Effect of White-Colored Mineral Trioxide Aggregate in Different Concentrations on Candida albicans In Vitro

Mineral trioxide aggregate in membrane form as a barrier membrane in guided bone regeneration

Background/purpose

In the field of conservative dentistry and endodontics, mineral trioxide aggregate (MTA), commonly used, possesses advantages such as biocompatibility, antimicrobial properties and osteogenic potential. This study investigated the feasibility of utilizing membrane form mineral trioxide aggregate (MTA) as a barrier membrane in guided bone regeneration (GBR) procedures.

Materials and methods

Membranes were electrospun from three different formulations: 15 w/v% Polycaprolactone (PCL), 13 w/v% PCL + 2 w/v% MTA (2MTA), and 11 w/v% PCL + 4 w/v% MTA (4MTA). Physicochemical and mechanical properties of the electrospun membrane were compared, encompassing parameters such as surface morphology, fiber diameter distribution, chemical composition, phase identification, tensile stress, pH variation, and water contact angle. Moreover, the antimicrobial properties against of the electrospun membranes were assessed through direct exposure to streptococcus aureus (S. aureus) and candida albicans (C. albicans). Additionally, on the 7th day, biocompatibility and cell attachment were investigated with respect to L929 (fibroblast) and MC3T3 (pre-osteoblast) cells. Inhibition of L929 cell infiltration and the expression of osteogenic related genes including osteocalcin (OCN), alkaline phosphatase (ALP), and runt related transcription factor 2 (RUNX2) in MC3T3 cells on 7th and 14th days were also investigated.

Results

PCL, 2MTA, and 4MTA exhibited no statistically differences in fiber diameter distribution and tensile stress. However, as the MTA content increased, wettability and pH also increased. Due to the elevated pH, 4MTA demonstrated the lowest viability S.aureus and C.albicans. All membranes were highly biocompatibility and promoted cell attachment, while effectively preventing L929 cell infiltration. Lastly 4MTA showed increase in OCN, ALP, and RUNX2 expression on both 7th and 14th day.

Conclusion

The membrane form MTA possessed characteristics essential for a novel barrier membrane.

Radiographic and immuno-histochemical evaluation of root perforation repair using MTA with or without platelet-rich fibrin or concentrated growth factors as an internal matrix in dog's teeth: in vivo animal study

OBJECTIVES

To comparatively evaluate the in vivo outcome of MTA repair for contaminated and non-contaminated furcation perforations (FP) with or without PRF and CGF as a matrix in dogs' teeth.

METHODS

Ninety dog teeth were divided into five groups based on the iatrogenic FP repair approach after doing root canal treatment: negative control (without FP), positive control (FP without repair), MTA, MTA + PRF and MTA + CGF groups, where FP were repaired promptly in subdivision 1 (n = 10; non-contaminated) and after 4 weeks of oral contamination in subdivision 2 (n = 10;contaminated). After 3 months, the perforation site was assessed radiographically (vertical bone density), histologically (inflammatory cell count, epithelial proliferation, cementum and bone deposition) and immunohistochemically (OPN and TRAP antibodies localisation). Data collected were statistically analysed using SPSS software at a 0.05 significance level.

RESULTS

The MTA + PRF and MTA + CGF groups demonstrated significantly more bone formation, OPN immunolocalisation and fewer inflammatory cell counts than MTA group. MTA, MTA + PRF and MTA + CGF groups showed significantly favourable radiographic, histological and immunohistochemical healing features than the positive control, especially in non-contaminated subdivisions, that significantly showed better features than the contaminated subdivisions (P < 0.001).

CONCLUSION

The use CGF and PRF as a matrix beneath MTA in FP repair in dog's teeth is promising as it could increase hard and soft tissue regeneration in non-contaminated and contaminated perforations.

CLINICAL RELEVANCE

The repair of FP is challenging especially when associated with contaminated inter-radicular bone loss. Radiographic, histological and immunohistochemical comprehensive evaluation of the root and surrounding attachment apparatus response to different perforation repair protocols could give a predictable clinical outcome.

Biological and chemical properties of five mineral oxides and of mineral trioxide aggregate repair high plasticity: an in vitro study

Calcium silicate-based cements have diverse applications in endodontics. This study aimed to evaluate the antibiofilm action, biocompatibility, morphological structure, chemical composition and radiopacity of Five Mineral Oxides (5MO), Mineral Trioxide Aggregate Repair High Plasticity (MTA Repair HP), and Mineral Trioxide Aggregate (MTA) cements. MTT analysis was used to test the antibiofilm action of these cements against five anaerobic microorganisms, and test their biocompatibility with mouse macrophage (RAW 264.7) and osteoblasts (MG-63) cultures. Their morphological structure and chemical composition were evaluated by scanning electron microscopy (SEM) coupled to energy dispersion X-ray spectroscopy (EDX), and the phase analysis was performed by X-ray diffraction (XRD). Conventional radiography was used to assess the radiopacity of the cements. 5MO, MTA Repair HP and MTA were effective against Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum and Prevotella intermedia, they were biocompatible with macrophages and osteoblasts after 5 min of contact, and they had adequate radiopacity to be used clinically. Bismuth oxide (Bi2O3) is used as a radiopacifier in MTA and 5MO, and calcium tungstate, in MTA Repair HP. Titanium dioxide (TiO₂) (ANATASE) is responsible for the antimicrobial action and biocompatibility of 5MO.

