In vitrocomparison of induction capacity and biomineralization ability of mineral trioxide aggregate and a bioceramic root canal sealer

Outcome of root canal treatment using warm vertical compaction with bioceramic and resin-based sealers: A randomised clinical trial

This study aimed to compare the effect of a bioceramic sealer (iRoot SP) and a resin-based sealer (AH Plus) on the outcome of root canal treatment in a 2-year follow-up. Seventy-six teeth with irreversibly or necrotic pulp were recruited. After instrumentation and disinfection, the root canals were obturated using warm vertical compaction with iRoot SP (n = 43) or AH Plus (n = 33). Patients were followed up by clinical and radiographic examination at 6 12 and 24 months with recall rates of 84.2%, 65.8% and 48.7%, respectively. During each recall session, the success rates were 80%, 85.2% and 85% in the iRoot SP group and 82.8%, 91.3% and 88.2% in the AH Plus group. The success rates of the two groups did not differ significantly (p > 0.05). The bioceramic sealer resulted in a similar clinical performance and success rate to the resin-based sealer in endodontic treatment during a 2-year follow-up.

Conservative management of dens in dente

Dens Invaginatus (DI) or dens in dente is an uncommon anomaly which mostly affects permanent lateral incisors, and it is very rare in molars. This article presents the conservative endodontic management of four different cases of DI and a discussion of the endodontic literature for this malformation. Three upper lateral incisors Type II, IIIa and IIIb, and an upper first molar Type II are shown. The most conservative approach possible was carried out. Three of the cases were obturated using the continuous wave technique. In one of the cases, it was possible to treat only the invagination with MTA and preserve the pulp vitality of the main canal. To make a correct diagnosis and to treat in the most conservative way possible, a DI is necessary to know its classification and use tools such as CBCT and magnification.

In Vitro Study of the Biological and Physical Properties of Dual-Cure Resin-Modified Calcium Silicate-Based Cement

BACKGROUND

The aim of the present study was to compare the biological and mechanical properties of a novel dual-cure, resin-modified calcium silicate material, Theracal PT^® (TP), with those of Theracal LC^® (TL) and Biodentine^TM (BD).

METHODS

The cell counting kit-8 was used on human dental pulp cells to test cell the viability of the three materials. Antibacterial activity of TP, TL, and BD against Enterococcus faecalis was investigated under anaerobic conditions. The ability of the materials to support odontogenic differentiation was studied by examining the relative gene expression of osteocalcin (OCN), osteopontin (OPN), and Collagen I (ColI) using real-time polymerase chain reaction. For mechanical property tests, microhardness was evaluated using the Vickers microhardness (VHN) test, and the bond strength to the resin was evaluated using a shear bond test machine.

RESULTS

There was no significant difference in cell viability between TL and TP after 48 h, and BD showed the highest cell viability, while TP showed the highest antibacterial effect. At the 12-h time point, there was no significant difference in ColI and OCN expression between BD and TP, but TP showed a higher expression of OPN than BD. However, at the 48-h time point, ColI and OCN showed higher levels of expression for BD than for TP and TL. At the same time point, only OPN had a higher diffusion for TP than for BD. TP demonstrated a VHN of approximately 30-35. This value was higher than that of TL and lower than that of BD. In contrast to VHN, the shear bond strength to resin was significantly higher for TL and TP than for BD.

CONCLUSION

TP showed lower biocompatibility than BD but higher OPN expression and antibacterial effects than BD and TL. TP showed higher shear bond strength than BD and higher VHN than TL and BD at the 24-h time point.

Bioactivity Potential of Bioceramic-Based Root Canal Sealers: A Scoping Review

INTRODUCTION

Bioceramic-based root canal sealers are novel materials with a bioactivity potential that stands out compared with conventional root canal sealers. However, the term bioactivity may be overused and is often misunderstood. Hence, the objective of this study was to synthesize and map key concepts related to the bioactivity analysis of bioceramic-based root canal sealers.

METHODS

The present scoping review is reported in accordance with the PRISMA-ScR Statement and is registered in the Open Science Framework. Two blinded reviewers carried out a comprehensive search in six databases up to January 10th, 2022: MEDLINE, Scopus, Embase, Web of Science, Cochrane Library, and Lilacs/BBO. Eligibility was considered for in vitro and in vivo studies that evaluated the bioactivity potential of bioceramic-based root canal sealers.

RESULTS

A total of 53 studies were included in the qualitative synthesis. In vitro bioactivity was evaluated through the mineralization potential, formation of carbonated apatite on the surface, and the gene expression related to proteins involved in the mineralization process. Meanwhile, for in vivo studies, staining techniques associated with immunohistochemical tests were mainly used to detect mineralization on the material-host tissue interface.

CONCLUSIONS

According to the methodology used, the most prevalent methods to assess bioactivity in acellular form were the immersion of the material in Hank's balanced salt solution, followed by surface observation with scanning electron microscopy and energy dispersive X-ray. In cell cultures, the chosen method was usually Alizarin Red staining, followed by the evaluation of alkaline phosphatase enzymatic activity and the use of molecular biology tests.

Clinical outcome of bioceramic sealer iRoot SP extrusion in root canal treatment: a retrospective analysis

Background

During the obturation procedure, sealer extrusion occurs in some cases. iRoot SP is a kind of bioceramic sealer with superior physicochemical and biological properties. This article reports the outcome of iRoot SP extrusion in root canal treatment and the potential factors associated with the outcome.

Methods

Ninety-nine patients and one hundred and eighty-five teeth treated between 2014 and 2020 were included in this retrospective study. All of the cases were filled with a single-cone technique and the iRoot SP sealer. The minimum follow-up visit period was 1 year. The outcome was evaluated by clinical examination and radiographic examination at recall and was classified as healed, healing (success), or not healed (failure).

