The Effect of Calcium Hydroxide on the Bond Strength of Resilon/Epiphany Self-Etch and Assessment of Calcium Hydroxide Removal Techniques: An Ex-Vivo Study

Objective: Calcium hydroxide is the most widely used intracanal medicament in endodontics, which should be removed prior to permanent root canal filling to minimize its intervention with the bonding of endodontic sealers. This ex-vivo study aimed to evaluate the effect of pretreatment with calcium hydroxide on the bond strength of Resilon/Epiphany self etch (SE) to the radicular dentin after removing the calcium hydroxide by hand file or ultrasonic methods.Materials and Methods: Thirty-six single-rooted human extracted teeth were used in this study. After root canal preparation, the teeth were divided into three groups. In group 1, as the control, no pretreatment was performed; while in groups 2 and 3, this was carried out using calcium hydroxide paste. After one week, the paste was removed with hand stainless steel K-files in group 2 and ultrasonic instrumentation in group 3. All samples were obturated with Resilon/Epiphany SE. One-millimeter slices of mid-root dentin were prepared for the push-out test (14 slices per group). After the bond strength was assessed, the failure modes were examined. The data were analyzed using one-way ANOVA and Dunnett Post Hoc tests.Results: Group 2 significantly showed the lowest bond strength (0.947 ± 0.47) (P = 0.01). No significant differences were found between the control group (2.32 ± 1.43) and group 3 (1.78 ± 1.04) (P = 0.01).Conclusions: Under the conditions of this ex vivo study, calcium hydroxide as the intracanal medicament and its removal using hand instrumentation adversely affected the bond strength of Resilon/Epiphany SE

Evaluation of three imaging techniques for the detection of vertical root fractures in the absence and presence of gutta-percha root fillings

Aim  To compare the accuracy of digital radiography (DR), multidetector computed tomography (MDCT) and cone beam computed tomography (CBCT) in detecting vertical root fractures (VRF) in the absence and presence of gutta-percha root filling. Methodology  The root canals of 100 extracted human single-rooted teeth were prepared and randomly divided into four groups: two experimental groups with artificially fractured root and two intact groups as controls. In one experimental and one control group, a size 40, 0.04 taper gutta-percha cone was inserted in the root canals. Then DR, MDCT and CBCT were performed and the images evaluated. Statistical analyses of sensitivity, specificity and accuracy of each imaging technique in the presence and absence of gutta-percha were calculated and compared. Results  In the absence of gutta-percha, the specificity of DR, MDCT and CBCT was similar. CBCT was the most accurate and sensitive imaging technique (P < 0 .05). In the presence of gutta-percha, the accuracy of MDCT was higher than the other imaging techniques (P < 0.05). The sensitivity of CBCT and MDCT was significantly higher than that of DR (P < 0.05), whereas CBCT was the least specific technique. Conclusions  Under the conditions of this ex vivo study, CBCT was the most sensitive imaging technique in detecting vertical root fracture. The presence of gutta-percha reduced the accuracy, sensitivity and specificity of CBCT but not MDCT. The sensitivity of DR was reduced in the presence of gutta-percha. The use of MDCT as an alternative technique may be recommended when VRF are suspected in root filled teeth. However, as the radiation dose of MDCT is higher than CBCT, the technique could be considered at variance with the principles of ALARA

Comparison of the sealing ability of two root-end filling materials (MTA and CEM cement) following retropreparation with ultrasonic or Er,Cr:YSGG laser