The Evaluation of the Antibacterial and Antifungal Efficacy of Novel Kids Mineral Trioxide Aggregate (e-MTA) With ProRoot MTA and Glass Ionomer Cement

Background

Most pulpal and periapical problems could be treated nonsurgically. However, in cases of infections, certain operations must be performed that require using materials with good antibacterial and antifungal efficacy. ProRoot mineral trioxide aggregate (MTA) was marketed as gray- and white-colored preparations, composed of 75% Portland cement, 20% bismuth oxide, and 5% gypsum by weight. MTA, composed of powder and liquid as distilled water, formed a colloidal gel that further solidified and formed a hard cement within approximately four hours. The new endodontic material Kids e-MTA (Kids-e-dental, Mumbai, India) was introduced recently. It was also available as powder and liquid. It was a bioactive cement consisting of very fine hydrophilic particles of several mineral oxides.

Aim

This study compares the antimicrobial and antifungal efficacy of e-MTA (mineral trioxide aggregate) (Kids-e-dental, Mumbai, India), ProRoot MTA (Dentsply Sirona, Tulsa Dental, OK, USA), and glass ionomer cement (GIC) (GC Asia Dental Pte Ltd, Singapore).

Materials and methods

The agar diffusion method was used to test the materials. e-MTA, ProRoot MTA, and GIC were tested for their antibacterial efficacy against Enterococcus faecalis and antifungal efficacy against Candida albicans. The zone of inhibition was calculated and measured using a precision ruler. The collected data was put through Student’s unpaired t-test.

Results and conclusions

On conducting the tests and comparing the results, it was found that e-MTA had a slightly better antibacterial efficacy and almost similar antifungal efficacy compared to ProRoot MTA but significantly superior properties compared to GIC.

Antimicrobial and Antibiofilm Properties of Bioceramic Materials in Endodontics

Microbes are prevalent in the root canals of necrotic teeth, and they are the cause of primary and post-treatment apical periodontitis. Bacteria can dwell within the infected root canal system as surface-adherent biofilm structures, which exhibit high resistance to antimicrobial agents. Bioceramic materials, with their biocompatible nature and excellent physico-chemical properties, have been widely used in dental applications, including endodontics. This review focuses on the application of bioceramic technology in endodontic disinfection and the antibiofilm effects of endodontic bioceramic materials. Different bioceramic materials have shown different levels of antibiofilm effects. New supplements have emerged to potentially enhance the antibiofilm properties of bioceramics aiming to achieve the goal of microbial elimination in the root canal system.

Evaluation of the Antimicrobial Effect of Mineral Trioxide Aggregate Mixed with Fluorohydroxyapatite against E. faecalis In Vitro

Enterococcus faecalis is the dominant microorganism in chronic apical periodontitis. It is more resistant to local antiseptic agents than other endodontic microorganisms. Currently, mineral trioxide aggregate (MTA) is considered as an ideal material in many endodontic procedures. Some studies have shown that MTA has good antibacterial activity against E. faecalis. However, some studies have investigated the effect of incorporating some materials into MTA on its antibacterial activity against E. faecalis. No study has evaluated the effect of incorporating fluorohydroxyapatite nanoparticles (nano-FHA) on the antimicrobial activity of MTA. Therefore, the present study evaluated the antimicrobial effect of MTA mixed with nano-FHA on E. faecalis in vitro. The study was carried out on 18 samples in three groups: pure MTA, MTA mixed with 10 wt% of nano-FHA, and MTA mixed with 15 wt% of nan-FHA. The effect of nano-FHA on the antibacterial activity of MTA on E. faecalis was evaluated by evaluating the growth inhibition zone around each sample. The antimicrobial effect of samples on inhibiting E. faecalis biofilm formation and inhibiting microbial growth of E. faecalis in the planktonic phase was evaluated by disk agar diffusion (DAD), biofilm inhibition assay (BIA), and direct contact assay (DCA) tests, respectively. All the above tests were analyzed after 24 and 72 hours. Factorial designs were used for statistical analyses. Tukey tests were used for two-by-two comparisons. All the statistical analyses were carried out with SPSS 26. DAD results showed no formation of the growth inhibition zone in all the samples after 24 and 72 hours. The microbial colony counts in the BIA and DCA tests in the groups modified with FHA nanoparticles were significantly lower than the pure MTA group (P < 0.05). The microbial colony counts increased in all the groups over time (P < 0.05). Incorporating nano-FHA into MTA improved the antimicrobial activity of MTA against E. faecalis compared to pure MTA. The highest antimicrobial activity was achieved after incorporating 15 wt% of nano-FHA into MTA at the 72-hour interval.

Real-time nanoleakage and the flow characteristics of calcium silicate root canal filling materials

This study aimed to investigate the real-time nanoleakage and flow characteristics of calcium silicate-based (Ca-Si) root canal filling materials. Extracted human teeth (n = 30) were decoronated and standardized in their inner and outer dimensions. After root canal enlargement, the roots were filled with gutta-percha (GP) and AH26 sealer, GP and EndoSeal MTA sealer, or Biodentine. The roots were connected to a Nanoflow device (IB Systems) under hydrostatic pressure (40 cm∙H₂O) and fluid flow was traced through the filled roots. Data were detected at the nanoscale twice per second and automatically recorded in units of nL/s. Leakage was quantified as the mean slope until the curve plateaued over time, and all static flow intervals lasting longer than 1 s were analyzed to identify any increase in flow and duration. Data were statistically analyzed using the Kruskal-Wallis test. The calculated leakage values were 0.0670 ± 0.0516 nL/s for GP/AH26, 0.1397 ± 0.1579 nL/s for GP/EndoSeal MTA, and 0.0358 ± 0.0538 nL/s for Biodentine, with no statistically significant differences among the root filling materials (P > 0.05). An analysis of real-time flow data for 1000 s to identify spot trends and the overall tendency of flow until a plateau was reached revealed a stepwise increase in the roots filled with Ca-Si material, whereas the GP/AH26-filled roots showed a linear increase. Real-time measurements under hydrostatic pressure with the Nanoflow device enabled precise fluid flow tracing through the root canal filling material. In terms of nanoleakage, the tested root canal filling materials showed no significant differences, while the real-time flow patterns of roots filled with Ca-Si material showed different characteristics from those of GP/AH26-filled roots.

