Interfacial adaptation of NeoMTA Plus, BioRoot RCS and MTA in root-end cavities: A micro-CT study.

AIM: This study aimed to use the micro-computed tomography to evaluate the interfacial adaptation and the presence of gaps of NeoMTA Plus, BioRoot RCS, and MTA in the root-end cavities. METHODOLOGY: Thirty standardized bovine roots measuring 15 mm in length were selected. Chemical-mechanical preparation was performed up to instrument #80 and obturation with the cold lateral compaction technique with cement based on zinc oxide and eugenol. The roots were kept at 37°C for 7 days. Afterward, apicectomy of the apical 3 mm and a root-end filling cavity was performed at 3 mm depth. Micro-computed tomography (micro-CT) was performed to measure the volume of the retroactivity. The roots were divided by stratified randomization into three groups according to the retro-end filling material: NeoMTA Plus, BioRoot RCS, and MTA. A new micro-CT was performed to assess the presence of voids in the root-end filling material and between it and the canal wall. One-way ANOVA and Tukey tests were performed using the BioEstat 4.0 program. RESULTS: There was no difference in the initial volume values of the root-end cavities (p > .05). After the insertion of root-end filling materials, the most significant volumes of voids were observed in the NeoMTA Plus group (p < .05), with no difference for the BioRoot RCS and MTA Angelus groups (p > .05). CONCLUSION: Micro-computed tomography showed that MTA and BioRoot RCS have better interfacial adaptation and presented fewer number of gaps than NeoMTA Plus when used as root-end filling materials. RESEARCH HIGHLIGHTS: Micro-computed tomography evaluation of different root-end fillings materials.

Antibacterial Activity of Root Repair Cements in Contact with Dentin-An Ex Vivo Study.

This study assessed the antibacterial characteristics of the dentin/material interface and dentin surfaces exposed to experimental hydraulic calcium silicate cement (HCSC) with or without bioactive glass (BG) replacement (20% or 40%) or mixed with a silver nanoparticle (SNP) solution (1 or 2 mg/mL), and Biodentine, TotalFill BC RRM putty and Intermediate Restorative Material (IRM). Human root dentin segments with test materials were assessed at 1 or 28 days. In one series, the specimens were split to expose the dentin and material surfaces. A 24 h direct contact test was conducted against three-day established Enterococcus faecalis and Pseudomonas aeruginosa monospecies biofilms. In another series, the dentin/material interface of intact specimens was exposed to biofilm membranes for 3 days and the antibacterial activity was assessed via confocal microscopy. The interface was additionally characterised. All one-day material and dentin surfaces were antibacterial. Dentin surfaces exposed to HCSC with 40% BG-replacement, Biodentine and IRM had decreased antibacterial properties compared to those of the other cements. The HCSC mixed with a 2 mg/mL SNP solution had the highest antimicrobial effect in the confocal assay. The interfacial characteristics of HCSCs were similar. The test materials conferred antibacterial activity onto the adjacent dentin. The BG reduced the antibacterial effect of dentin exposed to HCSC; a 2 mg/mL SNP solution increased the antibacterial potential for longer interaction periods (three-day exposure).

Molecular mechanism of a novel root-end filling material containing zirconium oxide on the osteogenic/odontogenic differentiation of human osteosarcoma MG-63 cells.

