Dental Pulp Capping Materials Research Articles

Effects of inorganic phosphate on stem cells isolated from human exfoliated deciduous teeth

Calcium phosphate-based materials (CaP) are introduced as potential dental pulp capping materials for deciduous teeth. The present study investigated the influence of inorganic phosphate (Pi) on regulating stem cells isolated from human exfoliated deciduous teeth (SHED). SHEDs were treated with Pi. Cell cycle progression and apoptosis were examined using flow cytometry analysis. Osteo/odontogenic and adipogenic differentiation were analyzed using alizarin red S and oil red O staining, respectively. The mRNA expression profile was investigated using a high-throughput RNA sequencing technique. Pi increased the late apoptotic cell population while cell cycle progression was not altered. Pi upregulated osteo/odontoblastic gene expression and enhanced calcium deposition. Pi-induced mineralization was reversed by pretreatment of cells with Foscarnet, or p38 inhibitor. Pi treatment inhibited adipogenic differentiation as determined by decreased PPARγ expression and reduced intracellular lipid accumulation. Bioinformatic analysis of gene expression profiles demonstrated several involved pathways, including PI3K/AKT, MAPK, EGFR, and VEGF signaling. In conclusion, Pi enhanced osteo/odontogenic but inhibited adipogenic differentiation in SHED.

Investigation of a Novel Injectable Chitosan Oligosaccharide-Bovine Hydroxyapatite Hybrid Dental Biocomposite for the Purposes of Conservative Pulp Therapy.

This study aimed to develop injectable chitosan oligosaccharide (COS) and bovine hydroxyapatite (BHA) hybrid biocomposites, and characterise their physiochemical properties for use as a dental pulp-capping material. The COS powder was prepared from chitosan through hydrolytic reactions and then dissolved in 0.2% acetic acid to create a solution. BHA was obtained from waste bovine bone and milled to form a powder. The BHA powder was incorporated with the COS solution at different proportions to create the COS-BHA hybrid biocomposite. Zirconium oxide (ZrO2) powder was included in the blend as a radiopacifier. The composite was characterised to evaluate its physiochemical properties, radiopacity, setting time, solubility, and pH. Fourier-transform infrared spectroscopic analysis of the COS-BHA biocomposite shows the characteristic peaks of COS and hydroxyapatite. Compositional analysis via ICP-MS and SEM-EDX shows the predominant elements present to be the constituents of COS, BHA, and ZrO2. The hybrid biocomposite demonstrated an average setting time of 1 h and 10 min and a pH value of 10. The biocomposite demonstrated solubility when placed in a physiological solution. Radiographically, the set hybrid biocomposite appears to be more radiopaque than the commercial mineral trioxide aggregate (MTA). The developed COS-BHA hybrid biocomposite demonstrated good potential as a pulp-capping agent exhibiting high pH, with a greater radiopacity and reduced setting time compared to MTA. Solubility of the biocomposite may be addressed in future studies with the incorporation of a cross-linking agent. However, further in vitro and in vivo studies are necessary to evaluate its clinical feasibility.

Anti-Inflammatory and Mineralization Effects of an ASP/PLGA-ASP/ACP/PLLA-PLGA Composite Membrane as a Dental Pulp Capping Agent.

Dental pulp is essential for the development and long-term preservation of teeth. Dental trauma and caries often lead to pulp inflammation. Vital pulp therapy using dental pulp-capping materials is an approach to preserving the vitality of injured dental pulp. Most pulp-capping materials used in clinics have good biocompatibility to promote mineralization, but their anti-inflammatory effect is weak. Therefore, the failure rate will increase when dental pulp inflammation is severe. The present study developed an amorphous calcium phosphate/poly (L-lactic acid)-poly (lactic-co-glycolic acid) membrane compounded with aspirin (hereafter known as ASP/PLGA-ASP/ACP/PLLA-PLGA). The composite membrane, used as a pulp-capping material, effectively achieved the rapid release of high concentrations of the anti-inflammatory drug aspirin during the early stages as well as the long-term release of low concentrations of aspirin and calcium/phosphorus ions during the later stages, which could repair inflamed dental pulp and promote mineralization. Meanwhile, the composite membrane promoted the proliferation of inflamed dental pulp stem cells, downregulated the expression of inflammatory markers, upregulated the expression of mineralization-related markers, and induced the formation of stronger reparative dentin in the rat pulpitis model. These findings indicate that this material may be suitable for use as a pulp-capping material in clinical applications.