Catalytic and physical features of a naturally immobilized Yarrowia lipolytica lipase in cell debris (LipImDebri) displaying high thermostability

Lipase activity (337 U/g dry weight of cell debris) was detected in cell debris after ultrasound treatment of Yarrowia lipolytica cells cultivated in residual frying palm oil. It is a naturally immobilized lipase with protein content of 47%, herein called LipImDebri. This immobilized biocatalyst presents low hydrophobicity (8%), that can be increased adjusting pH and buffer type. Despite apparent intact cells, electron microscopy showed a shapeless and flat surface for LipImDebri and optical microscopy revealed no cell viability. Besides, an inferior mean diameter (3.4 mm) in relation to whole cells reveals structure modification. A high negative zeta potential value (- 33.86 mV) for pH 6 and 25 °C suggests that LipImDebri is a stable suspension in aqueous solution. Fourier Transform Infrared Spectra (FTIR) expose differences between LipImDebri and extracellular lipase extract signaling a physical interaction between enzyme and cell debris, which is possibly the reason for the high thermostability (k _d = 0.246 h^-1; t _1/2 = 2.82 h at 50 °C, pH 7.0). A good adjustment of LipImDebri kinetic data with Hill equation (R ² = 0.95) exposes an allosteric behavior related to the presence of more than one lipase isoform. These features reveal that LipImDebri can be a good catalyst for industrial applications.

Candida albicans Virulence Factors and Pathogenicity for Endodontic Infections

Candida albicans (C. albicans) is the fungus most frequently isolated from endodontic root canal infections. Although recognized by dental pulp and periradicular tissue cells that elicit immune responses, it eludes host defenses and elicits cell death. Then, C. albicans binds tooth dentin, forms biofilms, and invades dentinal tubules to resist intracanal disinfectants and endodontic treatments. Insensitive to most common medicaments, it survives sequestered within biofilms and intratubular dentin. Thus, C. albicans has been associated with cases of persistent or refractory root canal infections. Its treatment strategies may require alternative intracanal irrigants, intracanal medicaments such as chlorhexidine gel or human beta defensin-3 (HBD3), Ca-Si-based obturating materials, and microsurgical procedures.

Antimicrobial activity and pH measurement of calcium silicate cements versus new bioactive resin composite restorative material

Background

The purpose of this in vitro study is to compare the antimicrobial effect and pH of two calcium silicate cements Mineral trioxide aggregate high plasticity (Angelus PR, Brazil) and iRoot BP Plus (BioCeramix Inc., Vancouver, BC, Canada) and new bioactive restorative resin composite restorative material (ACTIVA, MA, Pulpdent, USA) against aerobic bacteria, strictly anaerobic bacteria and a yeast by using an agar diffusion test.

Methods

The materials were tested immediately after manipulation and were applied to the agar plates. Sodium hypochlorite (NaOCl) 5.25% was used as a positive control group. The dry filter paper acted as a negative control group for this study. The size of the inhibition zone for each material was measured after 12, 24 and 48 h. At the time of pH measurement; materials were prepared, crushed then dispersed in distilled water.

Results

The one-way Anova test revealed that iRoot BP Plus significantly showed superior antimicrobial efficacy compared to MTA-HP against the following species; Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Enterococcus faecium, Peptostreptococcus anaerobius and Candida albicans (P < 0.05). All of the tested materials did not show any antimicrobial effect against Porphyromonas gingivalis and Actinomyces israelii. The new bioactive resin composite material (ACTIVA) showed the least antimicrobial activity against the previously mentioned microorganisms except E. faecalis. NaOCl significantly showed the highest antimicrobial activity among the test group (P < 0.05). iRoot BP Plus was more alkaline (pH 12.1 ± 0.14/ 11.9 ± 0.25) in comparison to MTA-HP (pH 11.6 ± 0.16/ 11.2 ± 0.10) while ACTIVA was slightly acidic (pH 5.4 ± 0.09/ 6.5 ± 0.08).

Conclusions

According to the findings of this study, it was concluded that calcium silicate- based cements showed a potential antimicrobial activity mainly due to its high alkalinity. The new bioactive resin composite restorative material exhibits less antimicrobial activity due to its resinous ingredients and slightly acidic nature. Antimicrobial effect of calcium silicate cements against strictly anaerobic bacterial species is still questionable.

Bioactive tri/dicalcium silicate cements for treatment of pulpal and periapical tissues

Over 2500 articles and 200 reviews have been published on the bioactive tri/dicalcium silicate dental materials. The indications have expanded since their introduction in the 1990s from endodontic restorative and pulpal treatments to endodontic sealing and obturation. Bioactive ceramics, based on tri/dicalcium silicate cements, are now an indispensable part of the contemporary dental armamentarium for specialists including endodontists, pediatric dentists, oral surgeons andfor general dentists. This review emphasizes research on how these materials have conformed to international standards for dental materials ranging from biocompatibility (ISO 7405) to conformance as root canal sealers (ISO 6876). Potential future developments of alternative hydraulic materials were included. This review provides accurate materials science information on these important materials. STATEMENT OF SIGNIFICANCE: The broadening indications and the proliferation of tri/dicalcium silicate-based products make this relatively new dental material important for all dentists and biomaterials scientists. Presenting the variations in compositions, properties, indications and clinical performance enable clinicians to choose the material most suitable for their cases. Researchers may expand their bioactive investigations to further validate and improve materials and outcomes.

