Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Effect of Nanostuctured Hydroxyapetite Incorporation into a Resin Composite on Shear Bond Strength to Dentin and Interfacial Micromorphology after Storage in Different Media189196525810.21608/adjg.2017.5258ENMonaAbo El WafaDentist at ministry of health.MahaNiazyProfessor and Head of Operative Dentistry Department, Faculty of Dental Medicine for Girls.Al-Azhar University.HebaEl TayebLecturer of Dental Biomaterials Department, Faculty of Dental Medicine for Girls, Al Azhar
University.Journal Article20180208Aim: This study was designed to evaluate the effect of incorporation of hydroxyapatite nanorods into a resin composite restorative material and dental adhesive on shear bond strength to dentin and interfacial micromorphology after storage in different media. Materials and Methods: Ninety natural premolars (N=90) were selected for this study and randomly divided into three main groups (n =30) according to the material used (A), where A1: the resin composite restorative material reinforced with hydroxyapatite nanorods. A2: Adhesive resin material with incorporated hydroxyapatite nanorods, while A3: Resin composite (without nano-hydroxyapatite) as control group. Each group was subdivided into three subgroups (n=10) according the storage media (B) either Acid (B1), artificial saliva (B2) or distilled Water (B3).<br />All specimens were thermocycled then stored at room temperature and kept under each of the above mentioned media for 3 hours every day over 30 days (one month). All samples were individually and horizontally mounted on a Universal testing machine loaded to failure at cross head speed of 0.5 mm/ min then Shear bond strength was calculated. The fractured specimens were tested under scanning electron microscope to examine the dentin adhesive interface and mode of failure. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc significance difference tests. Differences were considered significant at P<0.05. Results: There was a statistically significant difference between groups (p ≤0.05). Adhesive resin with incorporated hydroxyapatite nanorods recorded statistically significant mean higher<br />shear bond strength (6.33±1.53, 11.35±0.78 and7.97±0.57) after storage in (acid, artificial saliva, distilled water), followed by resin composite incorporates nanorods Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701The Antibacterial Potentiality of Photo-activated Disinfection Versus a Chemical Disinfection Solution on Carious Dentin197203525910.21608/adjg.2017.5259ENRashaSamirA paper extracted from Master thesis entitled (The antibacterial Potentiality of Photo-activated Disinfection Versus Chemical
Disinfection on Carious Dentin).MahaNiazyProfessor and Head of Operative Dentistry Department, Faculty of Dental Medicine for Girls. Al-Azhar University.HagarBastawyAssociate Professor of Endodontics, Endodontic Department, Faculty of Dental Medicine- for Girls. Al-Azhar University.Journal Article20180208Aim: This study was conducted to assess the effect of different variables on antibacterial potential of photo-activated disinfection versus the effect of a chemical disinfection solution on carious dentin. Material and Methods: Seventy freshly extracted teeth were selected, All soft caries was removed by sterile excavator and specimens were weighted by five digit microbalance to be in range of 6-10 mg, Specimen divided into three groups: Group A1: disinfected with phot-activated disinfection (PAD) and divided into four subgroups(no=10 ) according to power& application time, Subgroup1(P1T1<br />: delivery power was 100mW, application time was 120 sec) Subgroup2 (P1T2: delivery power was 50mW application time was 30 sec) Subgroup3 (P2T1: delivery power was 100mW application time was 120 sec) Subgroup4 (P2T2: delivery power was 50mW,application time was 30 sec).Group A2: disinfected with chemical disinfectant (chlorohexidine scrub 2%).Group A3: disinfected with laser beam only & divided into two subgroups P1T1,P2T2. The specimens were plated &duplicated on blood agar then incubated in anaerobic gas pack jar at 37C for 7 days. Results: A statistically significant<br />difference was found among PAD, chlorohexidine, and laser groups in the percent decrease in the total bacterial count (P≤ 0.05). The greatest mean percent decrease was recorded in the PAD P1T1 followed by the cholorohexidine group, then the laser P1T1. Conclusion: The combination of toluidine blue O (TBO) and diode laser could be effective in reducing the bacterial viability. Chlorohexidine as chemical disinfectant was equally effective to photo-activated disinfectant with high delivery power and long contact time in reducing the total bacterial count. Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Effect of Incorporation of Hydroxyapatite Nanorods on the Rheological Properties, Micro-shear Bond Strength and Degree of Conversion of Two Dental Adhesives205213526010.21608/adjg.2017.5260ENNesreenMohammedPaper extracted from thesis titled Effect of Incorporation of Hydroxyapatite Nanorods on the Rheological Properties, Microshear
Bond Strength and Degree of Conversion of Two Dental Adhesives.InasMotaweaDemonstrator of Dental Biomaterials. Faculty of Dental Medicine, Al-Azhar University (for Girls), Egypt.HebaEltayebAssistant Professor and Head of Dental Biomaterials,-Faculty of Dentistry for girls. Al azhar UniversityJournal Article20180208Purpose: The purpose of this study was to evaluate the effect of incorporation of<br />different concentrations of hydroxyapatite nanorods into two adhesives of two commercial<br />adhesive systems in order to evaluate the effect on rheological properties, microshear<br />bond strength and degree of conversion. Materials and Methods: One hundred<br />twenty specimens were used in the present study. The specimens were divided into two<br />main groups (n=60) according to the type of commercial adhesive used AdheSE Bond<br />(I) and Tetric-N Bond Universal (II). Then each group was subdivided into 4 subgroups<br />(n=15) according to the concentration of incorporated HAp nanorods 0( control), 0.2,<br />2, 10wt%HAp nanorods (A, B, C and D, respectively). Each subgroup was further<br />divided into 3 divisions according to the type of test performed (n=5). For rheological<br />properties measurements, a rheometer was used to measure the viscosity and the<br />viscoelastic behavior of the adhesives. For microshear bond strength testing (μSBS),<br />the specimens were tested by using a universal testing machine. The type of failure<br />was determined by using scanning electron microscope. The degree of conversion was<br />measured using Fourier Transform Infrared (FTIR) spectroscopy. The data were analyzed<br />using one-way analysis of variance (ANOVA) and Tukey’s post hoc significance<br />difference tests. Differences were considered significant at p≤0.05. Two ways analysis<br />of variance ANOVA test was used to study the statistical significance of the interaction<br />between variables (material and HAp nanorods concentrations). Results: The viscosity<br />of experimental adhesives increased gradually with increasing the concentrations of<br />HAp nanorods. In μSBS test, the AdheSE containing 0.2 and 2wt.% HAp nanorods produced<br />significantly the highest values. Regarding degree of conversion (DC), Tetric-N<br />Bond containing 10wt.% HAp nanorods produced significantly the highest value of<br />DC. Conclusion: Incorporation of HAp nanorods with low concentration (0.2wt %) in<br />AdheSE Bond had a positive impact on the bond strength. However, HAp nanorods as<br />fillers were not suitable to be incorporated in Tetric-N Bond.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Surgical Templates for Dental Implant Positioning;Current Knowledge and Clinical Perspectives215222526110.21608/adjg.2017.5261ENMohammedKolaDepartments of Prosthodontics and 1Preventive Dental Sciences, College of Dentistry, Salman bin Abdulaziz University,
Al-Kharj, KSA (Saudi Arabia),AltafShahDepartments of Prosthodontics and 1Preventive Dental Sciences, College of Dentistry, Salman bin Abdulaziz University,