Results

The overall success rate of all teeth was 96.8%. The success rate of adequately filled teeth was 97.3%, while that of iRoot SP extrusion was 95.8%; the difference was not statistically significant. Factors such as gender, age, tooth position, follow-up visit period, size of periapical lesion, treatment type and extruding sealer amount had no influence on the outcome of iRoot SP extruded teeth.

Conclusions

The results suggested that iRoot SP extrusion has no adverse effect on the outcome of root canal treatment, which may contribute to the endodontic treatment.

Effect of Different Treatment Regimen and Types of Endodontic Sealers on Pain and Periapical Radiographic Changes

INTRODUCTION: The study aims as a pilot study to evaluate the effect of different treatment regimen and different types of endodontic sealers on pain and periapical radiographic changes was studied. MATERIALS AND METHODS: Forty patients in need of an endodontic root canal treatment on anterior teeth were selected and divided into two groups (20 patients each), according to the endodontic treatment protocol (single or multiple visits). Then, each group was subdivided into two subgroups according to sealer used 10 each (AH Plus Jet resin sealer, Total Fill Bioceramic Sealer). To record pain intensity of the patients at different intervals: 1, 2, 3, 7 days, a visual analog scale was used. Furthermore, patients were recalled after 1, 3, 6, 9 months to evaluate periapical radiographic changes. RESULTS: Showed that as regard pain assessment both tested endodontic sealers, as well as single or multiple visits have no statistically significant difference between pain values of patients during all the observation period from immediately post-operative, after 4, 12, 24, 48, 72 h as well as after 7 days (p > 0.05). As regard lamina dura thickness, results showed that with both tested endodontic sealers as well as single or multiple visits, there was no statistically significant difference between lamina dura thickness of patients after 1 month, 3, 6 as well as after 9 months. CONCLUSIONS: Neither number of visits of endodontic treatment nor type of sealer used for obturation affects post-operative pain and thickness of lamina dura.

Effects of iRoot SP on osteogenic differentiation of human stem cells from apical papilla

BACKGROUND

Research shows that nano-bioceramics can modulate the differentiation of dental stem cells. The novel ready-to-use calcium-silicate-based root-canal sealer iRoot SP is widely used in root filling. Accordingly, the aim of this study was to evaluate the effects of iRoot SP on proliferation and osteogenic differentiation in human stem cells from the apical papilla (hSCAPs).

METHODS

hSCAPs were isolated and characterized in vitro, then cultured with various concentrations of iRoot SP extract. Cell proliferation was assessed by CCK-8 assay, and scratch-wound-healing assays were performed to evaluate cell-migration capacity. hSCAPs were then cultured in osteogenic medium supplemented with iRoot SP extracts. Alkaline phosphatase (ALP) activity assay was used to evaluate ALP enzyme levels. Alizarin red staining and cetylpyridinium chloride (CPC) assays were performed to assess calcified-nodule formation and matrix-calcium accumulation of hSCAPs. The mRNA and protein expression levels of the osteogenic markers OCN, OSX, Runx2, and DSPP were determined by qRT-PCR and Western blotting. The data were analyzed using one-way ANOVA and LSD-t tests.

RESULTS

iRoot SP at low concentrations (2, 0.2, and 0.02 mg/mL) is nontoxic to hSCAPs. iRoot SP at concentrations of 0.02 and 0.2 mg/mL significantly increases cell-migration capacity. In terms of osteogenic differentiation, 0.2 mg/mL iRoot SP promotes intracellular ALP activity and the formation of mineralized nodules. Moreover, the expression of osteogenic markers at the mRNA and protein levels are upregulated by iRoot SP.

CONCLUSION

iRoot SP is an effective filling material for periapical bone regeneration.

Calcium Silicate-Based Root Canal Sealers: A Narrative Review and Clinical Perspectives

Over the last two decades, calcium silicate-based materials have grown in popularity. As root canal sealers, these formulations have been extensively investigated and compared with conventional sealers, such as zinc oxide-eugenol and epoxy resin-based sealers, in in vitro studies that showed their promising properties, especially their biocompatibility, antimicrobial properties, and certain bioactivity. However, the consequence of their higher solubility is a matter of debate and still needs to be clarified, because it may affect their long-term sealing ability. Unlike conventional sealers, those sealers are hydraulic, and their setting is conditioned by the presence of humidity. Current evidence reveals that the properties of calcium silicate-based sealers vary depending on their formulation. To date, only a few short-term investigations addressed the clinical outcome of calcium silicate-based root canal sealers. Their use has been showed to be mainly based on practitioners' clinical habits rather than manufacturers' recommendations or available evidence. However, their particular behavior implies modifications of the clinical protocol used for conventional sealers. This narrative review aimed to discuss the properties of calcium silicate-based sealers and their clinical implications, and to propose rational indications for these sealers based on the current knowledge.

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.

Comparison of the Effects of a Bioceramic and Conventional Resin-Based Sealers on Postoperative Pain after Nonsurgical Root Canal Treatment: A Randomized Controlled Clinical Study

Background: This clinical trial aimed to compare the effects of bioceramic sealer and resin-based sealer on the incidence and intensity of postoperative pain. Methods: Patients with anterior teeth or premolars requiring root canal treatment were assigned to group 1 (n = 51). Those with molars requiring treatment were assigned to group 2 (n = 57). In groups 1En and 2En, root canals were obturated with Endoseal MTA using the single-cone technique. In groups 1AH and 2AH, the sealer used was AH Plus with the continuous wave technique. On the day of canal filling, each patient was instructed to indicate their pain intensity over the 7 day postoperative period, at rest and, while biting, using a visual analog scale. Results: There was no significant difference in the incidence or intensity of postoperative pain between the Endoseal MTA and AH Plus groups during the 7 day postoperative period (p > 0.05). Less time was needed to seal the root canals with Endoseal MTA, especially in group 2 (p < 0.05). Conclusions: Endoseal MTA and AH Plus had similar effects on the incidence and intensity of postoperative pain. The obturation time was shorter when using Endoseal MTA compared to AH Plus.