Evaluation of Antibacterial Efficacy of MTA with and without Additives Like Silver Zeolite and Chlorhexidine

INTRODUCTION

Microorganisms, predominantly Enterococcus faecalis are found responsible in the progression of pulpal, periradicular diseases and in endodontic failures. Unsuccessful conventional treatment might necessitate the need for a surgical approach; where in retrograde restorative materials are used to seal the apex. Among the root end filling materials, Mineral Trioxide Aggregate (MTA) is considered biocompatible and is most commonly used in clinical applications but it has limited antibacterial activity. Metallic silver and chlorhexidine have been added into various dental materials to enhance the antibacterial activity.

AIM

This study aimed to compare the antibacterial effect of MTA, MTA mixed with silver zeolite and MTA mixed with chlorhexidine against Enterococcus faecalis.

MATERIALS AND METHODS

Test materials used in the study were divided into three groups namely Group 1- MTA, Group 2-MTA + Silver Zeolite, Group 3-MTA + Chlorhexidine. Direct contact test was done by placing a standardized suspension of Enterococcus faecalis on the test materials in a 96 well microtiter plate. The bacterial growth was measured spectrophotometrically using ELISA reader at intervals of one, three and seven days.

STATISTICAL ANALYSIS

Data was collected by recording the optical density and analyzed using two-way ANOVA and Tukey's multiple post hoc test followed by paired-t test.

RESULTS AND CONCLUSION

All test groups showed antibacterial activity against Enterococcus faecalis at day one, three and seven. MTA with silver zeolite showed the maximum antibacterial activity followed by MTA with 2% chlorhexidine. The least antibacterial effect was shown by MTA mixed with sterile water.

Clinical Evaluation of Success of Primary Teeth Pulpotomy Using Mineral Trioxide Aggregate(®), Laser and Biodentine(TM)- an In Vivo Study

INTRODUCTION

Pulpotomy technique basically consists of removing the coronal pulp and fixing the radicular pulp with a medicament. It is the most widely accepted clinical procedure for treating primary teeth with coronal pulp inflammation caused by caries with no involvement of the radicular pulp.

AIM

To evaluate the success and efficacy of Mineral Trioxide Aggregate (MTA), Lasers and Biodentine as pulpotomy agents both clinically and radiographically.

MATERIALS AND METHODS

In the present study, 60 primary molars in children whose pulpal status warranted pulpotomy were selected and randomly assigned into three groups that included MTA, Laser and Biodentine allocating 20 teeth to each group. The pulpotomy procedure was then performed on all selected teeth followed by restoration with stainless steel crowns. Later the patients were recalled for 3 months and 6 months for clinical and radiographic evaluation.

RESULTS

Statistical analysis was done using Fisher exact test to determine pair wise comparison of three agents with respect to clinical and radiographic criteria. Kruskal-Wallis ANOVA, Mc Nemars test was applied to evaluate the efficacy of each agent between 3 months and 6 months. The results showed that maximum success rate was found in MTA group. However, the comparison between three groups was statistically not significant (p<0.05).

CONCLUSION

Pulpotomies performed with either MTA, Laser or Biodentine are equally efficient with similar clinical/radiographic success and hence can be considered as alternatives to Formocresol.

Boon of MTA Apexification in Young Permanent Posterior Teeth

Single visit apexification using mineral trioxide aggregate (MTA) is a new boon in effective management of nonvital tooth with an open apex which has steadily gained popularity with clinicians; also it shortens the treatment period and improves patient compliance. Importance of this approach lies in expedient cleaning and shaping of the root canal system, followed by its apical seal with MTA. There are several case reports available describing the use of MTA as an apexification agent in incisors and premolar, but presented cases are the unique case reports demonstrating successful apexification procedure using MTA in young permanent mandibular molars. After eight-month follow-up, teeth were without any abnormal clinical symptoms; rather there were radiographic resolution of the periapical lesion and induction of root end closure with new hard tissue formation over MTA.

Evaluation of antifungal activity of white-colored mineral trioxide aggregate on different strains of Candida albicans in vitro

AIM

The purpose of this study was to evaluate the antifungal action of various concentrations of white mineral trioxide aggregate (MTA) against seven different strains of Candida albicans using the tube dilution test.

MATERIALS AND METHODS

Fresh mix of MTA was prepared at concentrations of 100, 50, 25, and 12.5 mg/ml and added to a broth tube containing Sabouraud's liquid medium. A total of 1287 broth tubes were prepared and divided into experimental and control groups. Stock cultures of seven strains of C. albicans were obtained. Fresh inoculate of the microorganism was prepared by growing overnight cultures. Aliquots of the test C. albicans were taken and added to the test tubes. All tubes were incubated at 37°C for 1-, 24-, 72-, and 168-h time periods. At each time period, the presence of C. albicans colonies was assessed.

STATISTICAL ANALYSIS USED

Differences among the groups were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

Results showed that one strain showed resistance even after 3 days at the lower MTA concentrations of 12.5 and 25 mg/ml. Growth reoccurred with three strains at MTA concentration of 12.5 mg/ml after 7 days. A significant difference was found between strain 3 and other strains at MTA concentrations of 12.5 and 25 mg/ml at the 3-days time period and between tubes containing 12.5 mg/ml and tubes containing higher concentrations of MTA at the 7-days time period.

