Gray Mineral Trioxide Aggregate Research Articles

Comparison of curative effect between different retrograde filling materials in young permanent molar root canal therapy.

The first mandible and maxilla permanent molars are the first permanent teeth that grow next to the deciduous teeth and may decay due to carelessness. Their caries can spread to the pulpal tentacles and cause pulpal and periapical diseases. In the current study, we tried to compare the curative effect of different retrograde filling materials, i.e. white MTA, gray MTA, Portland cement, and IRM, in young permanent molar root canal therapy. Because IL-1β stimulates bone degradation by osteoclasts, IL-1β gene expression was also measured for further evaluation. For this purpose, 400 students (240 boys and 160 girls) aged 8 to 11 years referred to the Pediatric Dental Center for first permanent molar root canal therapy were selected during two years. After recording the demographic characteristics of each patient, the first permanent molar teeth were examined by a general dentist with Abslang and decayed teeth were considered to have both discolorations in their grooves and apparent opacity. The patients, who need root canal therapy, were divided into four groups. The first group was treated with gray MTA. The second group was treated with white MTA. The third group received Portland cement for root canal therapy. The fourth group was treated with IRM. Also, IL-1β gene expression was evaluated by the real-time PCR technique. Relative changes in gene expression in PBMC cells were performed using One Way ANOVA. SPSS 18 software was used to determine the correlation of gene expression in PBMCs. The results showed that there was no significant difference between the groups in terms of age (p = 0.12) and gender (p = 0.24). Also, the need for endodontic treatment in the mandible (n = 278) was higher than the maxilla (n = 85) and both jaws (n = 37). But there was no significant difference between the groups in terms of the need for endodontic treatment (p = 0.32). The results of Pearson correlation coefficients between studied groups in terms of IL-1β gene expression showed that gray MTA and white MTA were not statistically different, but MTAs were generally different from Portland cement and IRM, with higher IL-1β gene expression. In general, the results showed that the teeth in the vicinity of gray MTA and white MTA showed a more appropriate response than Portland cement and IRM, so the use of MTA and its preference over other materials is recommended. In the case of Portland cement, more studies are needed to reach a conclusion comparing this material with MTA.

Effect of chlorhexidine gluconate as hemostatic agent in healing and repair after mineral trioxide aggregate vital pulp therapy in young permanent teeth – A clinical study

Objectives: The aim of the study was to evaluate the clinical success of mineral trioxide aggregate (MTA) partial pulpotomy as a definitive procedure in deeply carious permanent posterior teeth using 0.12% chlorhexidine (CHX) gluconate or normal saline as hemostatic agents. Materials and Methods: A pilot randomized control clinical trial was conducted on subjects with a deep carious lesion on 20 immature posterior teeth of subjects (10.8 ± 2.62 years). Caries and the superficial layer of exposed pulp were removed and then flushed with 0.12% CHX or saline solution. Gray MTA was placed, followed by resin-modified glass ionomer and composite. Results: 12 months follow-up showed 100% clinical and 90% radiographical success in both groups. Dentine Bridge was formed 90% in both the study and control group, which showed MTA partial pulpotomy is an effective procedure (P = 0.000). Conclusion: MTA partial pulpotomy using 0.12% CHX gluconate as a hemostatic agent for the treatment of deeply carious immature permanent posterior teeth appears to increase the radiographic rate of formation of dentin bridge as compared to the normal saline.

Clinical and radiographic success of (partial) pulpotomy and pulpectomy in primary teeth: A systematic review.