Although the novel root-end filling material containing zirconium oxide (NRFM-Zr) which is hydroxyapatite-based may promote osteoblast differentiation, the molecular mechanism remains unclear. The aim of this study is to investigate it underlying the osteogenic/odontogenic differentiation of human osteosarcoma MG-63 cells induced by NRFM-Zr, compared with calcium silicate-based mineral trioxide aggregate (MTA), and glass ionomer cement (GIC). Firstly, three different types of root filling materials were co-cultured with MG-63 cells, and their cell toxicity, alkaline phosphatase (ALP) activity, and calcium ion concentration were evaluated. Next, gene expression profiling microarray was employed to analyze the impact of the materials on the gene expression profile of MG-63 cells. The results of cell viability revealed that NRFM-Zr group had no significant difference compared to the negative control group. After 5 and 7 days of cultivation, both the NRFM-Zr and MTA groups exhibited significantly higher ALP activity compared to the negative control (p < 0.05). Moreover, the NRFM-Zr group had the highest calcium ion concentration, while the GIC group was the lowest (p < 0.05). Gene expression profiling microarray analysis identified 2915 (NRFM-Zr), 2254 (MTA) and 392 (GIC) differentially expressed genes, respectively. GO functional and KEGG pathway analysis revealed that differentially expressed genes of NRFM-Zr, MTA and GIC participated in 8, 6 and 0 differentiation-related pathways, respectively. Comparing the molecular mechanisms of osteogenic/odontogenic differentiation induced by hydroxyapatite-based NRFM-Zr and calcium silicate-based MTA, it was found that they shared similarities in their molecular mechanisms of promoting osteogenic differentiation. NRFM-Zr primarily promotes differentiation and inhibits cell apoptosis, thereby enhancing osteogenic/odontogenic differentiation of MG-63 cells. Furthermore, the inducing efficacy of NRFM-Zr was found to be superior to MTA.

Utility of biphasic calcium phosphate cement as a seal for root-end filling.

The recently developed biphasic calcium phosphate cement (BCPC) consists of α-tricalcium phosphate-tetracalcium phosphate as the solid phase and calcium phosphate solution as the liquid phase. BCPC powder is composed of a single solid solution with a monomodal size distribution. Here, we used a bacterial leakage model to examine the utility of BCPC as a seal for root-end filling. We prepared large (median particle size=9.96 µm; BCPC-L) and small (median particle size=4.84 µm; BCPC-S) BCPC powders. In total, 45 single-rooted teeth were instrumented, resected at the root-end, and retrofilled with experimental materials. Mineral trioxide aggregate (MTA) was used as the control. After visual confirmation of BCPC powder size and retrofilling quality by microscopy, bacterial leakage tests were conducted using Enterococcus faecalis. The bacterial leakage tests did not reveal any significant differences between BCPC-S and MTA. Our findings suggest that BCPC-S is useful for root-end filling.

In-vitro evaluation of microleakage of bioceramic root-end filling materials: A spectrophotometric study.

AIM: To evaluate the microleakage of newer bioceramic root-end filling materials. MATERIAL AND METHOD: Sixty freshly extracted human single-rooted mandibular premolar teeth were selected for the study. Teeth with fractured root, cracks, anddilacerations were rejected. All teeth were cleaned with ultrasonic scalers. Standard access opening was done and root canal treatment was performed with rotary files followed by obturation. After storing in saline for a week apical 3 â€‹mm of the root was resected at 900 angles to the long axis of the root. Retro cavity preparation was done with ultrasonic tips. The teeth were divided into four groups of 15 specimens each. Group I - Biodentin, GroupII-Bioaggregate, Group III - MTA Plus, and Group IV - MTA. After the restoration of retro cavities of all the teeth as per manufacture instructions, two coats of nail varnish were applied to leave apical 3 â€‹mm. All teeth were stored in 2% methylene blue for 72 â€‹h followed by emersion in 65% nitric acid for the next 72 â€‹h for Dye extraction. The obtained supernatant solution was then centrifuged and optical density or absorbance was measured with a UV spectrophotometer. RESULT: Microleakage was found to be increasing in this order: Biodentin â€‹< â€‹Bioaggregate â€‹< â€‹MTA Plus â€‹< â€‹MTA. No significant difference was found in the microleakage of Biodentin compared to that of Bioaggregate(p â€‹> â€‹0.01). CONCLUSION: All materials exhibit some amount of microleakage. Biodentin shows the least microleakage among all the bioceramic material groups. Hence, Biodentin and bioaggregate are better material of choice for the retrograde filling to prevent microleakage.

Biocompatibility of a High-Plasticity, Calcium Silicate-Based, Ready-to-Use Material.