Efficacy of photobiomodulation when used with calcium hydroxide for pulp capping of dogs’ teeth

Objective: The current study assessed the effect of calcium hydroxide [Ca(OH)2] and Photobiomodulation [PBM] on pulp capping when [Ca(OH)2] is used as a dental pulp capping material on dental pulp exposures of dogs’ teeth. Methods: 48 teeth in 3 mongrel dogs were divided in random into two major study groups; group I where Ca(OH)2 was used as a pulp capping agent and group II in which both Ca(OH)2+PBM were used. The groups were equally divided according to the observation period following completion of pulp capping into Subgroup (A) 1week, Subgroup (B) 2 and subgroup (C)16weeks. The teeth were examined for histological inflammatory response as well as dentine bridge formation Results: With regards to inflammatory response at 1 week significantly less intense inflammation was observed in Ca(OH)2+PBM (group II) compared to the Ca(OH)2 (group I) for the same time period with no significant difference for between group I and group II for other time intervals. As for dentin bridge formation PBM+Ca(OH)2 groups showed statistically significant thicker dentine bridge formation at 16 weeks than Ca(OH)2 alone group for the same time period with no significant difference for between group I and group II for other time intervals.

Development of a novel direct dental pulp-capping material using 4-META/MMA-TBB resin with nano hydroxyapatite

In the case of dental pulp exposure, direct pulp capping is often performed to preserve vital dental pulp tissue. Numerous studies regarding the development of direct pulp-capping materials have been conducted, but materials with an appropriate sealing ability, which induce dense reparative dentin formation, have not been developed. Although nano hydroxyapatite (naHAp) is a bone-filling material with bioactivity and biocompatibility, the inductive effects of naHAp on reparative dentin formation remain unclear. In the present study, the effects of dental adhesive material 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate tri-n-butylborane [4-META/MMA-TBB or Super-bond (SB)], which included 10%, 30%, and 50% naHAp (naHAp/SB) on odontoblastic differentiation of dental pulp stem cells (DPSCs) and reparative dentin formation were investigated. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer analysis were performed to verify the existence of naHAp particles on the surface of naHAp/SB discs. The tensile adhesive strength of naHAp/SB was measured using a universal testing machine. As a result, 10% naHAp/SB and 30% naHAp/SB showed almost the same tensile adhesive strength as SB but 50% naHAp/SB showed significantly lower than the other experimental group. WST-1 proliferation assay and SEM analysis revealed that naHAp/SB did not affect the proliferation of DPSCs. Calcium release assay, quantitative RT-PCR, and western blotting analysis demonstrated that naHAp/SB did not release calcium ion but 30% naHAp/SB increased the expression of calcium-sensing receptor (CaSR) in DPSCs. Additionally, quantitative RT-PCR, western blotting analysis, Alizarin Red S- and von Kossa staining revealed that 30% naHAp/SB induced odontoblastic differentiation of DPSCs, which was inhibited by a MEK/ERK inhibitor and CaSR antagonist. Furthermore, 30% naHAp/SB promoted dense reparative dentin formation in an experimentally-formed rat dental pulp exposure model. These findings suggest that 30% naHAp/SB can be used as an ideal direct pulp capping material.

