The Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Root Surface Strain And Cracks Development By Two Reciprocating Nickel Titanium Files2689269412088510.21608/edj.2020.29260.1118ENTarekElsewifyEndodontic Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt0000-0001-9266-7838HishamElhalabyEndodontic Department, Faculty of Dentistry, Assuit University, Assuit, EgyptJournal Article20200502Aim: The aim of this study was to determine root surface strain (RSS) developed by two reciprocating NiTi files and the resultant cracks. <br /> Materials and Methods: Thirty mesial roots of mandibular molars were used. Ten roots were prepared using AF Blue R3 Reciprocating One-File System (FBR) (Fanta; ShangHai, China) for the mesiobuccal canal and WaveOne Gold primary (WOG) (Dentsply Tulsa Dental; Tulsa, OK, USA) for the mesiolingual canal. Ten roots were prepared using WOG and ten roots using FBR. An electrical strain gauge was fixed on the root surface connected to a strain amplifier. Maximum strain and time were recorded. Roots were cut transversely to evaluate for cracks. <br /> Results: WOG has developed RSS of (84.16±52.57) and cracks (2/10); FBR has developed RSS of (128.33±128.55) and cracks (5/10) without statistically significant difference. Preparation time of WOG was (55.28±26.24) which was statistically significantly less than FBR (109±57.3). <br /> Conclusion: Both files have developed RSS and cracks during canal shaping.https://edj.journals.ekb.eg/article_120885_84ea8f4b601cda65c951d99c5bd6f093.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Effect of Air-Blowing Time on The Microshear Bond Strength of Two Universal Adhesives to Enamel and Dentin2695270312088610.21608/edj.2020.33407.1153ENRasha HassanAfifiConservative Dentistry Department, Faculty of Dentistry Future University in Egypt0000-0002-1869-3824Mai MamdouhAkhaConservative Dentistry departement, Faculty of Dentistry, Cairo University Egypt.Journal Article20200621Objectives: The aim of this study was to investigate the effect of air blowing time on the microshear bond strength of two universal adhesives to enamel and dentine. Materials and methods: Thirty extracted sound human molars were used. Flat enamel and dentin surfaces were obtained by removing the buccal enamel surface of each tooth exposing the buccal enamel and dentin. The teeth were randomly divided into two equal groups (N= 15) according to the tested adhesive system either Single Bond Universal (SBU) or all bond universal (ABU). Each group was further divided into 3subgroups (N= 5) according to the air blowing time i.e (5 seconds, 10 seconds, and 15seconds). Each subgroup was further subdivided into two divisions according to the substrate either enamel or dentin. Each substrate received 2 resin composite microrods (N=10). After storage in distilled water (37°C/24 h), microshear bond test was performed in a universal testing machine. One-way ANOVA followed by Tukey post-hoc test was used to compare between more than two groups in non-related samples. Two-way ANOVA was used to test the interaction between different variables. Results: There was a statistically significant difference between (15sec), (10sec) and (5sec) groups for (SBU) and (ABU) in enamel (p≤ 0.001). There was also statistically significant difference between (15sec), (10sec) and (5sec) groups for (SBU) and (ABU) in dentin (p <0.001). Conclusions: Air blowing time of 15 seconds in enamel has a positive effect on microshear bond strength of universal adhesives. Air blowing time effect in dentin was material dependent.https://edj.journals.ekb.eg/article_120886_2070db47fe42ed6c12e03ea00cd96973.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Assessment of Tooth Shade After De-and Re-Hydration During Clinical Restorative Procedures: A Randomized Clinical Trial2705271412088710.21608/edj.2020.36507.1178ENShereen HafezIbrahimConservative dentistry department, faculty of dentistry , Cairo University0000-0002-1047-124XSamehAbou Steitfixed prosthodontics department, faculty of dentistry, Ahram Canadian UniversityJournal Article20200720Objectives: this study was aimed to assess any tooth color change resulting from dehydration due to rubber dam application and the required time for any change to recover to baseline. <br /> Materials and methods: Ten Participants with intact maxillary central incisors were recruited. with age ranging from 20 to 55 years according to inclusion and exclusion criteria. Patients were randomized. The spectrophotometer was used for evaluating tooth shade at A baseline, 10 min and 30 min. Further measurements were done at,40 min and 60 min during rehydration. Data was collected. For statistical analysis, ANOVA was used at the significance level P ≤ 0.05.