The Bio-C Sealer is a recently developed high-plasticity, calcium-silicate-based, ready-to-use material. In the present study, chemical elements of the materials were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biocompatibility of the Bio-C Sealer was investigated using cytotoxicity tests and histological responses in the roots of dogs' teeth. XRD, SEM, and FTIR produced hydrated calcium silicate in the presence of water molecules. In addition, FTIR showed the formation of calcium hydroxide and polyethylene glycol, a dispersing agent. The 1:4 dilutions of Bio-C Sealer presented weaker cytotoxicity than the Calcipex II in an in vitro system using the V-79 cell line. After 90 d, the periradicular tissue response of beagle dog roots was histologically evaluated. Absence of periradicular inflammation was reported in 17 of the 18 roots assessed with the Bio-C Sealer, whereas mature vertical periodontal ligament fibers were observed in the apical root ends filled with the Bio-C Sealer. Based on these results and previous investigations, the Bio-C Sealer is recommended as an effective root-end filling material. These results are relevant for clinicians considering the use of Bio-C Sealer for treating their patients.

Filling ability of three bioceramic root-end filling materials: A micro-computed tomography analysis.

This study aimed at evaluating the volume of gaps and voids, and the total porosity percentage of three calcium-silicate-based materials in mandibular molars apicoectomy by Micro-CT analysis. Thirty-three mesial roots of extracted human mandibular molars were instrumented and obturated. The apical 3mm of each root was resected and prepared. Root-end cavities were filled with EndoSequence BC Putty (BC); ProRoot MTA (MTA) and Biodentine (BIO). Samples were scanned using a Micro-CT scanner and the tridimensional images reconstructed. Percentage of gaps (VG%) and of voids (VV%) were obtained. Porosity percentage (Po%) was also assessed. Data were analysed using Student's t-test (P < 0.05). All materials presented gaps and voids. VG% was 2.006 (BC), 1.882 (MTA) and 1.450 (BIO), and VV% was 0.039 (BC), 0.021 (MTA) and 0.024 (BIO) with no statistical difference. Po% were 56.73 (BC), 51.94 (MTA) and 50.45 (BIO), with BC being statistically (P > 0.05) more porous.

Cytotoxicity, Cell Adhesion, and Apoptotic Gene Expression in Periodontal Ligament Fibroblasts treated with Endodontic Sealers.

OBJECTIVE: The present study assessed cytotoxicity, cell adhesion, and apoptotic gene expression in periodontal ligament fibroblasts (PLF) treated with 2 endodontic sealers. METHODS: PLF cells were obtained from nonerupted third molars and cultured. MTS and LIVE/DEAD assays were performed using different treatments and time periods. Cellular adhesion was evaluated using immunocytochemistry for integrin ß1 and vinculin expression, and the gene expressions of nuclear factor kB (NF-кB), P53, and apoptotic protease-activating factor 1 (Apaf-1) were evaluated using PCR. RESULTS: Cell proliferation at 12, 24, and 48 h was statistically significant in the control and PLF groups receiving different treatments; PLF treated with culture medium containing non-hardened (NH) sealers showed a decrease in the number of cells. PLF treated with culture medium containing hardened (H) sealers also exhibited a decreased cell population. Integrin ß1 and vinculin were expressed in both cell cultures treated with Acroseal (NH and H); however, the cell morphology changed and the cell population decreased. The gene expression of NF-kB and that of P53 were significantly different between the control group and the groups treated with the different sealers; mineral trioxide aggregate (MTA) (NH and H) inhibited Apaf-1, and PLF treated with Acroseal H exhibited increased Apaf-1 expression. CONCLUSION: Both sealers showed a certain level of cytotoxicity. The gene expression of NF-κB and P53 in PLF treated with the sealers showed significant changes compared to that of the control group, and MTA inhibited Apaf-1.

The cold ceramic material.

The purpose of this paper was to review the composition, sealing ability, biocompatibility and various physical properties of cold ceramic (CC) material that potentially used as a root filling material. The review of the articles was performed by electronic and manual searching methods regarding the properties of CC from November 2000 to May 2016. The results revealed that there were many published reports carried out on the properties of CC. Only one article had extensively studied the composition of CC, five studies had investigated the sealing ability of CC, three articles had studied the biocompatibility, and some studies had investigated the radiopacity, setting time, pH value, and solubility of CC. It was concluded that CC material had good potential for endodontic use. Furthermore, clinical studies are needed in these areas.

Hard tissue reaction to mineral trioxide aggregate and experimental root-end filling material in guinea pig mandibles.