The aim of this systematic review was to evaluate the clinical outcome of partial pulpotomy, pulpotomy and pulpectomy for treating primary teeth with normal or infected pulp or with irreversible pulpitis. Two reviewers on Pubmed and ISI Web of Science performed a comprehensive literature review of publications from 1966 until July 2019. Pico outline was used to facilitate literature research. Among abstracts, publications were selected according to the following criteria: prospective clinical study, correct indication for the performed treatment, clear definition of clinical and/or radiographic success criteria and at least 6-month follow-up period. The strict selection criteria under the keywords "pulpotomy", "partial pulpotomy" and "pulpectomy" resulted in a limited amount of randomised controlled trials (RCT) or controlled clinical trials (CT). Qualitative assessment of the selected clinical studies and level of evidence was included according to the criteria described by the Oxford Centre for Evidence-Based Medicine (CEBM). Prerequisites for a successful pulpotomy are symptom-free teeth, sterile removal of coronal pulp and haemostasis. Both MTA and formocresol perform well for partial pulpotomies after caries exposure. Formocresol had been the most popular amputation material for pulpotomies. Due to the potential side effects, other medicaments, such as ferric sulfate, mineral trioxide aggregate (MTA) or NaOCl are suggested. Grey and white MTA yeld the same results. Lasers are not recommended due to their large diversity. Regarding pulpectomy, the conditions, procedures, and evaluation for the treatment were not well defined in the studies. Nevertheless, there is evidence to use calcium hydroxide, zinc oxide eugenol paste or iodoform based pastes as root filling materials for non-vital molars. Pulpectomies showed better success rates than pulpotomies. Stainless steel crowns are recommended as definite restorations after both endodontic treatments. Longer follow-up periods, further clinical studies with comparable conditions and clear definition of evaluation criteria are needed to further confirm the results of endodontic treatment in primary teeth.

Mineral trioxide aggregate

The purpose of this two-part series is to review the composition, properties, products, and clinical aspects of mineral trioxide aggregate (MTA) materials.search engines to include relevant scientific citations from the peer-reviewed journals published in English. MTA is a refined form of the parent compound, Portland cement (PC). It demonstrates a strong biocompatible nature owing to the high pH and its ability to form hydroxyapatite. MTA materials provide a better seal than traditional endodontic materials as observed in dye leakage, fluid filtration, protein leakage, and bacterial penetration leakage studies, and it has been recognized as a bioactive material. Currently a variety of MTA commercial products are available, including Proroot® Gray MTA and White MTA both from DENTSPLY Tulsa Dental Specialties , and MTA Angelus Although these materials are indicated for various dental uses. This first of this series highlights and discusses the composition, physical, and/or chemical properties of MTA. A subsequent article will offer an overview of the material aspect (commercial products) and clinical considerations for MTA materials.

Biocompatibility and biomineralization of the experimental nanoparticulate mineral trioxide aggregate (MTA)

To investigate the tissue response and the biomineralization ability of the experimental nanoparticulate mineral trioxide aggregate compared to grey MTA and Fillapex MTA. Polyethylene tubes containing materials or empty tubes for control were inserted into the subcutaneous tissues of 30 rats. After 7, 15, 30, 60, and 90 days, the rats were killed and the tubes were removed for analysis using hematoxylin-eosin staining, von Kossa staining, and under polarized light. Inflammation was graded through a score system; the biomineralization ability was recorded as present or absent. The results were statistically analyzed using the Kruskal-Wallis test (p<0.05). On days 7 and 15 there was a significant difference between the Nano MTA (median score of 3) and MTA Fillapex groups (median score of 4), being MTA Fillapex the material with the highest number of inflammatory cells. At 30, 60, and 90 days there was no difference between the Nano MTA, Grey MTA, and MTA Fillapex groups. All materials induced the formation of mineralized tissue in all experimental periods. Nano MTA showed biocompatibility and biomineralization similar to grey MTA Angelus.

