Comparative study of subcutaneous tissue responses to a novel root-end filling material and white and grey mineral trioxide aggregate

Comprehensive review of composition, properties, clinical applications, and future perspectives of calcium-enriched mixture (CEM) cement: a systematic analysis

This review aims to comprehensively explore calcium-enriched mixture (CEM) cement as a crucial biomaterial in dentistry/endodontics. With its growing clinical relevance, there is a need to evaluate its composition, chemical/physical/biological properties, clinical applications, and future perspectives to provide clinicians/researchers with a detailed understanding of its potential in endodontic procedures. Through systematic analysis of available evidence, we assess the advantages/limitations of CEM cement, offering valuable insights for informed decision-making in dental/endodontic practice. Our findings highlight the commendable chemical/physical properties of CEM cement, including handling characteristics, alkalinity, color stability, bioactivity, biocompatibility, sealing ability, and antimicrobial properties. Importantly, CEM cement has shown the potential in promoting regenerative processes, such as dentinogenesis and cementogenesis. It has demonstrated successful outcomes in various clinical applications, including vital pulp therapy techniques, endodontic surgery, open apices management, root resorption/perforation repair, and as an orifice/root canal obturation material. The efficacy and reliability of CEM cement in diverse clinical scenarios underscore its effectiveness in endodontic practice. However, we emphasize the need for well-designed clinical trials with long-term follow-up to further substantiate the full potential of CEM cement. This review serves as a robust reference for researchers/practitioners, offering an in-depth exploration of CEM cement and its multifaceted roles in contemporary dentistry/endodontics.

Synthesis of biocompatible hydrogel of alginate-chitosan enriched with iron sulfide nanocrystals

This work aimed to synthesize and characterize a biocompatible hydrogel of alginate and chitosan enriched with iron sulfide nanocrystals. Three concentrations of iron sulfide nanocrystals (FeS2NCs) 0.03905, 0.0781, and 0.2343 mg/ml were used. Gel swelling was determined using phosphate-buffered saline solution at 1, 2, 4, 6, 24, 48, and 72 h. The microstructure, the morphology, and the elastic strength were determined by optical microscopy, scanning electron microscopy, and rheological studies, respectively. The functional groups were identified through Fourier Transform Infrared spectroscopy. Biocompatibility was determined in a murine model; after seven days of subdermal inoculation, histological sections stained with H&E were analyzed, and then histopathological features were evaluated. All the compounds obtained showed a loss modulus lower than the storage modulus. The 0.2343 mg/ml FeS2NCs hydrogel showed higher swelling than the control. In the in vivo evaluation, no adverse effects were found. The presence of FeS2NCs was well tolerated in the subcutaneous tissue of mice, according to histopathological analysis. The hydrogels synthesized with added FeS2NCs demonstrate a swelling ratio of 150 %, rheologically exhibiting gel-like behavior rather than viscous liquids. Furthermore, they did not present any adverse effects on the subcutaneous tissue.

Biocompatibility of Ajwain Oil Combined with Eugenol and Zinc Oxide as a Deciduous Root Canal Obturating Material: An In Vivo Study

Aim and objectives

The present study was intended to assess the biocompatibility of newly formulated materials such as zinc oxide (ZO) admixed with ajwain oil (A) as well as ajwain eugenol (E) (1:1 ratio) against ZOE through an animal model as root canal obturating materials in deciduous teeth.

Materials and methods

The study involved randomly selected 24 albino rats, which were divided into three groups based on test materials. Two polyethylene tubes (PETT) (8 mm long × 1 mm internal diameter) were inserted into connective tissues of the dorsal side on either side of each rat viz empty tube (negative control) and another containing test material (test group). Animals were sacrificed at the end of the 7th and 21st days. PETT with surrounding connective tissues were excised. Histopathological evaluations of the material's biocompatibility were done by determining inflammatory tissue responses. Non-parametric tests such as Kruskal-Wallis and Mann-Whitney U were used for statistical analysis (p < 0.05).

Results

Histopathological examination on the 7th day showed increased polymorphonuclear cells for all test materials compared to the negative control (p = 0.92), suggesting acute inflammation. The inflammation subsided gradually after 21 days (p = 0.48). The lymphocytes increased after 21 days for all the materials indicating chronic inflammation (p = 0.79), as well as fibroblasts (p = 0.34) and capillaries (p = 0.35), indicating healing and repair.

Conclusion

The newly formulated obturating materials were found to be biocompatible compared to ZOE.