CONCLUSION

White MTA in concentrations of 100 and 50 mg/ml is effective in inhibiting the seven tested strains of C. albicans for periods up to 1 week.

Antimicrobial effects of several calcium silicate-based root-end filling materials

The purpose of this study was to evaluate, in vitro, the antimicrobial effect of iRoot BP, iRoot BP Plus, and mineral trioxide aggregate (MTA) against Entercoccus faecalis and Candida albicans by using direct contact test. The materials were tested immediately after application to the microtiter wells and after setting for 1-day and for 7-days. Ten microliters of microbial suspension was added to each well for direct contact with each material for 1 h at 37°C and 100% humidity. Then fresh media was added and, survival of bacteria and fungi was determined by using 10-fold serial dilution and inoculated onto agar plates. In fresh and 1-day samples all of tested materials showed statistically significant antimicrobial effects compared to control groups (p<0.05). In 7-day samples, there were no significantly differences compared to control groups. MTA, iRoot BP and iRoot BP Plus had similar antimicrobial efficacy against E. faecalis and C. albicans.

The effects of incorporation of silver-zeolite on selected properties of mineral trioxide aggregate

The purpose of this study was to evaluate some physical and chemical properties of MTA incorporated with antibacterial silver zeolite (SZ). 0%, 0.2% or 2% mass fraction of SZ was added to MTA powder. The amounts of calcium released from the specimen in deionized water were measured with an atomic absorption spectrophotometer. The setting times of the samples were evaluated using Gilmore-type needles. For solubility and water absorption tests, the samples were placed in a cylindrical polystyrene-sealed container. At 7 days, the samples were removed from solutions and blotted dry for solubility and water absorption test. The highest calcium release was detected in 2% SZ MTA at 24 h. The addition of 2% SZ to MTA reduced the setting time statistically (p<0.05). 2% SZ MTA was significantly more soluble than MTA and 0.2 % SZ MTA (p<0.05). Further research is needed prior to clinical use of MTA with incorporated SZ.

Antifungal activity of several root canal sealers against Candida albicans

OBJECTIVE

The purpose of this in vitro study was to evaluate the antifungal activity of several root canal sealers (iRoot SP, MTA Fillapex and GuttaFlow) against Candida albicans and compare them to that of AH Plus Jet.

MATERIALS AND METHODS

A 10 μL fungi in suspension was allowed to directly contact the sealers, which were freshly mixed or allowed to set for 1 or 7 days. Fresh media was then added and survival of fungi was determined by using 10-fold serial dilution and inoculated onto agar plates. After incubation for 48 h, colony-forming units (CFU) were calculated and their log10 values converted. The data were analyzed using ANOVA and Tukey tests (α = 0.05).

RESULTS

Freshly mixed AH Plus Jet totally inhibited the growth of fungi and showed the highest antifungal activity. GuttaFlow did not show any significant antifungal activity at all times. Freshly mixed iRoot SP and MTA Fillapex were found to be antifungal. Statistical differences were found between freshly mixed and set samples (p < 0.05) in favor of the former, except GuttaFlow. No statistically significant differences were found among the tested sealers at the 1 and 7-day samples (p > 0.05).

CONCLUSIONS

Fresh AH Plus Jet had very potent antifungal activity. All sealers, except GuttaFlow, exhibited antifungal activity when freshly mixed.

Effect of acid etching on marginal adaptation of mineral trioxide aggregate to apical dentin: microcomputed tomography and scanning electron microscopy analysis

The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scanning electron microscopy (SEM). Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials: (i) white-colored MTA (WMTA), (ii) etched WMTA (EWMTA), (iii) gray-colored MTA (GMTA) and (iv) etched GMTA (EGMTA). After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the Kruskal-Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of (0.007 1±0.004) mm(3), (0.053±0.002) mm(3), (0.003 6±0.001) mm(3) and (0.005 9±0.002) mm(3) respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be (492.3±13.8) µm, (594.5±17.12) µm, (543.1±15.33) µm and (910.7±26.2) µm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found (P<0.05). No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA.

The effect of various concentrations of iodine potassium iodide on the antimicrobial properties of mineral trioxide aggregate--a pilot study

BACKGROUND

Mineral trioxide aggregate (MTA) is a multi-purpose dental material with various uses in dentistry. Iodine potassium iodide (IKI) is the most commonly used iodine compound in endodontics. We aimed to assess the antimicrobial activity of tooth-colored ProRoot MTA combined with IKI.

MATERIALS AND METHODS

The antimicrobial activity of IKI was assessed at three concentrations (1%, 2%, and 4%) as the mixing agents combined with MTA against Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. For each microorganism, three plates were inoculated with 100 μl of a microbial suspension (McFarland 0.5). Four wells were prepared in each plate. MTA (70 mg) was mixed with any of the three concentrations of IKI (25 μl) or sterile distilled water (25 μl) and placed in each well. The plates were incubated for 24 h at 37°C. Zones of inhibition (ZOI) were measured in millimeters by a blinded observer. Data were analyzed using analysis of variance and the Dunnett t-test.

RESULTS

All MTA mixtures with water or IKI solutions showed inhibitory zones. The mean ZOI of each MTA/IKI mixture was not significantly different from MTA/water mixture (P > 0.05). MTA/1% IKI had smaller ZOI than MTA/water against E. coli, E. faecalis, and C. albicans. MTA/2% IKI showed larger ZOI only against P. aeruginosa. MTA/4% IKI showed larger ZOI against P. aeruginosa and E. coli (P < 0.05).

CONCLUSIONS

Substitution of IKI solutions (1%, 2%, and 4%) for water did not significantly increase the antimicrobial activity of MTA.