Comparative evaluation of four bioceramic-based endodontic sealers

Introduction: Perforations are characterized by a communication between the root canal system and the external surface of the tooth. Objective: To analyze the literature on the perforations that can occur during root canal treatment and the different bio ceramic materials used to seal them such as gray MTA, ProRoot MTA, Biodentine and Endo Sequence. Methodology: Electronic bibliographic databases (PubMed, EBSCO, Cochrane) were used using the keywords perforations, bioceramics, MTA, ProRoot MTA, Biodentine, EndoSequence. Results: MTA was the first bioceramic cement, providing good sealing, biocompatibility, and antimicrobial activity. However, it has been demonstrated that new bio ceramic cements have a better sealing capacity. ProRoot MTA is an excellent choice for sealing mainly furcated holes, a disadvantage is the change of color in the pieces. Biodentine, a biocompatible calcium silicate-based bio ceramic cement used in endodontic treatments, provides better sealing capabilities than other bio ceramic cements. Endosequence is a new bio ceramic cement, it can be found as a pre-mixed putty making it easier for the operator to handle, in addition, its sealing capacity is better compared to other bio ceramic cements. Conclusion: According to the literature reviewed, Biodentine and EndoSequence are the best bio ceramic materials for sealing and repairing endodontic holes.

Solubility of Calcium Silicate Based Cements – a Comparative Study

Abstract Calcium silicate based cement is a group of biomaterials, based on Portland cement. Its physicochemical properties such as solubility are of the utmost importance. It should have low solubility in tissue fluid since the dissolution of materials may lead to treatment failure. The aim of this study is to evaluate the solubility of five calcium silicate cements after being placed in distilled water for a period of 28 days. Material and methods: The purpose of this study was to compare solubility of a four new calcium silicate-based cements, such as: gray MTA Angelus; white MTA Angelus; BioAggregate and Biodentine with conventional mineral trioxide aggregate White ProRoot. Solubility is evaluated using standardized samples of materials, which are weighed before and after 28-day immersion in distilled water. Results: The lowest solubility is found at White ProRoot and the significantly highest solubility – at Biodentine.

Hyperglycemic condition influence on mineral trioxide aggregate biocompatibility and biomineralization.

This study aimed to investigate in vitro and in vivo the influence of hyperglycemic condition on biocompatibility and biomineralization of gray mineral trioxide aggregate (GMTA) and white mineral trioxide aggregate (WMTA). For the in vitro study, fibroblast-like cells L929 were cultured under high or normal glucose concentration to investigate the effects of both MTA's on cell proliferation and inflammatory cytokines production IL-1β, IL-6, and TNF-α. For the in vivo study, polyethylene tubes containing MTA materials and empty tubes were implanted into dorsal connective tissues of Wistar rats previously assigned normal and hyperglycemic. After 7 and 30 days, the tubes with surrounding tissues were removed and subjected to histological, fluorescence and immunohistochemical analyzes of IL-1β, IL-6, and TNF-α. In vitro study showed that, under high glucose condition, GMTA reduced cell proliferation and IL-6 production compared with WMTA. Moreover, in vivo study revealed that hyperglycemic condition did not modify the inflammatory response and cytokines production in the tissue close to both materials. Independently of hyperglycemic status, mineralized areas were observed with both materials, but the fluorescence intensity of WMTA was diminished on 14 days in hyperglycemic animals. It is possible to conclude that GMTA was able to inhibit the proliferation rate and IL-6 production under high glucose concentration in vitro. Furthermore, cytokines production and inflammatory response were not upregulated in hyperglycemic animals; however, a decrease in the calcium deposition was observed in presence of WMTA, suggesting a delay in the mineralization process.

Biocompatibility evaluation of Jordanian Portland cement for potential future dental application.