How to cite this article

Dahake PT, Joshi SS, Kale YJ, et al. Biocompatibility of Ajwain Oil Combined with Eugenol and Zinc Oxide as a Deciduous Root Canal Obturating Material: An In Vivo Study. Int J Clin Pediatr Dent 2023;16(3):431-436.

Evaluation of a collagen-bioaggregate composite scaffold in the repair of sheep pulp tissue

Purpose:

This study aimed to compare the effects of the collagen-BioAggregate mixture (CBA-M) and collagen-BioAggregate composite (CBA-C) sponge as a scaffolding material on the reparative dentin formation.

Materials and methods:

CBA-C sponge (10:1 w/w) was obtained and characterized by Scanning Electron Microscopy (SEM) and Mercury Porosimetry. Cytotoxicity of the CBA-C sponge was tested by using the L929 mouse fibroblast cell line. Dental pulp stem cells (DPSCs) were isolated from the pulp tissue of sheep teeth and characterized by flow cytometry for the presence of mesenchymal stem cell marker, CD44. The osteogenic differentiation capability of isolated DPSCs was studied by Alizarin Red staining. The cells were then used to study for the compatibility of CBA-C sponge with cell proliferation and calcium phosphate deposition. The effect of CBA-C sponge and CBA-M on the induction of dentin regeneration was studied in the perforated teeth of sheep for the eight-week period. All the analyses were performed with appropriate statistical hypothesis tests.

Results:

CBA-C sponge was found to be biocompatible for DPSCs. The DPSCs seeded on the CBA-C sponge were able to differentiate into the osteoblastic lineage and deposit calcium phosphate crystals in vitro. Reparative dentin formation was observed after the second week in the CBA-C sponge applied group. At the end of eight weeks, a complete reparative dentin structure was formed in the CBA-C sponge applied group, whereas necrotic tissue residues were observed in groups treated with the CBA-M.

Conclusion:

CBA-C sponge represents a better microenvironment for reparative dentin formation probably due to maintaining DPSCs and allowing their osteogenic differentiation and thus calcium phosphate deposition.

A Comparative Study of Biocompatibility in Rat Connective Tissue of a New Mineral Trioxide Compound (Theracal) versus MTA and a Bioactive G3 Glass

The aim of this paper was to assess the differences in tissue response to implantation during 15, 30 and 45 days in the subcutaneous connective tissue of Wistar rats from three biomaterials: Angelus MTA^®, Theracal LC^®, and Angelus MTA^® to which 25% bioglass G3 was added. Twenty-four Wistar rats were used, the materials were inserted into the rat’s dorsal area in silicone tubes 5 mm long by 1.5 mm diameter. Histological reaction was assessed at 15, 30, and 45 days after implantation. They were then stained with hematoxylin eosin and evaluated by two observers. Data were analyzed using Fisher’s exact test and Mann–Whitney’s U test was used to determine the association between variables. Angelus MTA induced the formation of dystrophic calcifications twice as much as Theracal LC (p < 0.05). The addition of G3 did not affect the greater or lesser occurrence of calcifications (p > 0.05). Theracal LC and MTA plus G3 caused an inflammatory reaction, which was chronic at 15 days and decreased in intensity, almost disappearing after 45 days. Theracal LC, as well as Angelus MTA plus G3, were well tolerated when implanted in the subcutaneous connective tissue of rat. Histologically, no inconvenience was found for the use by direct contact of Theracal LC, and the mixture of MTA with 25% bioactive glass G3, in the tissue of Wistar rats.

Effect of Incorporating Hydroxyapatite and Zinc Oxide Nanoparticles on the Compressive Strength of White Mineral Trioxide Aggregate

Statement of the Problem

Many efforts have been made to improve the properties of mineral trioxide aggregate (MTA), including the incorporation of nanoparticles.

Purpose

The aim of this study was to investigate the incorporation of zinc oxide and hydroxyapatite nanoparticles on the compressive strength of white MTA (WMTA).

Materials and Method

In this in vitro study, the following materials were evaluated: MTA, MTA+5% zinc oxide (ZnO) nanoparticles, MTA+10% zinc oxide nanoparticles, MTA+5% hydroxyapatite (HA) nanoparticles, MTA+10% zinc oxide nanoparticles. The compressive strength of the groups under investigation was measured on days 4 and 21 after mixing the MTA using a universal testing machine. Two-way ANOVA test was used to compare the groups and determine the significance of the effect of time and material on the compressive strength (p<0.05).