An in vitro evaluation of antifungal activity of bioaggregate

OBJECTIVE

The aim of this study was to evaluate, in vitro, the antifungal effect of bioaggregate (BA) against Candida albicans by using the direct contact method.

STUDY DESIGN

BA was tested freshly mixed and after 24-hour set on C. albicans. The tested BA was incubated with C. albicans in plastic tissue clusters for 1 hour, 24 hours, and 3 and 5 days. Aliquots of 0.1 mL were taken from each well at the end of the incubation periods and transfered to tubes containing 5 mL fresh Sabouraud broth. All tubes were vortexed and then incubated at 37°C and observed for the subsequent 5 days. Growth of the fungi was observed daily by the presence of turbidity in the tubes. The results were statistically analyzed by using Kaplan-Meier test.

RESULTS

The freshly mixed and set BA had no antifungal effect at 1 and 24 hours of contact. Both mixes demonstrated complete fungicidal activity after 24 hours' contact. Statistical analysis showed a highly significant difference between the negative and positive control groups (P < .001) and a significant difference between the freshly mixed and 24-hour set BA groups (P < .001) at 24 hours.

CONCLUSIONS

BA (freshly mixed and 24-hour set) was effective against C. albicans after 24 hours.

Short-term antimicrobial properties of mineral trioxide aggregate with incorporated silver-zeolite

The purpose of this in vitro study was to determine whether adding silver-zeolite (SZ) to mineral trioxide aggregate (MTA) would enhance the antimicrobial activity of MTA against Staphylococcus aureus (ATCC #25923), Enterococcus faecalis (ATCC #29212), Escherichia coli (ATCC#25922), Pseudomonas aeruginosa (ATCC #27853), Candida albicans (ATCC #90028), Porphyromonas gingivalis (ATCC #33277), Actinomyces israelii (ATCC #12102), and Prevotella intermedia (ATCC# 15032). SZ was added at 0.2% and 2% mass fraction concentration to MTA powder. The control group was MTA powder with no SZ. The antimicrobial effect test was accomplished by placing freshly mixed MTA specimens on agar plates inoculated with microorganisms and comparing the zones of inhibition at 24, 48, and 72 h. The amounts of silver ion release from MTA specimens were measured with atomic absorption spectrophotometry at 10-min, 24-, 48-, and 72-h periods. The pH of MTA specimens was measured with a pH meter at 10-min, 24-, 48-, and 72-h periods. MTA with 2% and 0.2% SZ specimens showed inhibitory effects on some microorganisms at all time periods, whereas no antimicrobial activity showed for P. intermedia and A. israelii. MTA without SZ inhibited C. albicans, E. Coli, and P. intermedia. The highest silver release was detected in 2% SZ MTA at 24 h. The incorporation of SZ may enhance the antimicrobial activity of MTA.

Direct pulp capping with mineral trioxide aggregate: an immunohistologic comparison with calcium hydroxide in rodents

INTRODUCTION

The aim was to evaluate the proliferation of pulp cells 1, 3, and 7 days after direct pulp capping with ProRoot MTA (MTA) and to compare the results with calcium hydroxide (Ca(OH)(2)).

METHODS

An occlusal cavity was prepared in 36 molar teeth of 18 Wistar rats. Then MTA or Ca(OH)(2) was placed on the exposed pulp. All cavities were restored with composite. After 1, 3, and 7 days the animals were killed. One hour before scarification 5-bromo-2'-deoxyuridine (BrdU) was injected into the intraperitoneal cavity for immunohistologic analysis. BrdU was incorporated into the cell nucleus during the S phase of the cell cycle. Proliferating cells were tagged and counted by using alkaline phosphatase and anti-alkaline phosphatase antibody staining. Three animals (6 molar teeth) served as controls and were not further treated. The number of the tagged cells was statistically analyzed by comparing the results of the 3 groups. A Bonferroni correction was performed, because the data of the Ca(OH)(2)- group was used 3 times for pairwise comparison.

RESULTS

The marked cells were identified as fibroblasts, endothelial cells (after 1, 3, and 7 days), and Höhl cells (after 7 days). The MTA group showed a similar amount of Höhl cells when compared with the Ca(OH)(2) group (P > .05). One day and 7 days after capping, no significant differences were observed between the 2 tested groups and the controls (P > .05). After 3 days, significantly more cells were stained in the MTA and Ca(OH)(2) groups than in the control group (P < .016).

CONCLUSIONS

Immunohistologic analysis demonstrated that MTA showed similar results when compared with Ca(OH)(2) within the first week after direct pulp capping.

Comparative evaluation of antimicrobial activity of three cements: new endodontic cement (NEC), mineral trioxide aggregate (MTA) and Portland

Using the agar diffusion method, we conducted an in vitro study to evaluate the antimicrobial activity of mineral trioxide aggregate (MTA), new endodontic cement (NEC) and Portland cement at different concentrations against five different microorganisms. A base layer was made using Muller-Hinton agar for Escherichia coli (ATCC 10538) and Candida (ATCC 10231). For Actinomyces viscosus (ATCC 15987), Enterococcus faecalis (ATCC 10541) and Streptococcus mutans (ATCC 25175) blood agar medium was used. Wells were formed by removing the agar, and the materials were placed in the well immediately after manipulation. The plates were kept at room temperature for 2 h for prediffusion, and then incubated at 37 degrees C for 72 h. The inhibition zones were then measured. The data were analyzed using ANOVA and the Tukey test to compare the differences among the three cements at different concentrations. The positive controls showed bacterial growth, while the negative controls showed no bacterial growth. All materials showed antimicrobial activity against the tested strains except for Enterococcus faecalis. NEC created larger inhibition zones than MTA and Portland cement. This difference was significant for Portland cement (P < 0.05), but not for MTA (P > 0.05). Among the examined microorganisms, the largest inhibition zone was observed for Actinomyces group (P < 0.05). The antimicrobial activity of the materials increased with time and concentration (P < 0.05). It was concluded that NEC is a potent inhibitor of microorganism growth.