Background:The demand for novel Portland cement (PC)-based formulations to be used in dental applications is ever increasing in viewing the foregoing knowledge on the favorable effects of these formulations on cellular proliferation and healing, leading to treatment success.Aim:This study investigated the effect of white and gray mineral trioxide aggregate (W-MTA and G-MTA) and white and gray Jordanian PC (W-PC and G-PC) in their raw state on the viability of Balb/C 3T3 fibroblasts using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Materials and Methods:Materials were prepared in the form of disks, with a diameter of 5 mm and a thickness of 2 mm. In the first experiment, Balb/C 3T3 fibroblasts were cultured with the material disks using culture plate inserts. In the second experiment, material elutes were added to cultured cells. The elutes were prepared by adding 2 ml serum-free media to 10 disks of each material and then incubated at 37°C for different time intervals. Material elutes were analyzed using ion chromatography for traces of calcium. The data were analyzed using analysis of variance followed by Dunnett test (α = 0.05) or Tukey test (α = 0.05).Results:In response to material disks, G-PC had a proliferative effect on cells at day 1 and day 2 with a significant difference from the control at day 1. G-MTA reduced cell viability with a significant difference from the control level at day 2. Elutes of PC showed biocompatible and even proliferative effects on Balb/C 3T3 fibroblasts. Calcium ions were found to leach continuously over the measurement period for all the materials tested in this work.Conclusion:Jordanian PC in its raw state was found to be biocompatible, and the results of this work give promise of its wider use as a base for further development to improve the physiochemical and mechanical properties of the material.

Comparative Study of the Antibacterial effect of MTA, Nano-MTA, Portland cement, AND Nano-Portland cement

The root end filling materials antibacterial properties is a must nowadays as there is none of the available root canal filling materials can provide a hermetic seal.The aim of the current study isto compare the antibacterial effect of Gray Portland cement and white MTA angelus in the conventional and nano-particle forms. Agar diffusion test was used to examine the tested materials, where Enterococcus faecalis ATCC29212 (American Type Culture Collection 29212) cultured in agar BHI (brain heart infusion) in anaerobic condition at 37oCfor 72 hours.Then, the agar was added to 12 sterile petri plates and the prepared bacterial suspension was inoculated. Punch holes of 6 mm diameter were formed on each agar plate and each 3 plates were filled with the materials tested (Portland cement, Nano-Portland cement, MTA angelus, and Nano-MTA angelus). The results showed that conventional Portland cement has the highest antibacterial property, followed by Nano-Portland cement, MTA angelus, Nano-MTA angelus respectively with significant difference according to Kruskal Wallis ANOVA test followed by Mann-Whitney U test.

Biocompatibility of Regular and White MTA and A Grey Portland Cement in Human Dental Pulp Cells

Currently many materials have been used with pulpotomies in primary teeth. These include MTA, that as a direct pulp capping material seemed to stimulate natural dentin repair at pulpal exposure sites. The composition of this product is based on Portland cement. Later, white MTA was introduced as an esthetic improvement over the original material (grey MTA). A number of studies have been performed on this new material to determine if it shows the same properties as gray MTA. The biocompatibility of MTA has been previously investigated in vitro using a number of the cell lines. However, the use of primary cultures (in this case pulp fibroblasts) is often desirable. Objective: The objective of this in vitro study was to compare the cytotoxicity in a pulp fibroblasts culture, of regular (grey) MTA, white MTA and Portland cement Material and method: A cytotoxicity study was made in a primary pulp fibroblasts culture of MTA, white and grey, and a grey Portland cement. Results: Without taking into account concentrations, there were no significant differences between regular MTA and white MTA (p=0.146). A significant difference was recorded between grey Portland cement, which were less biocompatible, and regular MTA (p=0.029), and white MTA (p=0.002). Conclusion: The results found in the present study might be an additional argument to support that MTA is biocompatible, and may be considered as a pulp dressing agent in pulpotomized primary molars with carious pulp exposures. However, the grey Portland cement, under the same conditions, shows reduced biocompatibility.

Alternative to Avoid Tooth Discoloration after Regenerative Endodontic Procedure: A Systematic Review.

