Cytotoxicity and Bioactivity of Dental Pulp-Capping Agents towards Human Tooth-Pulp Cells: A Systematic Review of In-Vitro Studies and Meta-Analysis of Randomized and Controlled Clinical Trials

Alternative Direct Restorative Materials for Dental Amalgam: A Concise Review Based on an FDI Policy Statement

Dental restorative procedures remain a cornerstone of dental practice, and for many decades, dental amalgam was the most frequently employed material. However, its use is declining, mainly driven by its poor aesthetics and by the development of tooth-coloured adhesive materials. Furthermore, the Minamata Convention agreed on a phase-down on the use of dental amalgam. This concise review is based on a FDI Policy Statement which provides guidance on the selection of direct restorative materials as alternatives to amalgam. The Policy Statement was informed by current literature, identified mainly from PubMed and the internet. Ultimately, dental, oral, and patient factors should be considered when choosing the best material for each individual case. Dental factors include the dentition, tooth type, and cavity class and extension; oral aspects comprise caries risk profiles and related risk factors; and patient-related aspects include systemic risks/medical conditions such as allergies towards certain materials as well as compliance. Special protective measures (eg, a no-touch technique, blue light protection) are required when handling resin-based materials, and copious water spray is recommended when adjusting or removing restorative materials. Cost and reimbursement policies may need to be considered when amalgam alternatives are used, and the material recommendation requires the informed consent of the patient. There is no single material which can replace amalgam in all applications; different materials are needed for different situations. The policy statement recommends using a patient-centred rather than purely a material-centred approach. Further research is needed to improve overall material properties, the clinical performance, the impact on the environment, and cost-effectiveness of all alternative materials.

Biocompatibility, bioactivity and immunomodulatory properties of three calcium silicate-based sealers: an in vitro study on hPDLSCs

OBJECTIVES

To assess the biocompatibility, bioactivity, and immunomodulatory properties of three new calcium silicate cement-based sealers: Ceraseal (CS), Totalfill BC Sealer (TFbc) and WellRoot ST (WR-ST) on human periodontal ligament stem cells (hPDLSCs).

MATERIALS AND METHODS

HPDLSCs were isolated from extracted third molars from healthy patients. Eluates (1:1, 1:2, and 1:4 ratio) and sample discs of CS, TFbc and WR-ST after setting were prepared. A series of assays were performed: cell characterization, cell metabolic activity (MTT assay) cell attachment and morphology (SEM assay), cell migration (wound-healing assay), cytoskeleton organization (phaloidin-based assay); IL-6 and IL-8 release (ELISA); differentiation marker expression (RT-qPCR assay), and cell mineralization (Alizarin Red S staining). HPDLSCs cultured in unconditioned (negative control) or osteogenic (positive control) culture media were used as a comparison. Statistical significance was established at p < 0.05.

RESULTS

All the tested sealers exhibited similar results in the cytocompatibility assays (cell metabolic activity, migration, attachment, morphology, and cytoskeleton organization) compared with a negative control group. CS and TFbc exhibited an upregulation of at least one osteo/cementogenic marker compared to the negative and positive control groups. CS and TFbc also showed a significantly higher calcified nodule formation than the negative and positive control groups. Both the marker expression and calcified nodule formation were significantly higher in CS-treated cells than TFbc treated cells. WR-ST exhibited similar results to the control group. CS and TFbc-treated cells exhibited a significant downregulation of IL-6 after 72 h of culture compared to the negative control group (p < 0.05).

CONCLUSION

All the tested sealers exhibited an adequate cytocompatibility. CS significantly enhances cell differentiation by upregulating the expression of key genes associated with bone and cementum formation. Additionally, CS was observed to facilitate the mineralization of the extracellular matrix effectively. In contrast, the effects of TFbc and WR-ST on these processes were less pronounced compared to CS. Furthermore, both CS and TFbc exhibited an anti-inflammatory potential, contributing to their potential therapeutic benefits in regenerative endodontics.

CLINICAL RELEVANCE

This is the first study to compare the biological properties and immunomodulatory potential of Ceraseal, Totalfill BC Sealer, and WellRoot ST. The results act as supporting evidence for their use in root canal treatment.

Exploring vital pulp Therapies: A bibliometric analysis of the most cited articles

Aim

The aim of this study was to identify and analyze the most cited articles on vital pulp therapies.

Methodology

Bibliographical data related to the abstract, citations, keywords, and other relevant information was extracted using different combinations of keywords. Further evaluation and visualization of the selected data were performed with the help of various tools, including MS Excel, Microsoft Word, Google open refine, BibExcel, and VOS viewer. An initial search revealed 91 documents, of which 40 were chosen for further analysis. We used the Kolmogorov-Smirnov test and Spearman correlation coefficient test, and our adopted significance level was p < 0.05.

Results

In total, the articles received 1,905 citations, with six of them receiving at least 100 citations. Among the top 40 articles, the United States of America (10 articles) and Ireland (6 articles) were the countries with the highest number of cited articles. The journals "Journal of Endodontics" (14 articles; 650 citations) and "International Endodontic Journal" (13 articles; 577 citations) published most of the articles among the 50 most cited ones. Duncan H. was the author with the highest number of works cited (11 articles; 339 citations). Of the articles, systematic reviews accounted for 32%, literature reviews for 14%, in vitro experimental studies for 12%, clinical trials for 8%. Among the biomaterials used in vital pulp therapies, mineral trioxide aggregate (MTA) was discussed in 37 articles (74%), followed by calcium hydroxide, mentioned in 30 studies (60%). Interestingly, the publication year did not demonstrate a significant impact on citation count.

Conclusion

The present study provided a detailed list of the top 50 most cited and classic articles on vital pulp therapies. This will help researchers, students, and clinicians in the field of endodontics with an impressive source of information.

Comparative bioactivity and immunomodulatory potential of the new Bioroot Flow and AH Plus Bioceramic sealer: An in vitro study on hPDLSCs

OBJECTIVES

To evaluate the cytocompatibility, bioactivity, and anti-inflammatory potential of the new pre-mixed calcium silicate cement-based sealers Bioroot Flow (BrF) and AH Plus Bioceramic Sealer (AHPbcs) on human periodontal ligament stem cells (hPDLSCs) compared to the epoxy resin-based sealer AH Plus (AHP).

MATERIALS AND METHODS

Standardized discs and 1:1, 1:2, and 1:4 eluates of BrF, AHPbcs and AHP after setting were prepared. The following assays were performed: cell attachment and morphology via SEM, cell viability via a MTT assay, cell migration/proliferation via a wound-healing assay, cytoskeleton organization via immunofluorescence staining; cytokine release via ELISA; osteo/cemento/odontogenic marker expression via RT-qPCR, and cell mineralized nodule formation via Alizarin Red S staining. HPDLSCs were isolated from extracted third molars from healthy patients. Comparisons were made with hPDLSCs cultured in unconditioned (negative control) or osteogenic (positive control) culture media. Statistical significance was established at p < 0.05.

RESULTS

Both BrF and AHPbcs showed significantly positive results in the cytocompatibility assays (cell metabolic activity, migration, attachment, morphology, and cytoskeleton organization) compared with a negative control group, while AHP showed significant negative results. BrF exhibited an upregulation of at least one osteo/cementogenic marker compared to the negative and positive control groups. BrF showed a significantly higher calcified nodule formation than AHPbcs, the negative and positive control groups, while AHPbcs was higher than the negative control group. Both were also significantly higher than AHP group.

CONCLUSION

BrF and AHPbcs exhibit adequate and comparable cytocompatibility on hPDLSCs. BrF also promoted the osteo/cementogenic differentiation of hPDLSCs. Both calcium silicate-based sealers favored the downregulation of the inflammatory cytokine IL-6 and the calcified nodule formation from hPDLSCs. BrF exerted a significantly higher influence on cell mineralization than AHPbcs.