Physicochemical properties and effect of bioceramic root canal filling for primary teeth on osteoblast biology

OBJECTIVE

Bio-C Pulpecto (Bio-CP) was recently developed as the first bioceramic root filling material for primary teeth. To evaluate the physicochemical properties of radiopacity, setting time, pH, cytocompatibility and potential of Bio-CP to induce mineralisation, compared with (1) Calen thickened with zinc oxide (Calen-ZO), and (2) zinc oxide and eugenol (ZOE).

METHODOLOGY

Physicochemical properties were evaluated according to ISO 6876. Saos-2 (human osteoblast-like cell line) exposed to extracts of the materials were subjected to assays of methyl thiazolyl tetrazolium, neutral red, alkaline phosphatase (ALP) activity and mineralised nodule production. The results were analysed using one-way or two-way ANOVA and Tukey's or Bonferroni's post-tests (α=0.05).

RESULTS

All the materials showed radiopacity higher than 3 mm Al. Bio-CP had lower pH than Calen-ZO, but higher pH than ZOE. Calen-ZO and Bio-CP did not set. The setting time for ZOE was 110 min. The cytocompatibility order was Calen-ZO > Bio-CP > ZOE (1:2, 1:4 dilutions) and Calen-ZO > Bio-CP = ZOE (1:12, 1:24 dilutions) and Calen-ZO = Bio-CP > ZOE (1:32 dilution). Bio-CP induced greater ALP activity at 7 days, and greater mineralised nodule production, compared to Calen-ZO (p<0.05). Conclusions Bio-CP showed adequate physicochemical properties, cytocompatibility and potential to induce mineralisation.

Periodontal response to a tricalcium silicate material or resin composite placed in close contact to the supracrestal tissue attachment: a histomorphometric comparative study

OBJECTIVE

Subgingival dental restorations and periodontal health have been studied for many years; however, there is a low histological evidence on the behavior of new materials in the supracrestal tissue attachment. The aim of this study is to analyze the periodontal response when a tricalcium silicate material (TSM) or composite margin restorations is placed to 0.5 mm and 1.5 mm from the bone crest with a histomorphometric analysis in dogs.

METHODS

Nine mongrel dogs were used in this study: four dogs (8 canine teeth) for TSM group, 4 dogs (8 canine teeth) for composite group, and 1 dog (2 canine teeth) with cavities without restorations. Cavity preparation of 2×2×1 mm was created on the buccal aspect of the canines at 0.5 and 1.5 mm of the crestal bone. Cavities were restored with composite and TSM or were left unrestored as control. After 12 weeks of healing, the dogs were euthanized and blocks containing the tooth and soft tissues were processed.

RESULTS

In all the specimens, the junction epithelium was stablished apical to the tooth preparations. A shorter distance to the bone (0.5 cavity) implies greater apical periodontal migration regardless of the material used. In the TSM groups, the connective tissue height and the distance between bone level and apical margin preparation were greater than those in the composite groups, while the epithelium height was less. However, there were no statistically significant differences comparing TSM and composite groups at either 0.5 mm or 1.5 mm (p > 0.05).

CONCLUSION

Histologic analysis did not show periodontal reattachment to TSM or composite. In both cases, bone crest migrates apically. For that reason, it is recommended to perform composite restorations at the subgingival level whenever the distance to the bone crest is at least 2 mm.

CLINICAL RELEVANCE

Both composite and TSM do not achieve reinsertion of the connective tissue in the biological width.

Synthesis, Characterization, and Antibacterial Evaluation of a Cost-Effective Endodontic Sealer Based on Tricalcium Silicate-White Portland Cement

Mineral trioxide aggregate (MTA) is an ideal yet costly endodontic sealer material. Tricalcium silicate-white Portland cement (TS-WPC) seems to have similar characteristics to those of MTA. This work aims to characterize a modified TS-WPC and evaluate its antibacterial properties as a potential endodontic sealer material. The modified TS-WPC was synthesized from a 4:1 mixture of sterilized Indocement TS-WPC and bismuth trioxide using a simple solution method with 99.9% isopropanol. The mixture was stirred until it was homogenous, centrifuged, and dried. The material was then characterized using infrared spectroscopy, X-ray diffraction, and electron microscopy and subjected to antibacterial evaluation against Enterococcus faecalis using a Mueller-Hinton agar inhibition test. The results showed that the material was characterized by main functional groups of hydroxyls, silicate, bismuth trioxide, and tricalcium silicate, like those of a commercial MTA-based sealer, both tested after hydration. Modified TS-WPC before hydration showed similar powder morphology and size to the commercial one, indicating the ease of manipulation. Both materials exhibited antibacterial activity due to calcium dihydroxide's ability to absorb carbon dioxide, which is essential for the anaerobic E. faecalis, with minimum inhibitory effect and bactericidal concentrations of 12,500 ppm and 25,000 ppm, respectively. The modified TS-WPC has the potential to become a cost-effective alternative endodontic sealer material.

iRoot SP Promotes Osteo/Odontogenesis of Bone Marrow Mesenchymal Stem Cells via Activation of NF-κB and MAPK Signaling Pathways

The regeneration of bone and tooth tissues, and related cellular therapies, has attracted widespread attention. Bone marrow mesenchymal stem cells (BMSCs) are potential candidates for such regeneration. iRoot SP is a premixed bioceramic root canal sealer widely used in clinical settings. However, the effect of iRoot SP on the biological features of BMSCs has not been elucidated. In the present study, we found that 0.2 mg/ml iRoot SP conditioned medium promoted osteo/odontogenic differentiation and enhanced mineralization of BMSCs without affecting the proliferative ability. Mechanistically, the NF-κB and MAPK signaling pathways were activated in SP-treated BMSCs, and differentiation was inhibited when cultured with the specific inhibitor. Taken together, these findings demonstrate that iRoot SP promotes osteo/odontogenic differentiation of BMSCs via the NF-κB and MAPK signaling pathways, which could provide a new theoretical basis for clinical applications of iRoot SP and a new therapeutic target for the regeneration of bone and tooth tissue in the future.

