Endodontics

Introduction: The aim of this study was to investigate the effect of prior calcium hydroxide (Ca [OH] 2 ) intracanal placement on the bond strength of AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), iRoot SP (Innovative Bioceramix, Vancouver, BC, Canada), and MTA Fillapex (Angelus Soluções Odontol ogicas, Londrina, PR, Brazil). Methods: The root canals of 90 human incisor teeth were prepared with the ProTaper System (Dentsply Maillefer, Ballaigues, Switzerland) up to a master apical file size of F5. Canals were filled using the single-cone technique either immediately (the control group, n = 30) or after a 7-day Ca(OH) 2 placement. Ca(OH) 2 removal was performed either manually using F5 with distilled water irrigation (the Ca[OH] 2 group, n = 30) or manually using Protaper F5 followed by passive ultrasonic irrigation with 2.5 % NaOCl with a final flush of 17 % EDTA and then distilled water (the PUI group, n = 30). After obturation, a 2-mm-thick middle section of each root was then subjected to push-out testing. Results: Using 1-way analysis of variance, AH Plus showed a higher bond strength than iRoot SP and MTA Fillapex in the control group (P < .05). With prior Ca(OH) 2 placement, AH Plus and iRoot SP showed a similar bond strength (P > .05), which was higher than MTA Fillapex (P < .05). Conclusions: Prior Ca(OH) 2 placement seemed to improve the dislodgment resistance of iRoot SP but did not affect AH Plus and MTA Fillapex. (J Endod 2012;38:696-699)

Objective. The objective of this study was to compare the shaping ability of manual H-files, rotary nickel-titanium ProTaper system, and reciprocating SafeSiders in long oval-shaped root canals. Study design. The roots of 45 human premolars were sectioned at 2 levels in the middle third and reassembled using a 3-piece metal mold. Pre-and postinstrumentation cross-sectional images were superimposed and evaluated in terms of change in buccolingual-to-mesiodistal canal ratio, maximum buccolingual and mesiodistal canal dimensions, and cross-sectional areas. Ratios of touched canal wall and canal outline with more than 200 m dentin removal to the original canal perimeter were also calculated.

Aim: To compare strontium ranelate as a pulp capping agent to bisphosphonate and calcium hydroxide. Materials and methods: The pulps of 36 premolars from 4 dogs were exposed and capped with one of 3 test materials, namely strontium ranelate, bisphosphonate, and calcium hydroxide. Half of the specimens underwent histologic evaluation at 6 weeks and the remaining half were assessed at 12 weeks. Each slide was scored from 1 to 3 according to hard tissue formation, inflammation, and odontoblastic differentiation. The pH of the 3 materials was also measured. Data were inspected using SPSS software and the recorded scores were statistically analyzed at 6 and 12 weeks. Results: Calcium hydroxide was the only material that exhibited discontinuous dentin bridge at both evaluation periods. Strontium ranelate showed irregular hard tissue formation in few of the samples at 12 weeks; while bishphonate did not induce any hard tissue formation. All the materials exhibited severe to moderate inflammatory reaction at 6 weeks which subsided to mild inflammation at 12 weeks. Differentiation of odontoblasts was observed with all materials at both evaluation periods with no significant differences among them. The average pH obtained for Dycal base was 9, and 12 for the catalyst; for bisphosphonate the value was 6.8; and 8.6 for strontium ranelate. Conclusions: Strontium ranelate was not as effective as calcium hydroxide as a pulp capping agent, while bisphosphonate failed to show any potential for hard tissue formation up to 12 weeks. However, all the test materials allowed healing of the pulp tissues.

Aim: The aim of this study was to assess the effect of degree of curvature on extrusion of debris from root canals; and to compare the amount of extruded debris after instrumentation with WaveOne Gold reciprocating (WOG; Dentsply Maillefer, Ballaigues, Switzerland) and OneShape rotating (OS; MicroMega, Besançon, France) single file systems. Materials and methods: Sixty mesiobuccal canals were assigned to 2 equal groups according to the degree of curvature, whether severe (25-40°) or moderate (10-15°) as measured using Schneider method. The canals in each group were further subdivided into 2 subgroups (n=15) according to the instrument used for preparation; WaveOne Gold (WOG) or OneShape (OS) files. The extruded debris was collected in preweighed glass vials. Data were statistically analyzed using One-way ANOVA and Tukey's post-hoc tests. Results: The least amounts of debris were obtained with WaveOne Gold instruments in both curvatures, with no significant difference between them (P > 0.05). Larger amounts of debris occurred with OneShape instruments in severely curved canals; but this difference was of no statistical significance. Statistically significant differences were recorded only when OneShape instruments were used in moderately curved canals. Conclusions: Debris extrusion occurs independent of the motion or design of the instrument. However, moderate root canal curvatures allowed more extrusion of debris than severe curves. WaveOne Gold results were not affected by the degree of canal curvature; and outperformed OneShape instruments in both types of curves.

