statistical analysis was performed with the Shapiro-Wilk test (P=0.05).

Results

hTDM showed statistically a significant difference for percentage weight change (P=0.1). The encapsulation efficiencies for hTDM hydrogel with antibiotic and hydrogel with antibiotic was 96.08%±0.02 and 94.62%±0.11, respectively. MIC and MBC values of amoxicillin-clavulanate against E. faecalis were 2.4 µg/mL and 9.6 µg/mL, respectively. The antibacterial activity of antibiotic loaded hTDM hydrogels was significantly greater than loaded hydrogels alone by 31% after 4 days and 100% at 14 days, respectively (P≤0.001).

Conclusions

This in vitro study showed antibiotic-loaded injectable hTDM hydrogel could be an alternative system to transfer antibiotic-based intracanal medicaments for use in regenerative endodontics.

In vitro biocompatibility and bioactivity of calcium silicate‑based bioceramics in endodontics (Review)

Calcium silicate-based bioceramics have been applied in endodontics as advantageous materials for years. In addition to excellent physical and chemical properties, the biocompatibility and bioactivity of calcium silicate-based bioceramics also serve an important role in endodontics according to previous research reports. Firstly, bioceramics affect cellular behavior of cells such as stem cells, osteoblasts, osteoclasts, fibroblasts and immune cells. On the other hand, cell reaction to bioceramics determines the effect of wound healing and tissue repair following bioceramics implantation. The aim of the present review was to provide an overview of calcium silicate-based bioceramics currently applied in endodontics, including mineral trioxide aggregate, Bioaggregate, Biodentine and iRoot, focusing on their in vitro biocompatibility and bioactivity. Understanding their underlying mechanism may help to ensure these materials are applied appropriately in endodontics.

Regeneration of pulp-dentin complex using human stem cells of the apical papilla: in vivo interaction with two bioactive materials

OBJECTIVES

To compare the regenerative properties of human stem cells of the apical papilla (SCAPs) embedded in a platelet-rich plasma (PRP) scaffold, when implanted in vivo using an organotypic model composed of human root segments, with or without the presence of the bioactive cements - ProRoot MTA or Biodentine.

MATERIAL AND METHODS

SCAPs were isolated from third molars with incomplete rhizogenesis and expanded and characterized in vitro using stem cell and surface markers. The pluripotency of these cells was also assessed using adipogenic, chondrogenic, and osteogenic differentiation protocols. SCAPs together with a scaffold of PRP were added to the root segment lumen and the organotypic model implanted on the dorsal region of immunodeficient rats for a period of 4 months.

RESULTS

Presence of SCAPs induced de novo formation of dentin-like and pulp-like tissue. A barrier of either ProRoot MTA or Biodentine did not significantly affect the fraction of sections from roots segments observed to contain deposition of hard material (P > 0.05). However, the area of newly deposited dentin was significantly greater in segments containing a barrier of Biodentine compared with ProRoot MTA (P < 0.001).

CONCLUSIONS AND CLINICAL RELEVANCE

SCAPs offer a viable alternative to other dental stem cells (DSCs) in their regenerative properties when enclosed in the microenvironment of human tooth roots. The present study also suggests that the presence of bioactive materials does not hinder or impede the formation of new hard tissues, but the presence of Biodentine may promote greater mineralized tissue deposition.

Cytotoxicity and Bioactivity of Calcium Silicate-based Cements in a Culture of Stem Cells from the Apical Papilla

Introduction

The present in vitro study evaluated the cytotoxicity and bioactivity of commonly-used calcium silicate-based cements in a culture of stem cells from the apical papilla (SCAPs).

