Evaluation of removal efficiency of capping materials used in pulp revascularization in vitro.

BACKGROUND: This study aimed to evaluate the removal efficiency of different capping materials used in pulp revascularization (PR) in a failure scenario. METHODS: The apices of freshly extracted 30 maxillary incisors were cut to mimic the immature teeth; then, root canals were shaped up to #6 Peeso reamers. The regeneration steps of the American Association of Endodontists (AAE) were followed to simulate PR treatment in vitro. The canals were dressed with the Ciprofloxacin and Metronidazole medicament mixture for 2 weeks. Then capping material groups were created: BioDentine (BD), ProRootMTA (PMTA), and RetroMTA (RMTA) (n = 10). The sealed specimens were stored for 2 weeks at 37 ºC in phosphate-buffered saline then the samples were examined by micro-computed tomography (µ-CT) analysis. Set capping materials were retrieved using a specific cement removal kit by a single blind operator. The residue materials were examined again by µCT. Kruskal-Wallis and Mann-Whitney U tests sought the significance for residue volumes. One-way ANOVA and Tukey post hoc tests with the Bonferroni corrections sought significance for the duration (p = 0.05). RESULTS: In the first examined µCT data, the mean (SD) capping material volumes of the PMTA, BD, and RMTA were 6.447 µm3 (1.086), 8.771 µm3 (0.491), and 8.114 µm3 (2.447), respectively. In the last examined µCT data, the median (IQR) residual volumes of the PMTA, BD, and RMTA were 0.051 µm3 (0.1), 0.313 µm3 (0.5), and 0.124 µm3 (0.1), respectively. A significant difference was found between BD and PMTA in the residual volumes (p < 0.05). The mean (SD) durations of the retrieving procedures of PMTA, BD, and RMTA were 19.83 min (2.34), 19.24 (3.60), and 22.04 (1.68), respectively (p = 0.063). CONCLUSIONS: Within the limitations of the presented study, it was concluded that the capping materials were largely removed from the root canals using a non-invasive approach. Nevertheless, this duration of the retrieving could be described as long.

Constituents, properties and clinical applications of OrthoMTA & RetroMTA: A systematic review.

Aim: OrthoMTA and RetroMTA are newly developed mineral trioxide aggregates that were developed to achieve maximum benefits and clinical performance. This systematic review aimed at assessing and describing the constituents, properties and uses of OrthoMTA and RetroMTA. Methodology: Literature search was performed using the keywords, "OrthoMTA", "RetroMTA", "BioMTA", "constituents" and "properties" in the databases, PubMed, Cochrane, Semantic scholar and Europe PubMed Central. Original articles in English describing the properties, constituents, uses/indications, history and recent advances on OrthoMTA and RetroMTA were considered for the study. Results: A total of 35 articles were selected for the systematic review based on keywords selected. Among the 35 articles, 5 articles described the composition and properties of OrthoMTA and RetroMTA, 7 articles depicted the usage of OrthoMTA and RetroMTA and the remaining articles discussed on the various properties of both OrthoMTA and RetroMTA. Conclusion: The present review confirmed that RetroMTA exhibits an excellent property, namely, short setting time, less tooth discoloration, high compressive strength, higher shear bond strength with time, higher push-out bond strength, low solubility, low cytotoxicity, biocompatibility, antibacterial property, and can be used in reparative processes in case of blood contamination. However, even OrthoMTA showed less microleakage, is biocompatible and possesses antibacterial properties.

Radiopacity quantification and spectroscopic characterization of OrthoMTA and RetroMTA.