Results

The highest and lowest compressive strength values were respectively measured for the second group, MTA/21 days, and the fourth group, MTA+Nano ZnO/4 days. Two-way ANOVA indicated that incorporation of zinc oxide and hydroxyapatite nanoparticles into MTA did not have a significant effect on compressive strength (p= 0.05). Compressive strength in all the groups increased over time from day 4 to day 21. However, this increase was not statistically significant (p= 0.06) except for the MTA group, which exhibited significant increase in compressive strength over time from day 4 to day 21 (p=0.007).

Conclusion

Incorporation of HA and ZnO nanoparticles into MTA had no detrimental effects on its strength and these nanoparticles can be used to improve the other properties of MTA.

Biocompatibility of new bioactive resin composite versus calcium silicate cements: an animal study

Background

The purpose of this study was to compare the biocompatibility of three bioactive materials, namely ACTIVA bioactive restorative resin composite, iRoot BP plus and Mineral Trioxide Aggregate (MTA) Angelus-HP.

Methods

Seventy-five Wistar male rats were subjected to subcutaneous implantation of four polyethylene tubes; one empty tube was used as control (Group 1), and the other tubes were filled with ACTIVA (Group 2), iRoot BP (Group 3) and MTA-HP (Group 4). Then, the rats were subdivided into 3 groups according to the sacrification time into one, two and 4 weeks (n = 25 rats). Tissue specimens were submitted to histopathological and immunohistochemical analysis of α-SMA and caspase 3.

Results

The one-way Anova test revealed that ACTIVA group exhibited minimal inflammation in comparison to calcium silicate cements (iRoot BP and MTA-HP groups). iRoot BP group significantly revealed a more severe degree of chronic inflammation in comparison to other groups (P < 0.05). ACTIVA group showed marked regression of inflammation and fibrosis comparable to the control, while iRoot BP group revealed remarkable fibrosis and calcification, with less degrees in MTA-HP group (P < 0.05). Immunostaining of both α-SMA and caspase 3 revealed lower indexes in ACTIVA group consistent with the control (P < 0.05).

Conclusions

ACTIVA showed a higher degree of biocompatibility to subcutaneous tissues in comparison to both iRoot BP and MTA-HP cements in regard to decrease the intensity of inflammation, with subsequent fibrous connective tissue remodeling and better healing patterns.

Clinical significance

Preliminary data suggests that the application of ACTIVA in retrograde fillings.

Biocompatibility of a bioceramic silicone-based sealer in subcutaneous tissue

This study evaluated the biocompatibility of a new silicone-based sealer (GuttaFlow Bioseal) in rat subcutaneous tissue and compared the results with those for GuttaFlow2 and AH Plus. Each of 16 Wistar rats received four subcutaneous tissue implants, namely, GuttaFlow Bioseal, GuttaFlow2, AH Plus, and one empty polyethylene tube. Eight rats were euthanized at day 8 and the remaining eight at day 30. Histological sections were stained with haematoxylin and eosin and analysed with a light microscope. Scores were established for inflammatory reaction, macrophage infiltrate, thickness of the fibrous capsule, and vascular changes. Differences between groups were assessed by using the Friedman test with Bonferroni correction. Histological analysis showed that GuttaFlow Bioseal had the lowest inflammatory reaction of all tested sealers at day 8. At day 30, the silicone-based sealers had similar inflammation profiles, but inflammation scores were nonsignificantly higher for AH Plus than for the negative control. The inflammatory reaction decreased from day 8 to day 30 in all sealers. GuttaFlow Bioseal had the most macrophage infiltrate. Under the present experimental conditions, GuttaFlow Bioseal induced limited inflammatory reactions at days 8 and 30, and initial inflammatory reactions to GuttaFlow2 and AH Plus subsided within 30 days. All tested sealers exhibited satisfactory biocompatibility at day 30 after subcutaneous implantation.

Effect of Irrigants on the Push-Out Bond Strength of Two Bioceramic Root Repair Materials

The purpose of this study was to compare different irrigants’ effect on two EndoSequence root repair materials’ push-out bond strength. Sixty root slices were filled either with EndoSequence premixed fast-set putty or regular-set paste, and then immersed either in sodium hypochlorite, chlorhexidine gluconate, or saline (as control) for 30 min, after which the slices were subjected to the push-out test. The surface structures were evaluated with Scanning Electron Microscopy and Fourier Transform Infrared. Fast-set putty exhibited greater displacement resistance when immersed in saline and subjected to adhesive failure mode, while regular-set paste showed greater resistance when immersed in chlorhexidine and subjected to cohesive failure mode. Infrared analysis showed changes in organic filler, and carbonate and phosphate bands after using irrigants. The lowest carbonate/phosphate ratio was found for chlorhexidine in both materials. Therefore, sodium hypochlorite reduced EndoSequence root repair materials’ displacement resistance markedly.

