Biological effects of new chemical-mechanical caries removal products on human dental pulp stem cells.

AIM: The aim of this study was to compare the biological effects of four chemical caries removal materials and to assess their cytotoxicity using human dental pulp stem cells (hDPSCs). METHODS: The products evaluated are: 1 - Papain based product (BRIX 3000®); 2 - Papain/chloramine based products (NATURAL-CARE and Papacárie Duo®); and 3 - Chloramine based product (Cariesolut); The following in vitro experiments were carried out: IC50 measurement, cell metabolic activity (MTT) assay, cell migration, immunofluorescence experiment, cell apoptosis analysis, and reactive oxygen species (ROS) production analysis. Statistical analyses were performed using one-way ANOVA followed by Tukey's post hoc test (p<0.05). RESULTS: The IC50 values were: Brix 3000: 0.596%; Papacárie Duo: 0.052%; NATURAL CARE: 1.034%; and Cariesolut: 0.020%. The MTT assays showed non-adequate cell viability of all CMCR tested at 2% at 24, 48, and 72 h (p<0.001). The same behaviour was observed at 0.1% in the Papacárie Duo and Cariesolut groups. In contrast, 0.1% of Brix 3000 at all times and NATURAL CARE at 24h treated cells showed cell viability rates similar to the control group. At 0.01% only Brix 3000 did not show statistically significant differences at any time. Delayed cell migration was observed in all hDPSCs treated with Papacárie Duo and Cariesolut (p<0.01 and p<0.001). Phalloidin staining images showed a high confluence of cells in the presence of NATURAL CARE, similar to the control group. On the contrary, no cells were observed in Brix3000 and Cariesolut at 2% and 0.1% concentrations. Papacárie Duo showed cells at all concentrations, but hDPSCs treated at 0.01% exhibited better proliferation and spreading than those in the control group. Apoptosis assay showed that Brix 3000 at 0.1% and 0.01% had a percentage of live cells higher than 99%, with 68.4% live cells at 2%, 3.69% early apoptotic cells, and 27.9% late apoptotic cells. Conversely, the remaining materials showed abundant apoptotic cells, even at low concentrations. 0.1% and 0.01%of BRIX 3000 did not affect the ROS production levels, while 2% of BRIX 3000 counterparts significantly increased the percentage of CM-H2DCFDA positive cells. Again, all concentrations of Cariesolut showed significantly higher levels of ROS production than those observed in control cells. CONCLUSION: Our results suggest that Brix 3000 would be the most suitable material for chemical caries removal.

Biological properties of Ceraputty as a retrograde filling material: an in vitro study on hPDLSCs.

OBJECTIVES: To assess the cytocompatibility and bioactive potential of the new calcium silicate-based cement Ceraputty on human periodontal ligament stem cells (hPDLSCs) compared to Biodentine and Endosequence BC root repair material (ERRM). MATERIALS AND METHODS: hPDLSCs were isolated from extracted third molars from healthy donors. 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, osteo/cemento/odontogenic marker expression via RT-qPCR, and cell calcified nodule formation via Alizarin Red S staining. hPDLSCs cultured in unconditioned or osteogenic media were used as negative and positive control groups, respectively. Statistical analysis was performed using one-way ANOVA or two-way ANOVA and Tukey's post hoc test. Statistical significance was established at p < 0.05. RESULTS: The highest Ca2+ peak was detected from Biodentine samples, followed by ERRM and Ceraputty. hPDLSC viability was significantly reduced in Ceraputty samples (p < 0.001), while 1:2 and 1:4 Biodentine and ERRM samples similar results to that of the negative control (p > 0.05). Biodentine and ERRM exhibited an upregulation of at least one cemento/odonto/osteogenic marker compared to the negative and positive control groups. Cells cultured with Biodentine produced a significantly higher calcified nodule formation than ERRM and Ceraputty (p < 0.001), which were also higher than the control groups (p < 0.001). CONCLUSION: Ceraputty evidenced a reduced cytocompatibility towards hPDLSCs on its lowest dilutions compared to the other tested cements and the control group. Biodentine and ERRM promoted a significantly higher mineralization and osteo/cementogenic marker expression on hPDLSCs compared with Ceraputty. Further studies are necessary to verify the biological properties of this new material and its adequacy as a retrograde filling material. CLINICAL RELEVANCE: This is the first study to elucidate the adequate biological properties of Ceraputty for its use as a retrograde filling material.