Al-Kharj, KSA (Saudi Arabia),HeshamKhalilDepartment of Maxillofacial Surgery, College of Dentistry, King Saud University, Al- Riyadh, KSA (Saudi Arabia),NehadHarbyDepartment of Removable Prosthodontics, Al-Azhar university, College of Dentistry, Cairo branch for boys (EgyptAhmedRabahDepartment of Prosthodontics, Alfarabi College of Dentistry, Al-Riyadh, KSA (Saudi Arabia),SehamSabraDepartment of Prosthodontics, Alfarabi College of Dentistry, Al-Riyadh, KSA (Saudi Arabia),DeeptiRaghavDepartment of Prosthodontics, Shree Bankey Bihari Dental College and Research Centre, Ghaziabad, IndiaJournal Article20180208Dental implants have been used in a variety of different forms for many years.<br />Since the mid‑20th century, there has been an increase in interest in the implant process for the replacement of missing teeth. Branemark was one of the initial pioneers who applied scientifically based research techniques to develop an endosseous implant that forms an immobile connection with bone. The need for a dental implant to completely<br />address multiple physical and biological factors imposes tremendous constraints on the surgical and handling protocol. Metallic dental implants have been successfully used for decades, but they have serious shortcomings related to their bony union and the fact that their mechanical properties do not match those of bone. However, anatomic<br />limitation and restorative demands encourage the surgeon to gain precision in planning and surgical positioning of dental implants. Ideal placement ofthe implant facilitates the establishment of favorable forces on the implants and the prosthetic component as well as ensures an aesthetic outcome. Therefore, it is advisable to establish a logical<br />continuity between the planned restoration and the surgical phases, it is essential to use a transfer device that for sure increases the predictability of success. The surgical guide template is fabricated by a dental technician after the presurgical restorative appointments that primarily include determination of occlusal scheme and implant angulations.<br />Here, authors genuinely attempted to review the evolution and clinical applicability of surgical templates used in the placement of dental implants.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Effect of Natural Cross-Linkers on Shear Bond Strength to Dentin After Storage in Different Media223229526210.21608/adjg.2017.5262ENKamalElmobsherDentist at Ministry of Health, Cairo, Egypt.MahaNiazyProfessor and Head of Operative Dentistry Department, Faculty of Dental Medicine for girlsAl Azhar University.InasMotaweaAssistant Professor and Head of Dental Biomaterials Department, Faculty of Dental Medicine for girls Al Azhar UniversityMayadaSultanLecture of Operative Dentistry, Faculty of Dental Medicine, Assuit UniversityJournal Article20180208Objectives: This study was designed to evaluate the effect of natural cross linkers (Propolis and Hesperidin) on shear bond strength (SBS) to dentin after storage in different media. Materials and Methods: Ninety extracted molars were used and divided into three main groups according to dentin surface treatment (n=30) where, A1: treated with Propolis, A2: treated with Hesperidin and A3: receive no treatment to serve as a control group. Each group was further subdivided into 3 subgroups (n=10) according to the storage media either stored in Acids (B1) or stored in Artificial saliva (B2) or<br />stored in distilled Water (B3). The shear bond strength (SBS) was determined using a universal testing machine. Results: The dentin specimens treated with Propolis showed significantly highest SBS. Conclusion: Both Propolis and Hesperidin cross linking agents are considered beneficial in improving bonding to dentin, though Propolis was much more effective. Storage media has deteriorating effect on resin-dentin shear bond strength.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Remineralization Potential of Grape Seed Versus Amorphous Calciumphosphate-Nanoparticles on Sound and Caries Affected Dentin231237526310.21608/adjg.2017.5263ENShaimaaAlrafeeAssistant Lecturer of Operative Dentistry, Faculty of Dental Medicine for Girl’s, AL-Azhar Universit.MahaNiazyProfessor of Operative Dentistry, Faculty of Dental Medicine for Girl’s, AL-Azhar UniversityMohamedEl-yassakyProfessor of Operative Dentistry, and Dean of Faculty of Dental Medicine Sinai UniversityJournal Article20180208Objectives: This study was conducted to evaluate the remineralization potential of grape seed extract versus amorphous calcium phosphate nanoparticles on sound and caries affected dentin.