Influence of nanostructured calcium aluminate and calcium silicate on the liver: histological and unbiased stereological analysis

AIM

To examine the potential systemic toxicity of nanostructured materials based on calcium silicate and calcium aluminate, for potential application in Dentistry.

METHODOLOGY

Twenty-four Albino Wistar rats aged 2 months were used as an in vivo animal model for subcutaneous implantation of the investigated materials, placed in polyethylene tubes. Thirty days after implantation, the livers of the rats were analysed and following histological and stereological parameters were evaluated for volume density of hepatocytes and blood sinusoids, number and numerical density of hepatocytes, surface of hepatocytes and their nucleuses, nucleocytoplasmic ratio and mitotic index of hepatocytes. Stereological measurements were achieved using Cavalieri's principle, with grid P2 and unbiased analysis. Additionally, immunohistochemistry studies were performed to further analyse changes in liver tissue. Several haematological and biochemical parameters of blood of experimental animals were also analysed, as well as local tissue reactions around the implants. Statistical analysis was performed using parametric (anova and t-test) and nonparametric tests (Kruskal-Wallis and Mann-Whitney U-test) depending on data distribution.

RESULTS

Implanted dental cements led to an increase in stereological and histological parameters in liver tissue compared to control rats. Although the investigated parameters mostly showed significant differences between control and experimental animals, the liver tissue of the experimental animals did not have visible signs of pathological changes. This was supported by the analysis of blood parameters which were not significantly different between control and experimental animals. Also, the subcutaneous tissues had minimal inflammatory reactions. Immunohistochemistry studies revealed that nanostructured materials induced proliferation of hepatocytes, but that the immunological response to the materials was not strong enough to induce proliferation of immunoreactive cells in liver in the observed time period.

CONCLUSIONS

This study was performed as a contribution to the attestation of the biocompatibility of dental cements based on calcium silicate and calcium aluminate. Although these materials induced several changes in the liver structure, they were not clinically relevant and represent a normal and reversible response of the liver to the presence of biocompatible materials in the body. Blood and immunohistochemistry analyses and local tissue reactions further confirmed that these materials possess good biocompatible potential.

Conservative Management of Unset Mineral Trioxide Aggregate Root-End Filling: A Case Report

This case report presents conservative management of unset mineral trioxide aggregate (MTA) after being placed as a root-end filling material following periapical surgery. Periapical surgery was indicated for a maxillary lateral incisor of a 15-year-old male due to persistent exudate and a large periapical lesion. During surgery Angelus MTA was placed as root-end filling. The next session it was noticed that MTA had failed to completely set. In an orthograde approach, calcium-enriched mixture (CEM) cement was used to obturate the root canal space. The patient was followed up for 27 months and did not exhibit any clinical signs and symptoms. Radiographic images showed complete healing of the lesion.

Cytotoxic effects of mineral trioxide aggregate, calcium enrichedmixture cement, Biodentine and octacalcium pohosphate onhuman gingival fibroblasts

Background. This in vitro study compared the effects of mineral trioxide aggregate (MTA), calcium enriched mixture(CEM) cement, Biodentine (BD) and octacalcium phosphate (OCP) on the viability of human gingival fibroblasts (HGFs). Methods. After completion of the setting time of the materials under study, fibroblasts were placed in 24-well insert platesand 1 mg of each material was added to the respective wells. The plates were then incubated at 37°C. The inserts were removedat 24, 48 and 168 hours and 2,5-diphenyltetrazolium bromide was added to assess cytotoxicity via the MTT colorimetricassay. Data were analyzed at different time intervals using repeated-measures ANOVA, followed by the Bonferronitest at three levels of significance of P < 0.05, P < 0.01 and P < 0.001. Results. Cytotoxicity of the materials under study was not significantly different at 24 and 48 hours compared to the controlgroup. However, at 168 hours, a significant difference was noted between MTA (P < 0.05) and Biodentine (P < 0.01)and the control group. Conclusion. Cytotoxicity of MTA, CEM, Biodentine and OCP against HGFs was similar to that of the control group at 24and 48 hours. Over time, MTA and Biodentine exhibited less cytotoxicity than other materials.