Are Denture Adhesives Safe for Oral Cells?

PURPOSE: To compare the cytotoxicity of six commercially available denture adhesives on human gingival cells: Poligrip Flavour Free Fixative Cream, Fixodent Pro Duo Protection, Novafix cream, FittyDent, Polident Total Action, and Fixodent Pro Plus Duo Protection. MATERIAL AND METHODS: Eluates of denture adhesives were brought into contact with human gingival cells and compared to untreated cells (w/o any dental adhesive elute). Cell toxicity was assessed by measuring cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assays), cell morphology (immunofluorescence assays), induction of apoptosis/necrosis and production of reactive oxygen species (ROS) (flow cytometry assays). In addition, the pH of each sample was determined. Data were analyzed using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test. RESULTS: All denture adhesives tested led to a reduction in pH, especially Fixodent Pro Duo Protection and Fixodent Pro Plus Duo Protection. The cell viability assays showed that Fixodent Pro Duo Protection (1:1 72 hours, p = 3.04 × 10-6 ; 1:2 72 hours, p = 2.07 × 10-6 ; 1:4 72 hours, p = 2.04 × 10-6 ) and Fixodent Pro Plus Duo Protection (1:1 72 hours, p = 2.01 × 10-6 ; 1:2 72 hours, p = 3.03 × 10-6 ; 1:4 72 hours, p = 2.02 × 10-6 ) significantly decreased cell viability at all dilutions. Compared to the control group and the rest of the adhesives, Poligrip Flavour Free Fixative Cream (PFF 1:1 72 hours, p = 2.24 × 10-6 ; 1:2 72 hours, p = 2.44 × 10-6 ; 1:4 72 hours, p = 2.04 × 10-6 ) showed a significantly higher cell viability score at all dilutions. Fixodent Pro Duo Protection and Fixodent Pro Plus Duo Protection, both adhesives containing zinc salts in their composition, were responsible for necrosis, and the number of cells was much reduced, with aberrant morphology and pyknotic nucleus. Finally, Fixodent (1:2, p = 2.04 × 10-6 , 1:4, p = 0.00036; 1:2, p = 8.82 × 10-6 , 1:4, p = 2.30 × 10-6 ) products significantly promoted ROS production in gingival cells. CONCLUSIONS: The results suggest that denture adhesives containing zinc in their composition could be responsible of the decrease of cell viability, ROS production, aberrant cell morphology, and induction of apoptosis and cell death. However, other possible additional cytotoxic factors must be considered. Thus, more studies are necessary to confirm this hypothesis.

Biological effects of acid-eroded MTA Repair HP and ProRoot MTA on human periodontal ligament stem cells.

OBJECTIVE: The aim of this study was to analyze the biological effects of MTA Repair HP and ProRoot MTA on human periodontal ligament stem cells (hPDLSCs) after exposure to acidic and neutral environments. MATERIALS AND METHODS: Discs of each material (n = 30) were exposed to phosphate buffered saline (pH = 7.4) or butyric acid (pH = 5.2) for 7 days, and biological testing was carried out in vitro on hPDLSCs. Cell viability and apoptosis assays were performed using eluates of each root-end filling material. To evaluate cell attachment to the different materials, hPDLSCs were directly seeded onto the material surfaces and analyzed by scanning electron microscopy. The chemical composition of the root-end filling materials was determined by energy-dispersive x-ray and eluates were analyzed by inductively coupled plasma-mass spectrometry. Statistical differences were assessed by ANOVA and Tukey test (p < 0.05). RESULTS: Under an acidic environment, both materials displayed similar ion release abilities, with the increased release of Si and Ca ions. Substantial changes in microstructure were observed for both materials after exposure to acidic pH. In addition, material exposure to an acidic environment showed a similar degree of cell adherence, and, surprisingly, MTA Repair HP exhibited higher cell viability rates at pH 5.2 than ProRoot MTA. CONCLUSIONS: Exposure to an acidic environment promoted Si and Ca ion release from ProRoot MTA and MTA Repair HP. Moreover, we observed optimal biological properties of ProRoot MTA and MTA Repair HP in terms of cell viability, cell death, and cell attachment in both environments. CLINICAL RELEVANCE: These results may suggest that MTA Repair HP and ProRoot exhibited optimal biological properties in terms of cell viability, cell death and cell attachment in acidic environment, being considered as materials for root-end filling and perforations.