Cytotoxicity and Bioactivity of Mineral Trioxide Aggregate and Bioactive Endodontic Type Cements: A Systematic Review

Background

Knowledge of the cytotoxicity and bioactivity of endodontic materials may assist in understanding their ability to promote dental pulp stem cell activity and pulp healing in primary teeth.

Materials and methods

This systematic review was carried out by searching the electronic databases such as PubMed, Google Scholar, and Cochrane reviews for the articles published between January 2000 and December 2018 using the appropriate MeSH keywords. An independent investigator evaluated the abstracts and titles for possible inclusion, as per the stipulated inclusion and exclusion criteria. The topics considered for extracting data from each study were: cell lineage, cytotoxicity assay used, and type of material tested.

Results

Seven eligible studies were selected for assessing the quality of evidence on the bioactivity of bioactive endodontic cements (BECs) (1 human cell line, 2 animal cell lines, and 4 in vitro, animal, and human studies) and 13 studies were selected for reviewing the quality of evidence on cytotoxicity (7 human cell lines, 4 animal cell lines, and 2 animal model studies). Very limited studies had been conducted on the bioactivity of materials other than mineral trioxide aggregate (MTA). With regards to cytotoxicity, the studies were diverse and most of the studies were based on MTT assay. Mineral trioxide aggregate is the most frequently used as well as studied root-end filling cement, and the literature evidence corroborated its reduced cytotoxicity and enhanced bioavailability.

Conclusion

There was a lack of sufficient evidence to arrive at a consensus on the ideal material with minimal cytotoxicity and optimal bioactivity. More focused human/cell line-based studies are needed on the available root filling materials.

Clinical significance

The present systematic review provides an update on the available literature evidence on the cytotoxicity and bioactivity of various BECs including MTAs and their influence on the different cells with respect to their composition and strength.

How to cite this article

Maru V, Dixit U, Patil RSB, et al. Cytotoxicity and Bioactivity of Mineral Trioxide Aggregate and Bioactive Endodontic Type Cements: A Systematic Review. Int J Clin Pediatr Dent 2021;14(1):30–39.

Calcium silicate-based root canal sealers: a literature review

Epoxy resin-based sealers are currently widely used, and several studies have considered AH Plus to be the gold-standard sealer. However, it still has limitations, including possible mutagenicity, cytotoxicity, inflammatory response, and hydrophobicity. Drawing upon the advantages of mineral trioxide aggregate, calcium silicate-based sealers were introduced with high levels of biocompatibility and hydrophilicity. Because of the hydrophilic environment in root canals, water resorption and solubility of root canal sealers are important factors contributing to their stability. Sealers displaying lower microleakage and stronger push-out bond strength are also needed to endure the dynamic tooth environment. Although the physical properties of calcium silicate-based sealers meet International Organization for Standardization recommendations, and they have consistently reported to be biocompatible, they have not overcome conventional resin-based sealers in actual practice. Therefore, further studies aiming to improve the physical properties of calcium silicate-based sealers are needed.

When to install the endodontic post? First visit with root canal filling versus a separate second visit for post-restoration: A randomized controlled trial

BACKGROUND

The vibrations created by post-space preparation during the first visit for endodontic treatment could have a significant effect on the intensity of post-operative pain than that association with post-space preparation at the second appointment.

OBJECTIVE

The aim of this study was to evaluate the effect of vibrations generated during post-installation, on post-operative pain in endodontically treated teeth.

METHODS

One hundred patients with asymptomatic teeth requiring primary root canal treatment and post-installation were enrolled in this study. Fifty patients underwent endodontic treatment with post-installation at the first visit (group 1), while the remaining 50 patients underwent post-installation at the second visit (group 2). The intensity of post-operative pain in both groups was evaluated 1, 2, 3 days and 1 week after the first visit using the visual analogue scale. The time required to achieve complete pain relief for each patient was also recorded. The patients' age, sex, tooth type, size of the periapical lesion and time required for complete post-operative pain relief for each tooth were recorded.

RESULTS

The pain intensity score was significantly higher in group 1 than group 2 (P < .05). No significant differences were observed in parameters such as sex, tooth type, jaw and size of the periapical lesion (P > .05), whereas age had a significant effect on the post-operative pain scores (P < .05).

CONCLUSION

Vibrations occurring during post-installation on the same visit as that of root canal filling may increase the post-operative pain.

Effect of a novel bioceramic root canal sealer on the angiogenesis-enhancing potential of assorted human odontogenic stem cells compared with principal tricalcium silicate-based cements

Objective:

This study evaluated the angiogenesis-enhancing potential of a tricalcium silicate-based mineral trioxide aggregate (ProRoot MTA), Biodentine, and a novel bioceramic root canal sealer (Well-Root ST) in human dental pulp stem cells (hDPSCs), human periodontal ligament stem cells (hPLSCs), and human tooth germ stem cells (hTGSCs).

Methodology:

Dulbecco's modified Eagle's medium was conditioned for 24 h by exposure to ProRoot MTA, Biodentine, or Well-Root ST specimens (prepared according to the manufacturers’ instructions). The cells were cultured in these conditioned media and their viability was assessed with 3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H tetrazolium (MTS) on days 1, 3, 7, 10, and 14. Angiogenic growth factors [platelet-derived growth factor (PDGF), basic fibroblast growth factor (FGF-2), and vascular endothelial growth factor (VEGF)] were assayed by sandwich enzyme-linked immunosorbent assay (ELISA) on days 1, 7, and 14. Human umbilical vein endothelial cell (HUVEC) migration assays were used to evaluate the vascular effects of the tested materials at 6–8 h. Statistical analyses included Kruskal–Wallis, Mann–Whitney U, and Friedman and Wilcoxon signed rank tests.