CLINICAL RELEVANCE

This is the first study to elucidate the biological properties and immunomodulatory potential of Bioroot Flow and AH Plus Bioceramic Sealer. The results act as supporting evidence for their use in root canal treatment.

Spectrophotometric Analysis of Color Stability Induced by Various Calcium Silicate Cements in Full Pulpotomy of Permanent Molars: Theracal PT, Biodentine, and ProRoot MTA

AIM

The objective of this study was to assess the color stability induced by Theracal PT, Biodentine, and ProRoot MTA in teeth subjected to full pulpotomy, over a span of 6 months.

MATERIALS AND METHODS

The study employed a total of 48 freshly extracted intact human third molar teeth. Samples were randomly assigned into four groups (n = 12). All teeth, with the exception of the control group, underwent endodontic access. All materials were mixed in accordance with the manufacturer's guidelines and applied at a thickness of 3 mm at the orifice level before they set. The study groups were negative control (was not prepared), positive control (ProRootMTA), Biodentine, and Theracal PT. Glass ionomer and composite resin material was applied to the cavities. The color measurements were performed using the VITA Easy Shade spectrophotometer. All measurements were repeated 3 times in the determined area on the middle buccal surface of the tooth at baseline that (T0); after access preparation and material placement and setting) and then subsequently at 7 (T1), 30 (T2), 90 (T3), and T4 (180) days later. Data were statistically analyzed by using Kruskal-Wallis H at a confidence level of 95% (P < .05).

RESULTS

Compared with the negative control group, Biodentine and Theracal PT showed color stability (ΔE ≤ 3.7). The teeth treated with MTA showed clinically observable discoloration (ΔE ≥ 3.7) at T0, T1, T2, T3, and T4 intervals. At all-time intervals, the MTA group induced more discoloration than Biodentine and Theracal PT (P < .05).

CONCLUSIONS

Theracal PT and Biodentine caused least discoloration compared to PMTA even 6 months after its application in teeth undergoing pulpotomy, thereby offering clinicians a reliable alternative for use in the esthetic zone.

Evaluation of the genotoxicity, cytotoxicity, and bioactivity of calcium silicate-based cements

BACKGROUND

As calcium silicate-based cements (CSCs) have found success in various vital pulp therapy applications, several new CSC products have emerged. This study aimed to assess the genotoxicity, cytotoxicity, and bioactivity of four CSCs by comparing the newly introduced materials Bio MTA+ and MTA Cem with previously studied materials, Biodentine and NeoMTA.

METHODS

Genotoxicity was evaluated using the micronucleus (MN) assay in human peripheral blood lymphocyte cells, measuring MN frequency and nuclear division index (NDI). Cytotoxicity was assessed in human dental pulp stem cells through the Water-Soluble Tetrazolium Salt-1 (WST-1) colorimetric assay. Bioactivity was determined by ELISA, measuring the levels of angiogenic and odontogenic markers (BMP-2, FGF-2, VEGF, and ALP). Statistical analyses included ANOVA, Dunnet and Sidak tests, and Wald chi-square test. (p < .05).

RESULTS

The MN frequency in the groups was significantly lower than that in the positive control group (tetraconazole) (p < .05). NDI values decreased with increasing concentration (p < .05). Bio MTA+ and NeoMTA showed decreased cell viability at all concentrations in 7-day cultures (p < .01). All materials increased BMP-2, FGF-2, and VEGF levels, with Biodentine and NeoMTA showing the highest levels of BMP-2 and FGF-2 on day 7. Biodentine displayed the highest VEGF levels on day 7. Biodentine and NeoMTA groups exhibited significantly higher ALP activity than the Bio MTA+ and MTA Cem groups by day 7.

CONCLUSION

Bio MTA+ and MTA Cem demonstrated no genotoxic or cytotoxic effects. Moreover, this study revealed bioactive potentials of Bio MTA+ and MTA Cem by enhancing the expression of angiogenic and osteogenic growth factors.

Influence of bioceramic cones on the quality of root canal filling relative to bond strength and adaptation of the adhesive interface

AIM

To evaluate the bond strength (BS) and analysis of the adhesive interface in root canals filled with bioceramic gutta percha sealers and cones.

MATERIAL AND METHODS

Ninety-six maxillary canines were divided into eight groups according to the endodontic sealer (AH Plus, AH Plus Bioceramic, Bio-C Sealer or Bio-C Sealer Ion+ and gutta percha cones (conventional or bioceramic) tested. They were analyzed using the BS test, failure pattern, analysis of the adhesive interface by scanning electron microscopy and confocal laser scanning microscopy. The BS data were compared between groups using the analysis of variance test with the Turkey post-test. The chi-square test was used to assess the type of failure and the non-parametric Mann-Whitney and Kruse-Wallis tests (P < 0.05).

RESULTS

Analysis of variance showed higher BS values for the groups of bioceramic gutta percha cones in Bio-C Sealer Ion+ (8.38 ± 4.27), AH Plus Bioceramic (6.19 ± 3.28), Bio-C Sealer (5.70 ± 3.18), AH Plus (4.61 ± 2.11) and for conventional gutta percha cones in AH Plus sealers (4.26 ± 2.35), Bio-C Sealer Ion + (3.63 ± 2.29), Bio-C Sealer (2.94 ± 2.32) and AH Plus Bioceramic (1.19 ± 0.89) (P < 0.05). Relative to the type of failure and adaptation of the types of filling material, a higher percentage of mixed failures was observed (gaps between 1 µm-10 µm) for the group with bioceramic gutta percha cones (P < 0.001).

CONCLUSION

The bond between sealers and bioceramic gutta percha cones showed higher bond strength values and greater penetration into the dentin tubules.

CLINICAL RELEVANCE

The filling the root canal system with bioceramic sealers should be associated with bioceramic gutta percha cones.

Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth: A systematic review and meta-analysis

OBJECTIVES

Different materials have been used for capping the pulp after exposure during caries removal in permanent teeth. The purpose of this study was to collate and analyze all pertinent evidence from randomized controlled trials (RCTs) on different materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth.

MATERIALS AND METHODS

Trials comparing two or more capping agents used for direct pulp capping (DPC) or pulpotomy were considered eligible. An electronic search of four databases and two clinical trial registries was carried out up to February 28, 2021 using a search strategy properly adapted to the PICO framework. Screening, data extraction, and risk of bias (RoB) assessment of primary studies were performed in duplicate and independently. The primary outcome was clinical and radiological success; secondary outcomes included continued root formation, tooth discoloration, and dentin bridge formation.

RESULTS

21 RCTs were included in the study. The RoB assessment indicated a moderate risk among the studies. Due to significant clinical and statistical heterogeneity among the studies, performing network meta-analysis (NMA) was not possible. An ad hoc subgroup analysis revealed strong evidence of a higher success of DPC with Mineral Trioxide Aggregate (MTA) compared to calcium hydroxide (CH) (odds ratio [OR] = 3.10, 95% confidence interval [CI]: 1.66-5.79). MTA performed better than CH in pulp capping (both DPC and pulpotomy) of mature compared to immature teeth (OR = 3.34, 95% CI: 1.81-6.17). The GRADE assessment revealed moderate strength of evidence for DPC and mature teeth, and low to very low strength of evidence for the remaining subgroups.

CONCLUSIONS

Considerable clinical and statistical heterogeneity among the trials did not allow NMA. The ad hoc subgroup analysis indicated that the clinical and radiographic success of MTA was higher than that of CH but only in mature teeth and DPC cases where the strength of evidence was moderate. PROSPERO Registration: number CRD42020127239.

Comparative biological properties of resin-free and resin-based calcium silicate-based endodontic repair materials on human periodontal ligament stem cells

OBJECTIVES

To investigate the effect of three different calcium silicate-based materials (CSBM) on the biological behavior of human periodontal ligament stem cells (hPDLSCs).