Non-Invasive Forehead Segmentation in Thermographic Imaging.

The temperature of the forehead is known to be highly correlated with the internal body temperature. This area is widely used in thermal comfort systems, lie-detection systems, etc. However, there is a lack of tools to achieve the segmentation of the forehead using thermographic images and non-intrusive methods. In fact, this is usually segmented manually. This work proposes a simple and novel method to segment the forehead region and to extract the average temperature from this area solving this lack of non-user interaction tools. Our method is invariant to the position of the face, and other different morphologies even with the presence of external objects. The results provide an accuracy of 90% compared to the manual segmentation using the coefficient of Jaccard as a metric of similitude. Moreover, due to the simplicity of the proposed method, it can work with real-time constraints at 83 frames per second in embedded systems with low computational resources. Finally, a new dataset of thermal face images is presented, which includes some features which are difficult to find in other sets, such as glasses, beards, moustaches, breathing masks, and different neck rotations and flexions.

In vitro biocompatibility of ammonia-free silver fluoride products on human dental pulp stem cells.

OBJECTIVES: Silver fluoride (SF) is a preventive and therapeutic option for dental pathological processes involving structural alterations of the hard tissues, either during their formation or those caused by caries or other pathological reasons. This study aimed to compare the biological properties of two commercial SF products, one of them with ammonium (Riva Star; SDF) and the other ammonium-free (Riva Star Aqua; AgF), both with or without potassium iodide (KI), by the assessment of the cytotoxicity of the materials' eluates. METHODS: Human dental pulp stem cells (hDPSCs) were obtained from healthy 18-23-year-old donors. Three dilutions were prepared for the tested materials (0.005%, 0.0005%, and 0.0001%). The following groups were assessed: (AgF, AgF+KI, SDF, SDF+KI, KI, negative control). A series of cytocompatibility assays were performed: MTT assay, IC50 assay, wound healing (migration) assay, cell cytoskeleton staining, analysis of cell apoptosis and necrosis, and reactive oxygen species production. The normality in the distribution of the data was previously confirmed via a Q-Q plot. Statistical significance was tested using one way ANOVA and Tukey's post hoc test. RESULTS: The incorporation of KI improved the cytocompatibility of both SF products in terms of viability, migration, morphology, apoptosis, and reactive oxygen species production. This difference was higher in the AgF group. The lowest dilutions of SF+KI and AgF+KI showed a similar cytocompatibility to that of the control group (MTT assay (p > 0.05 after 24, 48, and 72 h of culture); migration assay (p > 0.05 after 24, 48, and 72 h of culture); reactive oxygen species production (p > 0.05 after 72 h of culture). SIGNIFICANCE: Riva Star Aqua shows lower cytotoxicity than Riva Star on hDPSCs. It can be considered as a good alternative in the conservative treatment of dental caries and in the preservation and remineralisation of viable dentine tissue.

Assessment of the anti-inflammatory and biological properties of Bioroot Flow: A novel bioceramic sealer.