BACKGROUND/PURPOSE: Root-end filling materials are used to fill and seal the root apex during periradicular surgery. Mineral trioxide aggregate (MTA) is a widely-used material because of its particular characteristics. Cold ceramic (CC) is an experimental material that has been recently introduced. The purpose of this study was to compare bone tissue response to CC and MTA in an animal model. MATERIALS AND METHODS: Forty-five male guinea pigs (weighing 750-850 g) were anesthetized with 10 mg/kg ketamine HCL and 12 mg/kg xylazine. A triangular incision of around 15 mm was prepared in the posterior site along the symphysis in both right and left sides of the mandible. A 3 mm × 3 mm diameter cylindrical hole was prepared in each side using a trephine. Two Teflon cylindrical tube applicators were filled with white MTA and CC and inserted into the defects separately. Histopathological evaluation of the specimens was completed after 2 weeks and 12 weeks. The extent of inflammation was recorded and analyzed using the Mann-Whitney U test and SPSS software version 12 at a significance level of 0.05. RESULTS: MTA and CC produced moderate and mild hard tissue responses respectively after 2 weeks and 12 weeks. No significant differences were found in the distribution of the responses between the two groups at either time point. CONCLUSION: Both CC and MTA demonstrated biocompatibility with minor adverse impact on hard tissue and healing recovery after 12 weeks.

Effect of MTA particle size on periapical healing.

AIM: To examine the effect of reduction in MTA particle size on dento-alveolar and osseous healing in dogs. METHODOLOGY: Root canals of 24 mandibular premolars in four 2-year-old beagles were prepared and filled with gutta-percha and sealer. Two to four weeks later, during periapical surgery, the root-end cavity preparations in these teeth were filled with either grey ProRoot MTA or modified (reduced particle sizes with faster setting time) MTA. The animals were sacrificed 4 months later. Degrees of inflammation, type of inflammatory cells, fibrous connective tissue adjacent to the root-end filling materials, cementum formation over the resected roots and root-end filling materials and bone healing were examined. Data were analysed using the McNemar test. RESULTS: No significant differences in healing of periapical tissues were found when comparing ProRoot MTA to a modified MTA containing reduced particle sizes. CONCLUSION: Reducing the particle sizes of MTA did not impact its biological properties.

Comparison of Mineral Trioxide Aggregate and iRoot BP Plus Root Repair Material as Root-end Filling Materials in Endodontic Microsurgery: A Prospective Randomized Controlled Study.

INTRODUCTION: This prospective randomized controlled study evaluated the clinical and radiographic outcome of endodontic microsurgery when using iRoot BP Plus Root Repair Material (BP-RRM; Innovative BioCeramix Inc, Vancouver, BC, Canada) or mineral trioxide aggregate (MTA) as the retrograde filling material and analyzed the relationship between some potential prognostic factors and the outcome of the surgery. METHODS: By using strict inclusion and exclusion criteria, 240 teeth were successfully enrolled and randomly and equally allocated to either the MTA or BP-RRM treatment group. A standardized surgical procedure was performed by a single operator. The patients were followed up at 1 week, 3 months, 6 months, and 12 months; follow-up included clinical and radiographic examination. Clinical and radiographic evaluations acquired at the 12-month follow-up were taken as the primary outcome. For the identification of prognostic factors, the dichotomous outcome (success vs failure) was taken as the dependent variable. RESULTS: A total of 158 teeth were analyzed at the 12-month follow-up, including 87 teeth in the MTA group and 71 teeth in the BP-RRM group. The success rate in the MTA and BP-RRM groups was 93.1% (81/87 teeth) and 94.4% (67/71 teeth), respectively (P > .05). Three significant outcome predictors were identified: quality of root filling (P < .05), tooth type (P < .05), and size of the lesion (P < .05) CONCLUSIONS: These results suggest that BP-RRM is comparable with MTA in clinical outcome when used as root-end filling materials in endodontic microsurgery.