Materials and Methods

NeoMTA Plus (Avalon Biomed), Biodentine^TM (Septodont) and MTA HP Repair (Angelus) cements were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and sulphorhodamine-B (SRB) viability assays. Cells were seeded (1*10⁴ cells mL^-1) in 96-well plates and exposed to 1:4 diluted extract in 24 h and 72 h. For the analysis of bioactivity, alkaline phosphatase (ALP) enzyme activity and Alizarin Red S (AZR) were assessed after 24 h of cell culture in 12-well plates (1*10⁴ cells mL^-1), where cells were exposed to 1:4 diluted extract on days 1 and 7. Minimum Essential Eagle's Medium alpha modification was used as control. ANOVA and Tukey's post hoc test were used to compare the different cements at each experimental time point.

Results

No significant differences were found between the cements and the control specimens on MTT at 24 h and 72 h (P>0.05); however, the calcium silicate-based cement materials showed higher cell viability compared to the control group (P<0.05). In the 24-h SRB, NeoMTA Plus showed lower cell viability than Biodentine^TM and MTA HP Repair (P<0.05), with all groups similar to the control group (P>0.05). Compared to 24-h results, only NeoMTA Plus presented increased cell viability at 72 h (P<0.05). ALP activity was similar across the materials at 1 day (P>0.05). ALP activity was higher for Biodentine^TM when compared to NeoMTA Plus (P<0.05), nevertheless, it was similar to MTA HP Repair and control groups (P>0.05) at 7 days. At 1- and 7-day periods of AZR assay, Biodentine^TM presented higher levels of mineralized nodule formation (P<0.05).

Conclusion

All evaluated calcium silicate-based cements demonstrated cell viability and bioactivity, suggesting that these (bio)materials may be indicated for use in regenerative dentine-pulp complex procedures.

The effects of mineral trioxide aggregate on osteo/odontogenic potential of mesenchymal stem cells: a comprehensive and systematic literature review

The significance of dental materials in dentin-pulp complex tissue engineering is undeniable. The mechanical properties and bioactivity of mineral trioxide aggregate (MTA) make it a promising biomaterial for future stem cell-based endodontic therapies. There are numerous in vitro studies suggesting the low cytotoxicity of MTA towards various types of cells. Moreover, it has been shown that MTA can enhance mesenchymal stem cells' (MSCs) osteo/odontogenic ability. According to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), a literature review was conducted in the Medline, PubMed, and Scopus databases. Among the identified records, the cytotoxicity and osteo/odontoblastic potential of MTA or its extract on stem cells were investigated. Previous studies have discovered the differentiation-inducing potential of MTA on MSCs, providing a background for dentin-pulp complex cell therapies using the MTA, however, animal trials are needed before moving into clinical trials. In conclusion, MTA can be a promising candidate dental biomaterial for futuristic stem cell-based endodontic therapies.

Evaluation of the adhesion of human dental pulp stem cells to different endodontic biomaterials before and after setting

Background. Stem cell-based treatment modalities have been potential strategies for tissue regeneration in many conditions. Several studies have evaluated the biologic properties of DPSCs and their efficacy in the treatment of a variety of diseases. The present study was undertaken to evaluate the adhesion behavior of DPSCs on different endodontic materials before and after setting. Methods. The crowns of the selected teeth were removed, and the root canals were prepared and obturated with gutta-percha and AH26 sealer. A retrograde cavity was prepared at root ends. Different materials were placed in the cavities. Then the samples were attached to the wells with the use of a chemical glue. Dental pulp stem cells were allowed to proliferate to reach a count of 2 million and transferred to -12well plates in association with a culture medium. Finally, the samples attached to the wells were exposed to the stem cells immersed in the culture medium before and after setting. Then adhesion of the stem cells was evaluated using SEM. Results. The SEM results showed cellular adhesion in the samples containing CEM cement both before and after setting. The samples containing MTA Angelus and ProRoot MTA exhibited cellular adhesion before setting, with no cellular adhesion after setting. The samples containing AH26 and MTA Fillapex sealers exhibited cellular adhesion after setting, with no adhesion before setting. The samples containing simvastatin exhibited no cellular adhesion before setting; this material had dissolved in the culture medium after setting evaluation. Conclusion. The results of the present study showed that of all the materials tested, CEM cement had the highest capacity for dental pulp stem cell adhesion.