This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

English

The aim of this study was to investigate and compare the short and long term antibacterial effects of white and gray mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) on Streptococcus Sanguinis and Enterococcus faecalis which are commonly associated with endodontic infections. The test materials, including white MTA (WMTA), gray (GMTA), and CEM were manipulated strictly in accordance with the manufacturer's instructions. A total of 72 culture plates were prepared and divided into three experimental groups (one group for each of freshly mixed and set WMTA cements; one group for each of freshly mixed and set GMTA cements; one group for each of freshly mixed and set CEM cements. Each group consisted of 24 plates in which 12 plates were cultured by S. sanguinis and the other 12 plates were cultured by E. faecalis. Antibacterial activities of the materials against the S. sanguinis and E. faecalis were evaluated using agar diffusion test (ADT). The materials were tested in form of set (24-h, 1 week and 1 month) and freshly mixed. In the E. faecalis groups, plates containing freshly mixed and set WMTA, GMTA, and CEM cements did not show any antibacterial properties. The antimicrobial activity of freshly mixed GMTA was lower than WMTA and higher that of CEM. The largest mean diameters of inhibition zone of bacterial growth were found in set WMTA cement group at any time period. In conclusion, the origin of MTA as well as the preparation techniques may affect its antimicrobial activities. Key words: White mineral trioxide aggregate (WMTA), gray mineral trioxide aggregate (GMTA), calcium enriched mixture (CEM), growth inhibition zone, S. sanguinis, antibacterial activity, agar diffusion test, E. faecalis. &nbsp

Sealing Ability of the Formed Apical Calcified Bridge in Open Apex Roots

A successful endodontic treatment requires that the apex of the treated tooth becompletely and densely sealed with root canal filling material. One of the mostdifficult endodontic problems is the management of necrotic immature tooth due tothe blunderbuss apex and the difficulty in achieving a tight seal between the root canalsystem and the external surface of the tooth. The aim of this study was to evaluate thesealing ability the apical calcified bridge formed by calcium hydroxide paste, whiteMTA or gray MTA during apexification procedure.Thirty premolars with single root canals were prepared to simulate an open apex.These roots were divided into 3 groups as follow: Group A: 10 roots filled withCa(OH)2 paste, Group B: 10 roots filled with white MTA, and Group C: 10 rootsfilled with gray MTA. Each root was placed in a polyethylene vial containing 25 m1of synthetic tissue fluid (STF) and incubated at 37°C for 3 months. After 3 monthsand the formation of calcified bridge, each root was immersed in 2% freshly preparedMethylene blue dye in 5 ml plastic vial for seven days. After the leakage period, theroots were removed from the dye and the leakage in all roots was examined bymeasuring the linear extent of dye penetration from the apical end of the canalpreparation to the coronal direction by means of a light stereomicroscope at (40 X)magnification with calibrated grid.Ca(OH)2 paste group has the highest mean value of apical dye penetrationfollowed by WMTA, while GMTA group shows the lowest mean value of apical dyepenetration. There was a highly significant difference in the apical dye penetration(p<0.01) among these groups, statistically a high significant difference is found(p<0.01) between Ca(OH)2 group and WMTA group, and between Ca(OH)2 groupand GMTA group; whereas, significant difference is found (p<0.05) between WMTAgroup and GMTA group.The apical calcified bridge formed by GMTA has the best sealing ability followedby that formed by WMTA. While the apical calcified bridge formed by Ca(OH)2 pastehas the lowest sealing ability as compared with that formed byWMTA and GMTA.

RUNX-2, OPN and OCN expression induced by grey and white mineral trioxide aggregate in normal and hypertensive rats.