INTRODUCTION: BioRoot Flow (BRF) is a novel premixed bioceramic sealer indicated for endodontic treatments, but the biological and immunomodulatory effects of this endodontic sealer on human periodontal ligament stem cells (hPDLSCs) have not been elucidated. METHODS: To ascertain the biological impact of BRF, TotalFill BC Sealer (TFbc), and AH Plus (AHP) on human Periodontal Ligament Stem Cells (hPDLSCs), assessments were conducted to evaluate the cytocompatibility, cellular proliferation, migratory capacity, osteo/cementogenic differentiation potential, the ability to form mineralized nodules, and the immunomodulatory characteristics of hPDLSCs following treatment with these endodontic sealers. RESULTS: Biological assays showed adequate cell metabolic activity and cell migration in BRF, while SEM assay evidenced that TFbc and BRF groups demonstrated a superior cell adhesion process, including substrate adhesion, cytoskeleton development, and spreading on the niche-like structures of the cement as compared to the AHP group. TFbc and BRF-treated groups exhibited a significantly lower IL6 and IL8 production than AHP (* p <.05). The bioceramic sealers stimulated heightened expression of BSP, CEMP-1, and CAP genes within a 7-14 day period. Notably, BRF and TFbc demonstrated a significant enhancement in the mineralization of hPDLSCs when compared to the negative control. Among these, cells treated with BRF showed a more substantial accumulation of calcium (*** p < .001). CONCLUSIONS: Taken together, these findings indicate that BRF can potentially enhance cell differentiation by promoting the expression of essential genes related to bone and cement formation. In addition, BRF and TFbc displayed anti-inflammatory effects.

Premixed calcium silicate-based ceramic sealers promote osteogenic/cementogenic differentiation of human periodontal ligament stem cells: A microscopy study.

To evaluate the effects of premixed calcium silicate based ceramic sealers on the viability and osteogenic/cementogenic differentiation of human periodontal ligament stem cells (hPDLSCs). The materials evaluated were TotalFill BC Sealer (TFbc), AH Plus Bioceramic Sealer (AHPbc), and Neosealer Flo (Neo). Standardized discs and 1:1, 1:2, and 1:4 eluates of the tested materials were prepared. The following in vitro experiments were carried out: ion release, cell metabolic activity 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell migration, immunofluorescence experiment, cell attachment, gene expression, and mineralization assay. Statistical analyses were performed using one-way ANOVA followed by Tukey's post hoc test (p < .05). Increased Ca2+ release was detected in TFbc compared to AHPbc and Neo (*p < .05). Biological assays showed a discrete cell metabolic activity and cell migration in Neo-treated cell, whereas scanning electronic microscopy assay exhibited that TFbc group had a better cell adhesion process of substrate attachment, spreading, and cytoskeleton development on the niche-like structures of the cement than AHPbc and Neo. The sealers tested were able to induce overexpression of the CEMP-1, ALP, and COL1A1 genes in the first days of exposure, particularly in the case of TFbc (***p < .001). All materials tested significantly increased the mineralization of hPDLSCs when compared to the negative control, although more pronounced calcium deposition was observed in the TFbc-treated cells (***p < .001). Our results suggested that TFbc promotes cell differentiation, both by increasing the expression of key osteo/odontogenic genes and by promoting mineralization of the extracellular matrix, whereas this phenomenon was less evident in Neo and AHPbc. RESEARCH HIGHLIGHTS: TFbc group had a better cell adhesion process of substrate attachment, spreading, and cytoskeleton development on the niche-like structures of the cement than AHPbc and Neo. The sealers tested were able to induce overexpression of the CEMP-1, ALP, and COL1A1 genes in the first days of exposure, particularly in the case of TFbc. All materials tested significantly increased the mineralization of hPDLSCs when compared to the negative control, although more pronounced calcium deposition was observed in the TFbc-treated cells.

3D Graphene/silk fibroin scaffolds enhance dental pulp stem cell osteo/odontogenic differentiation.