METHODS

Eluates of Biodentine, NeoPutty and TheraCal PT prepared at 1:1, 1:2, and 1:4 ratios were extracted under sterile conditions. The cytotoxicity of the extracts to the hPDLSCs was assessed using the MTT assay. Scratch wound healing assay was utilized for assessing cell migration. Scanning electron microscopy was used to detect cell attachment and morphology. Calcium ion release was measured using inductively coupled plasma-optical emission spectrometry; the pH-value was evaluated with a pH-meter. ANOVA with post hoc Tukey test was used for statistical analysis.

RESULTS

Cell viability was significantly higher for Biodentine and NeoPutty at day 1 with all dilutions (p < 0.05), while at day 3 and day 7 with dilutions 1:2 and 1:4; all materials showed similar behavior (p > 0.05). Biodentine had the highest percentage of cell migration into the scratched area at day 1 for all dilutions (p < 0.05). Stem cells were attached favorably on Biodentine and NeoPutty with evident spreading, and intercellular communications; however, this was not shown for TheraCal PT. Biodentine showed the highest pH values and calcium ion release (p < 0.05).

CONCLUSIONS

The resin-free CSBM showed better performance and favorable biological effects on hPDLSCs and were therefore considered promising for usage as endodontic repair materials.

CLINICAL SIGNIFICANCE

Proper selection of materials with favorable impact on the host stem cells is crucial to ensure outcome in different clinical scenarios.

Preliminary in vitro cytotoxic evaluation of Uncaria gambier (Hunt) Roxb extract as a potential herbal-based pulpotomy medicament

BACKGROUND

The downfall of formocresol as a pulpotomy medicament highlights the importance of cytotoxic evaluation and the establishment of a safe concentration of dental material prior to its usage in the oral cavity. Uncaria gambir is an herbal plant that possesses antimicrobial, anti-inflammatory and antioxidant properties, suggesting its potential as an alternative medicament for pulpotomy. However, there are not many studies published on its cytotoxicity, with some using non-standardised techniques and reported variable outcomes. Here, we investigated the concentration and time-dependent toxicity of Uncaria gambir extract towards the M3CT3-E1 cell line and compared it with the gold standard pulpotomy medicament: mineral trioxide aggregate (MTA).

METHODS

Uncaria gambir extracts at concentrations ranging from 1000 to 7.8 µg/ml and MTA eluates at 4- and 48 h setting times were prepared. 10% dimethyl sulfoxide (DMSO) and culture media were used as positive and negative controls respectively. Cell viability on days 1, 2, 3 and 7 was analysed using Alamar Blue and Live and Dead Cell assay. Any morphological cellular changes were evaluated using transmission electron microscopes (TEM). Data were analysed using a two-way mixed Analysis of Variance (ANOVA).

RESULTS

The interaction between the concentration and exposure time on the fluorescence intensity of Uncaria gambir extract and MTA 48 h was found to be statistically significant (p < 0.001). No cytotoxic effects on the cells were exerted by both MTA 48 h and Uncaria gambir extract at a concentration below 500 µg/mL. TEM analysis and Live and Dead Cell assay for both materials were comparable to the negative control. No significant differences in fluorescent intensity were observed between Uncaria gambir extract at 500 µg/mL and MTA 48 h (p > 0.05).

CONCLUSION

Uncaria gambir extracts at a maximum concentration of 500 μg/mL are non-cytotoxic over time and are comparable to the MTA.

Epigenetic therapeutics in dental pulp treatment: Hopes, challenges and concerns for the development of next-generation biomaterials

This opinion-led review paper highlights the need for novel translational research in vital-pulp-treatment (VPT), but also discusses the challenges in translating evidence to clinics. Traditional dentistry is expensive, invasive and relies on an outmoded mechanical understanding of dental disease, rather than employing a biological perspective that harnesses cell activity and the regenerative-capacity. Recent research has focussed on developing minimally-invasive biologically-based 'fillings' that preserve the dental pulp; research that is shifting the paradigm from expensive high-technology dentistry, with high failure rates, to smart restorations targeted at biological processes. Current VPTs promote repair by recruiting odontoblast-like cells in a material-dependent process. Therefore, exciting opportunities exist for development of next-generation biomaterials targeted at regenerative processes in the dentin-pulp complex. This article analyses recent research using pharmacological-inhibitors to therapeutically-target histone-deacetylase (HDAC) enzymes in dental-pulp-cells (DPCs) that stimulate pro-regenerative effects with limited loss of viability. Consequently, HDAC-inhibitors have the potential to enhance biomaterial-driven tissue responses at low concentration by influencing the cellular processes with minimal side-effects, providing an opportunity to develop a topically-placed, inexpensive bio-inductive pulp-capping material. Despite positive results, clinical translation of these innovations requires enterprise to counteract regulatory obstacles, dental-industry priorities and to develop strong academic/industry partnerships. The aim of this opinion-led review paper is to discuss the potential role of therapeutically-targeting epigenetic modifications as part of a topical VPT strategy in the treatment of the damaged dental pulp, while considering the next steps, material considerations, challenges and future for the clinical development of epigenetic therapeutics or other 'smart' restorations in VPT.

Partial Pulpotomy in Young Permanent Teeth: A Systematic Review and Meta-Analysis

The aim of the present systematic review was to evaluate the clinical and radiographic success of partial pulpotomies in deep caries processes or post-eruptive defects in young, vital permanent teeth. Four electronic databases, PubMed, Scopus, Embase, and Google Scholar, were searched, followed by a manual search in the reference lists. Randomized controlled trials evaluating partial pulpotomy with a follow-up period of ≥12 months were included. A meta-analysis using a random effects model was performed. A total of 3127 articles were retrieved, and after duplicate removal, 2642 were screened by title and abstract; 1 additional article was found during the manual search, and 79 were identified. Finally, six papers were included in the review. Regardless of the partial pulpotomy modalities or material used, there were no significant differences between clinical and radiographic success rates (cumulative success rate 91.8-92.3%). Five studies were included in the meta-analysis that did not indicate any statistically significant differences in success rates when mineral trioxide aggregate was compared to other materials (95% confidence interval: 0.239 to 1.016; p = 0.055). The present research systematically evaluates the evidence and summarizes the available data on partial pulpotomy in young permanent teeth. Given its high clinical and radiographic success rate, partial pulpotomy should be considered when vital pulpal therapy needs to be performed in highly damaged young permanent teeth, as this procedure provides a biological benefit and allows more invasive endodontic treatments to be postponed.

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.

Regeneration of dentin-pulp complex: Effect of calcium-based materials on hDPSCs differentiation and gene expression

OBJECTIVE

Dentin-pulp complex is object of interest in the regenerative endodontic field as well as the natural function of human dental pulp stem cells (hDPSCs) that may differentiate into specific cells able to repair and/or regenerate both hard and soft dental structures. The aim of the present study was to evaluate the capacity of hDPSCs to differentiate in odontoblastic-like cells by evaluating the expression of specific odontogenic-related genes and to prove the ability of treatment with calcium-based materials such as calcium carbonate (CaCO3), calcium hydroxide (Ca(OH)₂), and mineral trioxide aggregate (MTA).

METHODS

hDPSCs were obtained and isolated from a third molar of a young patient. Odontogenic-related gene expression was assessed unti1 28 days of culture as well as alkaline phosphatase activity (ALP). hDPSCs were cultured in odontoblastic-induction medium used as control, and in presence of different concentrations of CaCO_3, Ca(OH)₂, and MTA.

RESULTS

The results demonstrated an upregulation in odontoblastic cell-related genes, in particular of the early differentiation marker known as matrix extracellular phosphoglycoprotein (MEPE), as well as increased ALP activity and the presence of calcium deposits, mainly by stimulation with calcium derivatives. In this regard, treatment of pulp tissue with CaCO₃, Ca(OH)₂ and even better with MTA seemed to be effective for dentinogenesis.

SIGNIFICANCE

The ease of isolation of hDPSCs from discarded or extracted teeth offers a promising source of autologous cells that may be applied for regenerative purpose in combination with selected bioactive materials. However, further investigations should be conducted to confirm the obtained results.