Proliferation, odontogenic/osteogenic differentiation, and cytokine production by human stem cells of the apical papilla induced by biomaterials: a comparative study

Introduction

Clinical applications of bioactive materials are increasing in biomedical tissue engineering. This study sought to assess the effect of calcium enriched mixture (CEM) cement, Biodentine, mineral trioxide aggregate (MTA), octacalcium phosphate (OCP), and Atlantik on proliferation, odontogenic/osteogenic differentiation, and pro-inflammatory cytokine production by human stem cells of the apical papilla (SCAPs).

Materials and methods

Proliferation of SCAPs treated with different biomaterials was evaluated using trypan blue exclusion test and flow cytometry. Differentiation of cells was evaluated using ALP activity, alizarin red staining, and RT-PCR. The expression of genes of pro-inflammatory cytokines was also evaluated using RT-PCR.

Results

The SCAPs treated with biomaterials showed significantly higher proliferation, increased ALP activity, higher number of calcified nodules, and up-regulation of genes related to odontogenic/osteogenic markers compared to the control group. The expression of pro-inflammatory cytokines increased in all groups compared to the control group.

Conclusion

The tested biomaterials could induce odontogenic/osteogenic differentiation in SCAPs. MTA had a greater potential for induction of differentiation of SCAPs to odontoblast-like cells while OCP had higher potential to induce differentiation of SCAPs to osteoblast-like cells (MTA↔ BD↔ CEM↔ Atlantik↔ OCP).

Characterization of different biodegradable scaffolds in tissue engineering

The aim of the present study was to compare the characteristics of acellular dermal matrix (ADM), small intestinal submucosa (SIS) and Bio‑Gide scaffolds with acellular vascular matrix (ACVM)‑0.25% human‑like collagen I (HLC‑I) scaffold in tissue engineering blood vessels. The ACVM‑0.25% HLC‑I scaffold was prepared and compared with ADM, SIS and Bio‑Gide scaffolds via hematoxylin and eosin (H&E) staining, Masson staining and scanning electron microscope (SEM) observations. Primary human gingival fibroblasts (HGFs) were cultured and identified. Then, the experiment was established via the seeding of HGFs on different scaffolds for 1, 4 and 7 days. The compatibility of four different scaffolds with HGFs was evaluated by H&E staining, SEM observation and Cell Counting Kit‑8 assay. Then, a series of experiments were conducted to evaluate water absorption capacities, mechanical abilities, the ultra‑microstructure and the cytotoxicity of the four scaffolds. The ACVM‑0.25% HLC‑I scaffold was revealed to exhibit the best cell proliferation and good cell architecture. ADM and Bio‑Gide scaffolds exhibited good mechanical stability but cell proliferation was reduced when compared with the ACVM‑0.25% HLC‑I scaffold. In addition, SIS scaffolds exhibited the worst cell proliferation. The ACVM‑0.25% HLC‑I scaffold exhibited the best water absorption, followed by the SIS and Bio‑Gide scaffolds, and then the ADM scaffold. In conclusion, the ACVM‑0.25% HLC‑I scaffold has good mechanical properties as a tissue engineering scaffold and the present results suggest that it has better biological characterization when compared with other scaffold types.

Cytotoxicity of intracanal dressings on apical papilla cells differ upon activation with E. faecalis LTA

Objective

The aim of this study was to investigate the cytotoxic effects of modified triple antibiotic paste and an experimental composition using calcium hydroxide on lipoteichoic acid (LTA)-primed apical papilla cells (APC).