Reparative dentinogenesis induced by mineral trioxide aggregate: a review from the biological and physicochemical points of view

This paper aims to review the biological and physicochemical properties of mineral trioxide aggregate (MTA) with respect to its ability to induce reparative dentinogenesis, which involves complex cellular and molecular events leading to hard-tissue repair by newly differentiated odontoblast-like cells. Compared with that of calcium hydroxide-based materials, MTA is more efficient at inducing reparative dentinogenesis in vivo. The available literature suggests that the action of MTA is attributable to the natural wound healing process of exposed pulps, although MTA can stimulate hard-tissue-forming cells to induce matrix formation and mineralization in vitro. Physicochemical analyses have revealed that MTA not only acts as a "calcium hydroxide-releasing" material, but also interacts with phosphate-containing fluids to form apatite precipitates. MTA also shows better sealing ability and structural stability, but less potent antimicrobial activity compared with that of calcium hydroxide. The clinical outcome of direct pulp capping and pulpotomy with MTA appears quite favorable, although the number of controled prospective studies is still limited. Attempts are being conducted to improve the properties of MTA by the addition of setting accelerators and the development of new calcium silicate-based materials.

Comparative evaluation of antimicrobial action of MTA, calcium hydroxide and Portland cement

The present study aimed to evaluate and compare the antimicrobial effect of MTA Dentsply, MTA Angelus, Calcium Hydroxide and Portland cement. Four reference bacterial strains were used: Pseudomonas aeruginosa, Escherichia coli, Bacteroides fragilis, and Enterococcus faecalis. Plates containing Mueller-Hinton agar supplemented with 5% sheep blood, hemin, and menadione were inoculated with the bacterial suspensions. Subsequently, wells were prepared and immediately filled with materials and incubated at 37°C for 48 hours under anaerobic conditions, except P. aeruginosa. The diameters of inhibition zones were measured, and data analyzed using ANOVA and the Tukey test with 1% level of significance. MTA Dentsply, MTA Angelus and Portland cement inhibited the growth of P. aeruginosa. Calcium Hydroxide was effective against P. aeruginosa and B. fragillis. Under anaerobic conditions, which may hamper the formation of reactive oxygen species, the materials failed to inhibit E. faecalis, and E. coli.

MTA preparations from different origins may vary in their antimicrobial activity

OBJECTIVE

The antimicrobial effects of 4 mineral trioxide aggregate (MTA) preparations, 2 white-colored (WMTA-1, WMTA-2) and 2 gray-colored (GMTA-1, GMTA-2), against C. albicans and E. faecalis were assessed in vitro.

METHODOLOGY

Minimal inhibitory concentration (MIC) for each preparation was determined using the tube dilution test and Sabouraud agar media for C. albicans and brain heart infusion media for E. faecalis. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 24-, 48-, and 72-hour time periods. Samples of 0.1 mL from each of the experimental and control tubes were subcultured on agar or brain heart infusion plates to confirm visible signs of bacterial or fungal growth.

RESULTS

MIC of MTA against the 2 microorganisms tested varied among the 4 preparations tested. WMTA-1 and WMTA-2 inhibited C. albicans growth at concentrations of 3.125 mg/10 mL and 25 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). WMTA-1 and WMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 50 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). GMTA-1 and GMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 3.125 mg/10 mL, respectively, and statistically significant differences were found between GMTA-1 and GMTA-2 (P < .001). Both GMTA-1 and GMTA-2 inhibited C. albicans growth at a concentration of 3.125 mg/10 mL and no statistical differences were found between the preparations. Subculture of the broth tubes in agar or brain heart infusion plates confirmed the turbidity test result.

CONCLUSION

The origin of MTA as well as the type of preparation may affect its antimicrobial characteristics. Clinicians should be aware of variations that may exist among such MTA preparations.

The nociceptive and anti-nociceptive effects of white mineral trioxide aggregate

AIM

To assess the nociceptive and antinociceptive effects of white mineral trioxide aggregate (WMTA) using the orofacial formalin test in rats.

METHODOLOGY

Rats (n = 10 in each group) were separately injected into the ipsilateral upper lip with either 40 microL of a 2.5% formalin solution and eugenol (50 mg kg(-1)) or WMTA (5, 10 and 20 mg dissolved in 0.2 mL saline) alone. In a second experiment to evaluate antinociception effects, 15 min prior to formalin injection, rats were pre-treated with either white ProRoot MTA (20 mg dissolved in 0.2 mL saline) or eugenol. The time each rat spent rubbing the injected site with its paw, as an index of nociception, was recorded for a period of 45 min.

RESULTS

Administration of 40 microL white ProRoot MTA (5, 10 and 20 mg per 0.2 mL) alone did not produce any significant nociceptive response. Moreover, prior treatment with WMTA caused significant (P < 0.001) inhibition of formalin-induced nociception. Injection of eugenol (50 mg kg(-1)) provoked the first phase of a nociceptive response, although its intensity was reduced compared with that produced by formalin. Pre-treatment with eugenol significantly (P < 0.0001) inhibited the induction of nociception by formalin. Comparison of the behavioural responses observed in WMTA and eugenol-treated rats alone or in combination with formalin revealed that WMTA did not only induce pain behaviour but also prevented formalin-induced nociception.