<br /> Results: Color change (ΔE): there was a statistically significant change in mean (ΔE) values (P-value <0.001, Effect size = 0.602). Pair-wise comparisons revealed that there was no statistically significant change in mean (ΔE) values from 10 to 30 minutes. From 30 to 40 minutes, there was a statistically significant decrease in mean (ΔE) value followed by non-statistically significant change from 40 to 60 minutes (A statistically significant decrease after rehydration).<br /> Conclusions: There is an obvious change in teeth shade upon dehydration as clinically assessed by spectrophotometer. It is recommended by the clinicians to wait more than 60 min in order to properly assess color match, or to carry out the shade matching procedure on another dental visit. Dental shade matching procedures should be performed before the teeth exposure to dehydration to avoid shades mismatch that may not be satisfactory and would require modification or even remake of restorations.https://edj.journals.ekb.eg/article_120887_ee8670a3ae62b89e1888e114a8a3d8a6.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Comparative evaluation of mechanical properties of three resin composite materials with different filler particle sizes2715272012088810.21608/edj.2020.36673.1183ENAmal M.El ShahawiResearcher at Restorative and dental materials Department,National Research Centre.Cairo.Mai M.ElbatanonyResearcher at Restorative and dental materials department,National Research Centre,Cairo.Journal Article20200721Aim: The aim of this study was to evaluate and compare the mechanical properties of three resin composites core materials with different filler particle sizes. Materials and methods: nanofilled (Filtek Z350 XT , 3M, ESPE USA), microhybrid (Te Econom, Ivoclar, Vivadent, India) and nanohybrid (Nexcomp, Meta biomed, korea) resin composites were used during this study. Mechanical properties regarding the compressive strength, diametral tensile strength and surface hardness were tested and results were collected and evaluated. Data were statistically analyzed using one-way Analysis of Variance and Tukey HSD test. Results: The nanofilled type revealed the highest significant compressive and diametral tensile strength values while the nanohybrid type showed the least significant hardness values among the results of the two types of composite resin for the three tests. Conclusions: after evaluation it was shown that the tested nanofilled resin composite type is more appropriate for use as core material compared to the other tested types.https://edj.journals.ekb.eg/article_120888_ddf85c50741509988d9f257bac0070ce.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Color Matching of a Single Shade Structurally Colored Universal Resin Composite with the Surrounding Hard Dental Tissues2721272712088910.21608/edj.2020.36824.1192ENAhmad SafwatMorsy64-osthman ben affan st.,
heliopoliceWael MohamedGamalOperative department, faculty of dentistry, modern university for technology and information0000-0002-7057-5200MonaRiadoperative dentistry, Cairo university0000-0001-9750-8115Journal Article20200728Color matching between the resin composite and the teeth is the most aimed target by<br /> the patient to evaluate the quality of the treatment. The aim was to investigate the ability<br /> of the uni-shade restorative material to match the tooth shade and the blending effect of<br /> the single shade structurally colored universal resin composite. Materials and methods<br /> disc shaped specimen (6×2 mm) were prepared from Omnichroma® single shade resin<br /> composite. Color shade was recorded for 10 freshly extracted premolars by Easyshade®<br /> according to CIE Lab system. Standardized class V cavities (4×2×1.5 mm) were prepared<br /> on the buccal surface of each tooth away 0.5mm from the CEJ. Cavities were then<br /> restored with resin composite, cured for 40s, and their color was recorded after 24 hours<br /> storage in distal water. Two tests have been done, the first was to determine the<br /> differences of the color parameters between disc and resin composite in teeth (T1). The<br /> second was to record the change in color between the sound teeth and the resin<br /> composite in teeth (T2). The color change data statistically analyzed using paired t-test. It<br /> was considered statistically significant at(a=0.05). Results All color parameters in the<br /> two tests showed significant changes except (ΔL) in T2 which showed nonsignificant<br /> differences. The specimens showed decrease in lightness and showed shifting toward the<br /> green and yellow direction, while in T2 they became lighter than the teeth and directed<br /> toward the green and blue scale. Conclusion OMNICHROMA single shade resin<br /> composite matches the shade of enamel.https://edj.journals.ekb.eg/article_120889_73fcefcf9469fbe35ba8bc0eaa3f7aef.