Interdisciplinary Approach for Management of Iatrogenic Internal Root Resorption: A Case Report

For management of a symptomatic maxillary lateral incisor with dull pain on chewing, suppurative sinus tract, defective metal-ceramic crown and iatrogenic internal root resorption, an interdisciplinary approach was taken. Two-visit nonsurgical treatment with calcium-enriched mixture (CEM) cement, replacement of metal-ceramic crown with all-ceramic crown and corrective periodontal plastic surgery were included in the treatment plan. Six-month and one-year follow-ups revealed complete resolution of signs and symptoms and radiographic healing. This case report highlights the importance of adequate cooling during crown preparation to preserve the pulp vitality and prevent internal resorptive lesions and also the profound sealing ability and biocompatibility of CEM cement.

Miniature Pulpotomy of Symptomatic Mature Permanent Teeth: A Report of Two Cases

Human dental pulp inflammation can progress to periapical lesion formation and conventional root canal treatment (RCT) has been the traditional method for disease management. This observational study presents two cases of vital pulp therapy in mature molars diagnosed with irreversible pulpitis and associated with apical periodontitis. In these two clinical cases, the involved teeth had deep carious lesions with a history of spontaneous/lingering pain and radiographic examinations revealed the presence of apical radiolucencies. A conservative miniature pulpotomy (MP) using calcium-enriched mixture (CEM) was performed and the teeth were permanently restored with amalgam. Clinical evaluations indicated resolution of pain 24 hours after treatment; the teeth showed normal vitality, remained asymptomatic and maintained normal function after recall examinations. Furthermore, the 18-month radiographic evaluation showed healing of the apical lesions. Vital pulp therapy using the MP technique with CEM appeared successful in avoiding RCT intervention. These two reports of case outcome suggest that simple MP using a CEM bioregenerative technique may provide a favorable outcome for permanent teeth diagnosed with irreversible pulpitis and associated with apical periodontitis.

Can Mineral Trioxide Aggregate and Nanoparticulate EndoSequence Root Repair Material Produce Injurious Effects to Rat Subcutaneous Tissues?

INTRODUCTION

The aim of this study was to evaluate the injurious effects of mineral trioxide Aggregate (MTA) and EndoSequence Bioceramic Root Repair Material (ERRM; Brassler USA, Savannah, GA) 7 and 30 days after their implantation into rat subcutaneous tissues.

METHODS

Twelve Wistar rats were selected for the present study. Each animal received 3 implants: one contained MTA, one contained ERRM, and one was an empty tube that served as a control. Half of the animals were killed after 7 days, and the remaining animals were killed 30 days after implantation. Histologic sections prepared from the skin specimens were stained with H&E, toluidine blue, Masson trichrome, and Congo red. The data were statistically analyzed with 1-way analysis of variance and paired t tests. The P value for significance was set at .05.

RESULTS

After 7 days, MTA produced a significantly greater inflammatory reaction that involved the deposition of amyloidlike protein and an increase in the mast cell population compared with ERRM (P < .05). After 30 days, the ERRM group exhibited significantly reduced inflammatory reactions compared to the MTA groups (P < .05). Areas of mononuclear cell aggregation, abscess formation, and necrosis were observed more frequently in the MTA group. The thickness of the fibrous capsule was significantly increased in the MTA compared with the ERRM groups (P < .05). Amyloidlike proteins were more frequently observed around the fibrous capsule and subdermal blood vessels and were more frequently deposited in the MTA than the ERRM specimens.

CONCLUSIONS

The findings of the present study suggest that both ERRM and MTA cause an injurious effect when implanted in rat subcutaneous tissues after 7 and 30 days. ERRM is significantly less injurious to tissues than MTA.

Biocompatibility of new nanostructural materials based on active silicate systems and hydroxyapatite: in vitro and in vivo study

AIM

To evaluate in vitro cytotoxicity and in vivo inflammatory response to new nanostructural materials based on active calcium silicate systems (CS) and hydroxyapatite (HA-CS).

METHODOLOGY

Cytotoxicity of eluates of new nanostructural noncommercial materials CS and HA-CS, and MTA (White MTA, Angelus(®) Soluções Odontológicas, Londrina, Brazil) as a control, were tested using the MTT assay on MRC-5 cells. Eluates of set materials were tested in 100% and 50% concentrations, 24 h, 7 days and 21 days post-elution. The pH values were determined for undiluted eluates of set materials. Polyethylene tubes containing the test materials (CS, HA-CS, MTA) were implanted in subcutaneous tissue of Wistar rats. Histopathological examinations were conducted at 7, 15, 30 and 60 days after the implantation. Data were statistically analyzed using three-way and one-way anova Tukey's post hoc test as well as Kruskall-Wallis test with Dunn's post hoc test at α = 0.05.