OBJECTIVES: The current in vitro study aims to evaluate silk fibroin with and without the addition of graphene as a potential scaffold material for regenerative endodontics. MATERIAL AND METHODS: Silk fibroin (SF), Silk fibroin/graphene oxide (SF/GO) and silk fibroin coated with reduced graphene oxide (SF/rGO) scaffolds were prepared (n = 30). The microarchitectures and mechanical properties of scaffolds were evaluated using field emission scanning electron microscopy (FESEM), pore size and water uptake, attenuated total reflectance fourier transformed infrared spectroscopy (ATR-FTIR), Raman spectroscopy and mechanical compression tests. Next, the study analyzed the influence of these scaffolds on human dental pulp stem cell (hDPSC) viability, apoptosis or necrosis, cell adhesion, odontogenic differentiation marker expression and mineralized matrix deposition. The data were analyzed with ANOVA complemented with the Tukey post-hoc test (p < 0.005). RESULTS: SEM analysis revealed abundant pores with a size greater than 50 nm on the surface of tested scaffolds, primarily between 50 nm and 600 µm. The average value of water uptake obtained in pure fibroin scaffolds was statistically higher than that of those containing GO or rGO (p < 0.05). ATR-FTIR evidenced that the secondary structures did not present differences between pure fibroin and fibroin coated with graphene oxide, with a similar infrared spectrum in all tested scaffolds. Raman spectroscopy showed a greater number of defects in the links in SF/rGO scaffolds due to the reduction of graphene. In addition, adequate mechanical properties were exhibited by the tested scaffolds. Regarding biological properties, hDPSCs attached to scaffolds were capable of proliferating at a rate similar to the control, without affecting their viability over time. A significant upregulation of ALP, ON and DSPP markers was observed with SF/rGO and SF/GO groups. Finally, SF/GO and SF/rGO promoted a significantly higher mineralization than the control at 21 days. SIGNIFICANCE: Data obtained suggested that SF/GO and SF/rGO scaffolds promote hDPSC differentiation at a genetic level, increasing the expression of key osteo/odontogenic markers, and supports the mineralization of the extracellular matrix. However, results from this study are to be interpreted with caution, requiring further in vivo studies to confirm the potential of these scaffolds.

Autogenous Tooth Bone Grafts for Repair and Regeneration of Maxillofacial Defects: A Narrative Review.

Autogenous tooth graft is an innovative and ingenious technique that employs a stepwise approach and utilizes human teeth as an autogenous source of bone graft. The structure of teeth closely resembles bone, both physically and biochemically, and can be efficiently used for the process as it depicts properties of osteoinduction and osteoconduction. Autogenous tooth bone has characteristics similar to bone grafts in terms of healing potential, physical properties, and clinical outcome. Autogenous tooth graft has shown reasonable promise as a graft material for the regeneration of maxillary and mandibular defects. Autogenous tooth bone graft finds its principal application in sinus and ridge augmentations and for socket preservation before implant placement. Additionally, it can be used successfully for alveolar cleft patients and patients with limited periodontal defects. The overall complication rates reported for autogenous tooth grafts are comparable to other graft sources. However, although long-term results are still underway, it is still recommended as a grafting option for limited defects in the cranio-facial region.

Dental Healthcare Amid the COVID-19 Pandemic.

The hustle and bustle of the planet Earth have come to a halt thanks to the novel coronavirus. The virus has affected approximately 219 million people globally; taken the lives of 4.55 million patients as of September 2021; and created an ambiance of fear, social distancing, and economic instability. The purpose of this review article is to trace the historical origin and evolution of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). The virus is highly contagious with a unique feature of rapid mutations-the scientific research is paving the way for discoveries regarding novel coronavirus disease (COVID-19) diagnosis, features, prevention, and vaccination. The connections between the coronavirus pandemic and dental practices are essential because COVID-19 is transmitted by aerosols, fomites, and respiratory droplets, which are also produced during dental procedures, putting both the patient and the dentist at risk. The main emphasis of this paper is to highlight the psychological, economic, and social impact of this pandemic on dental practices throughout the world and under what circumstances and guidelines can dental health care be provided. In the current situation of the pandemic, an appropriate screening tool must be established either by using rapid molecular testing or saliva point-of-care technology, which will be effective in identifying as well as isolating the potential contacts and carriers in hopes to contain and mitigate infection. The blessing in disguise is that this virus has united the leaders, scientists, health care providers, and people of all professions from all around the world to fight against a common enemy.

Could the Calcium Silicate-Based Sealer Presentation Form Influence Dentinal Sealing? An In Vitro Confocal Laser Study on Tubular Penetration.