Results:

None of tricalcium silicate-based materials were cytotoxic and all induced a similar release of angiogenic growth factors (PDGF, FGF-2, and VEGF) (p>0.05). The best cell viability was observed for hDPSCs (p<0.05) with all tricalcium silicate-based materials at day 14. Tube formation by HUVECs showed a significant increase with all tested materials (p<0.05).

Conclusion:

The tricalcium silicate-based materials showed potential for angiogenic stimulation of all stem cell types and significantly enhanced tube formation by HUVECs.

Histologic Response of Human Pulp and Periapical Tissues to Tricalcium Silicate-based Materials: A Series of Successfully Treated Cases

Pulpal/periapical responses of human teeth that are treated successfully with tricalcium silicate-based materials are extremely difficult to obtain because of the typical unavailability of these teeth for histologic examination. The present case series reports histologic and histobacteriologic findings of 3 human teeth that had undergone pulpotomy, orthograde retreatment, and apicoectomy/root-end filling using tricalcium silicate-based endodontic materials. The teeth were extracted after 34 days, 7 weeks, and 20 months, respectively, because of unusual circumstances. The extracted teeth were processed, paraffin embedded, sectioned, stained with hematoxylin-eosin or the modified Brown and Brenn technique, and examined with light microscopy. The recurrent observation for the 3 cases presented was the absence of inflammatory or foreign body reactions of the host tissues in contact with tricalcium silicate-based materials after different observation periods despite the identification of bacteria in dentinal tubules close to the site of operation. Wound healing was rapid with repair/regeneration of lost tissues with cementum and new bone trabeculae. Although the level of evidence for a case series is low because of the anecdotal nature of the reported episodes, the histologic results reported in the present case series illustrate the highly biocompatible and bioactive nature of the tricalcium silicate-based materials used in treating these cases.

Comparison of the biocompatibility of calcium silicate-based materials to mineral trioxide aggregate: Systematic review

The objective of this systematic review was to evaluate the biocompatibility and interaction of bioceramic materials with animal and human mesenchymal cells in vitro and in vivo and to compare them with mineral trioxide aggregate (MTA). Two independent researchers conducted PubMed/Medline, Web of Science, and Scopus searches to identify studies published in English, without restrictions on year of publication using the following keywords: “root canal sealer,” “root repair material,” “cytotoxicity,” and “bioceramics.” The articles were selected following the PRISMA statement. A total of 1486 titles were identified in the initial search. However, only 18 studies met the inclusion and exclusion criteria. The results showed that bioceramic materials have biological properties similar to those of MTA, including low cytotoxicity as well as promoting cell proliferation and adhesion, low expression of inflammatory cytokines, and reduced pulp inflammation. This systematic review therefore suggests that the choice of repair bioceramic materials or MTA based on biocompatibility should be the professional's decision.

Endodontic management of root perforating internal replacement resorption

This case report presents the management of a case of rarely seen perforating internal replacement resorption using calcium hydroxide (CH) medication and mineral trioxide aggregate (MTA) root canal obturation. A maxillary central incisor of a 20-year-old female was showing a sinus track on the mucosa. Radiographically, an irregularly shaped and perforating internal resorption area was seen at the middle third of the root canal. Appearances of the bone-like fuzzy material were observed inside the resorption site. The apical part of the canal was obliterated. Following 3 months of CH medication, the canal and the perforation were obturated with MTA filling. At 6-year follow-up, the tooth was clinically asymptomatic and showing radiographical appearances of the hard tissue repair, resembling a barrier and periodontal membrane healing around MTA at the perforation site.

Bioactive tri/dicalcium silicate cements for treatment of pulpal and periapical tissues

Over 2500 articles and 200 reviews have been published on the bioactive tri/dicalcium silicate dental materials. The indications have expanded since their introduction in the 1990s from endodontic restorative and pulpal treatments to endodontic sealing and obturation. Bioactive ceramics, based on tri/dicalcium silicate cements, are now an indispensable part of the contemporary dental armamentarium for specialists including endodontists, pediatric dentists, oral surgeons andfor general dentists. This review emphasizes research on how these materials have conformed to international standards for dental materials ranging from biocompatibility (ISO 7405) to conformance as root canal sealers (ISO 6876). Potential future developments of alternative hydraulic materials were included. This review provides accurate materials science information on these important materials. STATEMENT OF SIGNIFICANCE: The broadening indications and the proliferation of tri/dicalcium silicate-based products make this relatively new dental material important for all dentists and biomaterials scientists. Presenting the variations in compositions, properties, indications and clinical performance enable clinicians to choose the material most suitable for their cases. Researchers may expand their bioactive investigations to further validate and improve materials and outcomes.

Response of stem cells from human exfoliated deciduous teeth (SHED) to three bioinductive materials - An in vitro experimental study

Introduction

Stem cells have unmatched capacity and potential for regeneration and when used alone or in combination with scaffolds to replace or repair damaged cells, can differentiate into any mature cell.

Aim

To evaluate the functional differentiation potential of EMD (Enamel Matrix Derivative), MTA (Mineral Trioxide Aggregate) and Biodentine on Stem Cells from Human Exfoliated Deciduous teeth (SHED).

Objective

To determine functional differentiation potential (osteogenic/odontogenic) of various biomaterials on SHED.

Material and method

SHED derived from 5^th linear passage after sub-culturing were treated with EMD, MTA and Biodentine individually and their effect on cell viability was compared and evaluated by MTT (3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) assay for 7 days. Alizarin red S staining was used to assess mineralization potential of these materials by the staining calcium deposits for 14 days. The results were analyzed using One-way ANOVA, Post hoc Tukey’s test for multiple comparisons.