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Color Stability of Artificial White Spot Lesions treated with Resin Infiltration2729273812089010.21608/edj.2020.38201.1197ENMarwaAbdelHafezOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt0000-0003-0894-7146Dena SafwatMustafaOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.0000-0002-5228-9542Khaled AlyNourOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.0000-0001-8619-1888Journal Article20200806Objective: To evaluate the color stability of artificial white spot lesions treated with three different surface treatments after immersion in staining solution.<br /> Materials and Methods: An artificial white spot lesion was created in the middle of the labial surface using demineralizing solution. Sixty-five bovine teeth were randomly assigned into 5 groups (n=13) according to surface treatment. G1: Enamel submitted to demineralization only. G2: Polished Enamel. G3: Demineralized enamel treated with low-viscosity resin infiltrant. G4: Demineralized enamel treated with CPP-ACP for 1 month. G5: Demineralized enamel treated with Artificial saliva for 1 month. All specimens were then immersed in a staining solution (coffee) for 8 weeks. Color measurements, using the CIE L*a*b* system, were done immediately after treatment and after 2, 4 and 8 weeks of immersion, by Spectrophotometry. Digital photographs were also taken at each stage to a representative specimen from each group. In addition, representative specimen for each group was evaluated using Polarized Light microscope. Color change (ΔE) was analyzed by two-way mixed ANOVA. <br /> Results: Resin infiltrant group exhibited the lowest color change values at all times of measurement, followed by CPP-ACP and polished enamel, while the highest color change values were recorded in samples without treatment.<br /> Conclusion: Resin infiltrant can be considered an effective treatment in masking and reducing long-term staining susceptibility of white spot lesions after treatment.https://edj.journals.ekb.eg/article_120890_5dfcf45ba8176d1fc215389db1a76662.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Evaluation of the antibacterial efficacy of two herbals and their effect on dentin microhardness (A comparative in vitro study)2739275012089110.21608/edj.2020.38341.1200ENAmnaAbuidrisEndodontics, Dentistry, Cairo University, Cairo, Egypt.Saied MohamedAbdelazizProfessor of Endodontics, Faculty of Dentistry, Cairo UniversityNehal NabilRoshdy3Associate Professor of Endodontics, Faculty of Dentistry, Cairo University0000-0002-5718-5777Marwa YousryIssaLecturer at Pharmacognosy Dept., Faculty of Pharmacy, Cairo University. Cairo, Egypt.Journal Article20200807Objectives: The aim of the study was to compare the antibacterial efficacy and the effect on dentin microhardness of turmeric extract, thymus vulgaris oil, sodium hypochlorite and chlorhexidine when used as root canal irrigants.<br /> Material and methods: Sixty four permanent mandibular single rooted premolars were classified into 4 groups of 16 teeth each according to the final irrigant used. For the antibacterial test, 11 teeth per group (n=11), and the microhardness test, 5 specimens per group (n=5): Group I: 2% Turmeric extract. Group II: 2% Thymus vulgaris oil. Group III: 5.25% NaOCl. Group IV: 2% CHX. Forty four Samples were inoculated with E. faecalis, incubated then chemo-mechanically prepared according to the assigned group, sampled and incubated for 24 hours then Colony Forming Units were counted. Twenty samples were used to create dentin blocks, then were kept in airtight containers saturated with 5 ml of each irrigant for 5 minutes. Microhardness test was performed at different time intervals; After 24 hours, 3 days and 7 days using Vickers hardness indentation machine.<br /> Results: The highest antibacterial efficacy against E. faecalis was in 2% CHX followed by 5.25% NaOCl, 2% Thymus vulgaris oil and finally 2% Turmeric extract. In microhardness test 2% CHX showed the highest statistically significant value of dentin microhardness, followed by 2% Turmeric extract, 2% Thymus and finally 5.25% NaOCl.<br /> Conclusion: Herbals may serve as alternatives to conventional root canal irrigants as they possess antibacterial properties and cause minimal alteration in dentin microhardness when compared to chemical irrigants.https://edj.journals.ekb.eg/article_120891_8f435f0e5fc2ae812423044513dd5ce2.