<br />Materials and methods: Grape seed extract powder (GSE) was added to Clearfil SE primer with a concentration of 0.5 wt% to obtain primer + GSE while nanoparticles of amorphous calcium phosphate (NACP) were incorporated into the Clearfil SE adhesive at mass fractions of 20% to obtain adhesive + NACP. Class V cavity preparation was prepared on the anterior teeth of fifteen white rabbits. Rabbits were divided into three main groups according to the type of material used Group A (primer + GSE) Group B (adhesive + NACP), Group C (sodium fluoride NAF as positive control).<br />Each group was subdivided into two subgroups according to type of substrate in which right side was act as sound dentin while left side was act as artificial caries affected dentin. After 10 days the dentin was examined using EDX analysis to determine amount of calcium and phosphorus in each sample. Results: There was no statistically significant difference between mineral content of different materials compared with positive control group for both sound and caries affected dentin. Conclusion: - Grape seed extract and nano amorphous calcium phosphateAl-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Comparison of Root Canal Transportation and Centering Ability Prepared with Two Single Files Rotary Systems using Cone Beam Computed Tomography Scanning (Ex vivo study)239247526410.21608/adjg.2017.5264ENAsmaaEl-HadyDemonstrator, Endodontic Department, Faculty of Dental Medicine for Girls, Al-Azhar UniversityMervatFawzyProfessor of Endodontics, Endodontic Department, Faculty of Dental Medicine for Girls, AL-Azhar UniversityHagerEl NabyAssociate Professor of Endodontics, Endodontic Department, Faculty of Dental Medicine for Girls, AL-Azhar UniversityJournal Article20180208Purpose: The purpose of this study was to compare and evaluate canal transportation and centering ability of 2 single nickel-titanium rotary instruments, one manufactured by twisting (Twisted File) and the other by grinding (OneShape) using Cone- Beam Computed Tomography scanning (CBCTs).Materials and Methods: Forty mesiobuccal<br />canals of mandibular molars with an angle of curvature ranging from 25° to 35° and radius <15 mm were divided according to the instrument used in canal preparation into 2 groups (20 samples each): Group I: instrumented with Twisted File (TF) and Group II: instrumented with OneShape (OS). Each group was subdivided into subgroups (SG) A and B according to the technique of root canal preparation (single or modified). Canals were scanned using an i-CAT CBCT scanner before and after preparation to evaluate the change in the angle and radius of root canal curvature as well as<br />the amount of canal transportation and centering ratio at 1, 3, and 8 mm from the apex.<br />The significance level was set at P≤0.05. Results: At 1mm level, TF instruments used with modified technique produced a statistically significant less canal transportation compared to OS instruments (P ≤ 0.05). While at 8mm level, OS instruments used with single file technique produced a statistically significant less canal transportation and<br />more centered canal preparation compared to TF instruments (P ≤ 0.05). Conclusions: TF and OS single files systems used in continuous clockwise rotation are capable of preparing root canals with moderate and sever curvature, with minimal apical transportation. Cervical pre-flaring of the canal has an impact on canal shaping where it enhances the performance of Twisted File instruments. Twisted files with 0.08 tapers could be used for apical preparation without creating severe aberrations. Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701The Effects of Different Extract of LepidiumSativum on Induced Periodontitis in Dexamethasone Immunosuppressed Rats249253526510.21608/adjg.2017.5265ENHodaElSayed(B.D.S 2006) faculty of oral and dental medicine M.U.S.T university in Ministry of HealthNaglaaElkilaniProfessor and Head of Oral Medicine, Periodontology, Radiology, and DiagnosisFaculty of Dental Medicine for Girls,
Al-Azhar University-Girls Branch.MonaFaridProfessor and Head of the Oral and Dental Biology Department and Former Dean of Faculty of Dental Medicine for Girls,