Push-out Bond Strength of Root-end Filling Materials

Abstract The aim of this study was to evaluate the bond strength of root-end filling materials. Forty 2-mm-thick slices were obtained from human single-rooted teeth. After root canal preparation using a 1.5 mm diameter cylindrical drill, the dentinal walls were prepared by diamond ultrasonic tip (CVD T0F-2). The specimens were divided according the material (n=10): MTA Angelus (MTAA), MTA Sealer (MTAS, experimental), Sealer 26 (S26) and zinc oxide and eugenol cement (ZOE). The push-out test was performed in a mechanical test machine (EMIC DL 2000) at 1 mm/min speed. The failure type was evaluated by stereomicroscopy. The results were subjected to ANOVA and Tukey test, at 5% significance level. MTAA (19.18 MPa), MTAS (19.13 MPa) and S26 (15.91 MPa) showed higher bond strength (p<0.05). ZOE (9.50 MPa) showed the least bond strength values (p<0.05). Adhesive failure was prevalent in all groups, except for ZOE, which showed mixed failures. It was concluded that root-end filling materials MTA Angelus, MTA Sealer and Sealer 26 showed higher bond strength to dentinal walls than zinc oxide and eugenol cement after retrograde preparation.

Resumo O objetivo deste estudo foi avaliar a resistência de união de materiais retrobturadores. Quarenta fatias de 2 mm de espessura foram obtidas a partir de dentes unirradiculares humanos. Após o preparo do canal radicular usando uma broca cilíndrica de 1,5 mm de diâmetro, as paredes de dentina foram preparadas usando uma ponta de ultra-som diamantada (CVD T0F-2). As amostras foram divididas de acordo com os materiais (n=10): MTA Angelus (MTAA), MTA Sealer (MTAS, experimental), Sealer 26 (S26) e óxido de zinco e eugenol (ZOE). O teste de push-out foi realizado utilizando uma máquina de ensaios mecânicos (EMIC DL 2000) com velocidade de 1 mm/min. O tipo de falha foi avaliado em estereomicroscópio. Os resultados foram submetidos a ANOVA e teste de Tukey, com níveis de variância de 5%. MTAA (19,18 MPa), MTAS (19,13 MPa) e S26 (15,91 MPa) apresentaram os maiores valores de resistência de união (p<0,05). ZOE (9,50 MPa) apresentou os menores valores de resistência de união (p<0,05). A falha adesiva foi prevalente em todos os grupos, com exceção do ZOE, que apresentou falhas mistas. Concluiu-se que os materiais retrobturadores MTA Angelus, MTA Sealer e Sealer 26 apresentam maior resistência de união às paredes dentinárias que o óxido de zinco e eugenol após o preparo retrógrado.

A Randomized Controlled Study of Mineral Trioxide Aggregate and Super Ethoxybenzoic Acid as Root-end Filling Materials in Endodontic Microsurgery: Long-term Outcomes.

INTRODUCTION: The purpose of the present study was to evaluate the long-term clinical outcome of endodontic microsurgery when mineral trioxide aggregate (MTA) and super ethoxybenzoic acid (Super EBA; Harry J. Bosworth, Skokie, IL) were used as root-end filling materials. Additionally, this study aimed to compare the clinical outcome of endodontic microsurgery at the 1-year follow-up with that at the 4-year follow-up. METHODS: Two hundred sixty teeth were randomly assigned to either the MTA or Super EBA group in equal numbers using the minimization method. Endodontic microsurgery was performed according to the Yonsei protocol. The previous study of 192 teeth examined at the 1-year follow-up revealed a success rate of 95.6% for MTA and 93.1% for Super EBA. Patients were recalled 4 years after surgery, and treated teeth were classified as successes or failures with Molven's criteria. The Pearson chi-square test and the McNemar test were conducted to analyze and compare the success rates. RESULTS: A total of 182 teeth were examined at the 4-year follow-up. The success rate was 91.6% for MTA and 89.9% for Super EBA. Statistical analysis of the success rate did not show any significant difference between the 2 materials (P = .8). The overall success rate at the 4-year follow-up was 89.5%, which was slightly lower compared with 94.3% at the 1-year follow-up. However, there was no significant difference between the follow-up periods (P = .063). CONCLUSIONS: This study identified no significant difference in the 4-year success rates of MTA and Super EBA as root-end filling materials in endodontic microsurgery. Additionally, compared with short-term outcomes, long-term follow-up outcomes were not significantly different.

Contrast-to-noise ratio with different settings in a CBCT machine in presence of different root-end filling materials: an in vitro study.