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Debridement Efficiency Of Different Irrigating Protocols In Truss Cavity Access Preparation2797280610579910.21608/edj.2020.30740.1129ENHajer MohammedMuniendodontic department, faculty of dentistry, MTI university, Cairo, EgyptJournal Article20200529Minimal invasive dentistry and endodontic technological revolution used in endodontic treatment enable the application of conservative endodontic access(CEC)cavity to minimize tooth structure removal.This study examined the cleanliness of CEC.Methods:Eighty sound extracted upper first premolar divided into 4groups (n=20)according to the irrigation protocol G1:Conventional method with Irriflex irrigating needle;G2: ENDOVAC negative pressure irrigation system;G3: PUI with ED62 irrigation ultrasonic tip;G4: Er,Cr:YSGG Laser SWEEPS Mode. CEC done under high magnification.After instrumentation with M3ProGold rotary file to size 35/0.04 taper and irriganted, specimens examined under SEM, and cleanliness of pulp chamber and root canal walls at coronal,middle,apical third was measured. Data were measured, tabulated and statistically analyzed by ANOVA and t-student test (Phttps://edj.journals.ekb.eg/article_105799_cfeac5fd7a7cfe3d06a3f1d7f9c6ac89.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Accuracy of CBCT, Digital and Conventional Radiography in Evaluating the Shaping Performance of a Novel NiTi Rotary System ( An in Vitro Study)2751276112089210.21608/edj.2020.38395.1201ENSherifAmmarTeaching Assistant of Endodontics, Endodontic Department, Faculty of Dentistry, Egyptian Russian UniversityNihalSabetProfessor of Endodontics, Cairo University0000000335508333HagarBastawyAssociate Professor of Endodontics, Endodontic Department, Faculty of Dental Medicine for girls, Al-Azhar University, Cairo, Egypt.Journal Article20200812Aim: This study was designed to evaluate and compare the shaping abilities of ProTaper Gold and the ProTaper Universal systems using cone beam computed tomography (CBCT), digital and conventional radiography. Materials and Methods: Forty mesiobuccal root canals of extracted mandibular first molars with curvature ranging between 25-60° according to Schneider’s technique were selected and prepared using either ProTaper Gold (group I) or ProTaper Universal (group II). Root canals were scanned using CBCT, digital and conventional radiography before and after preparation for measurement of canal transportation and centering ratio at three levels (3, 6 and 9 mm) from the apex. Results: ProTaper Gold instruments resulted in lower mean canal transportation and higher mean centering ratio compared to ProTaper Universal instruments at 3, 6 and 9mm levels when conventional, digital radiographic or CBCT radiography were used, with a statistically significant difference, at 9 mm when the conventional and digital radiographic methods were used; and at 3 mm when CBCT radiographic method was used. Conclusions: ProTaper Gold instruments are more able to maintain the original canal configuration than did ProTaper Universal instruments considering canal transportation and centering ability. CBCT proved to present more details than conventional and digital periapical radiographs at the three tested levelshttps://edj.journals.ekb.eg/article_120892_2a3c6509dee5c063568bebd3c95d5b10.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Effect of Remineralizing Agents and Resin Infiltration on Resistance to Demineralization of Artificial Enamel Lesions2763277112089310.21608/edj.2020.38417.1202ENAliaaAyadOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt0000-0003-1699-3249Dena SafwatMustafaOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.0000-0002-5228-9542Khaled AlyNourOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.0000-0001-8619-1888Journal Article20200808objective: The purpose of this study was to evaluate the effect of different remineralizing agents and resin infiltration on resistance to demineralization of artificial enamel lesions using a pH cycling model.<br /> Materials and Methods: A total of 63 anterior bovine teeth were randomly assigned to nine groups (n=7). Artificial white spot lesions were created on the labial enamel surface using the demineralizing solution for all groups except for sound enamel group. Different surface treatments were then performed; G1: Artificial saliva, G2: Clinpro White Varnish™, G3: Tooth Mousse®, G4: MI Paste Plus®, G5: Artificial saliva/ ICON®, G6: Clinpro White Varnish™/ICON®, G7: Tooth Mousse®/ ICON®, G8: MI Paste Plus®/ ICON®, G9: sound enamel. All treated artificial enamel lesions were subjected to pH cycling. The whole nine groups were then submitted to cross-sectional microhardness using Vicker’s microhardness test, each specimen was measured at five predetermined depths. ANOVA was used to analyze the data. <br /> Results: Two-Way ANOVA revealed that the type of surface treatment had a significant effect. Meanwhile, depth of measurement had no significant effect on cross-sectional microhardness of artificial enamel lesions.