Al-Azhar University-Girls Branch.Journal Article20180208Objective : The present study was designated to evaluate the effect of<br />lepidiumsativum extract on structure and density of bone in immunosuppressed<br />rats with induced chronic periodontitis histologically, hostometrically<br />as well as radiodensitometric analysis by digital radiography assessment<br />(vista scan). Materials and methods: A total 36 wistar male rats<br />were divided randomly into 6 groups (6 rats/group). The study sample<br />was divided into:I - Control group: in this group rats were fed with<br />a normal diet.II-Control group with ligature: without receiving dexamethasone<br />injection, a sub marginal cotton ligature.III-Vehicle group:<br />in this group rats were received a weekly dose of dexamethasone for 6<br />weeks and received sub marginal cotton ligature (no treatment). SRP<br />1 (methanol group): rats were received methanol extract for 30 days,<br />these were subjected to scaling and root planning (SRP). SRP 2 (watery<br />group): in this group rats were subjected to (SRP). SRP 3 group submitted<br />only to SRP and received no further treatment.Results: methanol<br />extract has better anabolic effect on bone and regenerative on periodontal<br />ligaments than watery extract.This could be explained by the fact<br />that lepidiumsativum possesses anti-inflammatory, immunomodulatory<br />properties and antioxidative activity that may resolve periodontal inflammation.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701The Effect of Various Elements Substitution on Properties of Bioactive Glass Scaffolds for Bone Tissue Engineering.255270526610.21608/adjg.2017.5266ENFatmaAbdul-RahmanAssistant Lecturer of Dental Biomaterials, Faculty of Dental Medicine for Girls, Al-Azhar University.InasMotaweaAssistant Professor and Head of Dental Biomaterials Department, Faculty of Dental Medicine for Girls, Al- Azhar UniversityEatimadShoreibahProfessor of Oral Medicine & Periodontology, Faculty of Dental Medicine for Girls, Al-Azhar University.Journal Article20180208Aim: The aim of the present study was to synthesize and characterize sol-gel derived bioactive glass scaffold and evaluate the effect of substitution of Zirconium (Zr), Strontium (Sr), and Zinc (Zn) on the their bioactivity, biodegradability and mechanical properties. Materials and Methods: Bioactive glass scaffold samples with compositions 80% SiO2-15%CaO and 5% P2O5 and 75 % SiO2-15% CaO - 5% P2O5 and 5% MO (in mol%) (M=Sr, Zr or Zn) were synthesized using the sol–gel combined with foam replication method. The scaffolds were characterized by DTA, XRD, SEM and FTIR spectroscopy. Their mechanical properties were measured and their bioactivity/ biodegradability were evaluated in simulating body fluid (SBF). Results: All the scaffolds showed no distinct difference in phase composition, macroporous structure, percent<br />porosity or pore size distribution. Conclusions: Sr, Zr and Zn substitution decreased the mechanical properties of the bioglass system. Sr and Zr ions enhanced the formation of nano-structured hydroxycarbonate apatite (HCA) layer, whereas Zn ions diminished the bioactivity. Moreover, Sr ions increased the biodegradability of the bioglass system.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Evaluation of Lactate Dehydrogenase Activity During Orthodontic Tooth Movement271277526710.21608/adjg.2017.5267ENAmanyIbrahimDemonstrator, Department of Orthodontics, Faculty of Dental Medicine, Al-Azhar University for GirlsSamirIbrahimProfessor and Head of Orthodontic Department, Faculty of Dental Medicine, Al-Azhar University for Girls.TarekMareiAssistant Professor, Department of Orthodontics, Faculty of Dental Medicine, Al-Azhar University for GirlsHalaHazzaaAssistant Professor, Department of Oral medicine, Periodontology, Diagnosis and Radiology, Faculty of Dental Medicine,