Human dental pulp stem cell responses to different dental pulp capping materials

BackgroundDirect pulp capping is a vital pulp therapy for a pin-point dental pulp exposure. Applying a pulp capping material leads to the formation of a dentin bridge and protects pulp vitality. The aim of this study was to compare the effects of four dental materials, DyCal®, ProRoot® MTA, Biodentine™, and TheraCal™ LC in vitro.MethodsHuman dental pulp stem cells (hDPs) were isolated and characterized. Extraction medium was prepared from the different pulp capping materials. The hDP cytotoxicity, proliferation, and migration were examined. The odonto/osteogenic differentiation was determined by alkaline phosphatase, Von Kossa, and alizarin red s staining. Osteogenic marker gene expression was evaluated using real-time polymerase chain reaction.ResultsProRoot® MTA and Biodentine™ generated less cytotoxicity than DyCal® and TheraCal™ LC, which were highly toxic. The hDPs proliferated when cultured with the ProRoot® MTA and Biodentine™ extraction media. The ProRoot® MTA and Biodentine™ extraction medium induced greater cell attachment and spreading. Moreover, the hDPs cultured in the ProRoot® MTA or Biodentine™ extraction medium migrated in a similar manner to those in serum-free medium, while a marked reduction in cell migration was observed in the cells cultured in DyCal® and TheraCal™ LC extraction media. Improved mineralization was detected in hDPs maintained in ProRoot® MTA or Biodentine™ extraction medium compared with those in serum-free medium.ConclusionThis study demonstrates the favorable in vitro biocompatibility and bioactive properties of ProRoot® MTA and Biodentine™ on hDPs, suggesting their superior regenerative potential compared with DyCal® and TheraCal™.

Comparison of Chemical Composition between Indonesian White Portland Cement and MTA as Dental Pulp Capping Material

Pulp capping has been suggested as one treatment of choice after pulp exposure. Calcium hydroxide [Ca (OH)2] recognized as gold standard of direct pulp capping matter for some decades. Throughout the time, a new cement known as mineral trioxide aggregate (MTA) has developed into a prominent alternative. A recent study found that matter as the most effective pulp capping material. Despite the fact, MTA is an expensive material. Several studies in different country show that portland cement has highly similarity chemical composition with MTA. The purpose of this study is to evaluate the chemical composition of white portland cement that fabricated in Indonesia compared to MTA. White portland cement fabricated in Indonesia was used as a sample in this study and commercial MTA as a control. Samples and control were assessed using X-ray fluorescence spectrometry (XRF) to figure out chemical composition and concentration. Investigating the wavelength of the functional group using Fourier Transform Infrared Spectroscopy (FTIR). The results show that composition, concentration, and functional group either Indonesian white portland cement and MTA has highly similar. Hence, it has a chance to use Indonesian white portland cement for dental pulp capping material as MTA substitution.

Mineralogical and Microstructural Characteristics of Two Dental Pulp Capping Materials.

This paper aims to investigate the composition, surface, and microstructural characteristics, and bioactivity of two commercially available pulp capping materials known as TheraCal LC and BIO MTA+. The materials were prepared as cylindrical samples and assessed by X-ray diffraction (XRD) and complex thermal analysis for mineralogical characterization, and by scanning electron microscopy (SEM) coupled with energy dispersive of X-ray (EDX), Fourier-Transformed Infrared Spectroscopy (FT-IR), and atomic force microscopy (AFM) for microstructural and surface characteristics. The in vitro bioactivity was highlighted by surface mineralization throughout SEM coupled with EDX and FT-IR analysis. XRD analysis performed on both materials showed calcium silicate phases and different radiopacifying compounds. AFM measurements indicated a smoother and more homogenous surface with a lower average roughness for TheraCal LC due to the resin matrix from its composition. FT-IR analysis displayed bands for several compounds in both materials. Both materials exhibited bioactive properties showing surface mineralization after being immersed in solution similar to the human physiological environment. However, the MTA cement showed a better mineralization due to the anhydrous and hydrated phases.