Encapsulation of human endometrial stem cells in chitosan hydrogel containing titanium oxide nanoparticles for dental pulp repair and tissue regeneration in male Wistar rats

This study aimed to determine the impact of human endometrial stem cells (EnSCs) and titanium oxide nanoparticles (TiO₂ NPs) on dental pulp repair and regeneration in an animal model through dentine development and tissue regeneration. The EnSCs were put on a three-dimensional (3D) chitosan scaffold containing TiO₂ NPs after obtaining and purifying the collagenase enzyme. Pulps were exposed on the maxillary left first molar of all rats followed by direct pulp capping with the experimental scaffolds, as follows. Groups were: 1, control group without any treatment; 2, chitosan group (CS); 3, chitosan group with stem cells (CS/SCs); 4, chitosan group with stem cells and TiO₂ NPs (CS/EnSCs/TiO₂). Glass ionomer was used as a sealant in all groups. The teeth were extracted and histologically evaluated after 8 weeks. The quality and amount of dentine in the CS/EnSCs/TiO₂ group were higher than in the other groups. The combination of EnSCs with TiO₂ NPs and 3D chitosan scaffolds had a synergistic effect on each other, evidencing increased speed and quality of dentine formation. Using EnSCs with TiO₂ NPs on a 3D chitosan scaffold can be a suitable combination for direct pulp capping and dentine regeneration in a rat molar tooth model.

Fast-Setting Calcium Silicate-Based Pulp Capping Cements-Integrated Antibacterial, Irritation and Cytocompatibility Assessment

Calcium silicate-based cements (CSCs) are endodontic materials widely used in vital pulp-capping approaches. Concerning the clinical application, the reduced set time and pre-mixed formulations are relevant characteristics during the operative management of pulpal exposure, aiming to optimise the work time and improve cross-infection/asepsis control. Additionally, clinical success seems to be greatly dependent on the biological performance of the materials that directly contact the living pulp. As such, this work approaches an integrative biological characterisation (i.e., antibacterial, irritation, and cytocompatibility assays) of three fast-setting CSCs-Biodentine^TM, TotalFill^® BC RRM™ Fast Putty, and Theracal LC^®. These cements, after setting for 24 h, presented the expected topography and elemental composition (assessed by scanning electron microscopy, coupled with EDS analysis), in accordance with the information of the manufacturer. The set cements displayed a significant and similar antibiofilm activity against S. mutans, in a direct contact assay. Twenty-four-hour eluates were not irritant in the standardised CAM assay, but elicited distinct dose- and time-dependent cytotoxicity profiles on fibroblastic cells-i.e., Biodentine was devoid of toxicity, TotalFill presented a slight dose-dependent initial toxicity that was easily overcome, and Theracal LC was deleterious at high concentrations. When compared to long-setting ProRoot MTA cement, which highlighted the pursued integrative approach, Biodentine presented a similar profile, but TotalFill and Theracal LC displayed a poorer performance regarding antibiofilm activity/cytocompatibility features, and Theracal LC suggested eventual safety concerns.

Regeneration of the Pulp Tissue: Cell Homing versus Cell Transplantation Approach: A Systematic Review

BACKGROUND

The main objective of this systematic review was to compare the apical healing, root maturation and histological characteristics of teeth treated with cell-based versus cell-free techniques.

METHODS

The methodology of this review was based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A literature search strategy was carried out on PubMed, EMBASE and the Web of Science databases. The last search was done on 1 August 2021. Articles written in languages other than English were excluded. Two researchers independently selected the studies and extracted the data. As no randomized clinical trials were available, animal studies were included.

RESULTS

In total, 26 studies were included in the systematic review: 22 articles only researched the cell-free technique, 3 articles compared the cell-based to the cell-free technique, and 1 article compared the cell-based technique to apexification. In terms of apical healing, qualitative analysis of the data suggested that there seems to be no significant difference between cell-free and cell-based techniques. The results regarding tooth maturation are contradictory. The main difference between the cell-free and the cell-based techniques seems to be the histology of the treated tooth. The cell-free technique seems to result in cementum-like, bone-like or periodontal ligament-like tissue. One study, on the other hand, found that the cell-based technique resulted in regeneration of the whole pulp with an odontoblast layer, connective tissue, blood vessels and neuronal tissue.

CONCLUSIONS

Currently, the number of randomized clinical trials on this topic are very scarce. This is probably due to the limited infrastructure and lack of resources to apply the cell-based technique. Even though both techniques seem to be promising for clinical application, long-term data need to be provided regarding the healing and reparative patterns.

The Allogenic Dental Pulp Transplantation from Son/Daughter to Mother/Father: A Follow-Up of Three Clinical Cases

The study investigated allogenic pulp transplantation as an innovative method of regenerative endodontic therapy. Three patients were selected for the endodontic treatment of single-root teeth, who also had a son/daughter with deciduous teeth or third molars scheduled for extraction. Receptor teeth were endodontically instrumented and irrigated using a tri-antibiotic solution. During the transplant procedures, the teeth from the son/daughter were extracted, sectioned, and the pulp was carefully removed. The harvested pulp from the donor was inserted into the root canal of the host tooth (father/mother), followed by direct pulp capping and resin composite restoration. The teeth were followed-up with for 2 years and were surveyed with computed tomography, the electric pulp vitality test, and Doppler ultrasound examination. At the 6-month follow-up, positive pulp vitality and the formation of periapical lesions were verified in cases 1 and 2. Case 3 showed remarkable periapical radiolucency before transplantation, but after 1 year, such lesions disappeared and there was positive vitality. All teeth were revascularized as determined by Doppler imaging after 2 years with no signs of endodontic/periodontal radiolucency. In conclusion, although this was a case series with only three patients and four teeth treated, it is possible to suppose that this allogenic pulp transplantation protocol could represent a potential strategy for pulp revitalization in specific endodontic cases.

The Cytotoxicity and Genotoxicity of Bioactive Dental Materials

The promotion of biologically based treatment strategies in restorative dentistry is of paramount importance, as invasive treatments should be avoided to maintain the tooth's vitality. This study aimed to assess the biocompatibility of commercially available bioactive materials that can be used for dental pulp capping. The study was performed with a monocyte/macrophage peripheral blood SC cell line (ATCC CRL-9855) on the following six specific bioactive materials: ProRoot MTA (Dentsply Sirona), MTA Angelus (Angelus), Biodentine (Septodont), TheraCal LC (Bisco), ACTIVA BioACTIVE (Pulpdent) and Predicta Bioactive Bulk (Parkell). The cytotoxicity of the investigated agents was measured using a resazurin-based cell viability assay, while the genotoxicity was evaluated using an alkaline comet assay. Additionally, flow cytometry (FC) apoptosis detection was conducted with a FITC (fluorescein isothiocyanate) Annexin V Apoptosis Detection Kit I. FC cell-cycle arrest assessment was carried out with propidium iodide staining. The results of this study showed no significant cytotoxicity and genotoxicity (p > 0.05) in ProRoot MTA, MTA Angelus, Biodentine, ACTIVA BioACTIVE and Predicta Bioactive. Conversely, TheraCal LC presented a significant decrease (p < 0.001). In conclusion, due to excellent biocompatibility and low cytotoxicity, MTA, Biodentine, ACTIVA BioACTIVE and Predicta Bioactive may be suitable for pulp capping treatments. On the other hand, due to the high cytotoxicity of TheraCal LC, its use should be avoided in vital pulp therapies.