Al-Azhar University for Girls.Journal Article20180208Objective: This study was to evaluate the activity of Lactate Dehydrogenase enzyme<br />in different tooth malpositions in gingival crevicular fluid (GCF). Patients, materials<br />and methods: A sample of 18 patients with an age range from 13 to 19years, requiring<br />orthodontic treatment. The study groups were designed into two groups. Group<br />I: well aligned teeth (control group). Group II: malposed teeth. Group II was subsequently<br />divided into 3 sub-groups; Rotation, Spacing and Vertical malposition. Samples<br />were collected for assessment of lactate dehydrogenase level in GCF at baseline, one<br />week, two and four weeks after treatment. Lactate dehydrogenase was measured in<br />GCF using Enzyme Linked Immunosorbent Assay (ELISA) technique. Results: In both<br />groups (group I and group II subgroups) the gingival crevicular fluid lactate dehydrogenase<br />enzyme had a steady increase during orthodontic tooth movement with a statistically<br />significant increase at one week and two weeks compared with the base line<br />(P≤0.05). No statistical significant difference was found between each two subgroups<br />of group II (P≤ 0.05). Conclusions: The level of lactate dehydrogenase enzyme in gingival<br />crevicular fluid could be used as a biomarker for periodontal metabolism related<br />to orthodontic tooth movement. The level of lactate dehydrogenase enzyme (LDH) did<br />not show significant difference among different tooth malpositions during correction<br />by orthodontic treatment.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Evaluation of Smear Layer Removal and Calcium Ions Concentration in Intraradicular Dentin Treated with Apple Vinegar (SEM Study)279287526810.21608/adjg.2017.5268ENHebatullahSafwatDemonstrator, Endodontic Department, Faculty of Dental Medicine for Girls, Al-Azhar UniversityMohsenNour El DeenProfessor of Endodontics, Endodontic Department, Faculty of Dental Medicine for Girls, Al-Azhar UniversityHagarBastawyAssociate Professor of Endodontics, Endodontic Department, Faculty of Dental Medicine for Girls, Al-Azhar University.Journal Article20180208Aim: This study was conducted to evaluate the smear layer removal efficiency of apple vinegar and EDTA when used as final rinse using scanning electron microscope (SEM) and to quantify the calcium content of intraradicular dentin after being treated with apple vinegar or EDTA using energy dispersive X-ray microanalyzer (EDX).<br />Materials and methods: Fifty palatal roots of extracted human permanent maxillary molars with completely formed were selected and prepared with Universal Protaper rotary files. After using each file, canals were irrigated with 2 ml of 2.6% NaOCl for 1 minute. The samples were divided into 4 groups according to the final rinse used and the application time: (10 samples each), Group I: 17% EDTA for 1 minute.Group II: Apple vinegar for 1 minute. Group III: 17% EDTA for 3 minutes.Group IV: Apple vinegar for 3 minutes.Group V: control group is divided into: GV(A), Five samples<br />where the root canals were irrigated with sterile saline and GV(B), Five samples were used to assess the calcium content with energy dispersive X-ray microanalyzer (EDX), where the root canals will not receive any treatment. Results: Regarding smear layer removal, at coronal and middle thirds there was no statistically significant difference in the mean scores of smear layer produced by the tested groups.At the apical third the lowest mean smear layer score was recorded in specimens treated with apple vinegar for 1 minute (Group II) with a statistical significant difference from specimens treated with 17% EDTA for 1 minute (Group I). Regarding the calcium content, the highest mean value was recorded in specimens treated with apple vinegar for 1 minute (Group II) with statistically significant difference from that recorded in specimens treated with 17% EDTA for 1 minute (Group I) and specimens treated with apple vinegar for 3 minutes (Group IV). Conclusion: Apple vinegar was capable of adequately removing smear layer from intraradicular dentin when used as final rinse.Apple vinegar was more effective in removing smear layer from intraradicular dentin at the apical third<br />compared to 17% EDTA. Apple vinegar was more effective when used for one minute as final rinse in the removal of smear layer without affecting the calcium content of intraradicular dentin compared to 17% EDTA.