Results

It was observed that EMD imparted the highest cell viability at the end of 7 days (p < 0.001) followed by Biodentine and MTA. Likewise EMD showed highest potential to enhanced mineralization and expression of dentine sialoprotein (p < 0.001) followed by Biodentine and MTA at the end of 14 days (p<0.001).

Conclusion

It can be concluded that all the tested materials are bioinductive to SHED. EMD can be used for various vital pulp therapies as that of Biodentine and MTA with predictable as well as enhanced success rate.

The Effect of Commercially Available Endodontic Cements and Biomaterials on Osteogenic Differentiation of Dental Pulp Pluripotent-Like Stem Cells

The aim of this study is to compare the osteogenic differentiation capacity of the dental pulp pluripotent-like stem cells (DPPSCs) using conditional media pretreated with ProRoot-MTA, Biodentine (BD) or the newly manufactured pure Portland cement Med-PZ (MZ). DPPSCs, isolated from human third molars, are the most relevant cell model to draw conclusions about the role of biomaterials on dental tissue regeneration. Cytotoxicity, alkaline phosphatase (ALP) activity, and calcium deposition analysis were evaluated at different differentiation time points. Gene expression of key osteogenic markers (RUNX2, Collagen I and Osteocalcin) was determined by qRT-PCR analysis. The osteogenic capacity of cells cultured in conditioned media prepared from MZ or MTA cements was comparable. BD conditioned media supported cell proliferation but failed to induce osteogenesis. Relative to controls and other cements, high osteogenic gene expression was observed in cultures pre-treated with the novel endodontic cement MZ. In conclusion, the in vitro behavior of a MZ- endodontic cement was evaluated, showing similar enhanced cell proliferation compared to other commercially available cements but with an enhanced osteogenic capacity with prospective potential as a novel cement for endodontic treatments.

Gypsum-Based Material for Dental Pulp Capping: Effect of Chitosan and BMP-2 on Physical, Mechanical, and Cellular Properties

Effective pulp capping material must be biocompatible and have the ability to induce dentin bridge formation as well as having suitable physical and mechanical properties; however, many current materials do not satisfy the clinical requirements. This study aimed to assess the physical and mechanical properties of gypsum-based chitosan material (Gp-CT) and to evaluate its effects on cellular properties of stem cells from human exfoliated deciduous teeth (SHED). The experimental material was prepared with different concentrations of chitosan (CT) with or without BMP-2. Then, setting time, compressive strength, and pH were determined. In addition, cell viability, alkaline phosphatase (ALP) activity, and cell attachment were assessed. The setting time, compressive strength, and pH obtained were 4.1-6.6 min, 2.63-5.83 MPa, and 6.5-5.7, respectively. The cell viability to gypsum (Gp) with different CT concentrations was similar to that of the control on day 1 but statistically different from that of Gp alone on day 3. The ALP activity of SHED was significantly higher (p < 0.05) in CT- and BMP-2-containing materials than those in the control and Dycal at days 3 and 14. The scanning electron microscopy (SEM) image revealed that flattened cells were distributed across and adhered to the material surface. In conclusion, Gp-CT material shows promise as a potential material for direct pulp capping.

Influence of Nd:YAG laser on the penetration of a bioceramic root canal sealer into dentinal tubules: A confocal analysis

OBJECTIVE

The aim of this in vitro study, is to evaluate the penetration of a bioceramic root canal sealer into dentinal tubules at 3 mm and 5 mm from the apex after Nd:YAG laser irradiation.

METHODS

Forty freshly extracted human mandibular premolars were prepared using Reciproc® and irrigated with 17% ethylenediaminetetraacetic acid (EDTA). Teeth were divided into 4 groups: group 1, obturated with control sealer (AH Plus®); group 2, obturated with bioceramic sealer (Endosequence BC Sealer®); group 3, Nd:YAG laser + control sealer (AH Plus®); and group 4, Nd:YAG laser + bioceramic sealer (Endosequence BC Sealer®). The samples were transversely sectioned 3 mm and 5 mm from the apex and examined using confocal laser scanning microscopy. Two parameters were measured: 1) sealer penetration into dentinal tubules of the root canal and 2) sealer penetration into the perimeter of the root canal walls.

RESULTS

Penetration analysis showed that bioceramic sealer had a higher penetration at depths of 3 and 5 mm than that of the control sealer, regardless of laser use (p <0.05). Perimeter analysis showed that there was no difference between both sealers at a depth of 3 mm (p <0.05), regardless of laser use. At a depth of 5 mm, bioceramic sealer and laser showed a greater perimeter of penetration (p <0.05) than the control sealer.

CONCLUSION

The use of Nd:YAG laser did not compromise the penetration of bioceramic sealer into dentinal tubules of root canals at 3 mm and 5 mm from the apex.

Outcomes of necrotic immature open-apex central incisors treated by MTA apexification using poly(ε-caprolactone) fiber mesh as an apical barrier

BACKGROUND/PURPOSE

Although unset mineral trioxide aggregate (MTA) has some cytotoxicity, MTA is still a biocompatible material suitable for doing apexification. This study assessed the outcomes for 8 necrotic immature open-apex permanent maxillary central incisors treated by MTA apexification using poly(ε-caprolactone) fiber mesh (PCL-FM) as an apical barrier (so-called PCL-FM/MTA apexification) to prevent extrusion of MTA materials into the periapical tissues of open-apex teeth.

METHODS

Eight necrotic immature open-apex permanent maxillary central incisors with the open apices measuring 2.5 mm-3.5 mm in diameter in 8 patients (6 boys and 2 girls; age range, 8-10 years) were first cleaned using ultrasonic activated irrigation with 2.5% sodium hypochlorite solution and then treated by PCL-FM/MTA apexification procedure.