Biological properties of modified bioactive glass on dental pulp cells

Dental caries is a bacteria-caused condition classified among the most common chronic diseases worldwide. Treatment of dental caries implies the use of materials having regenerative and anti-bacterial properties, and controlling inflammation is critical for successful endodontic regeneration. ObjectivesThe aim of this study was to fabricate and characterize a novel composite incorporating sol-gel derived silver-doped bioactive glass (BG) in a chitosan (CS) hydrogel at a 1:1 wt ratio(Ag-BG/CS). MethodsThe effect of Ag-BG/CS on dental pulp cells (DPCs) proliferation was analyzed by CCK-8 assay, whereas the adhesion of DPCs was evaluated by confocal microscopy. The physical morphology of Ag-BG/CS was analyzed by scanning electron microscope. The anti-inflammatory effect of Ag-BG/CS was investigated by quantitative polymerase chain reaction (qPCR). Moreover, the effect of Ag-BG/CS on odontogenic differentiation of DPCs was studied by immunochemical staining, tissue-nonspecific alkaline phosphatase staining, qPCR, and western blot analyses. The antibacterial activity against dental caries key pathogenic bacteria was also evaluated. ResultsThe results of this study showed that Ag-BG/CS did not affect the proliferation of DPCs, it down-regulated the inflammatory-associated markers (IL-1β, IL-6, IL-8, TNF-α) of DPCs treated with Escherichia coli lipopolysaccharide (LPS) by inhibiting NF-κB pathway, and enhanced the in vitro odontogenic differentiation potential of DPCs. Furthermore, Ag-BG/CS strongly inhibited Streptococcus mutans and Lactobacillus casei growth. ConclusionsThis novel biomaterial possessed antibacterial and anti-inflammatory activity, also enhanced the odontogenic differentiation potential of LPS-induced inflammatory-reacted dental pulp cells. The material introduced in this study may thus represent a suitable dental pulp-capping material for future clinical applications.

Remineralization ability of two hydraulic calcium-silicate based dental pulp capping materials: Cell-independent model.

BackgroundThis study aimed to evaluate remineralizing ability of two hydraulic calcium-silicate cements (Biodentine and TheraCal LC).Material and MethodsArtificial carious lesions were introduced into the pulpal floors (1-1.5 mm) and axial walls of occlusal prepared cavity halves through pH cycling. Cycling was made through demineralizing solution (pH 3), for 8 hours and remineralizing solution (pH 7) for 16 hours. The total period of pH cycling was 14 days. Prepared cavities with the tested materials seated directly on the pulpal floor and in contact with the axial walls were stored in phosphate buffer solutions (PBS) (pH 7.2–7.4). The changes in the weight percentages (wt%) of calcium (Ca) and phosphorus (P) were detected using SEM and energy dispersive X-ray spectroscopy with reference to sound dentin after three intervals (one week, 3 and 6 months). Data were statistically analyzed using two-way ANOVA and Tukey’s post hoc test.ResultsDemineralized dentin, next to Biodentine, showed statistically higher intensities of Ca and P wt% after the three periods of incubation (p< 0.05). Surface mapping of both tested cements and their adjacent demineralized dentin showed increase in overall distribution of previous ions. SEM of subsurface layer under both materials showed filling of most intra-tubular areas with rod-like mineralized structure without significant difference.ConclusionsBiodentine has a higher ability to enrich the artificial carious dentin with significantly higher mineral contents available for remineralization. Both pulp-capping materials have significantly induced remineralization of demineralized dentin beneath them after total period of incubation. Key words:Artificial Caries, Hydraulic Cements, pH Cycling, Remineralization.

The emerging role of extracellular Ca2+ in osteo/odontogenic differentiation and the involvement of intracellular Ca 2+ signaling: From osteoblastic cells to dental pulp cells and odontoblasts.

Calcium ions (Ca2+ ) is the main element of dental pulp capping materials. Ca 2+ signaling plays a crucial role in a myriad of cell activities. An overwhelming array of studies have already reported the experimental and clinical benefits of Ca2+ -enriched materials in the treatment of teeth with accidental vital pulp exposure and incomplete root formation. Thus, Ca2+ signaling has always been an excellent target for the design of various novel biomaterials for use in revitalizing or regenerative endodontic procedures. However, the molecular mechanisms that enable dental pulp cells (DPCs) to detect and respond to extracellular Ca2+ have not been characterized in detail before. In this review, we mainly outline the pathways by which the cell detects and responds to extracellular Ca2+ , as well as the relevant regulatory paths in DPCs and odontoblasts, and discuss the potential role of Ca2+ as a therapeutic tool. Moreover, because DPCs share many of the same functional properties that are found in osteoblasts, some comparisons with bone cells were additionally incorporated into this text.