Dentinal tubule penetration influences root canal treatment sealing. The aim of this study was to compare dentinal penetration of two clinical presentations of silicate-based sealers using confocal laser. Sixty single-rooted human teeth from 50-70 year-old patients extracted for orthodontic/periodontal reasons were used. Canals were prepared using Mtwo system up to 35/0.04, with 5.25% NaOCl irrigation and final irrigation using 17% EDTA. Teeth were randomly assigned into study groups (ni = 20): EndoSequence BC sealer (ES, group 1), BioRoot RCS (BR, group 2); and a control group (nc = 20) with AH Plus (AHP). Root canals were obturated with 35/0.04 gutta-percha (single-cone technique). The samples were obtained from apical, middle, and coronal thirds. Dentinal tubule penetration depth and percentage of penetration around the canal perimeter were measured. The statistical analysis was performed using Mann Whitney U test and Wilcoxon t-test (95% confidence interval). ES exhibited a significantly higher penetration than AHP in apical and middle thirds (p < 0.05), and in middle and coronal thirds relative to BR (p < 0.05). The percentage of penetration around the canal perimeter was significantly higher for ES compared to BR in all thirds, but only in the apical third for AHP (p < 0.05). The pre-mixed silicate-based sealer exhibited better penetration than the powder/liquid one.

Topical fluoride varnishes promote several biological responses on human gingival cells.

OBJECTIVE: To compare the in vitro cytotoxicity of four commercial topical fluoride varnishes widely used in daily dental practice for the prevention of caries on human fibroblasts: Cervitec F, Fixofluor, Fluor Protector S and Duraphat. MATERIAL AND METHODS: Human gingival fibroblasts (hGF) were exposed to different concentrations of fluoride varnishes extracts. Biological assays, including MTT and IC50 value determination, annexin-V/7-AAD staining, cell migration and F-actin staining with phalloidin were carried out. Statistical analyses were performed using one-way ANOVA and Tukey's post hoc test. RESULTS: At 4% concentration, all of the fluoride varnishes extracts affected fibroblasts metabolic activity, exhibiting a high degree of cytotoxicity at all measured time points. At 0.1% and 1%, Duraphat and Fixofluor or Fluor Protector S and Cervitec F exerted the lowest or highest cytotoxic effects, respectively. Similar effects were evidenced when induction of apoptosis/necrosis and cell migration assays were analyzed. Immunocytochemical assays revealed a similar number of fibroblasts, without changes in the morphology and F-actin content at 0.1% concentration of all tested materials, while at 1% concentration, Fluor Protector S and Cervitec F showed few cells with aberrant morphology or non-adhered cells, respectively. CONCLUSIONS: Different commercial topical fluoride varnishes with the same therapeutic indication may exhibit different biological effects and cytotoxicity on fibroblasts.

Melatonin Treatment Alters Biological and Immunomodulatory Properties of Human Dental Pulp Mesenchymal Stem Cells via Augmented Transforming Growth Factor Beta Secretion.

INTRODUCTION: Melatonin is an endogenous neurohormone with well-reported anti-inflammatory and antioxidant properties, but the direct biological and immunomodulatory effects of melatonin on human dental pulp stem cells (hDPSCs) has not been fully elucidated. The aim of this study was to evaluate the influence of melatonin on the cytocompatibility, proliferation, cell migration, odontogenic differentiation, mineralized nodule formation, and immunomodulatory properties of hDPSCs. METHODS: To address the melatonin biological effects on hDPSCs, the cytocompatibility, proliferation, cell migration, odontogenic differentiation, mineralized nodule formation, and immunomodulatory properties of hDPSCs after melatonin treatment were evaluated. The statistical differences were evaluated using 1-way analysis of variance with the Tukey multiple comparison test. RESULTS: We found that melatonin did not alter hDPSC immunophenotype or cell viability, even at the highest concentrations used. However, using intermediate melatonin concentrations (10-300 µmol/L), a significantly higher proliferation rate (P < .05 and P < .01) and migration of hDPSCs (P < .01) were observed. Importantly, melatonin treatment (100 µmol/L) significantly increased the secretion of the anti-inflammatory cytokine transforming growth factor beta (P < .05 and P < .01) and provoked a more robust antiproliferative effect on mitogen-stimulated T cells (P < .05). Finally, and unlike previous results found with mesenchymal stem cells from other sources, melatonin fails to induce or accelerate the spontaneous osteogenic differentiation of hDPSCs. CONCLUSIONS: Together, these findings provide key data on the bioactivity of melatonin and its effects on hPDSC biological and immunomodulatory properties.