OBJECTIVES: To compare the contrast-to-noise ratio (CNR) of multiple acquisition settings for four types of retrograde filling materials in CBCT images taken for endodontic surgery follow-up. METHODS: 20 maxillary central incisors were endodontically treated and obturated with 4 different root-end filling materials: amalgam, mineral trioxide aggregate, SuperEBA(™) (Harry J Bosworth Company, Skokie, IL) and Biodentine™ (Septodont, Saint-Maur-des-Faussés, France). Teeth were placed in a skull and scanned, one by one, with the Planmeca ProMax(®) 3D Max (Planmeca, Helsinki, Finland); at different voltages: 66, 76, 84 and 96 kVp; with low, normal and high resolution and high definition (HD); with and without metal artefact reduction (MAR). Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. The dose-area product was registered, and the effective dose calculated. RESULTS: No statistically significant difference was noted between the four materials. 84 and 96 kVp with low resolution and the use of MAR-generated images that have statistically better CNR than 66 and 76 kVp with HD, normal and high resolutions and without MAR. The use of low resolution also generated the smallest value of effective dose. CONCLUSIONS: The best setting for radiographic follow-up in an endodontic surgery with retrograde filling on the Planmeca ProMax is 96 kVp with low resolution and high MAR; this setting produced one of the lowest effective doses.

Comparing the Marginal Adaptation of Cold Ceramic and Mineral Trioxide Aggregate by Means of Scanning Electron Microscope: An In vitro Study.

BACKGROUND: Long-term success of endodontic surgeries is often influenced by the type of root-end filling material (RFM). The aim of present study was to compare the marginal adaptation of two different RFM, cold ceramic (CC) and mineral trioxide aggregate (MTA), using scanning electron microscope (SEM). MATERIALS AND METHODS: About 20 extracted human single-rooted teeth were collected and stored into sodium hypochlorite 5.25%. The teeth were decronated from the cemento-enamel junction to prepare 16 mm roots. The working length was measured, and 1/3 coronal of the canal was prepared by Gates-Glidden drills. Apical flaring was followed by K file size # 40-70 based on step back technique. After filling of the canals, 3 mm above the apex was cut at 90° to the long axis. Furthermore, 3 mm of the filling was removed from the apical part using the ultrasonic device. All of the prepared specimens were divided into two groups and were retro filled by MTA and CC. The roots were cut horizontally from 1 mm above the apical part, and dentin-filling material interface was observed by SEM. Finally, the collected data were analyzed by Mann-Whitney test and using SPSS software version 18 at a significant level of 0.05. RESULTS: The mean interfacial adaptation was higher in CC group. However, no significant differences were observed by statistical test (P = 0.35). CONCLUSION: Both CC and MTA had similar marginal adaptation as RFM however in vivo studies are recommended for better determination.

Comparative cell attachment, cytotoxicity and antibacterial activity of radiopaque dicalcium silicate cement and white-coloured mineral trioxide aggregate.

AIM: To comparatively examine the cell attachment, cytotoxicity, and antibacterial activity of radiopaque dicalcium silicate cement (RDSC) and ProRoot white-coloured mineral trioxide aggregate (WMTA). METHODOLOGY: AlamarBlue was used for real-time and repeated monitoring of MG63 cell attachment on freshly mixed and set cements. The pH changes in the growth medium at different time-points were also measured. Cytotoxicity evaluation was performed according to ISO 10993-5 specifications. The antibacterial activity of the cement specimens was evaluated using Enterococcus faecalis. RESULTS: There were no significant differences (P > 0.05) between the two cements for cell attachment either in the fresh groups or in the set groups at all culture times. Neither freshly mixed group nor set groups had significant pH differences. In the case of cytotoxicity, RDSC was significantly (P < 0.05) superior to WMTA at 12 and 24 h of incubation. RDSC and WMTA possessed similar antimicrobial activity, substantiated by the formation of growth inhibition zones and bacteriostasis ratio in E. faecalis strains. CONCLUSIONS: The cell attachment, cytotoxicity and antibacterial efficacy of RDSC were comparable to those reported for ProRoot WMTA. The results of the current study suggest that this RDSC could be used as a root-end filling material and root sealer.

Biodentine versus Mineral Trioxide Aggregate versus Intermediate Restorative Material for Retrograde Root End Filling: An Invitro Study.