The aim of this article was to investigate the unknown radiopacity performances of OrthoMTA and RetroMTA via means of a contemporary image analyzing methods and energy dispersive X-ray spectroscopy. Three commercial hydraulic calcium silicate-based cements and a calcium hydroxide-based paste were used. Pure-grade zirconium oxide, bismuth oxide, zinc oxide, barium sulfate, and calcium hydroxide were as references. An energy-dispersive X-ray spectroscopy instrument was used for the elemental analysis. Radiographic image data was obtained according to the International Organization for Standardization 6876-2012 specifications. The region of interest was determined for each specimen. Mean (±SD) grey values of the X-ray image data was measured with an image analyzing software. The calibration curve was created by curve-plotting software and the mean grey-values were matched versus Al values (mm Al). Data were analyzed with one-way ANOVA followed by Tukey's multiple comparison test. Spectroscopic characterization of the commercial materials was shown with assigned Carbon, oxygen, aluminum, silicon, calcium, zinc, zirconium, barium, tungsten, bismuth, and sulfur elements. The major radiopacifier/s of OrthoMTA is Bi, of RetroMTA is Zr, of BioDentine are Ba and Zr, and of ProCal is Ba. The radiopacity values of all commercial materials are significantly different (p < .05). The rank of the radiopacity values: RetroMTA (3.36 ± 0.29mmAl) > OrthoMTA (2.56 ± 0.19mmAl) > BioDentine (2.02 ± 0.12mmAl) > ProCal (1.46 ± 0.60mmAl). The study reported that the radiopacity values and spectral characterization of RetroMTA and OrthoMTA cements. The pixel-based and reproducible method could be used universally to the quantification of the radiodensity of digitally collected X-ray data.

SHED's Response to Various Pulpotomy Materials: Cytotoxicity and Gene Expression Analysis.

PURPOSE: To examine the cytotoxicity and genetic expression of SHEDs cultured in eluates of various calcium silicate based pulpotomy materials. STUDY DESIGN: MTT assay, flow cytometry, alizarin red staining and scratch assay was used to assess the cellular viability, apoptosis, calcium matrix deposits and cell migration respectively. The gene expression of ALP, OCN and BMP -2, were measured with rtPCR. One way ANNOVA and Bonferroni post test was used for statistical analysis. RESULTS: MTT assay analysis reported that all the test specimen had no cytotoxic effects. The highest number of live cells [ % ] was found in RetroMTA. The highest percentage of cell migration was observed in SHEDs cultured in EndoCem Zr. The mean absorbance for calcium matrix deposition was higher or similar in all test specimens, when compared to control groups. The expression of BMP -2 and OCN were significantly higher in cells exposed to RetroMTA and NeoMTA respectively after 24 hrs of incubation. After 72 hrs of incubation the mRNA expression of ALP was significantly higher in MTA. CONCLUSIONS: SHEDs cultured in eluates of various calcium silicate based cements exhibited cytocompatibility and maintained odontogenic like phenotype differentiation in SHEDs.

Bio-Inductive Materials in Direct and Indirect Pulp Capping-A Review Article.

The article is aimed at analyzing the available research and comparing the properties of bio-inductive materials in direct and indirect pulp capping procedures. The properties and clinical performances of four calcium-silicate cements (ProRoot MTA, MTA Angelus, RetroMTA, Biodentine), a light-cured calcium silicate-based material (TheraCal LC) and an enhanced resin-modified glass-ionomer (ACTIVA BioACTIVE) are widely discussed. A correlation of in vitro and in vivo data revealed that, currently, the most validated material for pulp capping procedures is still MTA. Despite Biodentine's superiority in relatively easier manipulation, competitive pricing and predictable clinical outcome, more long-term clinical studies on Biodentine as a pulp capping agent are needed. According to available research, there is also insufficient evidence to support the use of TheraCal LC or ACTIVA BioACTIVE BASE/LINER in vital pulp therapy.

Histological evaluation of hard tissue formation after direct pulp capping with a fast-setting mineral trioxide aggregate (RetroMTA) in humans.