Effects of pulpotomy using mineral trioxide aggregate on prostaglandin transporter and receptors in rat molars

Mineral trioxide aggregate (MTA) is a commonly used dental pulp-capping material with known effects in promoting reparative dentinogenesis. However, the mechanism by which MTA induces dentine repair remains unclear. The aim of the present study was to investigate the role of prostaglandin E2 (PGE2) in dentine repair by examining the localisation and mRNA expression levels of its transporter (Pgt) and two of its receptors (Ep2 and Ep4) in a rat model of pulpotomy with MTA capping. Ep2 expression was detected in odontoblasts, endothelial cells, and nerve fibres in normal and pulpotomised tissues, whereas Pgt and Ep4 were immunolocalised only in the odontoblasts. Moreover, mRNA expression of Slco2a1 (encoding Pgt), Ptger2 (encoding Ep2), and Ptger4 (encoding Ep4) was significantly upregulated in pulpotomised dental pulp and trigeminal ganglia after MTA capping. Our results provide insights into the functions of PGE2 via Pgt and Ep receptors in the healing dentine/pulp complex and may be helpful in developing new therapeutic targets for dental disease.

Evaluation of cytotoxicity and pH changes generated by various dental pulp capping materials - an in vitro study.

Various materials are used in direct dental pulp capping method. Their biocompatibility and alkalizing abilities are of primary importance affecting therapeutic effects. The aim of this study was to evaluate and compare the cytotoxicity of various pulp-capping materials on human gingival fibroblasts and investigate the pH changes induced by these materials. Human gingival fibroblasts were cultured with nine direct pulp materials using culture plate inserts. The cytotoxic effects were recorded by using an MTT-based colorimetric assay after 3 and 24 h. In the second part of the experiment, the materials were inserted in dialysis tubes and transferred into plastic vials containing deionized water. The changes of the medium pH were measured after 3 and 24 h. We showed differences in cell viability of gingival fibroblasts after varied time of exposition for the tested materials. Cell viability after 24 h increased for Dycal, Biopulp, and Calcipro, and decreased for Calcipulpe, Angelus, Angelus White, and ProRoot Regular. Cell viability for ProRoot and Life did not change. Non-setting calcium hydroxide preparations followed by the MTA group and setting calcium hydroxide materials produced the highest pH. All the tested materials significantly increased pH (p < 0.0001) at 24 h. Currently used pulp capping materials varied in their cytotoxicity relative to human gingival fibroblasts and their alkalizing capacities. Since most likely pH does not affect the viability of cultured cells, further investigations are required to determine physicochemical properties of these materials and the biological activity of the dental pulp.

Ocena zmian pH wywoływanych przez materiały pokrywające miazgę zębową – badania in vitro

Ocena zmian pH wywoływanych przez materiały pokrywające miazgę zębową – badania in vitro

Characterization of Chlorhexidine-Loaded Calcium-Hydroxide Microparticles as a Potential Dental Pulp-Capping Material.

This study explores the delivery of novel calcium hydroxide [Ca(OH)2] microparticles loaded with chlorhexidine (CHX) for potential dental therapeutic and preventive applications. Herein, we introduce a new approach for drug-delivery to deep dentin-surfaces in the form of drug-loaded microparticles. Unloaded Ca(OH)2 [Ca(OH)2/Blank] and CHX-loaded/Ca(OH)2 microparticles were fabricated by aqueous chemical-precipitation technique. The synthesized-microparticles were characterized in vitro for determination of surface-morphology, crystalline-features and thermal-properties examined by energy-dispersive X-ray scanning and transmission electron-microscopy (EDX-SEM/TEM), Fourier-transform infrared-spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning-calorimetry (DSC). Time-related pH changes, initial antibacterial/biofilm-abilities and cytotoxicity of CHX-loaded/Ca(OH)2 microparticles were evaluated. Microparticles were delivered to dentin-surfaces with subsequent SEM examination of treated dentin-substrates. The in vitro and ex vivo CHX-release profiles were characterized. Ca(OH)2/Blank were hexagonal-shaped with highest z-average diameter whereas CHX-inclusion evidenced micro-metric spheres with distinguishable surface “rounded deposits” and a negative-shift in diameter. CHX:Ca(OH)2/50 mg exhibited maximum encapsulation-efficiency with good antibacterial and cytocompatible properties. SEM examination revealed an intact layer of microparticles on exposed dentin-surfaces with retention of spherical shape and smooth texture. Microparticles loaded on dentin-surfaces showed prolonged release of CHX indicating substantial retention on dentin-substrates. This study validated the inherent-applicability of this novel drug-delivery approach to dentin-surfaces using micro-metric CHX-loaded/Ca(OH)2 microparticles.