OBJECTIVE: The aim of this study was to evaluate the marginal adaptation of Biodentine in comparison with Mineral Trioxide Aggregate (MTA) and Intermediate Restorative Material (IRM), as a root end filling material, using Scanning Electron Microscopy (SEM). MATERIALS AND METHODS: Thirty permanent maxillary central incisors were chemo-mechanically prepared and obturated. Three millimetres of the root end were resected and 3mm retro cavity preparation was done using ultrasonic retrotips. The samples were randomly divided into three groups (n=10) and were restored with root end filling materials: Group I - MTA, Group II - Biodentine, Group III - IRM. The root ends were sectioned transversely at 1mm and 2mm levels and evaluated for marginal adaptation using SEM. The gap between dentin and retro filling material was measured at four quadrants. The mean gap at 1mm level and 2mm level from the resected root tip and combined mean were calculated. The data were statistically analyzed, using one-way ANOVA and Tukey's HSD post hoc test for intergroup analysis and paired t-test for intragroup analysis. RESULTS: The overall results showed no statistically significant difference between MTA and IRM but both were superior when compared to Biodentine. At 1mm level there was no statistically significant difference among any of the tested materials. At 2mm level MTA was superior to both IRM and Biodentine. CONCLUSION: In overall comparison, MTA and IRM were significantly superior when compared to Biodentine in terms of marginal adaptation, when used as retrograde filling material.

Cytotoxicity of newly developed pozzolan cement and other root-end filling materials on human periodontal ligament cell.

OBJECTIVES: The purpose of this study was to evaluate in vitro cytotoxicity of the pozzolan cement and other root-end filling materials using human periodontal ligament cell. MATERIALS AND METHODS: Endocem (Maruchi), white ProRoot MTA (Dentsply), white Angelus MTA (Angelus), and Super EBA (Bosworth Co.) were tested after set completely in an incubator at 37℃ for 7 days, Endocem was tested in two ways: 1) immediately after mixing (fresh specimens) and 2) after setting completely like other experimental materials. The methods for assessment included light microscopic examination, cell counting and WST-1 assay on human periodontal ligament cell. RESULTS: In the results of microscopic examination and cell counting, Super EBA showed significantly lower viable cell than any other groups (p < 0.05). As the results of WST-1 assay, compared with untreated control group, there was no significant cell viability of the Endocem group. However, the fresh mixed Endocem group had significantly less cell viability. The cells exposed to ProRoot MTA and Angelus MTA showed the highest viability, whereas the cells exposed to Super EBA displayed the lowest viability (p < 0.05). CONCLUSIONS: The cytotoxicity of the pozzolan cement (Endocem) was comparable with ProRoot MTA and Angelus MTA. Considering the difficult manipulation and long setting time of ProRoot MTA and Angelus MTA, Endocem can be used as the alternative of retrofilling material.

The Influence of Root-End Filling Materials on Bone Healing - An Experimental Study.

AIMS: The aim of this experimental study is to assess the bone healing phenomenon produced in the presence of several dental materials: a polycarboxylate cement, a glass-ionomer cement, a composite resin and MTA (mineral trioxide aggregate) based cement. METHODS: The biocompatibility of four root-end fillings materials, used in periapical surgery was investigated after intra-osseous implantation of the materials in rats' calvaria. Tissue reaction was studied at 2, 4, 6, 8, 10 and 12 weeks after implantation. We took into consideration the presence of inflammatory cells (polymorphonuclear leukocytes, macrophages, plasma cells, lymphocytes and giant cells) and classified the aspects of the histological samples according to the following scale: 0 - no inflammation, 1 - mild, isolated inflammation, 2 - moderate, localized inflammatory reaction, 3 - severe, diffuse and intense inflammatory reaction. RESULTS: The inflammatory reaction was present at the six intervals for all the tested materials, but at 12 week interval, the reaction was minimal in all cases. Also, a dissolution reaction was observed for all the materials, less intense for glass-ionomer cement and polycarboxilate cement. CONCLUSIONS: At the end of the experimental period, glass-ionomer cement and polycarboxilate cement suffered a lesser dissolution reaction as compared to the second group of tested materials.