Effect of dopamine pretreatment on root canal bonding with AH-plus sealer / 口腔疾病防治

Objective@# To observe the effect of dopamine pretreatment of the root canal on improving the bonding performance of AH-plus sealer.@*Methods @# A total of 32 freshly isolated permanent teeth with a single canal were collected, with no caries, no fracture of roots, and a root canal curvature<10°. All sample root canals were prepared to F2 with ProTaper rotating nickel-titanium instruments and then treated with 1 mg/mL, 2 mg/mL, or 3 mg/mL dopamine solution for 24 hours and divided into 4 groups (n = 8): 0 mg/mL dopamine group (blank control group), 1 mg/mL dopamine group, 2 mg/mL dopamine group, and 3 mg/mL dopamine group. Scanning electron microscopy was used to observe the combination of dopamine and root canal dentin wall; laser confocal scanning microscopy was used to observe the penetration of AH-plus sealer; and root canal filling was performed with AH-plus sealer and gutta-percha tip using the cold gutta-percha lateral pressure technique. The root canal samples were cut horizontally at the middle and the apical third sections of the root with a slice thickness of 1-2 mm. The push-out test was carried out under an Instron universal testing machine to compare the push-out bonding strength between each group. @*Results @#Scanning electron microscopy showed that most of the dentinal tubules were open in the control group after 0 mg/mL dopamine solution treatment for 24 hours. In the 1 mg/mL group, a small number of dopamine particles on the surface of the dentin tubules in the inner wall of the root canal were loose and unevenly distributed. In the 2 mg/mL group, most of the dentinal tubules were covered by dopamine particles, and the dopamine layer was uniform and dense. In the 3 mg/mL group, a large number of dopamine particles were deposited at the mouth of the dentinal tubules, but the distribution was uneven. Dopamine and AH-plus sealer can be seen to simultaneously infiltrate into dentinal tubules under a confocal laser scanning microscope. The interaction of the two factors, the anatomical location and dopamine concentration, had no significant effects on the bonding strength of AH-plus sealer (P>0.05). Root canals treated with 2 mg/mL dopamine had the highest bonding strength in all groups (P<0.05). Analysis of the push-out test of bonding strength with AH-plus sealer at different anatomical locations showed significant differences (P<0.05). The push-out bonding strength of the AH-plus sealer in the middle third section of the root was higher than that in the apical third section of the root.@*Conclusion@# Different dopamine concentrations could affect the bonding strength of AH-plus sealer in root canals. When treated with 2 mg/mL dopamine for 24 hours, the bonding effect of AH-plus sealer in root canals was improved.

The Effect of AH Plus and GuttaFlow Bioseal Sealers on the Fracture Resistance of Endodontically Treated Roots Instrumented with Reciprocal Rotary Systems

Objective: The objective of this study was to assess and compare the fracture resistance of roots treated endodontically using WaveOne gold, Reciproc blue, AH plus sealer and GuttaFlow Bioseal sealer. Materials and methods: Total 48 human mandibular premolars with single root were decoronated to a length of 13 mm. The roots were arbitrarily divided into 3 main groups (n=16 each group). Group I control group (roots were instrumented but not obturated), Group II obturated with gutta-percha and GuttaFlow Bioseal sealer and Group III obturated with gutta-percha and AH plus sealer. Each main group was additionally divided into 2 subgroups (n=8 each subgroup) conforming to the system used in root canal preparations, Subgroup A: Reciproc blue system and Subgroup B: WaveOne gold system. All root samples were kept for 1 week at 100% humidity to permit the sealers to set completely. Each sample was then exposed to fracture test utilizing a universal test machine, the data were analyzed statistically with one-way ANOVA test, two-way ANOVA test and Dunnett test (2-sided) at a significant level of 0.05. Results: The results revealed that the highest mean value of fracture resistance was noted in Group IIIB (611.125) followed by Group IIIA (543.250), Group IIB (519.875), Group IIA (511.875), Group IB (270.125) and Group IA (267.875) respectively with statistically highly significant differences among the different groups when compared to the control group. Conclusion: From the results of this study, it seems that the use of AH plus and GuttaFlow Bioseal sealers improved the fracture strength of instrumented roots whereas preparation of the root canals with WaveOne gold and Reciproc blue systems without obturation weakened the tooth structures.

Efeito de diferentes sistemas de obturação na resistência à fratura de raízes tratadas endodonticamente / The Influence of different obturation systems on the fracture resistance of endodontically treated roots

Objective: This study aimed to compare the fracture resistance of endodontically treated roots filled by different obturation systems. Material and methods: Ninety-six maxillary central incisors were used and decoronated, retaining 12 mm of the roots. On the basis of obturation systems, the roots were randomly divided into 4 groups (n=24): Group1 (COGR): control group (unprepared, unfilled), Group 2 (AVGR): ActiV GP points/ActiV GP sealer, Group 3 (GPGR): Gutta percha points / AH plus sealer, and Group4 (GAGR): Gutta percha points/ActiV GP sealer. The last three groups were obturated with the single cone technique. The roots were then stored in 100% relative humidity at 37 °C for 2 weeks. A vertical compressive force was exerted in a universal testing machine until fracture occurred. Data were statistically analyzed using one-way ANOVA. Results: Mean (SD) failure loads for groups ranged from 920.51 ± 210.37 to 1113.44 ± 489.42 N. The fracture resistance between the different study groups indicated no statistical difference (p>0.05). Conclusions: ActiV GP system did not exert a significant effect on the fracture resistance of endodontically treated teeth.(AU)