RESULTS

All materials significantly reduced cell viability; especially when undiluted eluates were used (P < 0.001). After 24 h elution, cell viability was 10 ± 1.8%, 49.5 ± 4.2% and 61 ± 7.4%, for MTA, and HA-CS, respectively. However, CS and HA-CS were significantly less toxic than the control material MTA (P < 0.05). Cytotoxicity could be at least partially attributed to pH kinetics over time. Dilution of eluates of all tested materials resulted in better cell survival. Histopathological examination indicated similar inflammatory reaction, vascular congestion and connective tissue integrity associated with CS, HA-CS and MTA at each observation period (P > 0.05). The only significant difference was found for capsule thickness, that is thicker capsule was associated with HA-CS compared to MTA at 60 days (P = 0.0039). HA-CS induced moderately thick capsules (median score 3, score range 2-3), whereas MTA resulted in thin capsule formation (median score 2, score range 1-3).

CONCLUSIONS

Evaluation of cytotoxicity and inflammatory response indicated better biocompatibility of CS and HA-CS, in comparison with MTA (White MTA, Angelus(®) Soluções Odontológicas, Londrina, Brazil).

Current perspectives of bio-ceramic technology in endodontics: calcium enriched mixture cement - review of its composition, properties and applications

Advancements in bio-ceramic technology has revolutionised endodontic material science by enhancing the treatment outcome for patients. This class of dental materials conciliates excellent biocompatibility with high osseoconductivity that render them ideal for endodontic care. Few recently introduced bio-ceramic materials have shown considerable clinical success over their early generations in terms of good handling characteristics. Calcium enriched mixture (CEM) cement, Endosequence sealer, and root repair materials, Biodentine and BioAggregate are the new classes of bio-ceramic materials. The aim of this literature review is to present investigations regarding properties and applications of CEM cement in endodontics. A review of the existing literature was performed by using electronic and hand searching methods for CEM cement from January 2006 to December 2013. CEM cement has a different chemical composition from that of mineral trioxide aggregate (MTA) but has similar clinical applications. It combines the biocompatibility of MTA with more efficient characteristics, such as significantly shorter setting time, good handling characteristics, no staining of tooth and effective seal against bacterial leakage.

In vitro cytotoxicity of four calcium silicate-based endodontic cements on human monocytes, a colorimetric MTT assay

Objectives

This study was performed to evaluate the cytotoxicity of four calcium silicate-based endodontic cements at different storage times after mixing.

Materials and Methods

Capillary tubes were filled with Biodentine (Septodont), Calcium Enriched Mixture (CEM cement, BioniqueDent), Tech Biosealer Endo (Tech Biosealer) and ProRoot MTA (Dentsply Tulsa Dental). Empty tubes and tubes containing Dycal were used as negative and positive control groups respectively. Filled capillary tubes were kept in 0.2 mL microtubes and incubated at 37℃. Each material was divided into 3 groups for testing at intervals of 24 hr, 7 day and 28 day after mixing. Human monocytes were isolated from peripheral blood mononuclear cells and cocultered with 24 hr, 7 day and 28 day samples of different materials for 24 and 48 hr. Cell viability was evaluated using an MTT assay.

Results

In all groups, the viability of monocytes significantly improved with increasing storage time regardless of the incubation time (p < 0.001). After 24 hr of incubation, there was no significant difference between the materials regarding monocyte viability. However, at 48 hr of incubation, ProRoot MTA and Biodentine were less cytotoxic than CEM cement and Biosealer (p < 0.01).

Conclusions

Biodentine and ProRoot MTA had similar biocompatibility. Mixing ProRoot MTA with PBS in place of distilled water had no effect on its biocompatibility. Biosealer and CEM cement after 48 hr of incubation were significantly more cytotoxic to on monocyte cells compared to ProRoot MTA and Biodentine.