Material and Methods

Human APC were tested for in vitro cytotoxicity of modified Triple Antibiotic Paste (mTAP – Ciprofloxacin, Metronidazole and Cefaclor at 1:1:1) and of a paste of Ciprofloxacin, Metronidazole and Calcium hydroxide (CMC – 1:1:2) and modified CMC (mCMC – 2:2:1) by using MTT assay. The substances were reconstituted in DMEM at 1,000 µg/mL and ¼ serially diluted before being kept in contact with cells for 1, 3, 5 and 7 days. Further, cells were primed with 1 µg/mL of Enterococcus faecalis LTA for 7 days prior to the viability test with 1,000 µg/mL of each substance. Statistical analysis was performed using one-way analysis of variance (ANOVA) and two-way ANOVA respectively followed by Tukey’s post-test. Significance levels were set at p<0.05.

Results

In the first assay, the higher cytotoxic rates were reached by mTAP for all experimental periods. CMC was found toxic for APC at 5 and 7 days, whereas mCMC did not affect the cell viability. Only CMC and mCMC were able to induce some cellular proliferation. In the second assay, when considering the condition with medium only, LTA-primed cells significantly proliferated in comparison to LTA-untreated ones. At this context, mTAP and CMC showed similar cytotoxicity than the observed for LTA-untreated cells, while mCMC was shown cytotoxic at 7 days only for LTA-primed APC. Comparing the medications, mTAP was more cytotoxic than CMC and mCMC.

Conclusion

mTAP showed higher cytotoxicity than CMC and mCMC and the effect of topic antimicrobials might differ when tested against apical papilla cells under physiological or activated conditions.

Biodentine™ material characteristics and clinical applications: a 3 year literature review and update

INTRODUCTION

Biodentine™ has frequently been acknowledged in the literature as a promising material and serves as an important representative of tricalcium silicate based cements used in dentistry.

AIM

To provide an update on the physical and biological properties of Biodentine™ and to compare these properties with those of other tricalcium silicate cements namely, different variants of mineral trioxide aggregate (MTA) such as ProRoot MTA, MTA Angelus, Micro Mega MTA (MM-MTA), Retro MTA, Ortho MTA, MTA Plus, GCMTA, MTA HP and calcium enriched mixture (CEM), Endosequence and Bioaggregate™.

STUDY DESIGN

A comprehensive literature search for publications from November 20, 2013 to November 20, 2016 was performed by two independent reviewers on Medline (PubMed), Embase, Web of Science, CENTRAL (Cochrane), SIGLE, SciELO, Scopus, Lilacs and clinicaltrials.gov. Electronic and hand search was carried out to identify randomised control trials (RCTs), case control studies, case series, case reports, as well as in vitro and animal studies published in the English language.

CONCLUSIONS

The enhanced physical and biologic properties of Biodentine™ could be attributed to the presence of finer particle size, use of zirconium oxide as radiopacifier, purity of tricalcium silicate, absence of dicalcium silicate, and the addition of calcium chloride and hydrosoluble polymer. Furthermore, as Biodentine™ overcomes the major drawbacks of MTA it has great potential to revolutionise the different treatment modalities in paediatric dentistry and endodontics especially after traumatic injuries. Nevertheless, high quality long-term clinical studies are required to facilitate definitive conclusions.

Effect of MTA and CEM on Mineralization-Associated Gene Expression in Stem Cells Derived from Apical Papilla

INTRODUCTION

This study assessed the effect of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement on odontogenic differentiation and mineralization of stem cells.

METHODS AND MATERIALS

After confirmation of stemness and homogeneity of stem cells derived from apical papilla (SCAPs) using flow cytometry, the cells were exposed for 3 weeks to either osteogenic medium (OS) or CEM extract+OS (CEM+OS) or MTA extract in OS (MTA+OS) or DMEM based regular culture media (negative control). Relative expression of alkaline phosphatase (ALP), dentine sialophosphoprotein (DSPP), osteocalcin (OSC), and osterix (SP7) were measured at days 14 and 21 using RT-qPCR method. At the same time points Alizarin Red staining method was used to assess mineralization potential of SCAPS. Gene expression changes analysis were made automatically using REST® software and a P<0.05 was considered significant.