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701The Effect of Zn-doped Adhesive alone or Combined with Calcium Phosphate Nanoparticles on the Integrity of the Bonded Resin- Dentin Interface289296526910.21608/adjg.2017.5269ENHayamTawficDemonstrator of Operative Dentistry, Faculty of Dental Medicine for Girls, AL-Azhar University.MahaNiazyProfessor and Head of Operative Department, Faculty of Dental Medicine for girls, Al-Azhar UniversityDoaaEl-SharkawyLecturer of Operative Dentistry, Faculty of Dental Medicine for Girls, Al Azhar University.Journal Article20180208Objectives: This study was designed to evaluate the ability of two experimental Zn-doped-adhesive (zinc chloride and zinc oxide nanoparticles) alone or with calcium phosphate nanoparticles to induce therapeutic effect on the bonded resin-dentin interface using two adhesive systems(total etch and self-etch). Material and Method: eighty human premolar dentin surfaces were assigned into four main groups (n=20) according to zinc doping (A1), the universal single bond doped with zinc chloride (ZnCl2), (A2) the universal single bond doped with zinc oxide nanoparticles (NZnO), (A3) the universal single bond doped with zinc chloride +calcium phosphate nanoparticles (NACP) (A4) the universal single bond (as a control). Each group was further subdivided into tow subgroups according to the adhesive technique either etch and rinse (B1) or self-etch (B2). Prepared samples were stored in distilled water for 24h, and then submitted to microtensile bond strength testing. Two samples from each group were prepared for observation of nanoleakage by the scanning electron<br />microscope (SEM). Data was collected and statistically analyzed. Results: In the total etch adhesive technique, the highest mean value was recorded in group(A4 B1), followed by (A2B1) and (A3B1) groups; with the least mean value for the (A1B1) group. Using the self-etch adhesive technique, the highest mean value was recorded in the (A2B2) and (A4B2) groups followed by (A3B2) group with the least mean value for (A1B2) group. Comparing the adhesive techniques, there was statistically significant difference with higher mean value for the etch and rinse adhesive technique except with NZnO group. Conclusion: Addition of zinc to the universal single bond significantly affected the microtensile bond strength except with ZnO nanoparticles group in the self-etch adhesive technique. Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Comparison Between Two Types of Feeding Obturators in Cleft Palate Babies297301527010.21608/adjg.2017.5270ENEhabAtitoLecturer, Department of Removable Prosthodontics, Faculty of Dentistry, Al-Azhar universityJournal Article20180208Abstract: This article compares clinical function rehabilitation of two different types of feeding device 1. Ready made obturator & 2. Custom obturator. Material and methods: 10 neonates baby reported to the Department of Pediatrics<br />department alhammadi hospital KSA with congenital cleft palate will be selected for study. Feeding device will be constructed for each baby & readymade feeding bottle will be getting. Comparison between both is done by fixing volume & measuring<br />feeding timeAl-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Effects of Different Tooth-Conditioning Agents on Bond Strength of A Resin-Modified Glass-Ionomer Cement to Enamel303309527110.21608/adjg.2017.5271ENAhmedAlammaryLecturer of Operative Dentistry Depatement, Faculty of Dental Medicine, Al-Azhar University (Asuit Branch)Journal Article20180208The purpose of this study was directed to evaluate the effects of different tooth<br />conditioning agents on shear bond strength of resin-modified glass– ionomer cement<br />(Fuji III LC) to enamel as well as on dissolution of calcium ions from the enamel surfaces.