Surgical management of a failed internal root resorption treatment: a histological and clinical report

This article presents the successful surgical management of a failed mineral trioxide aggregate (MTA) orthograde obturation of a tooth with a history of impact trauma and perforated internal root resorption. A symptomatic maxillary lateral incisor with a history of perforation due to internal root resorption and nonsurgical repair using MTA was referred. Unintentional overfill of the defect with MTA had occurred 4 yr before the initial visit. The excess MTA had since disappeared, and a radiolucent lesion adjacent to the perforation site was evident radiographically. Surgical endodontic retreatment was performed using calcium enriched mixture (CEM) cement as a repair material. Histological examination of the lesion revealed granulation tissue with chronic inflammation, and small fragments of MTA encapsulated within fibroconnective tissue. At the one and two year follow up exams, all signs and symptoms of disease had resolved and the tooth was functional. Complete radiographic healing of the lesion was observed two years after the initial visit. This case report illustrates how the selection of an appropriate approach to treatment of a perforation can affect the long term prognosis of a tooth. In addition, extrusion of MTA into a periradicular lesion should be avoided.

Comparative Osteogenesis of Radiopaque Dicalcium Silicate Cement and White-Colored Mineral Trioxide Aggregate in a Rabbit Femur Model

The radiopaque dicalcium silicate cement (RDSC) displayed a shortened setting time and good biocompatibility. This study aimed to compare the regenerative potential of RDSC and white-colored mineral trioxide aggregate (WMTA) using a rabbit femur model. The animals were sacrificed at one, three and six months to accomplish histological and biochemical analyses. The results indicated that after one month of implantation, WMTA was associated with a greyish color alteration within its mass, while RDSC presented color stability even at six months. Histological assay with Masson's Trichrome and Von Kossa stains showed the presence of newly formed bone surrounding the implanted sites in the rabbit femur. The histochemical data revealed that the RDSC group had significantly more bone regeneration than did the WMTA groups at three and six months. The conclusion drawn is that the encouraging results support the potential applications of RDSC as an improved alternative to WMTA for endodontic uses.

A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide

Objectives

The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement.

Materials and Methods

A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation.

Results

All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples.

Conclusions

This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable.

Vital pulp therapy using calcium-enriched mixture: An evidence-based review

Worldwide, casecontrol studies have revealed that the treatment outcomes of root canal therapy (RCT) are generally favorable; however, the overall epidemiological success rate of RCT in the general population is relatively low. On the other hand, vitality of dental pulp is a key factor in the long-term prognosis of permanent teeth; in recent years, vital pulp therapy (VPT) has received significant consideration as it has been revealed that the inflamed pulp has the potential to heal. In this review article, the current best evidence with regard to VPT using calcium-enriched mixture (CEM) cement in human permanent/primary teeth is discussed. A strategy based on a search using keywords for CEM cement as well as VPT was applied.

Treatment outcomes of primary molars direct pulp capping after 20 months: a randomized controlled trial

INTRODUCTION

The aim of this randomized controlled trial was to compare the radiographic and clinical success rates of direct pulp capping (DPC) using ProRoot mineral trioxide aggregate (MTA) or calcium enriched mixture (CEM).

METHODS AND MATERIALS

A total of 42 symptom-free carious vital primary molars (21 pairs) were selected in this split mouth trial and randomly pulpotomized in two experimental groups. Pinpoint pulp exposures were covered by the same blinded operator with MTA or CEM, and then restored by amalgam. Radiographic and clinical successes were evaluated at 20 month follow-up. Data were statistically analyzed using McNemar test.

RESULTS

Nineteen patients were available for 20-month follow-up; only one failed tooth was extracted in the CEM group. All available teeth were symptom-free, however, the final evaluated success rate was 89% in CEM (CI 95%: 0.82-0.96) and 95% in MTA (CI 95%: 0.85-1) groups without statistical difference (P=0.360). Worst case scenario was applied for missing value analysis; assuming that the 2 lost cases in CEM group had failed and the only lost case in MTA group was due to treatment success, as a result the success of CEM and MTA were 81% (CI 95%: 0.72-0.90) and 95% (CI 95%:0.85-1), respectively, with no statistical difference (P=0.078). In the reverse scenario, the success of MTA and CEM were 86% (CI 95%: 0.78-0.94) and 90% (CI 95%: 0.82-0.98), respectively; again with no statistical difference (P=0.479).

CONCLUSION

Effectiveness of MTA and CEM biomaterials for primary molars' DPC was similar; CEM can be a suitable alternative for MTA.