The aim of this study was to evaluate the effect of irrigation with CPP-ACP solution on EDTA treated root dentin microhardness when used as a final irrigant in single rooted teeth. Methodology: Twenty one extracted human single rooted teeth with single canals were used. All teeth were decoronated at 12mm length from the apex. Complete chemo-mechanical preparation was done using NaOCl as conventional irrigation protocol. Teeth were randomly divided into 3 groups (n = 7 in each) according to the final irrigation protocol as follows: Group (A) final irrigation with 17% EDTA for 5 minutes followed by CPP-ACP remineralizing solution for 10 minutes, Group (B) final irrigation with 17% EDTA for 5 minutes, and Group (C) final irrigation with normal saline for 5 minutes. Each root specimen was cut horizontally at 3 different levels (coronal, middle, apical). Vicker's Microhardness Testing was done at three different horizontal depths from the canal lumen (25µm, 50µm, 100µm). Results: The results showed the highest values of microhardness for group A, followed by group C and B respectively. There was a significant difference in microhardness values between group A and the other groups at the middle third of the root, whereas the difference at coronal and apical thirds was insignificant. In addition, the values of microhardness increased significantly at deeper depths of dentin away from the canal lumen towards cementum in all groups. Conclusion: Final irrigation with CPP-ACP remineralizing solution may improve mechanical properties of dentin including microhardness, especially after EDTA irrigation for smear layer removal.

Introduction: The purpose of this study was to evaluate the efficacy of XP-Endo finisher (XP) (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) on removal of debris from coronal, middle and apical thirds of oval root canals in comparison to passive ultrasonic irrigation (PUI), vibringe (VB) and conventional syringe irrigation (CSI). Methods: Eighty extracted single-rooted human mandibular premolars were used in this study. Specimens with a standardized length of 16 mm were mechanically prepared with Race (FKG Dentaire) till # 40/4%. Teeth were divided into 4 groups (n=20) according to the final irrigant activation protocol into the following groups: CSI, PUI, XP and VB. Root canals were then split longitudinally. Digital images were acquired to evaluate the amount of debris by using a digital camera mounted on a stereomicroscope at 25x magnification and transferred to the computer and scored in mm2 and recorded as a percentage of the overall canal surface area by using image analysis software. Debris percentage was analyzed by One-way ANOVA. Results: The XP and PUI groups revealed significantly lower debris percentage than the other groups in the coronal, middle, and apical regions (P≤0.05). There was no statistically significant difference between XP and PUI. Regarding all systems the coronal third was cleaner than the apical thirds. Conclusions: In our study, none of the activation systems completely removed the debris from the root canal walls; nevertheless, the XP and PUI showed the best results along all thirds in comparison to the other systems.

Introduction: The purpose of this study was to evaluate the efficacy of XP-Endo finisher (XP) (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) on removal of debris from coronal, middle and apical thirds of oval root canals in comparison to passive ultrasonic irrigation (PUI), vibringe (VB) and conventional syringe irrigation (CSI). Methods: Eighty extracted single-rooted human mandibular premolars were used in this study. Specimens with a standardized length of 16 mm were mechanically prepared with Race (FKG Dentaire) till # 40/4%. Teeth were divided into 4 groups (n=20) according to the final irrigant activation protocol into the following groups: CSI, PUI, XP and VB. Root canals were then split longitudinally. Digital images were acquired to evaluate the amount of debris by using a digital camera mounted on a stereomicroscope at 25x magnification and transferred to the computer and scored in mm2 and recorded as a percentage of the overall canal surface area by using image analysis software. Debris percentage was analyzed by One-way ANOVA. Results: The XP and PUI groups revealed significantly lower debris percentage than the other groups in the coronal, middle, and apical regions (P≤0.05). There was no statistically significant difference between XP and PUI. Regarding all systems the coronal third was cleaner than the apical thirds. Conclusions: In our study, none of the activation systems completely removed the debris from the root canal walls; nevertheless, the XP and PUI showed the best results along all thirds in comparison to the other systems.