<br />Methods. The enamel surfaces of lower incisors were treated with 10 and 20%<br />polyacrylic acid, 12% citric acid and 35% phosphoric acid for 20s. Fuji III LC was<br />applied to the etched enamel surfaces, and the shear bond strength of each specimen<br />was measured using an Instron Universal Testing Instrument. The amounts of calcium<br />ions dissolved from the treated enamel surfaces were also measured using a polarized<br />Zeeman atomic absorptiometer. Results. In specimens pretreated with distilled water,<br />10% polyacrylic acid, 20% polyacrylic acid, 12% citric acid and 35% phosphoric acid,<br />the mean values of shear bond strength were 5.5, 12.5, 15.2, 15.2 and 15.1 MPa, respectively,<br />and the amounts of Ca2 dissolved from the enamel surfaces were 5.6, 41.4, 88.5,<br />131.6 and 588.3 mg/cm2,respectively. Conclusions. The adhesion of a resin-modified<br />glass–ionomer cement to enamel was significantly improved by the use of tooth-conditioning<br />agents. Especially, treatments of an enamel surface with 20% polyacrylic acid<br />results in good shear both strength and relatively small degree of enamel erosion.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Effect of Denture Cleansers on Flexural Strength, Color Stability and Surface Roughness of Flexible and Microwave cured Acrylic Resin311323527210.21608/adjg.2017.5272ENInasMotaweaAssistant Professor of Dental Materials, Faculty of Dental Medicine (Girls), Al-Azhar University, EgyptHalaGamal El DeenAssistant Professor of Removable Prosthodontics Faculty of Dental Medicine (Girls), Al-Azhar University, EgyptHebaEltayebLecturer of Dental Materials, Faculty of Dental Medicine (Girls), Al-Azhar University, EgyptJournal Article20180208Purpose: The aim of the present study was to evaluate the effect of denture cleansers on the flexural strength, color stability and surface roughness of flexible denture base resin as well as micro wave cured denture base resin. Materials and Methods: A total of 144 specimens were fabricated. Seventy two specimens were constructed from each type of resin and were further subdivided into 3 subgroups (n=24) according to their immersion in different types of denture cleansers. Subgroup1: distilled water (control), subgroup 2: 5% sodium hypochlorite and subgroup 3: effervescent alkaline<br />tablets (Corega tabs). The color changes and surface roughness were measured for each subgroup before (baseline) and after immersion in the solutions. The flexural strength was also measured after their immersion. Results: For both groups (flexible denture base resin and microwave cured denture resin groups); control subgroup showed the statistically<br />significant higher flexural strength values, while subgroup treated with Corega Tabs recorded the statistically significant lowest flexural strength values. Regarding the color changes, for both groups (flexible denture base resin and microwave cured denture resin groups); subgroup treated with Corega Tabs recorded statistically significant highest (ΔE) mean values, followed by subgroup treated with sodium hypochlorite then the control subgroup. However, there was a statistically non-significant difference of the Ra values between the tested groups and subgroups. Conclusions: Within the<br />limitations of the study, it was concluded that the tested denture cleansers had no effect on the surface roughness of flexible and microwave cured acrylic resin, however, significantly influenced their flexural strength. Moreover, denture base polymers are susceptible to color change on immersion in Corega Tabs.Al-Azhar University, Faculty of Dental Medicine, Girls BranchAl-Azhar Dental Journal for Girls2537-03084320170701Effect of Balanced Occlusion Verses Lineal occlusion on Maximum Biting Force and Electromyographic Activity325329527310.21608/adjg.2017.5273ENHalaGamal EldeenAssistant Professor of Removable Prosthodontics Faculty of Dental Medicine (Girls), Al-Azhar University, EgyptJournal Article20180208Ten completely edentulous male patients participated in this study. All patients received two implants in the canion region. For each patient two complete dentures were constructed. The artificial teeth of one denture was arranged according to full bilateral balanced occlusion, while in the other denture the teeth were arranged according to lineal occlusion concept. The maximum biting force and electromyographic activity were measured after one month from insertion of each denture. The result of the study found that there are no statistical significant differences between the two occlusal concepts.<br />The study concluded that the lineal occlusion did not affect the value of the maximum biting force and electromyographic activity when compared to the bilateral balanced occlusion.