<br /> Conclusion: Remineralizing agents are effective in resisting demineralization in treated artificial enamel lesions and their effect is not potentiated by ICON® treatment.<br /> Clinical significance: One-month daily application of MI Paste Plus® was efficient to restore and maintain microhardness of enamel.https://edj.journals.ekb.eg/article_120893_d3cd31d839b1e7395f812fc6effd117b.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Comparing the Osteogenic and Bone Regenerative Capacities of MTA, Nano MTA, Nano Hydroxyapatite and Injectable Platelet Rich Fibrin in a Rat Bony Defect Model. An In Vivo Study2773278412089410.21608/edj.2020.39462.1210ENHajer MAbd El Hamidendodontic department, faculty of dentistry, MTI university, Cairo, EgyptDinaRadyOral biology department, Faculty of dentistry, Cairo university0000-0002-9672-6935Fatma MAbu Naeemendodontic department, faculty of dentistry, cairo university, egypt0000-0002-3115-0103Journal Article20200816Aim: Comparing bone regenerative capacity of Bulk MTA with Nano MTA, nanohydroxyapatite and injectable platelet rich fibrin (i-PRF) in a rat bony defect.Materials and methods: 100 male adult albino rats were anesthetized and a bone defect was created in the right tibiae. Rats were randomly divided into two groups according to dates of scarification 7-21 days, which were then subdivided into five subgroups ten animals in each based on the defect filled by: Nano MTA, Nano hydroxyapatite, i-PRF, BulkMTA and empty defect as control. All the right tibiae were dissected for histological analysis and histomorphometric measurements to assess bone regeneration. Bone area percentage were calculated. Results: New bone formation was observed in all sub-groups. On day 7, histological analysis revealed partially filled defects with woven bone trabeculae with variable trabecular pattern enclosing fibro-cellular tissue spaces containing blood capillaries and collagen fibers. On day 21, all experimental groups showed newly formed mature bone, including the presence of organized osteocytes and reversal lines indicating bone remodeling. Histomorphometric analysis revealed that statistically important differences between bone formations in all treated sub-groups comparing to the untreated control sub-group in both interval times. However, an increase in the bone area percentage was observed throughout experimental periods in all sub-groups without statistical difference.Conclusion: It could be concluded that Nano MTA induced the most favorable tissue response and osteopromotion properties followed by Nano HA and i-PRF compared with conventional MTA. Although the results are very encouraging, more studies on i-PRF properties are mandatory before routine clinical use.https://edj.journals.ekb.eg/article_120894_ba69a4d3b3d310eb5cfc8d261b6f1283.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Effect of Multiple Use and Sterilization of Single-Step Polishing Systems On the Surface Roughness of Resin Composite2785289512089510.21608/edj.2020.39629.1215ENMarwaAshourOperative Dentistry, Faculty of Dentistry, Ain Shams University, Cairo, EgyptMohammedAnwarOperative Dentistry, Faculty of Dentistry, Ain Shams University, Cairo, Egypt0000-0003-1125-4332Khaled AlyNourOperative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.0000-0001-8619-1888Journal Article20200817Aim: To evaluate the effect of multiple use and sterilization of Single-Step polishing tips on the surface roughness of resin composite. <br /> Materials and Methods: Eighty Nano-filled resin composite discs were prepared and cured against Mylar strip. Except for the control group, samples were wet ground against 600-grit SC paper, then divided into 3 groups (n = 25), Group D (Dimanto® - VOCO), Group G (PROGLOSS™ - KaVo Kerr), and Group O (OptraPol® - Ivoclar Vivadent). Five tips from each system were autoclaved and used for sample polishing, and this process was repeated for 5 successive Reuse/Sterilization cycles (S1 - S2 - S3 - S4 - S5). Samples were scanned using SEM, scans were analysed by Gwyddion 2.53 Image Analysis Software to attain surface roughness average Ra data, which were statistically analysed by two-way ANOVA and Tukey Post Hoc test. <br /> Results: Single-step polisher system, reuse/sterilization cycles and their interaction were found to have a statistical significant effect on the Ra of the tested groups. Control group had the least Ra. All S1 Groups and two of S2 groups, showed higher Ra without statistically significant difference between them or between them and the control. The following cycles showed a progressive increase in Ra values, with GS4, GS5, DS5, and roughened groups, showing the highest Ra without statistically significant difference between them.