To investigate whether hypertension affects mineralization associated with white and grey mineral trioxide aggregate (MTA Angelus® ) implanted subcutaneously into rats by assaying osteoblastic biomarkers. Polyethylene tubes containing grey MTA Angelus® , white MTA Angelus® , intermediate restorative material (IRM; positive control) or an empty tube (negative control) were implanted into the dorsal connective tissue of spontaneous hypertensive (n=12) and Wistar (normotensive; n=10) rats. Half of the rats in each group were killed after 7days, and the remaining after 30days. Tubes with surrounding tissue were removed, and immunostaining was performed to detect RUNX-2, OPN and OCN proteins. The normality of data was analysed using the Shapiro-Wilk test. Comparison of two independent groups was performed using the Mann-Whitney U-test, to detect a significant difference. A post hoc test accounting for multiple comparisons was performed following Tukey's test (P<0.05). Under hypertensive conditions after 30days, both MTA materials were associated with immunolabelling for RUNX-2 from low to moderate, which was less than that observed at normal blood pressure and the 7-day groups (P<0.05). The expression of OPN and OCN proteins under both MTA conditions was considered low after both 7 and 30days for the hypertensive condition, and was less than that in animals with normal blood pressure after 30days (P<0.05). No immunostaining for any biomarkers in the control and IRM groups was observed (P<0.05). Hypertension decreased the immunostaining of RUNX-2, OPN and OCN biomarkers in response to MTA. Thus, hypertension can jeopardize the mineralization ability of MTA and may have a negative impact on endodontic treatment outcomes.

Superfast Set, Strong and Less Degradable Mineral Trioxide Aggregate Cement.

Purpose Despite the good sealing ability and biocompatibility of mineral trioxide aggregate (MTA), its slow setting, high degradation, and weakness limit its use in surgical endodontics and high stress-bearing areas. This study aimed to develop two new liquids to control these drawbacks. They were prepared from calcium chloride, fumed silica, and hydroxyapatite or calcium phosphate and coded “H” and “P,” respectively. Methods Portland cement, Grey ProRoot® MTA, and white ProRoot MTA were mixed with distilled water (control) or liquid “H” or “P.” The pH, setting time, degradation rate, leachant/precipitate' composition, compressive strength, and morphology were assessed. Results Both liquids maintained MTA's high alkalinity and reduced the setting time by 1-2 orders of magnitude. Both liquids, H in particular, significantly reduced the degradation rate of Grey ProRoot and White ProRoot MTA®. Calcite has been identified as the main phase of the leachant or precipitate formed during the cement's degradation. Calcium hydroxide or hydroxyapatite was also identified with Grey ProRoot MTA mixed with H liquid. These liquids also significantly increased the compressive strength with no statistical differences between them; this was associated with the production of dense, consolidated structures. Conclusions The modified MTA could be used in surgical endodontics and high stress-bearing areas.

Hydration behaviors of calcium silicate-based biomaterials.

Calcium silicate (CS)-based biomaterials, such as mineral trioxide aggregate (MTA), have become the most popular and convincing material used in restorative endodontic treatments. However, the commercially available CS-based biomaterials all contain different minor additives, which may affect their hydration behaviors and material properties. The purpose of this study was to evaluate the hydration behavior of CS-based biomaterials with/without minor additives. A novel CS-based biomaterial with a simplified composition, without mineral oxides as minor additives, was produced. The characteristics of this biomaterial during hydration were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectrometry. The hydration behaviors of commercially available gray and white MTAs with mineral oxide as minor additives were also evaluated for reference. For all three test materials, the XRD analysis revealed similar diffraction patterns after hydration, but MTAs presented a significant decrease in the intensities of Bi2O3-related peaks. SEM results demonstrated similar porous microstructures with some hexagonal and facetted crystals on the outer surfaces. In addition, compared to CS with a simplified composition, the FTIR plot indicated that hydrated MTAs with mineral oxides were better for the polymerization of calcium silicate hydrate (CSH), presenting Si-O band shifting to higher wave numbers, and contained more water crystals within CSH, presenting sharper bands for O-H bending. Mineral oxides might not result in significant changes in the crystal phases or microstructures during the hydration of CS-based biomaterials, but these compounds affected the hydration behavior at the molecular level.