OBJECTIVES: To histologically evaluate the morphology of the newly formed mineralized tissue and of the adjacent cells, in intact human teeth subjected to mechanical pulp exposure and capping with a fast-setting mineral trioxide aggregate (RetroMTA). MATERIALS AND METHODS: Seven caries-free third molars from three adults were subjected to pulp exposure, direct capping with RetroMTA, and restoration with a composite resin. Seven months later, the teeth were clinically and radiographically evaluated, extracted, and subjected to histological processing and evaluation. RESULTS: All teeth were clinically and radiographically inconspicuous and showed no presence of severe inflammatory reactions. Bacteria were absent in all teeth. All cases exhibited some degree of mineralized tissue in the area of exposure to varying extent. This newly formed mineralized tissue was mostly atubular and did not display the features of regular dentine in any of the cases. No cells exhibiting the features of odontoblasts or odontoblast-like cells were observed. Instead, the cells exhibited a flat or cuboidal shape, resembling fibroblasts. CONCLUSIONS: When the exposed pulps were directly capped with RetroMTA, the new calcified hard tissue was not "regular dentine," and did not seem to be the product of genuine odontoblast differentiation. These results suggest that the formation of calcified tissues after direct pulp capping with RetroMTA may be more appropriately regarded as a reparative process than as a genuine regeneration response. CLINICAL RELEVANCE: This is the first histological study on humans showing that regular dentine was not regenerated when a bioactive pulp-capping material (RetroMTA) was placed over exposed pulp tissue. TRIAL REGISTRATION: NCT03631511.

Dental Pulp Response to RetroMTA after Partial Pulpotomy in Permanent Human Teeth.

INTRODUCTION: A lack of information exists regarding the efficacy of RetroMTA (BioMTA, Seoul, Korea) directly applied on the pulp in vital pulp therapy. This study was designed to examine the clinical efficacy of RetroMTA compared with ProRoot mineral trioxide aggregate (MTA) (Dentsply Tulsa Dental, Tulsa, OK) for partial pulpotomy. METHODS: Partial pulpotomy was performed in 22 healthy human maxillary and mandibular third molars planned for extraction. The teeth were randomly divided into 2 groups (n = 11) and underwent partial pulpotomy with RetroMTA and ProRoot MTA as the control. The teeth were then restored with glass ionomer cement. Clinical and electric pulp tests were performed after 1 and 8 weeks. The teeth were radiographed and extracted at 8 weeks. Histologic sections were prepared and analyzed for pulp inflammation and dentinal bridge formation. Data were analyzed using the Mann-Whitney U test. RESULTS: Clinical examination after 1 and 8 weeks showed no sensitivity to heat, cold, or palpation in the ProRoot MTA and RetroMTA groups. Periapical radiographs taken before the extraction of teeth showed no evidence of periapical pathology. Electric pulp testing revealed no sensitivity. Data comparisons using the Mann-Whitney U test showed no significant difference between the materials with regard to the pulp inflammation type, intensity and extension (P = .3), or bridge continuity (P = .12). However, these data revealed a significant difference between the 2 materials in pulp morphology (P < .05) and bridge thickness (P < .01). CONCLUSIONS: This is the first work to evaluate a RetroMTA histologic outcome in partial pulpotomy in human permanent teeth. It shows pulp disorganization, an absence of inflammation, and discontinuous mineralization, which may represent a potential drawback with RetroMTA in this indication.

Comparison of Antibacterial Activities of ProRoot MTA, OrthoMTA, and RetroMTA Against Three Anaerobic Endodontic Bacteria.

OBJECTIVES: The aim of this study was to assess the antibacterial activities of OrthoMTA, RetroMTA, and ProRoot MTA against Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi). MATERIALS AND METHODS: Each material was mixed on a glass slab using a spatula and was placed in columns containing the filter membrane of the modified membrane-enclosed immersion test (MEIT) system. The materials were sterilized after setting. The columns containing the sterilized test materials were placed in microcentrifuge tubes containing 500 µl of bacterial suspension. The systems were then incubated at 37°C under anaerobic conditions. After 72 hours, the bacterial growth and concentration (colony-forming unit (CFU)/ml) were assessed. The results were analyzed using one-way analysis of variance (ANOVA) and Tukey's post-hoc test in SPSS 22 software. In all analyses, the differences were considered significant at P<0.05. RESULTS: OrthoMTA had the highest antibacterial activity against Pi. The mean number of CFU/ml of Fn in the presence of ProRoot MTA and RetroMTA was significantly lower than that in positive controls. There were significant differences between the antibacterial activities of ProRoot MTA and OrthoMTA against Pg compared to positive controls. CONCLUSIONS: ProRoot MTA, OrthoMTA, and RetroMTA had similar antibacterial activities against the three evaluated anaerobic endodontic bacteria, except RetroMTA against Pg.