RESULTS

After 2 weeks of exposure, expression of all genes were between 3 and 52 times the expression of GADPH (all were upregulated except SP7 in the control, P<0.05). After 3 weeks, relative expressions of the genes: ALP, SP7, DSPP, and OSC were respectively 275.9, 528.3, 98.4, and 603.7 times the expression of GADPH in the control group (OS). These were respectively 17.405, 29.2, 11.8, and 6.5 in CEM+OS group, and 163.8, 119.7, 102.5, and 723.9 in MTA+OS group. All of these were confirmed as upregulated (P<0.05) except for ALP and OSC of DM+CEM group. After 2 weeks, alizarin red staining showed similar mineralized nodules in OS, MTA+OS, and CEM+OS. In third week, larger nodules were seen in MTA+OS and OS, but not in CEM+OS.

CONCLUSION

After 2 weeks, gene expressions were almost comparable in OS, CEM+OS, and MTA+OS. After 3 weeks, OS and MTA+OS upregulated genes much greater than in 2nd week. However, upregulation in CEM+OS might not increase in 3rd week compared to those in 2nd week.

Effects of Two Calcium Silicate Cements on Transforming Growth Factor-β1 Secretion from Human Dental Pulp Stem Cells

Introduction

The aims of this in vitro study were to evaluate the effects of two calcium silicate based cements, Calcum-enriched Mixture (CEM) and Biodentine on proliferation of human dental pulp stem cells (hDPSCs) and the effects of proposed cements on the secretion of Transforming Growth Factor β1 (TGF-β1).

Methods and materials

The cell cultures of human Dental Pulp Stem Cells (hDPSCs) at passage 3-5 were treated with various dilutions (1/1, 1/2, 1/4, 1/8, 1/16, and 1/32) of CEM and Biodentine extracts to assess the cell proliferation using 3-(4, 5-dimethylthiazol-2-Y1)-2, 5-diphenyltetrazolium brovide (MTT) assay after 48 and 72 h. The amount of TGF-β 1 secretion were estimated after 72 h using an enzyme-linked immunosorbent assay. Data were analyzed using the one-way analysis of variance (ANOVA) followed by the Dunnett's test at the level of significance set at 0.05.

Result

CEM showed the highest rates of cell proliferation compared to Biodentine after 72 h (P<0.05). A greater amount of TGF-β1 was secreted by hDPSCs treated with Biodentine compared to CEM (P<0.05). These differences were statistically significant (P<0.05).

Conclusion

In this in vitro study hDPSCs showed more proliferation capacity with CEM rather than Biodentine and TGF-β1 secretion rate in Biodentine was higher.

The Effect of Three Different Biomaterials on Proliferation and Viability of Human Dental Pulp Stem Cells (In-vitro Study)

BACKGROUND:

Biomaterial cytotoxicity on dental stem cells plays a critical role in managing the regeneration of dental tissue.

AIM:

The aim of the present study was to evaluate the effect of Nano-hydroxy apatite (NHA), Mineral trioxide aggregate (MTA), and Calcium-enriched mixture (CEM) on the proliferation, and viability of human dental pulp stem cells (hDPSCs) isolated from third molar teeth.

METHODS:

Cultured DPSCs were characterized and the tested biomaterials were shaped into cylinders then inserted directly on the DPSCs. Proliferation and viability percentage of DPSCs were evaluated at 1, 3, 5, 7, 9, 11, and 14 days of culture.

RESULTS:

The biomaterials supplemented DPSCs showed a significant initial decrease in cell count and viability percentage at day one. Then, a rise in cell counts and viabilities was noticed after that. There was a decrease in cell counts, and viabilities in the NHA supplemented cells in comparison to other tested biomaterials.

CONCLUSIONS:

All tested biomaterials maintain the proliferation of DPSCs for different durations. NHA showed less proliferative and more cytotoxic effect than other tested materials.