Dexamethasone and Doxycycline Doped Nanoparticles Increase the Differentiation Potential of Human Bone Marrow Stem Cells

Non-resorbable polymeric nanoparticles (NPs) are proposed as an adjunctive treatment for bone regenerative strategies. The present in vitro investigation aimed to evaluate the effect of the different prototypes of bioactive NPs loaded with zinc (Zn-NPs), doxycycline (Dox-NPs) or dexamethasone (Dex-NPs) on the viability, morphology, migration, adhesion, osteoblastic differentiation, and mineralization potential of human bone marrow stem cells (hBMMSCs). Cell viability, proliferation, and differentiation were assessed using a resaruzin-based assay, cell cycle analysis, cell migration evaluation, cell cytoskeleton staining analysis, Alizarin Red S staining, and expression of the osteogenic-related genes by a real-time quantitative polymerase chain reaction (RT-qPCR). One-Way ANOVA and Tukey’s test were employed. The resazurin assay showed adequate cell viability considering all concentrations and types of NPs at 24, 48, and 72 h of culture. The cell cycle analysis revealed a regular cell cycle profile at 0.1, 1, and 10 µg/mL, whereas 100 µg/mL produced an arrest of cells in the S phase. Cells cultured with 0.1 and 1 µg/mL NP concentrations showed a similar migration capacity to the untreated group. After 21 days, mineralization was increased by all the NPs prototypes. Dox-NPs and Dex-NPs produced a generalized up-regulation of the osteogenic-related genes. Dex-NPs and Dox-NPs exhibited excellent osteogenic potential and promoted hBMMSC differentiation. Future investigations, both in vitro and in vivo, are required to confirm the suitability of these NPs for their clinical application.

Cytocompatibility and bioactive potential of AH Plus Bioceramic Sealer: an in vitro study

Aim

To assess the cytocompatibility and bioactive potential of the new calcium silicate cement‐based sealer AH Plus Bioceramic Sealer (AHPbcs) on human periodontal ligament stem cells (hPDLSCs) compared with the epoxy resin‐based sealer AH Plus (AHP) and the calcium silicate cement‐based sealer Endosequence BC Sealer (ESbcs).

Methodology

Standardized sample discs and 1:1, 1:2 and 1:4 eluates of the tested materials were prepared. The following assays were performed: surface element distribution via SEM–EDX, cell attachment and morphology via SEM, cell viability via a MTT assay, cell migration/proliferation via a wound‐healing assay, osteo/cemento/odontogenic marker expression via RT‐qPCR and cell mineralized nodule formation via Alizarin Red S staining. HPDLSCs were isolated from extracted third molars. Comparisons were made with hPDLSCs cultured in unconditioned (negative control) or osteogenic (positive control) culture media. Statistical significance was established at p < .05.

Results

A higher peak of Ca²+ was detected from ESbcs compared with AHPbcs and AHP in SEM–EDX. Both AHPbcs and ESbcs showed significantly positive results in the cytocompatibility assays (cell viability, migration/proliferation, attachment and morphology) compared with a negative control group, whilst AHP showed significant negative results. Both AHPbcs and ESbcs exhibited an upregulation of at least one osteo/odonto/cementogenic marker compared with the negative and positive control groups. Both ESbcs and AHPbcs showed a significantly higher calcified nodule formation than the negative and positive control groups, indicative of their biomineralization potential and were also significantly higher than AHP group.

Conclusion

AH Plus Bioceramic Sealer exhibited a significantly higher cytocompatibility and bioactive potential than AH Plus and a similar cytocompatibility to that of Endosequence BC Sealer. Endosequence BC Sealer exhibited a significantly higher mineralization potential than the other tested sealers. The results from this in vitro study act as supporting evidence for the use of AH Plus Bioceramic Sealer in root canal treatment.

Scientific production on silicate-based endodontic materials: evolution and current state: a bibliometric analysis

OBJECTIVES

To perform a bibliometric analysis on silicate-based biomaterials in endodontics; to elucidate the evolution and distribution of scientific production regarding research on these biomaterials, the authors and institutions involved, and the most used descriptors/keywords in this field.

MATERIALS AND METHODS

A general advanced broad search was performed in Web of Science Core Collection, using the terms "Silicate" and "Endod*." By means of the "Analyze Results" and "Citation Analysis" tools from Web of Science, bibliometric data were extracted. Bibliometric networks on co-authorship and keyword co-occurrence were illustrated using VOSviewer software tool.

RESULTS

Research in the field of silicate-based endodontic materials in endodontics has followed an exponential crescent tendency over the period between 1995 and 2020. Two major co-authorship networks lead the research production in the field, headed by Gandolfi MG and Prati C, and Rodríguez-Lozano FJ and Forner L; respectively. "Mineral trioxide aggregate," "MTA", "Biocompatibility," "Biodentine," and "In vitro" were the terms with the highest occurrence. The modal study type in this research area are laboratory studies, representing 77.7% of the total number of records. The relationship between keywords illustrates the recent tendency to assess biological properties of MTA and Biodentine, which could be extrapolated to other silicate-based materials.

CONCLUSIONS

The results from the present study highlight the exponential increase and distribution of scientific production on silicate-based materials in endodontics, along with the modal keywords used as descriptors and the major authorship networks involved. The predominance of laboratory studies in this research field reinforces the need for clinical studies, to extrapolate the reported performance and characteristics of silicate-based materials into the clinical setting.

CLINICAL RELEVANCE

The present study may aid the clinician's continuing education and evidence-based practice by providing knowledge and facilitating the literature search on the field of silicate-based biomaterials in endodontics.

Expert consensus on dental caries management

Dental Caries is a kind of chronic oral disease that greatly threaten human being's health. Though dentists and researchers struggled for decades to combat this oral disease, the incidence and prevalence of dental caries remain quite high. Therefore, improving the disease management is a key issue for the whole population and life cycle management of dental caries. So clinical difficulty assessment system of caries prevention and management is established based on dental caries diagnosis and classification. Dentists should perform oral examination and establish dental records at each visit. When treatment plan is made on the base of caries risk assessment and carious lesion activity, we need to work out patient‑centered and personalized treatment planning to regain oral microecological balance, to control caries progression and to restore the structure and function of the carious teeth. And the follow-up visits are made based on personalized caries management. This expert consensus mainly discusses caries risk assessment, caries treatment difficulty assessment and dental caries treatment plan, which are the most important parts of caries management in the whole life cycle.

Short-Term Pain Evolution and Treatment Success of Pulpotomy as Irreversible Pulpitis Permanent Treatment: A Non-Randomized Clinical Study

The objective of this work was to evaluate (1) the short-term evolution of pain and (2) the treatment success of full pulpotomy as permanent treatment of irreversible pulpitis in mature molars. The study consisted of a non-randomized comparison between a test group (n = 44)—full pulpotomy performed by non-specialist junior practitioners, and a control group (n = 40)—root canal treatments performed by specialized endodontists. Short-term pain score (Heft–Parker scale) was recorded pre-operatively, then at 24 h and 7 days post-operatively. Three outcomes were considered for treatment success: radiographic, clinical and global success. For short-term evolution of pain, a non-parametric Wilcoxon test was performed (significance level = 0.05). For treatment success, a Pearson Chi square or Fisher test were performed (significance level = 0.017–Bonferroni correction). There was no significant difference between test and control groups neither regarding short term evolution of pain at each time point, nor regarding clinical (80% and 90%, respectively) or global success (77% and 67%, respectively). However, a significant difference in radiographic success was observed (94% and 69%, respectively). The present work adds to the existing literature to support that pulpotomy as permanent treatment could be considered as an acceptable and conservative treatment option, potentially applied by a larger population of dentists.

Comparative cytocompatibility of the new calcium silicate-based cement NeoPutty versus NeoMTA Plus and MTA on human dental pulp cells: an in vitro study

OBJECTIVES

The aim of the present in vitro study is to determine the cytocompatibility of the recently introduced NeoPutty in contact with human dental pulp cells compared with its precursor NeoMTA Plus and the classic gold standard MTA Angelus.

MATERIALS AND METHODS

Sample disks were obtained for each of the tested materials (5 mm diameter; 2 mm thickness; n = 30), along with 1:1, 1:2, and 1:4 material eluents. HDPCs were extracted and cultured with the tested materials (test groups) or in unconditioned medium (control group), and the following biocompatibility assays were performed: MTT assay, scratch wound assay, cell cytoskeleton staining assays, and cell attachment assessment via SEM. Additionally, material ion release and surface element composition were evaluated via ICP-MS and SEM-EDX, respectively. Each experimental condition was carried out three times and assessed in three independent experiments. Statistical significance was established at p < 0.05.