RESULTS

All the 8 permanent maxillary central incisors showed successful outcomes after PCL-FM/MTA apexification procedure. The mean duration for apical hard tissue barrier formation of the 8 incisors was 6.8 ± 0.5 weeks (range 6-7 weeks). The mean increased root length was 1.8 ± 0.7 mm (range 1-3 mm) at 7 weeks and 3.1 ± 0.6 mm (range 2-4 mm) at 3 months. The mean increased dentinal wall thickness at the most apical portion of the root was 1.3 ± 0.5 mm (range 1-2 mm) at 7 weeks and 2.4 ± 0.6 mm (range 1.5-3 mm) at 3 months. None of the teeth treated by PCL-FM/MTA apexification showed tooth discoloration after a follow-up period of 3 months.

CONCLUSION

PCL-FM/MTA apexification is an excellent technique for treatment of necrotic immature open-apex permanent maxillary central incisors.

Influence of iRoot SP and mineral trioxide aggregate on the activation and polarization of macrophages induced by lipopolysaccharide

BACKGROUND

Biomaterials could affect the inflammation reaction and wound healing via the activation and polarization of macrophages. However, the influence of iRoot SP and mineral trioxide aggregate (MTA) on macrophage polarization under inflammatory conditions was not reported although these two root filling materials have been applied extensively in patients undergoing endodontic treatment. Therefore, the present study aimed to explore the mechanism how iRoot SP and MTA affect the cell behavior of RAW 264.7 macrophages when stimulated by lipopolysaccharide (LPS) in vitro.

METHODS

The gene expression of three main related pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) was examined by quantitative real-time polymerase chain reaction (qRT-PCR) in RAW 264.7 macrophages when stimulated by iRoot SP and MTA in the presence of LPS. The protein expression of the M1 and M2 phenotype specific markers, CD11c and CD206, was assessed by immunofluorescence and flow cytometry in RAW 264.7 macrophages.

RESULTS

LPS promoted the expression of IL-1β, TNF-α, and IL-6 in RAW 264.7 macrophages as compared to the control group. Both iRoot SP and MTA were significantly able to enhance the expression of IL-1β, TNF-α, and IL-6 in RAW 264.7 macrophages as compared to LPS group. LPS could increase the expression of CD11c as compared to the control group while iRoot SP and MTA were able to enhance the expression of both CD11c and CD206 as compared to LPS group.

CONCLUSIONS

iRoot SP and MTA could potentially promote the release of pro-inflammatory cytokines in RAW 264.7 macrophages and induce into M1/M2 phenotype when cultured with LPS.

Cytocompatibility of Biodentine and iRoot FS with human periodontal ligament cells: an in vitro study

AIM

To evaluate the cytocompatibility of Biodentine and iRoot FS with human periodontal ligament cells (hPDLCs).

METHODOLOGY

Human periodontal ligament cells were characterized by flow cytometry and immunocytochemical analysis. Human periodontal ligament cell adhesion was assessed by scanning electron microscopy at day 3; proliferation by live/dead assay at days 1, 3 and 7; and osteogenic differentiation by alkaline phosphatase (ALP) activity staining, ALP quantification analysis and qRT-PCR at days 7 and 14. Data were analysed with anova and independent sample t-tests with SPSS 21.0.

RESULTS

Both iRoot FS and Biodentine increased the adhesion of hPDLCs at day 3. Compared to Biodentine, iRoot FS positively increased hPDLC proliferation on days 3 (P = 0.03) and 7 (P = 0.00). Osteogenic marker ALP was observed consistently in all samples, with iRoot FS having significantly higher ALP activity at day 14 (P = 0.00). Compared with Biodentine, iRoot FS significantly increased the mRNA level of ALP, COL1 and Runx2, and OCN increased only on day 14 (P < 0.05).

CONCLUSIONS

iRoot FS had a positive effect on the adhesion, proliferation and biomineralization of hPDLCs compared with Biodentine.

In vitro study of dentinal tubule penetration and filling quality of bioceramic sealer

This study aimed to evaluate the dentinal tubule penetration and filling quality of a bioceramic sealer (iRoot SP). Forty-two roots of extracted adult lower incisors were selected. After instrumentation with Protaper Universal to F3, 40 roots were chosen and randomly divided into 4 groups, as follows: iRoot SP single cone group, iRoot SP warm vertical group, AH Plus single cone group, and AH Plus warm vertical group. Before root canal filling, sealers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope. All samples were sectioned at 2, 4, and 6 mm to apex. Then, the percentages of void areas, gap regions, and segments of sealer that penetrated into dentinal tubules in each section were calculated. Non-parametric test was used for statistical analysis (α = 0.05). We found that filling techniques and types of sealer had no statistically significant effects on the occurrence of voids and gaps. The segments of iRoot SP penetrated into dentinal tubules were statistically more than that of AH Plus in both single cone and warm vertical techniques at 2 mm to apex (P < 0.05). Regardless of the filling technique used, iRoot SP can achieve comparable filling quality and better dentinal tubules penetration than AH Plus. Considering the good bioactivity of iRoot SP, it may help improve the seal of root canal system.