Shear Bond Strength Comparison of Different Adhesive Systems to Calcium Silicate-based Materials / 대한소아치과학회지

The aim of this study was to measure the shear bond strength (SBS) of different adhesive systems to calcium silicate-based materials (Biodentine and RetroMTA). Eighty cylindrical acrylic blocks, with a hole (5.0 mm diameter, 2.0 mm height) in each, were prepared. The holes were filled with Biodentine (BD) and RetroMTA (RMTA), and the specimens were divided into 2 groups. Each group was classified into 4 subgroups: Clearfil™ SE (CSE) ; AQ bond (AQ) ; All bond universal Self-etch (ABU-SE) ; and All bond universal Total-etch (ABU-TE). After the application of different adhesive systems, composite resin (Z350) was applied over BD and RMTA. The SBS was measured using a universal testing machine, and the data were compared using the Kruskal-Wallis test and the Mann-Whitney test. The highest and lowest values of SBS were observed for BD-ABU-SE and RMTA-AQ, respectively. No significant differences were found in the SBS between ABU-TE and ABU-SE and between ABU-TE and CSE to BD and RMTA. According to the data, BD showed a higher SBS than did RMTA when BD and RMTA are compared in the same adhesive agents. Further, among all groups, composite resin with ABU-SE showed better bond strength to BD and RMTA.

Effects of RetroMTA on osteoblastic differentiation in MC3T3-E1 cells / 대한치과재료학회지

Mineral trioxide aggregate (MTA) provides a very good sealing, acceptable biocompatibility, dentin bridge formation and osteo-inductive effect. However, MTA has a few drawbacks. RetroMTA including calcium-zirconia complex has been developed to overcome drawbacks of MTA, especially long setting time and difficult handling characteristics. Therefore, the aim of this study was to evaluate the effects of RetroMTA on biocompatibility, osteogenic differentiation and mineralization in MC3T3-E1 cells compared with conventional MTA. Cytotoxicity was assessed by WST-1 assay. The gene expression of osteogenic markers was detected by real-time PCR. ALP activity and mineralization behavior were evaluated using ALP and alizarin red staining. There was no statistically significant difference between ProRoot MTA and RetroMTA with material extracts at dilutions of 1/4, 1/10 and 1/50 in cell viability assay. Expression of osteogenic markers in both ProRoot MTA and RetroMTA groups was significantly higher than in control group. In the mineralization assay, RetroMTA showed significantly higher formation of mineralized nodules than in control. In conclusion, RetroMTA promotes osteogenic differentiation and potential mineralization. It appears to be a potential alternative to ProRoot MTA as a root-end filling material.

The effect of human blood on the setting and surface micro-hardness of calcium silicate cements.

OBJECTIVES: The purpose of the present study was to evaluate the effects of human blood on the setting and microhardness of calcium silicate cements. MATERIALS AND METHODS: Three types of silicate-based cements were used: ProRoot MTA (PMTA), OrthoMTA (OMTA), and RetroMTA (RMTA). Mixed cement was placed into polyethylene molds with lengths of 2 and 4 mm. After storage for 4 days under three different storage conditions, i.e., saline, saline after 5 min of human blood, and human blood, the polyethylene molds were removed. With the specimens set, the surface microhardness was measured using a Vickers microhardness tester, crystalline structure was analyzed with X-ray diffraction (XRD), and the surface characteristics were examined with scanning electron microscopy (SEM). RESULTS: All specimens of 4 mm in length were set with all materials, and the blood groups exhibited lower microhardnesses than did the saline groups (p < 0.05). Among the 2-mm specimens that were stored in blood, the numbers of specimens that set were significantly different across the materials (p < 0.001). Regarding the microhardnesses of the RMTA and OMTA groups, there were no significant differences between storage conditions. For the PMTA group, only one specimen that was set in the blood group exhibited reduced microhardness. XRD showed changes of crystalline structure in the PMTA and OMTA blood group, whereas RMTA did not. SEM analysis revealed more rounded and homogeneous structures and demonstrated a clear lack of acicular or needle-like crystals in the PMTA and OMTA blood groups, while RMTA did not reveal substantial differences between the saline- and blood-stored groups. CONCLUSION: Blood contamination detrimentally affected the surface microhardnesses of all materials; furthermore, among the 2-mm specimens, blood contamination interfered with normal setting. Therefore, RMTA might be a more suitable choice when blood contamination is unavoidable due to limited depth. Clinical relevance RetroMTA might be a more suitable choice in situations in which blood contamination is unavoidable.