RESULTS

1:2 dilutions of all the tested materials exhibited a comparable cell viability to that of the control group at 48 and 72 h of culture (p < 0.05). The same was observed for 1:4 dilutions of the tested materials at 24, 48, and 72 h of culture (p > 0.05). All the tested materials exhibited adequate cytocompatibility in the remaining biocompatibility assays. MTA exhibited a significantly higher calcium ion release compared to NeoPutty and NeoMTA Plus (p < 0.05).

CONCLUSION

The results from the present work elucidate the adequate cytocompatibility of NeoPutty, NeoMTA Plus, and MTA Angelus towards human dental pulp cells.

CLINICAL RELEVANCE

Within the limitations of the present in vitro study, our results may act as preliminary evidence for its use in vital pulp therapy as a pulp capper. However, results need to be interpreted with caution until further clinical supporting evidence is reported.

In vitro bioactivity of newly introduced dual-cured resin-modified calcium silicate cement

Background:

This study was designed to investigate the in vitro bioactivity of a new dual cured calcium silicate cement (TheraCal PT) compared to its light cured (TheraCal LC) and chemically set (Biodentine) counterparts.

Materials and Methods:

The study is an in vitro original research article. Prepared cements discs were immersed in deionized water. Ca²+ release was evaluated using inductively coupled plasma-optical emission spectrometry while pH was assessed using a pH meter after 1, 14, and 28 days. Discs for surface characterization were immersed in phosphate-buffered saline (PBS) and were examined using an environmental scanning electron microscope with energy dispersive X-ray (ESEM/EDX), immediately after setting and at 1, 14, and 28 days intervals after that. Attenuated total reflectance (ATR)/Fourier transform infrared (FTIR) and Raman spectroscopy analyses were performed after setting and after 28 days storage in PBS. Statistical analysis was performed using the two-way repeated measure analysis of variance test followed by Bonferroni test for multiple comparisons (P < 0.05).

Results:

Biodentine exhibited the highest mean values for Ca²+ release (792,639,278 ppm) and pH (10.99, 12.7, 11.54) at all time intervals. ESEM/EDX displayed a continuous layer of calcium phosphate formed by Biodentine and TheraCal LC while TheraCal PT developed scarce interrupted precipitates after immersion in PBS. ATR/FTIR and Raman spectroscopy for the formed precipitates confirmed the presence of phosphate and Ca (OH) ₂ in Biodentine, TheraCal LC and TheraCal PT.

Conclusion:

TheraCal PT exhibited limited in vitro bioactivity which may limit its prognosis in clinical applications for vital pulp therapy. TheraCal LC is considered a potential bioactive calcium silicate cement despite its lower Ca²+ release compared to Biodentine. Highest bioactivity was observed in Biodentine.

First multi-target QSAR model for predicting the cytotoxicity of acrylic acid-based dental monomers

OBJECTIVE

Acrylic acid derivatives are frequently used as dental monomers and their cytotoxicity towards various cell lines is well documented. This study aims to probe the structural and physicochemical attributes responsible for higher toxicity of dental monomers, using quantitative structure-activity relationships (QSAR) modeling approaches.

METHODS

A regression-based linear single-target QSAR (st-QSAR) model was developed with a comparatively small dataset containing 39 compounds, the cytotoxicity of which has been assessed over the Hela S3 cell line. By contrast, a classification-based multi-target QSAR model was developed with 138 compounds, the cytotoxicity of which has been reported against 18 different cell lines. Both models were set up following rigorous validation protocols confirming their statistical significance and robustness.

RESULTS

The performance of the linear mt-QSAR model, developed with various feature selection and post-selection similarity searching-based schemes, superseded that of all non-linear models produced with six machine learning methods by hyperparameter optimization. The final derived st-QSAR and mt-QSAR linear models are shown to be highly predictive, as well as revealing the crucial structural and physicochemical factors responsible for higher cytotoxicity of the dental monomers.

SIGNIFICANCE

This study is the first attempt on unveiling the cytotoxicity of dental monomers over several cell lines by means of a single multi-target QSAR model. Further, such a model is ready to get widespread applicability in the screening of new monomers, judging from its almost accurate predictions over diverse experimental assay conditions.

Local Drug Delivery Systems for Vital Pulp Therapy: A New Hope

Vital pulp therapy (VPT) is deliberated as an ultraconservative/minimally invasive approach for the conservation of vital pulpal tissues, preservation of dental structure, and maintenance of tooth function in the oral cavity. In VPT, following the exposure of the dental pulp, the environment is prepared for the possible healing and probable refunctionalisation of pulpal connective tissue. However, to succeed in VPT, specific biomaterials are used to cover and/or dress the exposed pulp, lower the inflammation, heal the dental pulp, provoke the remaining odontoblastic cells, and induce the formation of a hard tissue, i.e., the dentinal bridge. It can be assumed that if the employed biomaterial is transferred to the target site using a specially designed micro-/nanosized local drug delivery system (LDDS), the biomaterial would be placed in closer proximity to the connective tissue, may be released in a controlled and sustained pattern, could properly conserve the remaining dental pulp and might appropriately enhance hard-tissue formation. Furthermore, the loaded LDDS could help VPT modalities to be more ultraconservative and may minimise the manipulation of the tooth structure as well as pulpal tissue, which could, in turn, result in better VPT outcomes.

Are resin-containing pulp capping materials as reliable as traditional ones in terms of local and systemic biological effects?

The aim of this study was to compare the local and systemic effects of current pulp capping materials containing resin with those of traditional materials in an animal study. A total of 48 rats were used: a control group (n=12) (sub-control and negative control), a resin-containing group (n=18) (Calcimol LC, Theracal LC, Activa-BioActive Base/Liner), and a traditional group (n=18) (Biodentine, ProRoot MTA, Dycal). The materials which had been placed in polyethylene tubes were implanted in subcutaneous pockets. The rats were sacrificed at 1, 2, or 4 weeks. Evaluations were made of subcutaneous connective tissue, the left kidney, liver, and blood samples. Of all the study groups, MTA demonstrated biocompatibility at a level close to that of the control groups. Inflammation was observed to be more severe in resin-containing materials, but Activa Base/Liner showed a more successful local and systemic tissue response.

Comparative Biological Properties and Mineralization Potential of 3 Endodontic Materials for Vital Pulp Therapy: Theracal PT, Theracal LC, and Biodentine on Human Dental Pulp Stem Cells

INTRODUCTION

The aim of this study was to assess the biological properties and mineralization potential of the new Theracal PT (Bisco Inc, Schaumburg, IL) compared with its predecessor Theracal LC (Bisco Inc) and the hydraulic silicate-based cement Biodentine (Septodont, Saint-Maur-des-Fossés, France) on human dental pulp stem cells (hDPSCs) in vitro.

METHODS

Standardized sample discs were obtained for each material (n = 30) together with 1:1, 1:2, and 1:4 material eluates. Previously characterized hDPSCs were cultured with the different materials in standardized conditions, and the following assays were performed: a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a wound healing assay, Annexin-V-FITC and 7-AAD staining (BD Biosciences, San Jose, CA), reactive oxygen species production analysis, cell adhesion and morphology evaluation via scanning electron microscopy and immunofluorescence, quantification of the expression of osteo/odontogenic markers via real-time quantitative reverse-transcriptase polymerase chain reaction, and alizarin red S staining. Statistical significance was established at P < .05.

RESULTS

All of the tested dilutions of Theracal LC exhibited a significantly higher cytotoxicity and reactive oxygen species production (P < .001) and a lower cell migration rate than the control group (hDPSCs cultured in growth medium without material extracts) at all of the measured time points (P < .001). Both 1:4 Theracal PT and Biodentine-treated hDPSCs exhibited similar levels of cytocompatibility to that of the control group, a significant up-regulation of at least 1 odontogenic marker (Biodentine: dentin sialophosphoprotein (P < .05); Theracal PT: osteonectin and runt-related transcription factor 2 [P < .001]), and a significantly higher mineralized nodule formation (P < .001).