Current trends and future perspectives of dental pulp capping materials: A systematic review.

To systematically review the literature to analyze the current trends and future perspectives of dental pulp capping materials through an analysis of scientific and technological data. This study is reported in accordance with the PRISMA Statement. Nine databases were screened: PubMed (MedLine), Lilacs, IBECS, BBO, Web of Science, Scopus, SciELO, Google Scholar, and The Cochrane Library. Additionally, the following patent applications were searched online in Questel Orbit (Paris, France), USPTO, EPO, JPO, INPI, and Patentscope databases. A total of 716 papers and 83 patents were included. Calcium hydroxide was the main type of material studied, especially for direct pulp capping, followed by MTA. Patents related to adhesives or resins increased from 1998 e 2008, while in the last years, a major increase was observed in bioactive materials (containing bioactive proteins), materials derived from MTA (calcium silicate, calcium phosphate and calcium aluminate-based cements) and MTA. It was possible to obtain a scientific and technological overview of pulp capping materials. MTA has shown favorable results in vital pulp therapy that seem to surpass the disadvantages of calcium hydroxide. Recent advances in bioactive materials and those derived from MTA have shown promising results that could improve biomaterials used in vital pulp treatments. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1358-1368, 2018.

Effect of Silicon and Calcium on Human Dental Pulp Cell Cultures

This study was designed to investigate the odontogenic effects of Silicon, Calcium and Phosphorous on human dental pulp cells. Human dental pulp cells derived from extracted pristine teeth were cultured in growth media with supplements of Si 25ppm, Si 25ppm+Ca 8.3ppm, Si 25ppm+Ca 8.3ppm+P 4.16ppm, Si 50ppm, Si 50ppm+Ca 16.7ppm, Si 50ppm+Ca 16.7ppm+P 8.3ppm and media without additional supplement as control, for the time intervals of 16 hours, 7, 12, and 21 days. Cell proliferation rates were measured by the optical density of crystal violet dye stained cells. ALP activity was measured by fluorometric assay. Expression of Dentin Sialoprotein (DSP) was measured by ELISA. Mineralization of cultures was measured by Alizarin Red staining. The data were presented as the mean of triplicates and normalized on a per million cell basis. Statistical analysis was conducted using ANOVA and Tukey HSD post-hoc tests. Culture with 50ppm supplemental Si at day 21 yield significantly higher levels of ALP activity, DSP expression and mineralization (<i>P</i>&lt;0.05) compared to the control group and other supplemented groups. Cultures with Si 25ppm+Ca 8.3ppm supplemental and Si 50ppm+Ca 16.7ppm supplemental displayed significantly higher cell proliferation rates compared to the control group at day 12 (<i>P</i>&lt;0.05) and at day 21 (<i>P</i>&lt;0.05). Supplemental silicon in concentration of 50 ppm could significantly induce differentiation and mineralization of normal human dental pulp cells. Calcium has a synergetic effect in up-regulating the proliferation rates. This is the first report to demonstrate the silicon- and calcium-induced mineralized tissue formation of human dental pulp cell cultures, leading to the potential development and clinical application of a future novel dental pulp capping material.