Objective: Comparar a resistência à fratura de raízes tratadas endodonticamente obturadas através de diferentes sistemas. Materiais e Métodos: Noventa e seis incisivos centrais superiores foram utilizados, tiveram as coroas removidas, restando 12 mm de raíz. De acordo com o sistema de obturação, as raízes foram divididas em 4 grupos (n=24): Grupo1 (COGR): grupo controle (sem preparo, sem preenchimento), Grupo2 (AVGR): cones ActiV GP / cimento ActiV GP, Grupo3 (GPGR): cones de guta percha / cimento AH plus, e Grupo4 (GAGR): cones de guta percha / cimento ActiV GP. Os últimos três grupos foram obturados através da técnica de cone único. As raízes foram armazenadas em 100% de umidade relativa a 37 °C durante 2 semanas. Uma força compressiva vertical foi aplicada através de uma máquina de ensaio universal até ocorrer fratura. Os dados foram analisados estatisticamente através de ANOVA ­ 1 fator. Resultados: A carga média (SD) obtida no momento da falha variou entre 920.51 ± 210.37 até 1113.44 ± 489.42 N. A resistência à fratura entre os diferentes grupos estudados não indicaram diferença estatística. Conclusão: O sistema ActiV GP não exerceu um efeito significante na resistência à fratura em dentes tratados endodonticamente.(AU)

Sealing ability of two commonly used root canal sealers with and without smear layer

AIM: The aim of current research was to find out the sealing ability of two commonly used sealers in the presence and absence of smear layer at different time interval. MATERIAL AND METHODS: Total of 180 single rooted vital teeth were used. Transversal section was made with the help of digital slow speed cutting saw to divide the root and crown part. After removal of crown roots part was instrumented and prepared. The 180 teeth were randomly divided into two equal groups (n=90) 1 and 2. In group 1 the smear layer was kept intact but it was removed from group 2 with EDTA (17%). Group 1 was then divided into two sub-groups, A1, A2. Group 2 was again separated into two sub-groups, B1 and B2. Each sub-group contained of 45 samples. In sub-groups A1 and B1, AH Plus sealer, in sub-groups A2 and B2, Ketac-endo sealer and cold lateral condensation technique was used for obturation with gutta percha. All samples were kept in an incubator at 37°C for 24 hours, with help of nail polish/varnish all samples root surfaces was painted only excluding apical area after words each sub group were further divided in to three groups of 15 to represent immersion periods of 7,15 and 30 days. All samples were then kept in 5 % methylene blue dye solution at 37o c for their respective time periods. After specific time period, the roots of every group were cut longitudinally and evaluate under a stereomicroscopes to evaluate apical micro leakage in millimeter. Data was subjected to Repeated measure ANOVA with post-hoc analysis using Tukey and bonferroni tests. RESULTS: Overall analysis indicated significant reduction in sealing ability canals in with and without smear layer over different time periods (p <0.0001). CONCLUSION: Current study has concluded that AH plus sealer provides significantly better seal in the absence of smear layer than in the presence of smear layer in addition it gave better seal than Ketac-Endo sealer in the absence and presence of smear layer.

Comparison of therapeutic efficacy of AH Plus sealer and Zinc oxide eugenol sealer in root canal treatment / 中国基层医药

Objective To compare the therapeutic effects of AH Plus sealer and Zinc oxide eugenol sealer in root canal treatment.Methods 206 patients with 227 teeth who needed root canal treatment were divided into observation group(103 patients with 114 teeth) and control group(103 patients with 113 teeth) randomly,and observation group and control group received AH Plus sealer and Zinc oxide eugenol sealer,respectively.Results There were 105 teeth filled exactly,4 overfilled,5 underfilled in observation group,and 103 teeth filled exactly,4 overfilled,5 underfilled in control group.No significantly differences in root canal filling was found between observation group and control group (P ＞ 0.05).In postoperative 1 d,there were 97 teeth with no response,9 with mild,6 with moderate,2with severe in observation group,and 83 teeth with no response,14 with mild,9 with moderate,7 with severe in control group.In postoperative 7d,there were 112 teeth with no response,2 with mild in observation group,and 104 teeth with no response,9 with mild in control group.The intensity of acute postoperative reaction of observation group were significantly lower than those of control group in postoperative 1d and 7d,respectively(t =2.2210,P ＜0.05 ;t =2.1711,P ＜ 0.05).In postoperative 6-month and 12-month,the number of teeth judged as being successful were 109 and 106 in observation group,and 107 and 103 in control group.No statistically significant differences in success rates were found between observation group and control group in postoperative 6-month and 12-month,respectively(P ＞ 0.05).Conclusion The root canal treatment using AH Plus sealer,which was considered to be one of ideal root canal filling materials,can significantly reduce the intensity of acute postoperative reaction.