CONCLUSIONS

The newly introduced TheraCal PT offers an improved in vitro cytocompatibility and mineralization potential on hDPSCs compared with its predecessor, TheraCal LC, and comparable biological properties to Biodentine.

Biomineralization potential and biological properties of a new tantalum oxide (Ta2O5)-containing calcium silicate cement

Objective

The present study evaluated the biological effects and biomineralization potential of a new tantalum oxide (Ta₂O₅)–containing material designed for vital pulp therapy or perforation repair (NeoMTA 2), compared to NeoMTA Plus and Bio-C Repair.

Material and methods

Human dental pulp stem cells (hDPSCs) were exposed to different eluates from NeoMTA Plus, NeoMTA 2, and Bio-C Repair. Ion release from each material was determined using inductively coupled plasma-optical emission spectrometry (ICP-MS). The biological experiments performed were MTT assays, apoptosis/necrosis assays, adhesion assays, migration assays, morphology evaluation, and reactive oxygen species (ROS) production analysis. Biomineralization was assessed by Alizarin red S staining. Finally, osteo/odontogenic gene expression was determined by real-time quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR). Data were analyzed using one-way ANOVA followed by Tukey’s multiple comparison test.

Results

NeoMTA 2 displayed a significantly higher calcium release compared to the other materials (p < 0.05). When hDPSCs were cultured in presence of the different material eluates, all groups exhibited similar hDPSC viability and migration rates when compared to untreated cells. Substantial cell attachment and spreading were observed in all materials’ surfaces, without significant differences. hDPSCs treated with NeoMTA 2 displayed an upregulation of ALP, Col1A1, RUNX2 (p < 0.001), ON, and DSPP genes (p < 0.05), and showed the highest mineralization potential compared to other groups (p < 0.001). Finally, the more concentrated eluates from these materials, specially NeoMTA Plus and NeoMTA 2, promoted higher ROS production in hDPSCs compared to Bio-C Repair and control cells (p < 0.001), although these ROS levels did not result in increased cell death.

Conclusions

The new tantalum oxide (Ta₂O₅)–containing material shows an adequate cytocompatibility and the ability to promote biomineralization without using chemical osteogenic inducers, showing great potential as a new material for vital pulp therapy.

Clinical relevance

NeoMTA 2 seems to be a promising material for vital pulp therapy. Further studies considering its biocompatibility and biomineralization potential are necessary.

Biological interactions between calcium silicate-based endodontic biomaterials and periodontal ligament stem cells: A systematic review of in vitro studies

BACKGROUND

Most recently, the biological interactions, that is cytocompatibility, cell differentiation and mineralization potential, between calcium silicate-based biomaterials and periodontal ligament stem cells (PDLSCs) have been studied at an in vitro level, in order to predict their clinical behaviour during endodontic procedures involving direct contact with periodontal tissues, namely root canal treatment, endodontic surgery and regenerative endodontic treatment.

OBJECTIVE

The aim of the present systematic review was to present a qualitative synthesis of available in vitro studies assessing the biological interaction of PDLSCs and calcium silicate-based biomaterials.

METHODOLOGY

The present review followed PRISMA 2020 guidelines. An advanced database search was performed in Medline, Scopus, Embase, Web of Science and SciELO on 1 July 2020 and last updated on 22 April 2021. Studies assessing the biological interactions of PDLSCs with calcium silicate-based sealers (CSSs) and/or cements (CSCs) at an in vitro level were considered for inclusion. The evaluation of the 'biological interaction' was defined as any assay or test on the cytotoxicity, cytocompatibility, cell plasticity or differentiation potential, and bioactive properties of PDLSCs cultured in CSC or CSS-conditioned media. Quality (risk of bias) was assessed using a modified CONSORT checklist for in vitro studies of dental materials.

RESULTS

A total of 20 studies were included for the qualitative synthesis. CSCs and CSSs, as a group of endodontic materials, exhibit adequate cytocompatibility and favour the osteo/cementogenic differentiation and mineralization potential of PDLSCs, as evidenced from the in vitro studies included in the present systematic review.

DISCUSSION

The influence of the compositional differences, inclusion of additives, sample preparation, and varying conditions and manipulations on the biological properties of calcium silicate-based materials remain a subject for future research.

CONCLUSIONS

Within the limitations of the in vitro nature of the included studies, this work supports the potential use of calcium silicate-based endodontic materials in stem cell therapy and biologically based regenerative endodontic procedures.

REGISTRATION

OSF Registries; https://doi.org/10.17605/OSF.IO/SQ9UY.

CKAP4 Antibody-Conjugated Si Quantum Dot Micelles for Targeted Imaging of Lung Cancer

At present, various fluorescent nanomaterials have been designed and synthesized as optical contrast agents for surgical navigation. However, there have been no reports on the preparation of fluorescent contrast agents for lung cancer surgery navigation using silicon quantum dots (Si QDs). This study improved and modified the water-dispersible Si QD micelles reported by Pi et al. to prepare Si QD micelles-CKAP4. The data showed that the Si QD micelles-CKAP4 were spherical particles with a mean hydrodiameter of approximately 78.8 nm. UV-visible absorption of the Si QD micelles-CKAP4 ranged from 200 to 500 nm. With an excitation wavelength of 330 nm, strong fluorescence at 640 nm was observed in the fluorescence emission spectra. Laser confocal microscopy and fluorescence microscopy assay showed that the Si QD micelles-CKAP4 exhibited good targeting ability to lung cancer cells and lung cancer tissues in vitro. The in vivo fluorescence-imaging assay showed that the Si QD micelles-CKAP4 was metabolized by the liver and excreted by the kidney. In addition, Si QD micelles-CKAP4 specifically targeted lung cancer tissue in vivo compared with healthy lung tissue. Cytotoxicity and hematoxylin and eosin staining assays showed that the Si QD micelles-CKAP4 exhibited high biosafety in vitro and in vivo. Si QD micelles-CKAP4 is a specifically targeted imaging agent for lung cancer and is expected to be a fluorescent contrast agent for lung cancer surgical navigation in the future.

Dental Pulp Autotransplantation: A New Modality of Endodontic Regenerative Therapy-Follow-Up of 3 Clinical Cases

The aim of this study was to develop a novel method of endodontic therapy, which we refer to as dental pulp autotransplantation. Three patients (2 males and 1 female) were selected for endodontic treatment of a uniradicular premolar and extraction of a third molar (without odontosection). Electric assessment of pulp vitality and computed tomographic imaging were undertaken followed by endodontic access and instrumentation using triantibiotic solution for irrigation in the host tooth. A few minutes before the transplant procedure, the third molar was extracted, the tooth was sectioned with a diamond blade in a low-speed handpiece, and the pulp was carefully removed. After premolar instrumentation, the harvested and preserved pulp tissue was reinserted into the root canal followed by direct pulp capping performed using Biodentine (Septodont, Saint-Maur-des-Fossés, France), a liner of resin-modified glass ionomer cement and composite resin restoration. The teeth were followed up for at least 12 months after the procedures and were analyzed using computed tomographic imaging, electric pulp vitality testing, and Doppler ultrasound examination. At the 3- and 6-month follow-ups, positive pulp vitality and regression of periapical lesions were verified. After 9-12 months, all teeth were revascularized as determined by Doppler imaging, and the tooth vitality was reestablished with no signs of endodontic/periodontal radiolucency or complications. Within the limitations of the study, considering that it was a case series with only 3 patients, we described a highly innovative procedure of pulp autotransplantation, which appears to be feasible, highlighting the potential for clinical application of pulp regeneration using this new modality of endodontic therapy.