Introduction: Pain is unwanted but common sensation after root canal treatment. Studies have shown that endodontic postoperative pain between 3 to 58%. Pain may occur in periodontal tissues after mechanical, chemical and microbial injuries. There are various parameters in treatment that can cause postoperative pain. one of these parameters is including working length. Also, the number of visits, selection of instruments and the selection of root canal sealers. Aim of the Study: To compare the potential effects of resin-based and bioceramic sealers on the occurrence and intensity of postoperative pain in patients with asymptomatic apical periodontitis. Methods: Sixty eight patients with asymptomatic apical periodontitis multirooted teeth were included. After confirming the diagnosis clinically and radiographically, patients were randomly assigned into two equal groups of 34 patients each. Standard endodontic treatment was performed in single visit. During the obturation the patients in the intervention group were treated using Endosequence BC sealer; while AH Plus sealer was used during obturation in patients assigned to the comparator group. Assessment was done 6, 12, 24, 48, 72 hours and 5 days postoperatively. Visual Analogue Scale (VAS) was used in the outcome measurement. Contact with the patients was done over the phone at each follow up time as a reminder for the patients and an appointment was scheduled to receive the chart. Then data was statistically analyzed. Results: Results showed that there was no statistically significant difference between the two sealers groups: AH Plus sealers and Endosequence BC sealer regarding intensity of postoperative pain at 6 hours, 12 hours, 24 hours, 48 hours, 72 hours and 5 days. Conclusion: Post endodontic pain in the teeth diagnosed with asymptomatic apical periodontitis (AAP) and obturated with resin based or bioceramic root canal sealers without extrusion beyond the apex was low. No differences were observed at 6, 12, 24, 48, 72 hours and 5 days post obturation. This means that resin-based and bioceramic root canal sealers act the same in incidence and postoperative pain severity.

Aim: The study attempted to evaluate the shaping ability of One Curve single file in comparison to ProTaper Next multiple-file NiTi in terms of transportation and centering ability in curved mesiobuccal canals of human extracted mandibular molars using CBCT scanning. Materials and Methods: Mesiobuccal canals of thirty extracted mandibular first and second molars with the angle of curvature ranging 20-45 ͦ (according to Schneider) were randomly allocated into two equal groups; One Curve (OC) and ProTaper Next (PTN) groups. Pre-and post-instrumentation CBCT imaging was performed to assess the centering ability and canal transportation of the tested instruments at 3, 5 and 8 mm from the apex. Results: Regarding the results of canal transportation and centering ability, there was no statistically significant difference mesiodistally among the two groups at 3, 5, and 8mm (P > 0.05). Conclusion: The canal transportation values of the two tested rotary systems are considered acceptable. Both of One Curve and ProTaper Next systems were not able to achieve perfect centering ability during root canal preparation.

Background: Many challenges encounter the endodontist, especially when dealing with necrotic teeth with chronic periapical lesions. Postoperative pain may be induced following conventional endodontic therapy and total eradication of the bacteria is almost unachievable even with recently available techniques. In recent years, diode laser usage in the endodontic field has gained acceptance. Thus, this study aimed to investigate the ability of the diode laser (DL) to decrease postoperative pain and achieve root canal sterility. Methods: 56 patients with anterior teeth with chronic periapical lesions in upper anterior teeth were randomly divided into two groups (n = 28). All patients were treated with two visits of conventional root canal treatment with ProTaper Universal. The DL group: root canals were irradiated with 200 µm fiber optic at both visits; the control group (Endo): the DL fiber was placed in root canal with no activation. Bacterial samples were collected from all the cases...