&quot;nBackground and Aims: Considering advantages and disadvantages of mineral trioxide aggregate (MTA), Calcium Enriched Mixture (CEM) cement has been developed recently. The purpose of this study was to compare the apical microleakage of the root-end cavities prepared by ultrasonic or Er,Cr:YSGG laser and filled with MTA or CEM cement. &quot;nMaterials and Methods: Eighty single-rooted, extracted human teeth were instrumented and obturated. Root-end resection was made by removing 3 mm of the apex. The teeth were randomly divided into two experimental (n=30) and two positive and negative control (n=10) groups. After that, the retrograde cavities were prepared using ultrasonic or Er,Cr: YSGG Laser. According to the root-end filling materials (MTA or CEM cement), each group was then divided into two subgroups. Finally, specimens were cleared for assessing the amount of apical dye (Indian ink) penetration. The data were analyzed using Kruskall-Wallis and Dunn tests. &quot;nResults: Laser/CEM cement group showed significantly the lowest mean apical dye penetration. There were no statistically significant differences between Laser/MTA, ultrasonic/MTA and ultrasonic/CEM cement groups. &quot;nConclusion: Based on the findings of this study, CEM cement demonstrated lower rate of apical leakage compared with MTA, when the root-end cavities prepared with Er,Cr:YSGG Laser. The sealing ability of MTA was not different following root-end preparation by ultrasonic or Er,Cr:YSGG Laser

Antimicrobial Effect of Citrus Aurantifolia Extract on Enterococcus Faecalis Within the Dentinal Tubules in The Presence of Smear Layer

Background and Aims: Instrumentation of the root canals results in formation of smear layer which covers the dentinal tubules. In infected teeth, it is ideal to achieve a material that has the ability to remove the smear layer besides antimicrobial activity. Therefore, this study was designed to evaluate the antimicrobial effect of Citrus aurantifolia extracts (lime juice and rind extract) on Enterococcus faecalis within dentinal tubules in the presence of smear layer.Materials and Methods: One-hundred and forty dentin tubes were prepared from bovine incisors. After removal the smear layer, the specimens were infected with Enterococcus faecalis. Then, the smear layer was reformed. Test solutions were used as the irrigants in study roups as follows: group 1: 5.25% NaOCl; group 2: 17% EDTA; group 3: NaOCl+EDTA; group 4: Lime juice; group 5: ethanolic rind extract of C.aurantifolia; group 6: 96% ethanol. Dentin chips were collected from inner and outer layers of dentinal walls and optical density was measured. The data were analyzed using one-way ANOVA and Tamhane tests.Results: In outer layer of dentin, the efficacy of rind extract was less than that of NaOCl+EDTA (P<0.05). Also Lime juice was less effective than EDTA, NaOCl and NaOCl+EDTA (P<0.05). In inner layer of dentin, Lime juice was significantly less effective than NaOCl and NaOCl+EDTA (P<0.05). The efficacy of rind extract was less than that of NaOCl+EDTA (P<0.05).Conclusion: In the presence of smear layer, the antimicrobial activity of Lime juice was less than that of NaOCl but the efficacy of rind extract was similar to that of NaOCl

The sealing ability of resilon and gutta-parcha following different smear layer removal methods: An ex vivo study

Objective: The objective of this study was to compare the ex-vivo sealing ability of Resilon/new Epiphany (SE) sealer to that of gutta-percha/AH-Plus following smear layer removal with EDTA or MTAD. Study design: One hundred extracted single-rooted human teeth were divided into 4 experimental groups and 2 positive and negative control groups. EDTA was used in groups 1 and 2. In groups 3 and 4 MTAD was used. The root canals were then obturated with gutta-percha/AH-Plus in groups 1 and 3 and Resilon/Epiphany (SE) in groups 2 and 4. After sterilization, the samples were coronally exposed to human saliva and monitored every 24 hours for 60 days. Results: In groups 1, 2, 3, and 4, 45%, 65%, 90%, and 65% of specimens leaked within 60 days, respectively. There were statistically significant differences between group 1 and 3 (P <.05). Conclusions: Resilon/Epiphany (SE) system is as effective as gutta-percha/AH-Plus in preventing saliva leakage. MTAD did not adversely affect the sealing ability of Resilon/Epiphany (SE). © 2010 Mosby, Inc. All rights reserved