Experimental resin-modified calcium-silicate cement containing N-(2-hydroxyethyl) acrylamide monomer for pulp tissue engineering

AIM

Our study aimed to measure (1) the flexural strength, (2) shear bond strength to dentin, (3) pH, and (4) calcium (Ca) release of a series of innovative resin-modified calcium-silicate pulp-capping cements (Rm-CSCs). Using an ex-vivo human vital tooth-culture model, we additionally assessed (5) their pulp-healing initiation when brought in direct contact with human dental pulp tissue.

METHODOLOGY

Three experimental Rm-CSCs, being referred to 'Exp_HEAA', 'Exp_GDM' and 'Exp_HEAA/GDM', contained either 20 wt% N-(2-hydroxyethyl) acrylamide (HEAA), 20 wt% glycerol dimethacrylate (GDM) or 10 wt% HEAA plus 10 wt% GDM, added to a common base composition consisting of 25 wt% urethane dimethacrylate (UDMA), 10 wt% 4-methacryloxyethyl trimellitate anhydride (4-MET), and 5 wt% N,N'-{[(2-acrylamido-2-[(3-acrylamidopropoxy)methyl] propane-1,3-diyl)bis(oxy)]bis-(propane-1,3-diyl)}diacrylamide (FAM-401). As Ca source and radiopacifier, 37 wt% tricalcium silicate powder (TCS) and 3 wt% zirconium oxide (ZrO 2) were respectively added.

RESULTS

All three experimental Rm-CSCs revealed a significantly higher flexural strength and shear bond strength to dentin (p < 0.05) than the commercial reference Rm-CSC TheraCal LC (Bisco). Exp_HEAA presented with a significantly higher Ca release and pH at 24 h compared with the other Rm-CSCs (p < 0.05). At 1 week, the Ca release and pH of Exp_HEAA and Exp_HEAA/GDM was significantly higher than those of Exp_GDM and TheraCal LC (p < 0.05). Using the ex-vivo human vital tooth culture model, Exp_HEAA revealed pulp-healing initiation capacity as documented by nestin and collagen-I expression.

CONCLUSIONS

Depending on the formulation, the innovative Rm-CSCs performed favorably for primary properties of relevance regarding pulp capping, this more specifically in terms of flexural strength, bond strength to dentin, as well as alkaline pH and Ca release. However, only Exp_HEAA revealed pulp-healing initiation in direct contact with human dental pulp tissue in the ex-vivo human vital tooth-culture model. This promising outcome for Exp_HEAA should be attributed to the combined use of (1) a novel hydrophilic acrylamide monomer, enabling sufficient polymerization while maintaining adequate hydrophilicity, with (2) the functional monomer 4-MET, possessing chemical bonding potential to dentin, and (3) tricalcium silicate powder to achieve an alkaline pH and to release Ca in a sufficient and controlled way.

Cytocompatibility and bioactive properties of the new dual-curing resin-modified calcium silicate-based material for vital pulp therapy

OBJECTIVE

The aim of the present study was to evaluate the in vitro biocompatibility of Theracal PT, Theracal LC, and MTA Angelus, considered as bioactive materials used for vital pulp treatment, on human dental pulp stem cells (hDPSCs).

MATERIALS AND METHODS

Human dental pulp stem cells (hDPSCs) were isolated from third molars, and material eluates were prepared (undiluted, 1:2, and 1:4 ratios). The hDPSC cytotoxicity, adhesion, morphology, viability, and cell migration were assessed. The mineralization nodule formation was determined by Alizarin red S staining (ARS). The odonto/osteogenic differentiation potential was assessed by osteo/odontogenic marker expression real-time qPCR. The chemical composition and ion release of the vital pulp materials were determined by energy dispersive X-ray (EDX) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Statistical differences were assessed by ANOVA and Tukey's test (p < 0.05).

RESULTS

The three vital pulp materials showed variable levels of calcium, tungsten, silicon, and zirconium release and in their chemical composition. Cytocompatibility assays revealed higher hDPSC viability and migration rates when treated with Theracal PT than with Theracal LC. The lowest cell adhesion and spreading were observed in all Theracal LC-treated groups, whereas the highest were observed when treated with MTA. Theracal PT and MTA promoted the upregulation of DSPP and RUNX2 gene expression (p < 0.05). After 21 days, both MTA Angelus and Theracal PT-treated cells exhibited a significantly higher mineralized nodule formation than the negative control (p < 0.05).

CONCLUSIONS

This study demonstrates the favorable in vitro cytocompatibility and bioactive properties of the recently introduced Theracal PT and the well-established MTA Angelus on hDPSCs, as opposed to Theracal LC. More studies, including in vivo animal testing are suggested before these new formulations might be used in the clinical setting.

CLINICAL RELEVANCE

Theracal PT is a new material that could be clinically suitable for vital pulp therapy. Further studies considering its biocompatibility and bioactivity are necessary.

Cytocompatibility and Bioactive Properties of Hydraulic Calcium Silicate-Based Cements (HCSCs) on Stem Cells from Human Exfoliated Deciduous Teeth (SHEDs): A Systematic Review of In Vitro Studies

The implementation of hydraulic calcium silicate-based endodontic cements (HCSCs) in biologically based endodontic procedures for the primary dentition has been recently investigated, focusing on the biological response of stem cells from human exfoliated deciduous teeth (SHEDs) towards them. The present systematic review aimed to present a qualitative synthesis of the available literature consisting of in vitro assays, which assessed the cytocompatibility and bioactive properties of HCSCs in direct contact with SHEDs. Following the PRISMA statement, an electronic database search was carried out in Medline, Scopus, Embase, Web of Science, and SciELO on March 31st and updated on November 16th, 2020. In vitro studies evaluating the biological response of SHEDs to the treatment with HCSCs were eligible. Within the term biological response, assays assessing the cytocompatibility (i.e., cell viability, migration, proliferation), cell plasticity or differentiation (i.e., osteo/odontogenic marker expression), and bioactivity or biomineralization (i.e., mineralized nodule formation) were included. A total of seven studies were included after the selection process. The study sample comprised an extensive range of cell viability, migration, proliferation, adhesion, and bioactivity assays regarding the biological response of SHEDs towards five different commercially available HCSCs (MTA, ProRoot MTA, Biodentine, iRoot BP Plus, and Theracal LC). Biodentine, MTA, and iRoot BP Plus showed significant positive results in cytocompatibility and bioactivity assays when cultured with SHEDs. The results from in vitro assays assessing the cytocompatibility and bioactivity of the HCSCs MTA, Biodentine, and iRoot BP Plus towards SHEDs support their use in vital pulp treatment for the primary dentition.

TVH-19, a synthetic peptide, induces mineralization of dental pulp cells in vitro and formation of tertiary dentin in vivo

Functional peptides derived from the active domains of odontogenesis-related proteins have been reported to promote dental hard tissue regeneration. The purpose of this study was to evaluate the effects of an artificially synthesized peptide, TVH-19, on odontoblast differentiation and tertiary dentin formation in indirect pulp capping (IPC) using in vitro and in vivo experiments. TVH-19 did not exhibit any effect on the proliferation of human dental pulp cells (hDPCs) but significantly promoted cell migration, compared with the control (p < 0.05). TVH-19-treated hDPCs showed significantly higher alkaline phosphatase (ALP) activity and stronger alizarin red staining (ARS) reactivity than the control group (p < 0.05). TVH-19 also upregulated the mRNA and protein expression levels of odontogenic genes. After generating IPC in rats, the samples of teeth were studied using micro-computed tomography (Micro-CT), hematoxylin & eosin (HE) staining, and immunohistochemical staining to investigate the functions of TVH-19. The in vivo results showed that TVH-19 induced the formation of tertiary dentin, and reduced inflammation and apoptosis, as evident from the downregulated expression of interleukin 6 (IL-6) and cleaved-Caspase-3 (CL-CASP3). Overall, the results of our study suggest that TVH-19 induces differentiation of hDPCs, promotes tertiary dentin formation, relieves inflammation, and reduces apoptosis, indicating the potential applications of TVH-19 in IPC.