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.

Comparison of physical and mechanical properties of mineral trioxide aggregate and Biodentine.

Background: Mineral trioxide aggregate (MTA) fulfills many of the ideal properties of the root‑end filling material. However, its low cohesive property often makes it difficult to handle. Biodentine, new calcium‑silicate‑based cement has been developed to improve some MTA drawbacks such as its difficult handling property and long‑setting time. Aim: The objective of this study was to compare at different times the microleakage of roots filled with Biodentine and white MTA (WMTA)‑Angelus and to investigate their setting time, handling properties and compressive strength. Materials and Methods: Root canals of single‑rooted teeth were instrumented, filled with either Biodentine or WMTA‑Angelus (n = 15 each) with two positive and two negative control roots and stored at 37°C. Sealing was assessed at 4, 24 h, 1, 2, 4, 8, and 12 weeks by a fluid filtration method. The initial setting time, handling properties, and compressive strength of the test groups were investigated by a vicat needle, questionnaire of operational hand feel, and universal instron machine, respectively. Results: Significant differences in microleakage were found between two groups at 4‑h and 24 h (P < 0.05) and no difference at 1, 2, 4, 8, and 12 weeks. No significant difference was seen in the setting time of MTA‑Angelus and Biodentine, though latter was found to have better handling consistency. Compressive strength of Biodentine was significantly higher than MTA‑Angelus. Conclusions: The results suggest that the new calcium‑silicate‑based endodontic cement provides improvement in sealing ability as well as clinical manageability of dental filling materials.

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 37degrees C 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.

Comparing the sealing properties of mineral trioxide aggregate and an experimental ceramic based root end filling material in different environments.

Background: An apical seal is an important factor in achieving success in surgical endodontics. Aim: The purpose of this study was to compare the sealing properties of mineral trioxide aggregate (MTA) with a new ceramic based root end filling material (Cold Ceramic) in different environments. Materials and Methods: One hundred teeth were selected. The root canals were instrumented and obturated. Except for the apical 2 mm, the root surfaces were sealed. After root resection, 3 mm depth root-end cavities were prepared. For each material, roots were divided into 3 equal subgroups and the root-end filling was done in different environments (dry, saliva contaminated, blood contaminated). Five roots served as positive and 5 roots as negative controls. Samples were immersed in 2% methylene blue dye. Roots were sectioned longitudinally and examined under stereomicroscope to record the extension of dye penetration. Results: All experimental groups demonstrated dye penetration. The lowest linear leakage was seen in Cold Ceramic blood contaminated group while the highest leakage was observed in MTA blood contaminated group. The linear dye penetration of both MTA and Cold Ceramic (CC) groups did not show any significant differences among different environments. Also, the difference between MTA and CC was not significant in dry and saliva contaminated subgroups. Only the difference between dye penetration of MTA and CC in blood contaminated subgroups showed significant difference ( P = 0.008). Conclusion: The sealing property of this ceramic based root end filling material (Cold Ceramic) is better than MTA in blood contaminated condition and at least similar to MTA in other conditions.

Sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate as a root end filling material: An ex vivo evaluation.

Aim: The aim of this study was to evaluate the sealing ability of white and gray mineral trioxide aggregate (MTA) mixed with distilled water and 0.12% chlorhexidine (CHX) gluconate when used as a root-end filling material using the dye-penetration technique. Materials and Methods: A total of 48 single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH Plus sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 8 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After application of nail polish, the teeth were exposed to India ink for 72 h and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. Results : No statistically significant differences were observed in the sealing ability of gray and white MTA mixed with distilled water and 0.12% CHX. Conclusion : CHX appears to be a good alternative to replace distilled water, as a solution to be mixed with MTA.

The effect of several root-end filling materials on MG63 osteoblast-like cells / 대한치과보존학회지

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 (TGFbeta1) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

Sealing ability of castor oil polymer as a root-end filling material

OBJECTIVE: The purpose of this study was to evaluate the sealing ability of castor oil polymer (COP), mineral trioxide aggregate (MTA) and glass ionomer cement (GIC) as root-end filling materials. Forty-five single-rooted human teeth were cleaned and prepared using a step-back technique. The apical third of each root was resected perpendicularly to the long axis direction. All teeth were obturated with gutta-percha and an endodontic sealer. After, a root-end cavity with 1.25-mm depth was prepared using a diamond bur. The specimens were randomly divided into three experimental groups (n=15), according to the root-end filling material used: G1) COP; G2) MTA; G3) GIC. The external surfaces of the specimens were covered with epoxy adhesive, except the root-end filling. The teeth were immersed in rhodamine B dye for 24 hours. Then, the roots were sectioned longitudinally and the linear dye penetration at the dentin/material interface was determined using a stereomicroscope. ANOVA and Tukey's tests were used to compare the three groups. The G1 group (COP) presented smaller dye penetration, statistically different than the G2 (MTA) and G3 (GIC) groups (p<0.05). No statistically significant difference in microleakage was observed between G2 and G3 groups (p>0.05). The results of this study indicate that the COP presented efficient sealing ability when used as a root-end filling material showing results significantly better than MTA and GIC.

Apical microleakage of MTA with 4-META/MMA & TBB resin as a root-end filling material / 대한치과보존학회지

We evaluated in vitro microleakage of Mineral Trioxide Aggregate (MTA) powder with 4-methacryloxyethyl trimellitate anhydride (4-META) / methyl methacrylate (MMA) & tri-n-butylborane (TBB) resin as a retrograde filling material by using methylene blue dye method. Fifty-two single rooted, extracted teeth were instrumented and obturated with gutta percha and AH plus sealer. The apical 3mm of each root was resected and 3mm deep ultrasonic root end preparation was done. External surface of roots was coated with nail varnish. Prepared teeth were randomly divided into five groups; Negative control: completely covered with nail varnish; Positive control: coated with nail varnish except for apical foramen; Group 1 (retrofilled with Portland cement); Group 2 (retrofilled with MTA); Group 3 (retrofilled with MTA powder mixed with 4-META/MMA & TBB resin). Immediately after completion of root-end filling, all specimens were submerged in methylene blue dye for 72 hours in 37degrees C incubator. The roots were longitudinally sectioned and measured for extent of dye penetration by three different examiners under microscope (x10). The results were statistically analyzed using one way ANOVA and Turkey's HSD test. No leakage was evident in negative control and complete leakage in positive control group. Group 3 showed significantly less leakage than group 1 and 2 (p 0.01). It was concluded that MTA powder with 4-META/MMA & TBB resin was excellent in reducing initial apical microleakage.