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.

Biological Effects of New Hydraulic Materials on Human Periodontal Ligament Stem Cells.

Background: The aim of this study was: to evaluate the biological properties of new hydraulic materials: Bio-C Repair and Bio-C Sealer. Methods: Periodontal ligament stem cells were exposed to several dilutions of Bio-C Repair and Bio-C Sealer. The ion release profile and pH were determined. Metabolic activity, cell migration and cell survival were assessed using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), wound-healing assays and Annexin assays, respectively. Cells were cultured in direct contact with the surface of each material. These were then analyzed via scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Statistical differences were assessed using a two-way ANOVA (α < 0.05). Results: Similar pH was observed in these cements. Bio-C Sealer released significantly more Ca and Si ions (p < 0.05) in comparison with Bio-C Repair. Undiluted Bio-C Sealer induced a significant reduction on cellular viability, cell survival and cell migration when compared to the control (p < 0.05). Moreover, SEM showed abundant cells adhered on Bio-C Repair and a moderate number of cells attached on Bio-C Sealer. Finally, EDX analysis identified higher percentages of Ca and O in the case of Bio-C repair than with Bio-C sealer, while other elements such as Zr and Si were more abundant in Bio-C sealer. Conclusions: Bio-C Repair displayed higher cell viability, cell adhesion and migration rates than Bio-C Sealer.

Physicochemical, cytotoxicity and in vivo biocompatibility of a high-plasticity calcium-silicate based material.

The purpose of this work was to evaluate the physicochemical properties, the cytotoxicity and in vivo biocompatibility of MTA Repair HP (MTA HP) and White MTA (WMTA). The setting time, flow, radiopacity and water solubility were assessed. To the cytotoxicity assay, primary human osteoblast cells were exposed to several dilutions of both materials eluates. MTT assay, apoptosis assay and cell adhesion assay were performed. The in vivo biocompatibility was evaluated through histological analysis using different staining techniques. No differences were observed between MTA HP and WMTA for setting time, radiopacity, solubility and water absorption (P > 0.05). However, MTA HP showed a significantly higher flow when compared to WMTA (P < 0.05). Cell viability results revealed that the extracts of WMTA and MTA HP promoted the viability of osteoblasts. After incubation of cells with the endodontic cement extracts, the percentage of apoptotic or necrotic cells was very low (<3%). Furthermore, SEM results showed a high degree of cell proliferation and adhesion on both groups. MTA HP showed similar in vivo biocompatibility to the WMTA and the control group in all time-points. The MTA HP presented adequate physicochemical and biological properties with improved flow ability when compared to WMTA. Such improved flow ability may be a result of the addition of a plasticizing agent and should be related to an improvement in the handling of MTA HP.

Hydrogen Peroxide Diffusion through Enamel and Dentin.

The purpose of this study was to evaluate the in vitro diffusion of commercial bleaching products (hydrogen peroxide (HP) or carbamide peroxide (CP) based) with different application protocols. Human enamel-dentin discs were obtained and divided into 20 groups. Four commercial products based on HP (Pola Office+(PO), Perfect Bleach (PB), Norblanc Office-automix (NO), and Boost (BT)), and one based on CP (PolaDay CP (PD)), were evaluated with different application protocols (3 applications × 10 min or 1 application × 30 min, with or without light activation). Artificial pulp chambers with 100 µL of a buffer solution were prepared. After each application, the buffer was removed and diffused HP was quantified by fluorimetry. Data were analyzed with two-way analysis of variance (ANOVA) and Tukey's test. In groups where 3 × 10 min applications were done, after the first 10 min, PB, NO, and PD showed similar diffusion (p < 0.05). After the second and third applications, diffusion proved similar for PO and PD, while PB exhibited the greatest diffusion. In the 30 min application groups, PO and BT showed no significant differences (p > 0.05), with similar results for NO and PD. Comparing products with or without light activation, PO, BT, and PB showed significantly greater diffusion with light activation (p < 0.05). Reapplication, and light activation, increased HP diffusion independently of the concentration of the product.