Influence of different pulp capping materials to induce coronal tooth discoloration

AimThis study aimed to evaluate the influence of white MTA, gray MTA, calcium hydroxide and calcium aluminate cement (CAC) in tooth color when used as pulp capping materials. MethodologyExtracted third molars were used (n=50). According to the experimental groups, a 2mm layer was placed in the pulp canal chamber: Group 1 – White MTA; Group 2 – Gray MTA; Group 3 – CAC; Group 4 – calcium hydroxide paste followed by calcium hydroxide cement. In the control group white gutta-percha was used. Vestibular, lingual, mesial and distal color readout was performed at baseline and after 30 days. Images were captured using a digital camera Nikon D80 and shade evaluation performed using Photoshop 7.0. The blue channel in red, green and blue color mode (RGB) was used to measure chromatic changes in a scale from 0 (darkest) to 255 (lightest). The data were evaluated by univariate analysis. ResultsAll teeth showed some discoloration after 30 days. The mean variation of pixel intensity for the blue channel was similar between groups. However, considering the mean pixel intensity for the blue channel after 30 days, teeth where CAC was used were significantly darker than those from the control group. ConclusionsThis study demonstrated that all tested materials induced teeth shade changes after 30 days of simulated pulpotomy. The mean variation of color was similar between groups and CAC caused the higher color change.

Growth factor release from dentine matrix by pulp-capping agents promotes pulp tissue repair-associated events.

To characterize growth factor release from dentine by pulp-capping agents and to determine the effects of liberated dentine extracellular matrix (dECM) components on pulp cells in the key wound healing processes of migration and cell growth. Powdered human dentine was exposed to solutions of calcium hydroxide, white and grey mineral trioxide aggregate (MTA) (ProRoot, (Dentsply Tulsa, Tulsa, OK, USA) over 14days. The solubilized dECM components were dialysed and lyophilized and characterized using multiplex quantitative ELISA. Following dECM component extraction dentine was analysed using Fourier-transformed infrared spectroscopy (FTIR). Primary rat dental pulp cells (RDPCs) were exposed to dECM components (0.1-100μgmL-1 ) released by calcium hydroxide, white and grey MTA, and cell growth and chemotactic responses were assessed. Statistical differences between the experimental and control groups were determined using one-way anova. A broad range of growth factors, many not previously reported in dentine, were liberated by these pulp-capping agents, including SCF, M-CSF, GM-CSF, IGFBP-1, NGF and GDNF. White and grey MTA liberated more growth factors than calcium hydroxide. FTIR analysis of dentine exposed to pulp-capping agents showed partial depletion of amide bands I, II and III, with little alteration in phosphate peaks compared to untreated dentine. dECM components released by white and grey MTA induced significantly more cell growth at low-to-moderate concentrations (P≦0.05) examined in this study and significantly enhanced cell chemotaxis at all concentrations compared with controls (P≦0.05). White and grey MTA solubilize a broad range of bioactive molecules from dentine, which can induce proliferation and chemotaxis in pulp cells.

Hypertension Undermines Mineralization-inducing Capacity of and Tissue Response to Mineral Trioxide Aggregate Endodontic Cement

IntroductionThis study evaluated the effect of hypertension on tissue response to and mineralization capacity of white and gray mineral trioxide aggregate (MTA) (Angelus Industry Ontological Products, Londrina, Brazil), an endodontic reparative cement. MethodsPolyethylene tubes containing gray MTA, white MTA, or intermediate restorative material (positive control) or an empty tube (negative control) were implanted into the dorsal connective tissue of spontaneous hypertensive and Wistar rats (n = 12 each). Six rats in each group were sacrificed after 7 days, and the remainder after 30 days. Tubes with surrounding tissue were removed, and a histologic analysis was performed using hematoxylin-eosin and von Kossa staining and examination by polarized light microscopy. ResultsThe inflammatory response to all materials was greater in hypertensive compared with normotensive rats (P < .05). Positive von Kossa staining and birefringent structures in polarized light were observed for both gray and white MTA (P > .05), but these were more pronounced in normotensive rats (P < .05). Necrotic areas with positive von Kossa staining were observed for intermediate restorative material. ConclusionsHypertension undermines tissue repair and mineralization, which can negatively affect treatment outcome. Nonetheless, mineralization in response to MTA was observed even under hypertensive conditions.