<br /> Conclusion: Single-step reusable polishing tips can polish resin composite back to matrix-set Ra values within the first and second reuse/sterilization cycles, afterwards the tips' polishability decreases significantly and becomes system dependent.https://edj.journals.ekb.eg/article_120895_2db7dfbc8fd6675414c19f772ca33b24.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Comparative Evaluation of the Push-out bond strength of Nano-formulations of MTA and Portland cement.2807281412089610.21608/edj.2020.40546.1243ENYousra MohamedNashaatdepartement of endodontics,faculty of dentistry,october 6 university,cairo,egypt00 00000229073989Nehal NabilRoshdyAssociate Professor of Endodontics, Faculty of Dentistry, Cairo University0000-0002-5718-5777Journal Article20200904Purpose: To investigate and compare the push-out bond strength of nano-formulation of ProRoot MTA (NPMTA) and Portland cement (NPC) with commercially available ProRootMTA (PMTA) and Portland cement (PC) aiming to develop a new root-end filling/ perforation repair material.<br /> Methods: Forty root-dentin slices prepared from freshly extracted single-rooted teeth were randomly allocated into four groups (n = 10) according to the tested cements: PMTA, PC, NPMTA and NPC. The root canal lumens were instrumented and filled with the test materials. The Universal testing machine was used for push-out bond strength evaluation. The maximum force employed at the time of dislodgment was recorded and the specimens were inspected under scanning electron microscope at x25 magnification to detect the nature of the bond failure. Kruskal–Wallis test was applied for the comparison between the groups. Mann-Whitney U test was used for pairwise comparison. <br /> Results: The mean push-out bond strength ± standard deviation values of PMTA, PC, NPMTA and NPC were 1.33 ± 0.4, 0.91 ± 0.34, 1.1 ± 0.39 and 2.22 ± 0.43 respectively. There was no statistically significant difference between the means of PMTA, PC and NPMTA (p=0.529) but the mean of NPC was significantly higher than the three groups (p=0.012). Under stereomicroscope PMTA, PC and NPMTA groups showed a majority of adhesive failure, while NPC showed a majority of mixed type failure.<br /> Conclusions: The force needed for NPMTA displacement is similar to PMTA and PC and significantly lower than the force required for NPC displacement.https://edj.journals.ekb.eg/article_120896_62c3aea4f347af66b3b84a8eaa9809bc.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948466Issue 4 - October (Conservative Dentistry and Endodontics)20201001Evaluation of the Antibacterial efficacy of newly formulated Nano Triple Antibiotic paste with Nano Anti-inflammatory drug as a root canal medicament. (A double blind randomized clinical trial)2815282412089710.21608/edj.2020.41856.1245ENYousra MohamedNashaatdepartement of endodontics,faculty of dentistry,october 6 university,cairo,egypt00 00000229073989Journal Article20200905Intracanal microorganisms' elimination is essential for root canal treatment long-term success. Proper mechanical preparation and irrigation in conjugation with intracanal medicaments can achieve this goal. The aim of this study was to evaluate the ability of Nano triple antibiotic paste with Nano diclofenac potassium anti-inflammatory drug (Nano TAPC) versus regular Triple antibiotic paste with diclofenac potassium anti-inflammatory drug (TAPC) and Calcium hydroxide (Ca (OH)2 ) used as intra-canal medication in reducing intracanal bacterial count. <br /> Methods: 60 patients with upper central incisors were chosen (all necrotic and asymptomatic) and then they were divided into three groups according to the intra-canal medication used: Ca (OH) 2, TAPC and Nano TAPC. Access cavity was performed for the targeted teeth followed by root canals preparation using rotary Protaper Next files with saline irrigation. Bacteriological samples were obtained from the root canals before (S1) and after instrumentation (S2) in the first treatment session. Subsequently, intracanal medication was placed and bacterial reduction was assessed in the second session after 3 days (S3) using colony forming unit test. <br /> Results: There was a statistically significant bacterial count reduction in all groups from S2 to S3. Nano TAPC intracanal medication achieved significant bacterial count reduction compared to that of TAPC intracanal medication and Ca (OH) 2.<br /> Conclusion: NTAPC as intracanal medication was more effective in reducing the root canal total bacterial count than that of the TAP and that of the Ca (OH) 2 in asymptomatic uniradicular necrotic teeth.https://edj.journals.ekb.eg/article_120897_8dd92c180913d159b61a662e75b8b709.pdf