Non-surgical retreatment is advised as the first treatment option, when preliminary root canal treatment fails (1). It is usually more challenging and needs more time than the initial treatment itself (2). Even though various techniques and improvements in instruments' design, kinematics, number, and innovation in irrigation systems had evolved,

Aim: The aim of this study was to compare the amount of apically extruded debris of (SAF) versus (FAFFF) during mechanical preparation of mandibular premolars. Methodology: Forty-eight extracted human mandibular premolars with single canals and standardized lengths were instrumented using FAFFF 20 taper 4%. Then samples were randomly divided into 4 groups (n=12 teeth) as follow: Group (A) Root canals were prepared by SAF (1.5mm) file, Group (B) Root canals were prepared by SAF size (1.5mm) file, followed by SAF size (2.0mm), Group (C) Root canals were prepared by (FAFFF) 25 taper 6%, followed by (FAFFF) 35 taper 4% and Group (D) Root canals were prepared by (FAFFF) 25 taper 6%. Debris extruded during instrumentation were collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 37 º C for 15 days for complete dehydration of extruded debris. Each Eppendorf tube with extruded debris was then weighed three consecutive times to obtain the final weight. Then the average weight of extruded debris was calculated. Results: Group B (SAF 2.0mm) showed Statistically the highest mean and standard deviation of extruded debris when compared to the other three groups. While, there was no statistically significant difference between group A, C and D. Conclusion: Under the conditions of this study, all systems caused apical debris extrusion. SAF (2mm) instrumentation was associated with the highest amount of debris extrusion compared to the other groups.

Aim: To assess and compare the cyclic fatigue resistance of EdgeFile X7, EdgeOne, WaveOne Gold and WaveOne rotary files using artificial canals with different angles and radii of curvature. Materials and methods: One hundred and sixty NiTi files from four different systems (N= 40 each) were used; Group 1: WaveOne, Group 2: WaveOne Gold, Group 3: EdgeOne and Group 4: EdgeFile X7. The files were tested for cyclic fatigue resistance using a custom made static model with various angles and radii of curvature (angle 60° radius 2.5mm and radius 5mm and angle 90° radius 2.5mm and radius 5mm). The files were operated according to the manufacturers' instructions inside the artificial canals till fracture. A digital stopwatch was used to record the time till fracture (TTF) in seconds and the length of the fractured segment (FL) was recorded. Results: The highest TTF values were found in the WaveOne Gold group followed by the EdgeOne group then the WaveOne group while the least was in the EdgeFile X7. There was no statistically significant difference between WaveOne Gold and EdgeOne at all angles and radii of curvature. There was a statistically significant difference between both the WaveOne Gold, EdgeOne and the EdgeFile X7. Angle 90° with 2.5mm radius showed the lowest cyclic fatigue resistance. WaveOne Gold and EdgeFile X7 showed lower FL compared to WaveOne. Conclusion: WaveOne Gold and EdgeOne showed superior comparable cyclic fatigue resistance which was higher than that of WaveOne while EdgeFile X7 showed the least cyclic fatigue resistance.

Introduction: Moringa oleifera is a tropical tree whose leaves are rich in antioxidant compounds. Paracetamol hepatotoxicity is a significant public health concern. Aim: The aim of this study was to investigate the possible protective role of Moringa oleifera leaves (MOL) aqueous extract on paracetamol induced liver injury in adult male albino rats. Materials and Methods: Forty adult male albino rats were used in the current study and were divided into four equal groups,: Group I served as control; Group II were given MOL for 14 days; Group III were given water for 7 days followed by paracetamol for another seven days; Group IV were given MOL for 14 days and Paracetamol on the seventh day for 7days.All medications were given by nasogastric tube. Specimens of liver were excised and processed for histological and histochemical studies. Blood samples were collected for biochemical study. Statistical analysis of the results was done. Results: MOL administration in group II didn't affect hepatic architecture or liver function tests. There was a significant increase in glutathione peroxidase and catalase activity and no significant difference in malondialdehyde level as compared to control. Paracetamol administration led to vacuolization of hepatocytes, cellular infiltrations and congestion in central and portal veins, with apparent increase in number of cholangiocytes. There were also significant decrease in the area percentage of PAS positive granules and significant decrease in area percentage of collagen fibers as compared to control. By electron microscope, distorted mitochondria, decrease of rough endoplasmic reticulum and increase of smooth endoplasmic reticulum & collagen fibrils were observed. Administration of Moringa before paracetamol ameliorated damaging effects of paracetamol. Minimal cellular infiltrations and apparent increase in number of cholangiocytes were still observed. Conclusion: MOL extracts could protect the liver against paracetamol effects through inhibition of lipid peroxidation and enhancement of antioxidant enzymes.