CONCLUSION

White mineral trioxide aggregate, when compared with eugenol, was more effective in treating nociceptive pain in the orofacial formalin test.

Comparison of mineral trioxide aggregate and formocresol as pulp medicaments for pulpotomies in primary molars

PURPOSE

The aim of this study was to compare the effect of white mineral trioxide aggregate (MTA) to that of formocresol (FC) as pulp dressing agents in pulpotomised primary molars.

METHODS

In this clinical trial study, 60 lower second primary molars of 46 children were treated by a conventional pulpotomy technique. The teeth were randomly assigned to the MTA (experimental) and FC (control) groups by random numbered table. Following removal of the coronal pulp and haemostasis, the pulp stumps were covered with an MTA paste in the experimental group. In the control group, FC was placed with a cotton pellet over the pulp stumps. The teeth of both groups were restored with stainless steel crowns. Children arrived for clinical and radiographic follow-up evaluation after 6, 12 and 24 months.

RESULTS

The treated teeth in FC group (n = 18) were clinically and radiographically successful after 24 months. The radiographic follow-up evaluation revealed one failure (furcation involvement) in 18 molars treated with MTA after 24 months. The treated teeth in MTA group were clinically successful 24 months postoperatively. Pulp canal obliteration was observed in one of the teeth treated with MTA and four of the teeth treated with FC.

CONCLUSION

MTA could be used as a safe medicament for pulpotomy in cariously exposed primary molars and could be a substitute for FC.

Evaluation of the antifungal effects of mineral trioxide aggregate materials

The aim of this study was to evaluate and compare the antifungal effect of white-coloured mineral trioxide aggregate (WMTA) and grey mineral trioxide aggregate (GMTA) using a tube-dilution test. MTA preparations were freshly mixed and tested after 24 h on Candida albicans. The experiment was carried out in 24-well culture plates. Fifty wells were used and divided into four experimental groups (freshly mixed WMTA, freshly mixed GMTA, 24 h-set WMTA and 24 h-set GMTA) of 10 wells each and control groups of five wells each. Plates of Sabouraud dextrose agar mixed with C. albicans served as positive control, and Sabouraud dextrose agar without C. albicans served as negative control. Fresh inoculate of C. albicans was prepared by growing an overnight culture from a stock culture. Aliquots of C. albicans were then taken from the stock culture and plated on the agar compound of the experimental and control groups. All plates were incubated at 37 degrees C for 1, 24 and 72 h. Growth of fungi was monitored daily by the presence of turbidity. Results showed that in the freshly mixed as well as 24 h-set MTA cements fungal growth was observed during 1-h incubation, whereas by increasing the incubation time, no fungal growth was observed in 24 and 72 h. It was concluded that MTA cements (freshly mixed and 24-h set) were effective against C. albicans.

Antibacterial effect of two mineral trioxide aggregate (MTA) preparations against Enterococcus faecalis and Streptococcus sanguis in vitro

The antibacterial effects of gray-colored MTA (GMTA) and white-colored MTA (WMTA) against Enterococcus faecalis and Streptococcus sanguis were assessed in vitro using the tube dilution test. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 0, 1, 24, 48, and 72-hour time periods. A direct correlation was found between GMTA and WMTA concentrations and their antibacterial effect. Tubes containing GMTA in concentrations of 50, 25, and 12.5 mg/ml did not show E. faecalis growth at any of the time periods tested whereas tubes containing WMTA showed E. faecalis growth at all concentrations and time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations of 50, 25 and 12.5 mg/ml and tubes containing similar concentrations of WMTA (p < 0.001). Tubes containing GMTA in concentrations of 50, 25, 12.5, 6.25, and 3.12 mg/ml and tubes containing WMTA in concentrations of 50, 25, and 12.5 mg/ml did not show S. sanguis growth at any of the time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations 6.25 and 3.12 mg/ml and tubes containing similar concentrations of WMTA (p < 0.001). It appears that the susceptibility of E. faecalis and S. sanguis to MTA differed and that GMTA requires lower concentrations than WMTA to exert the same antibacterial effect against each of the microorganisms tested.

Comparison of Antifungal Activity of White-Colored and Gray-Colored Mineral Trioxide Aggregate (MTA) at Similar Concentrations Against Candida albicans

The killing effect of similar concentrations of white-colored MTA and gray-colored MTA against Candida albicans was assessed in vitro using the tube dilution test. A direct correlation was found between MTA concentration and its killing effect on C. albicans. At time period zero, both white-colored and gray-colored MTA samples showed Candida growth regardless of the concentration. Tubes containing gray-colored MTA in concentrations of 50, 25, 12.5, 6.25, and 3.125 mg/ml and tubes containing white-colored MTA in concentrations of 50 and 25 mg/ml did not show C. albicans growth at any of the other time periods tested. Tubes containing white-colored MTA in concentrations of 12.5 mg/ml or less showed Candida growth at all the time periods tested. Statistically, a significant difference was found between tubes containing either 50 mg/ml or 25 mg/ml and tubes containing lower concentrations of white-colored MTA (p < 0.001). A significant difference was also found between tubes containing gray-colored MTA in concentrations of 12.5 mg/ml or less and tubes containing similar concentrations of white-colored MTA (p < 0.001). It appears that both gray-colored and white-colored MTA in concentrations of 50 mg/ml and 25 mg/ml are effective in killing C. albicans for periods of up to 1 wk. Lower concentrations of gray-colored MTA may still be effective while lower concentrations of white-colored MTA may not.