Physico-chemical and Biological Properties of a New Portland Cement-based Root Repair Material

Could conventional endodontic treatment have an impact on oral health-related quality of life? There are still unresolved questions regarding this theme. In order to answer them, a systematic review on the available literature was undertaken to identify the methodological quality of and the risk of bias in all relevant studies. A broad search for articles was conducted, and only articles published before May 2016 were considered for review. The following portals were used: Pubmed, VHL (Medline, SciELO, Lilacs and BBO), Cochrane Library, and Web of Science. The keywords used for the search were ‘quality of life’ and ‘root canal treatment.’ Furthermore, we included MeSH synonyms, related terms and free terms. Articles written in any language were included according to the PICOS approach (population, intervention, comparison, outcome and study design). After application of these eligibility criteria, selected articles were qualified by assessing their methodological quality and potential risk of bias. The initial search identified 302 references. After excluding duplicated abstracts and analysing the titles and abstracts, 6 were selected. One study was added via manual search of the reference lists. From these, 2 were eligible for quality assessment and were classified as being of high methodological quality and as having low risk of bias. Based on these studies, it can be concluded that conventional endodontic treatment improves oral health-related quality of life. However, these results should be interpreted with caution, due to the lack of important methodological details in the included studies. Additional investigations are warranted to provide more evidence on this subject.

Characterization and Differentiation of Stem Cells Isolated from Human Newborn Foreskin Tissue

Circumcision is described as a cultural, medical, and religious process which states surgical removal of the foreskin either partly or fully. Cells isolated from the circumcised tissues are referred as foreskin cells. They have been thought as feeder cell lines for embryonic stem cells. Their fibroblastic properties were also utilized for several experiments. The waste tissues that remain after the circumcision thought to have stem cell properties. Therefore, there have been very few attempts to expose their stem cell properties without turning them into induced pluripotent stem cells. Although stem cell isolation from prepuce and their mesenchymal multilineage differentiation potential have been presented many times in the literature, the current study explored hematopoietical phenotype of newborn foreskin stem cells for the first time. According to the results, human newborn foreskin stem cells (hnFSSCs) were identified by their capability to turn into all three germ layer cell types under in vitro conditions. In addition, these cells have exhibited a stable phenotype and have remained as a monolayer in vitro. hnFSSCs suggested to carry different treatment potentials for bone damages, cartilage problems, nerve damages, lesion formations, and other diseases that are derive from mesodermal, endodermal, and ectodermal origins. Owing to the location of the tissue in the body and differentiation capabilities of hnFSSCs, these cells can be considered as easily obtainable and utilizable even better than the other stem cell sources. In addition, hnFSSCs offers a great potential for tissue engineering approaches due to exhibiting embryonic stem cell-like characteristics, not having any ethical issues, and teratoma induction as in embryonic stem cell applications.

Effects of tricalcium silicate cements on osteogenic differentiation of human bone marrow-derived mesenchymal stem cells in vitro

Tricalcium silicate cements have been successfully employed in the biomedical field as bioactive bone and dentin substitutes, with widely acclaimed osteoactive properties. This research analyzed the effects of different tricalcium silicate cement formulations on the temporal osteoactivity profile of human bone marrow-derived mesenchymal stem cells (hMW-MSCs). These cells were exposed to four commercially available tricalcium silicate cement formulations in osteogenic differentiation medium. After 1, 3, 7 and 10 days, quantitative real-time polymerase chain reaction and Western blotting were performed to detect expression of the target osteogenic markers ALP, RUNX2, OSX, OPN, MSX2 and OCN. After 3, 7, 14 and 21 days, alkaline phosphatase assay was performed to detect changes in intracellular enzyme level. An Alizarin Red S assay was performed after 28 days to detect extracellular matrix mineralization. In the presence of tricalcium silicate cements, target osteogenic markers were downregulated at the mRNA and protein levels at all time points. Intracellular alkaline phosphatase enzyme levels and extracellular mineralization of the experimental groups were not significantly different from the untreated control. Quantitative polymerase chain reaction results showed increases in downregulation of RUNX2, OSX, MSX2 and OCN with increasing time of exposure to the tricalcium silicate cements, while ALP showed peak downregulation at day 7. For Western blotting, OSX, OPN, MSX2 and OCN showed increased downregulation with increased exposure time to the tested cements. Alkaline phosphatase enzyme levels generally declined after day 7. Based on these results, it is concluded that tricalcium silicate cements do not induce osteogenic differentiation of hBM-MSCs in vitro.

In vitro biocompatibility, inflammatory response, and osteogenic potential of 4 root canal sealers: Sealapex, Sankin apatite root sealer, MTA Fillapex, and iRoot SP root canal sealer

INTRODUCTION

The objective of this study was to compare the cytotoxicity, inflammatory response, osteogenic effect, and the signaling mechanism of these biologic activities of 4 calcium compound-based root canal sealers (ie, Sealapex [Sybron Kerr, WA], apatite root sealer [ARS; Dentsply Sankin, Tokyo, Japan], MTA Fillapex [Angelus Indústria de Produtos Odontológicos S/A, Londrina, PR, Brazil], and iRoot SP [Innovative BioCreamix Inc, Vancouver, Canada]) in human periodontal ligament cells.

METHODS

Cytotoxicity was assessed using the 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Levels of inflammatory mediators were measured by enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction, and Western blot analysis. Osteogenic potential was evaluated by alkaline phosphatase activity, alizarin red staining, and marker genes by reverse-transcription polymerase chain reaction. The signal transduction pathways were examined by Western blotting.

RESULTS

None of the sealers were cytotoxic. ARS, MTA Fillapex, and iRoot SP induced a lower expression of proinflammatory mediators than Sealapex. All sealers increased ALP activity and the formation of mineralized nodules and up-regulated the expression of osteoblastic marker messenger RNA. ARS, MTA Fillapex, and iRoot SP showed superior osteogenic potential compared with Sealapex. The expression and/or activation of integrin receptors and downstream signaling molecules, including focal adhesion kinase, paxillin, Akt, mitogen-activated protein kinase, and nuclear factor κB, was induced by ARS, MTA Fillapex, and iRoot SP treatment but not by Sealapex treatment.

CONCLUSIONS

We show for the first time that ARS, MTA Fillapex, and iRoot SP induce a lower expression of inflammatory mediators and enhance osteoblastic differentiation of PDLCs via the integrin-mediated signaling pathway compared with Sealapex.