Zeolite-silver-zinc nanoparticles: Biocompatibility and their effect on the compressive strength of mineral trioxide aggregate

BACKGROUND

This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Ze-Ag-Zn) nanoparticles and their effect on the compressive strength of Mineral Trioxide Aggregate (MTA).

MATERIAL AND METHODS

Biocompatibility was evaluated by an MTT assay on the pulmonary adenocarcinoma cells with 0.05, 0.1, 0.25, 0.5, 1 and 5 mg/mL concentrations of Ze-Ag-Zn. For compressive strength test, four groups containing 15 stainless-steel cylinders with an internal diameter of 4 and a height of 6 mm were prepared and MTA (groups 1 and 2) or MTA + 2% Ze-Ag-Zn (groups 3 and 4) were placed in the cylinders. The compressive strength was evaluated using a universal testing machine 4 days after mixing in groups 1 and 3, and 21 days after mixing in groups 2 and 4.

RESULTS

There was no significant difference between cytotoxicity of different concentrations. The highest (52.22±18.92 MPa) and lowest (19.57±5.76 MPa) compressive strength were observed in MTA group after 21 days and in MTA + 2% Ze-Ag-Zn group after four days, respectively. The effect of time and 2% Ze-Ag-Zn on the compressive strength were significant (P<0.05). Mixing MTA with Ze-Ag-Zn significantly reduced and passage of time from day four to 21 significantly increased the compressive strength.

CONCLUSIONS

Mixing MTA with 2% Ze-Ag-Zn had an adverse effect on the compressive strength of MTA, but this combination had no cytotoxic effects. Key words:Compressive strength, Cytotoxicity, Mineral Trioxide Aggregate, Nanoparticle, Zeolite-Silver-Zinc.

Biocompatibility of Mineral Trioxide Aggregate with TiO2 Nanoparticles on Human Gingival Fibroblasts

Background

The New compositions of white mineral trioxide aggregate (WMTA) or use of various additives like nanoparticles might affect MTA’s ideal characteristics This study was performed to evaluate the cytotoxicity of WMTA and WMTA with Titanium dioxide (TiO2) nanoparticles (1% weight ratio) at different storage times after mixing on human gingival fibroblasts (HGFs).

Material and Methods

HGFs were obtained from the attached gingiva of human premolars. HGFs were cultured in Dulbecco’s Modified Eagle medium, supplemented with 10% fetal calf serum, penicillin and streptomycin. The cells were exposed to WMTA (groups 1 and 2) and WMTA+TiO2 (groups 3 and 4). The fifth and sixth groups served as controls. Each group contained 15 wells. After 24h (groups 1, 3 and 5) and 48 h (groups 2, 4 and 6) of exposure, HGF viability was determined by Mosmann’s tetrazolium toxicity (MTT) assay. Statistical analysis of the data was performed by using one-way analysis of variance and Tukey post hoc test, with significance of p < 0.05.

Results

With both materials, the viability of HGFs significantly decrased with increasing the incubation time from 24h to 48 h (P<0.05). There was no significant difference between the materials regarding HGF viability (P>0.05).

Conclusions

Under the limitations of the present study, incorporation of TiO2 nanoparticles into MTA at 1 wt% had no negative effect on its biocompatibility.

Key words:Cytotoxicity, fibroblast, MTA, MTT assay, nanoparticle, TiO2.

Conservative Management of Unset Mineral Trioxide Aggregate Root-End Filling: A Case Report

This case report presents conservative management of unset mineral trioxide aggregate (MTA) after being placed as a root-end filling material following periapical surgery. Periapical surgery was indicated for a maxillary lateral incisor of a 15-year-old male due to persistent exudate and a large periapical lesion. During surgery Angelus MTA was placed as root-end filling. The next session it was noticed that MTA had failed to completely set. In an orthograde approach, calcium-enriched mixture (CEM) cement was used to obturate the root canal space. The patient was followed up for 27 months and did not exhibit any clinical signs and symptoms. Radiographic images showed complete healing of the lesion.