Biocompatibility of New Pulp-capping Materials NeoMTA Plus, MTA Repair HP, and Biodentine on Human Dental Pulp Stem Cells.

INTRODUCTION: The aim of the present study was to evaluate the in vitro cytotoxicity of MTA Repair HP, NeoMTA Plus, and Biodentine, new bioactive materials used for dental pulp capping, on human dental pulp stem cells (hDPSCs). METHODS: Biological testing was carried out in vitro on hDPSCs. Cell viability and cell migration assays were performed using eluates of each capping material. To evaluate cell morphology and cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analyzed by scanning electron microscopy. The chemical composition of the pulp-capping materials was determined by energy-dispersive X-ray and eluates were analyzed by inductively coupled plasma-mass spectrometry. Statistical differences were assessed by analysis of variance and Tukey test (P < .05). RESULTS: Cell viability was moderate after 24 and 48 hours in the presence of MTA Repair HP and NeoMTA Plus, whereas at 48 and 72 hours, Biodentine showed higher rates of cell viability than MTA Repair HP and NeoMTA Plus (P < .001). A cell migration assay revealed adequate cell migration rates for MTA Repair HP and NeoMTA Plus, both similar to the control group rates, meanwhile the highest cell migration rate was observed in the presence of Biodentine (P < .001). Scanning electron microscope studies showed a high degree of cell proliferation and adhesion on Biodentine disks but moderate rates on MTA Repair HP and NeoMTA Plus disks. Energy-dispersive X-ray pointed to similar weight percentages of C, O, and Ca in all 3 materials, whereas other elements such as Al, Si, and S were also found. CONCLUSIONS: The new pulp-capping materials MTA Repair HP, NeoMTA Plus, and Biodentine showed a suitable degree of cytocompatibility with hDPSCs, and good cell migration rates, although Biodentine showed higher rates of proliferation time-dependent.

Thermo-setting glass ionomer cements promote variable biological responses of human dental pulp stem cells.

OBJECTIVE: To evaluate the in vitro cytotoxicity of Equia Forte (GC, Tokyo, Japan) and Ionostar Molar (Voco, Cuxhaven, Germany) on human dental pulp stem cells (hDPSCs). METHODS: hDPSCs isolated from third molars were exposed to several dilutions of Equia Forte and Ionostar Molar eluates (1/1, 1/2 and 1/4). These eluates were obtained by storing material samples in respective cell culture medium for 24h (n=40). hDPSCs in basal growth culture medium were the control. Cell viability and cell migration assays were performed using the MTT and wound-healing assays, respectively. Also, induction of apoptosis and changes in cell phenotype were evaluated by flow cytometry. Changes in cell morphology were analysed by immunocytofluorescence staining. To evaluate cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analyzed by scanning electron microscopy (SEM). The chemical composition of the materials was determined by energy dispersive X-ray (EDX) and eluates were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Statistical analysis was performed with analysis of variance (ANOVA) and Student's t-test (α<0.05). RESULTS: Undiluted Equia Forte extracts led to a similar cell proliferation rates than the control group from 72h onwards. There were no significance differences between Equia Forte and Ionostar Molar in terms of cell apoptosis and phenotype. However, in presence of Equia extracts the migration capacity of hDPSCs was higher than in presence of Ionostar Molar (p<0.05). Also, SEM studies showed a higher degree of cell attachment when Equia Forte extracts were used. Finally, EDX analysis pointed to different weight percentages of C, O and Ca ions in glass ionomer cements, while other elements such as La, Al, Si, W, Mo and F were also detected. SIGNIFICANCE: In summary, Equia Forte promoted better biological responses in hDPSCs than Ionostar Molar.