Odontoblastic Differentiation, Inflammatory Response, and Angiogenic Potential of 4 Calcium Silicate-based Cements: Micromega MTA, ProRoot MTA, RetroMTA, and Experimental Calcium Silicate Cement.

INTRODUCTION: The aim of this study was to analyze the effects of different calcium silicate-based cements (CSCs) for pulp capping materials including MicroMega MTA (MMTA; MicroMega, Besanchon, France), RetroMTA (RMTA; BioMTA, Seoul, Korea), ProRoot MTA (PMTA; Dentsply, Tulsa, OK), and experimental CSC (ECSC) on odontoblastic differentiation, in vitro angiogenesis, and the inflammatory response in human dental pulp cells. METHODS: Differentiation was evaluated by alkaline phosphatase activity, alizarin red staining, and reverse-transcriptase polymerase chain reaction (RT-PCR) for the marker genes. The levels of inflammatory mediators and cytokines were measured by RT-PCR and an enzyme-linked immunosorbent assay. In vitro angiogenesis was assessed by RT-PCR for angiogenic genes and an endothelial tube formation assay. RESULTS: PMTA, MMTA, and ECSC increased the alkaline phosphatase activity and mineralization nodule formation and up-regulated messenger RNA (mRNA) expression of odontoblastic markers compared with RMTA. In addition, PMTA, MMTA, and ECSC up-regulated the mRNA of angiogenic genes in human dental pulp cells and increased the capillary tube formation of endothelial cells compared with RMTA. However, all CSCs showed similar expression levels of inducible nitric oxide synthase and cyclooxygenase-2 protein as well as proinflammatory mediators such as nitric oxide, prostaglandin E2, tumor necrosis factor alpha, interleukin (IL)-1ß, IL-6, and IL-8 mRNA. CONCLUSIONS: Taken together, our experimental results suggest that all CSCs are favorable materials for pulp capping, but PMTA, MMTA, and ECSC may be recommended over RMTA.

Color changes of teeth after treatment with various mineral trioxide aggregate-based materials: an ex vivo study.

INTRODUCTION: Mineral trioxide aggregate (MTA) materials have been used for many years as a pulp therapy material. The most widely used product, ProRoot MTA (Dentsply, Tulsa, OK), has a major drawback in that it causes tooth discoloration. Alternatives have recently been developed such as ENDOCEM Zr (MARUCHI, Wonju, Korea) and RetroMTA (BioMTA, Seoul, Korea). The purpose of this study was to compare the discoloration of these various MTA-based materials. METHODS: Discoloration of discs prepared from 4 different MTA-based materials (ProRoot MTA, MTA Angelus [Angelus, Londrina, PR, Brazil], ENDOCEM Zr, and RetroMTA) were observed at 15 and 30 minutes after exposure to light at an intensity of 1000 mA/cm(2). In a tooth model, 12 premolars were used per each group to retrofill the pulp chamber with MTA-based materials. The degree of discoloration was measured over a 16-week period using a digital spectrophotometer. RESULTS: Distinct color changes were observed for discs made from ProRoot MTA and MTA Angelus, but no clear change was observed for those made from either ENDOCEM Zr or RetroMTA. In the tooth model, more distinct, time-dependent color changes were observed for teeth filled with ProRoot MTA and MTA Angelus than for those filled with ENDOCEM Zr and RetroMTA. CONCLUSIONS: Less discoloration was observed with ENDOCEM Zr and RetroMTA (which contain zirconium oxide) than with ProRoot MTA and MTA Angelus (which contain bismuth oxide) in both of the test models used.