Nanoscale chemical surface characterization of four different types of dental pulp-capping materials

ObjectivesThe surface of any dental pulp-capping material has important implications for its clinical success because it is in direct contact with dental tissue, which influences its cytotoxicity. The aim was to determine the chemical composition of the first atomic layers of four pulp-protection agents because these atoms can initiate the pulp healing process. MethodsBiodentine (Septodont), ProRoot MTA (Dentsply), Dycal (Caulk) and TheraCal (Bisco) were prepared (n=5) according to manufacturer recommendations. The chemical surface composition was analyzed using X-ray photoelectron spectroscopy (XPS), and the bulk composition was analyzed by Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX). Both survey and high resolution XPS spectra of the elements detected were obtained, with element-dependent probe depths of 4–5nm; the binding energy scale was normalized to the C1s adventitious carbon peak at 285eV. ResultsThere was a significant difference between bulk and surface compositions for all the pulp-capping materials. The calcium surface concentrations at 0nm and 70nm were Dycal 7.9% and 15.1%; ProRoot MTA 14.1% and 17%; TheraCal 0% and 3.6%; and Biodentine 17.6% and 33.7%, respectively. Trace amounts of the following elements (<1%) were also found: Ti, S and Zr in Biodentine; Bi in ProRoot MTA and TheraCal; Na, P, Zn and N in Dycal. ConclusionsThe XPS results showed that Ca in the surface layer could vary from 0 to 18%, depending on the material. Aliphatic carbons, from the polymerization reactions, especially in Dycal and TheraCal, were found to mask the other components. Clinical significanceThis study compares, for the first time, the chemical composition of the first atomic layers of four pulp-capping materials. This information is relevant because the interaction between pulpar cells and the material's outermost atomic layer is an important factor for leading the pulpal response.

Calcium ions promote osteogenic differentiation and mineralization of human dental pulp cells: implications for pulp capping materials

Calcium (Ca) is the main element of most pulp capping materials and plays an essential role in mineralization. Different pulp capping materials can release various concentrations of Ca ions leading to different clinical outcomes. The purpose of this study was to investigate the effects of various concentrations of Ca ions on the growth and osteogenic differentiation of human dental pulp cells (hDPCs). Different concentrations of Ca ions were added to growth culture medium and osteogenic inductive culture medium. A Cell Counting Kit-8 was used to determine the proliferation of hDPCs in growth culture medium. Osteogenic differentiation and mineralization were measured by alkaline phosphatase (ALP) assay, Alizarin red S/von kossa staining, Ca content quantitative assay. The selected osteogenic differentiation markers were investigated by quantitative real-time polymerase chain reaction (qRT-PCR). Within the range of 1.8-16.2 mM, increased concentrations of Ca ions had no effect on cell proliferation, but led to changes in osteogenic differentiation. It was noted that enhanced mineralized matrix nodule formation was found in higher Ca ions concentrations; however, ALP activity and gene expression were reduced. qRT-PCR results showed a trend towards down-regulated mRNA expression of type I collagen and Runx2 at elevated concentrations of Ca ions, whereas osteopontin and osteocalcin mRNA expression were significantly up-regulated. Ca ions content in the culture media can significantly influence the osteogenic properties of hDPCs, indicating the importance of optimizing Ca ions release from dental pulp capping materials in order to achieve desirable clinical outcomes.

The effects of low-level diode laser treatment and dental pulp-capping materials on the proliferation of L-929 fibroblasts

Low-level laser therapy (LLLT) has been reported to improve tissue healing and might therefore be useful in dental pulp capping after trauma. We evaluated the effects of a low-level diode laser (lambda = 680 nm) and dental pulp-capping substances on cell proliferation. Calcium hydroxide and adhesive resin were applied as conditioned media to cultures. Half of the samples received irradiation with the diode laser at a fluence of 4 J/cm(2) for 60 s. Using a hemocytometer, cells were counted at 1, 3, 5, and 7 days, and the data were analyzed by ANOVA. All cultures exhibited continuous growth, except those treated with adhesive resin. As compared to the other two groups, cell proliferation was significantly lower in cultures treated with adhesive resin; it was also significantly lower in cultures treated with calcium hydroxide, as compared to the control group. When combined with dental pulp-capping materials, LLLT had no effect on L-929 cell proliferation.