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (α=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

Evaluation of the rat tissue reaction to experimental new resin cement and mineral trioxide aggregate cement

Objectives

New resin cement (NRC) has been developed as a root repairing material and the material is composed of organic resin matrix and inorganic powders. The aim of this study was to compare the rat subcutaneous tissue response to NRC and mineral trioxide aggregate (MTA) cement and to investigate the tissue toxicity of both materials.

Materials and Methods

Sixty rats received two polyethylene tube-implants in dorsal subcutaneous regions, MTA and NRC specimens. Twenty rats were sacrificed respectively at 1, 4 and 8 wk after implantation and sectioned to 5 µm thickness and stained with Hematoxylin-Eosin (H-E) or von-Kossa staining. The condition of tissue adjacent to the implanted materials and the extent of inflammation to each implant were evaluated by two examiners who were unaware of the type of implanted materials in the tissues. Data were statistically analyzed with paired t-test (p < 0.05).

Results

In specimens implanted with both NRC and MTA, severe inflammatory reactions were present at one wk, which decreased with time. At eighth wk, MTA implanted tissue showed mild inflammatory reaction, while there were moderate inflammatory reactions in NRC implanted tissue, respectively. In NRC group, von-Kossa staining showed more calcification materials than MTA group at eighth wk.

Conclusions

It was concluded that the calcium reservoir capability of NRC may contribute to mineralization of the tissues.

Surgical intervention for treating an extensive internal resorption with unfavorable crown-to-root ratio

Internal resorption is a rare lesion in permanent teeth. Managing perforating internal resorption is a great challenge for dentists. This report presents a successful surgical treatment of a maxillary central incisor that had extensive root perforation due to internal resorption. After unsuccessful nonsurgical approach, during surgical intervention apical part of the resorption defect was removed and the coronal part was filled with mineral trioxide aggregate. Three years later the tooth was symptom free with normal mobility and pocket depth despite unfavorable crown-to-root ratio. This case report have shown that surgical intervention and using mineral trioxide aggregate as root canal filling material in a tooth with extensive internal resorption and unfavorable crown-to-root ratio can be considered as a treatment option.

Periapical Healing After Direct Pulp Capping With Calcium-enriched Mixture Cement: A Case Report

This article describes a successful direct pulp capping of a mature symptomatic mandibular second molar in a 14-year-old girl. The patient was referred with sensitivity to cold beverages and pain on chewing on the second left mandibular molar. Clinical examinations revealed extensive coronal caries and sensitivity to percussion. Radiographically, the tooth was mature and had a widened apical periodontal ligament (PDL) and a narrow periapical lesion. The concluding diagnosis was symptomatic irreversible pulpitis with symptomatic apical periodontitis. Treatment included caries removal under rubber dam isolation, capping of exposure sites with calcium-enriched mixture (CEM) cement, and permanent coronal restoration. At three-, 10-, and 15-month follow-up, the tooth was functional, had normal response to cold test, and did not have sensitivity to percussion. The PDL space regained its normal width, and the periapical lesion healed.

Influence of white mineral trioxide aggregate on inflammatory cells before and after expiry date

INTRODUCTION

The aim of this study was to compare the effect of subcutaneously implanted white mineral trioxide aggregate (WMTA) on inflammatory reactions before and after expiry date.

METHODS

Fifty Wistar rats were used in this study. Polyethylene tubes were filled with WMTA with expiry dates of 2008, 2009, and 2011, and empty ones serving as the controls were implanted into the subcutaneous tissue. The rats were sacrificed at 7-, 14-, 28-, and 60-day intervals. 5-μm sections were stained with hematoxylin and eosin and observed under a light microscope. Inflammatory reactions were categorized as 0, none (without inflammatory cells); 1, mild (inflammatory cells < 25); 2, moderate (25-125 inflammatory cells); and 3, severe (more than 125 inflammatory cells). Statistical analysis was performed with Kruskal-Wallis test.

RESULTS

All the experimental materials provoked moderate to severe inflammatory reactions after 7 days, which significantly differed from the control group (P < 0.05). At 14-day interval, WMTA with expiry date of 2008 and the control group elicited mild to moderate infiltration of inflammatory cells. However, WMTA with expiry dates of 2009 and 2011 provoked moderate to severe inflammatory reactions, which were significantly different from WMTA with expiry date of 2008 and the control group (P < 0.05). At 28- and 60-day intervals, the overall inflammation subsided in all the groups to mild to moderate infiltration of inflammatory cells without any significant differences (P < 0.05).

CONCLUSION

It seems that the expiry date has less negative effects on the response of inflammatory cells. WMTA keeps its biocompatibility even after expiry date.