Maged Saleh Alkhuzae, Lamiaa Sayed Kheiralla And Gihan AbdElhady Elnaggar,

ABSTRACT


Purpose: The Purpose Of This Study Was To Compare Hybrid Ceramic Veneers And Pressable Laminate Veneers Regarding Resistance To Fracture Of Both Materials Following Thermal Cycling.

Materials and Methods: A Total Of Twenty Four Of Comparable Human Central Maxillary Incisors Were Extracted For Periodontal Reason, Were Selected For The Present Study. The Samples Were Divided Into Two Main Groups According To The Material Used For Construction Of Laminate Veneers Restoration. The Vita Enamic Hybrid Ceramic Laminate Veneers Were Fabricated From Vita Enamic Blocks Milled By A Cerec In-Lab CAD/CAM Machine. While The IPS E.max Press Ceramic Laminate Veneers Were Fabricated From Machinable CAD/CAM Wax Discs (CAD Wax) To Have Equal And Standardized Thickness Of All Samples. All Samples Were Subjected To Thermocycling Between 5C� To 55C� In Water Bath For A Total Of 1750 Cycle With 10 Seconds Dwell Time At Each Bath Using Thermocycling Device. The Fracture Load Strength Test Was Performed Using The Universal Testing Machine. Result: It Was Found That IPS Emax Ceramic Press Group Recorded Higher Mean Value Of Fracture Resistance (430.4 � 47.7 N) When Compared Vita Enamic Hybrid Ceramic Group (289.02 � 87.24N) With No Statistically Significant Difference (P>0.05) Between Two Groups As Indicated By Student T-test Conclusion: IPS Emax Ceramic Press Veneer Materials Recorded Higher Mean Value Of Fracture Resistance When Compared Vita Enamic Hybrid Ceramic Veneer Materials With No Statistically Significant Difference

Wasfi A. Qaid , Mohamed R. Farid And Mohamed F. Haridy,

ABSTRACT
Statement Of Problem: All-ceramic Onlay Has Become More Popular In Dental Clinics Due To Their Lifelike Appearance, Durability, And Biocompatibility. However, Their Drawbacks Include Fracture Susceptibility And Inadequate Marginal Fit And Fracture Susceptibility.

Purpose: The Aim Of This Study Was To Compare Hybrid Ceramic And Pressable Ceramic Onlay Restoration Regarding Vertical Marginal Discrepancy Of Both Materials Following Thermal Cycling.

Materials and Methods: A Total Of Twenty Four Extracted Intact Molar Were Fixed In Epoxy Resin. Standardized Onlay Preparation Was Performed On All Specimens By Computer Numerically Controlled Milling Machine (CNC). The Samples Were Divided Into Two Main Groups (I-Vita Enamic Hybrid Ceramic Materials & II- IPS E.max Press Ceramic Materials) According To The Ceramic Material Used For Construction Of Onlay Restoration. All Onlay Ceramic Restorations Were Fabricated And Treated And Cemented On The Prepared Teeth. All Samples Were Subjected To Thermocycling Between 5C� To 55C� In Water Bath For A Total Of 2000 Cycle With 10 Seconds Dwell Time At Each Bath Using Thermocycling Device. The Marginal Gap Distance Between The Outer Margins Of Each Onlay And The Shoulder Finish Line Of Prepared Tooth In A Vertical Direction Was Measured. The Data From The Two Groups Were Collected, Tabulated And Statistically Analyzed. The Results Were Analyzed Statistically Using Student?s ?t? Test. The Level Of Significance Was Taken At P < 0.05. Result: It Was Found That Vita Enamic Hybrid Ceramic Onlay Group Recorded Statistically Significant (P<0.016), (P<0.001), (P<0.0001), And (P<0.0001) Higher Vertical Marginal Gap Mean Value When Compared To IPS Emax Ceramic Onlay Group.

Conclusions: The Material Used For Fabrication Of The Indirect Ceramic Restorations Has A Crucial Effect On Its Performance Regarding The Marginal Gap. Differences In Marginal Fit Were Recorded For Ceramic Partial Restorations Fabricated By Different Manufacturing Techniques E.g. IPS E.max Press Ceramic Was Better In The Marginal Sealing Values Than The Vita Enamic Ceramic Onlay.

Mostafa Abd El Hamid Abd El Ghany, Ahmed Gamal Ahmed Hassan And Emad Mohamed Tolba,

ABSTRACT


Introduction: Removable Prostheses Are Provided To Enable Oral Masticatory Function And To Improve The Quality Of Life For Edentulous Patients. The Main Objective In Denture Fabrication Is The Preservation Of The Remaining Oral Structures. In This Regards Efforts Should Be Made To Decrease Stresses To Residual Alveolar Ridges. Aim Of The Study: To Evaluate And Compare The Effect Of Ball And Socket And Bar Attachments On Supporting Structures In Implant Supported Overdenture Using Three Dimensional Finite Element Analysis (3D FEA).

Materials and Methods: A Three Dimensional (3D) Digital Model Simulating An Edentulous Mandible And A Mandibular Over Denture Was Constructed. The Mandibular Over Denture Was Supported By Two Implants Placed In The Canine Region Bilaterally With Ball And Socket Attachment In One Model (model I) And Bar Attachment In The Other Model (model II). The Digital Model Was Created From Scanning Of Edentulous Natural Mandible And A Suitable Set Of Anatomical Artificial Teeth By Identica Hybrid 3D Dental Scanner. The Stimulated Denture As Well As The Mucosa Was Drawn By Solid Work Software 2017.

Results: The Stresses Generated In Case Of Using Ball And Socket Attachment Were In General Less Than Those Generated In Case Of Bar Attachment. The Exceptions Were In Case Of Spongy Bone And Mucosa. Conclusion: Ball And Socket Attachment System Transmitted Lesser Amount Of Stresses To The Implants As Compared To The Bar-Clip Attachment System.

Ahmed M. Abou-Aly, Fatma A. El-Hendawy And Manal A. El-Ebiary,

ABSTRACT

Objectives: The Aim Of This Study Was To Evaluate Microleakage Of Bioactive Composite When Used In Class I Primary Molars.

Materials and Methods: Thirty Sound, Non-restored Freshly Extracted Human Primary Molars Were Included In The Study, Teeth Were Collected From The Pediatric Dentistry Department, Faculty Of Dentistry, Tanta University And From Private Clinics. A Standard Class I Cavity Was Prepared On The Occlusal Surface Of Each Tooth. The Scotchbond Universal Adhesive System Was Applied To All Prepared Teeth Then Cured With LED Curing Unit. Then Teeth Were Randomly Divided Into Two Groups (n = 15). Group A: ?Activa?; Group B: ?Filtek Z250 XT?. Then All The Samples Were Subjected To Thermocycling For 1000 Cycles At 50C And 550C And Covered With Nail Varnish. Later, Samples Were Immersed In 2% Methylene Blue Dye For 24 H. Teeth Were Sectioned Longitudinally In A Mesiodistal Direction And Studied Under A Stereomicroscope For Dye Penetration. Data Obtained Were Analyzed Using Independent T-test.

Results: The Mean Microleakage Value Of ?Activa? Was Lower Than Mean Microleakage Value Of ?Filtek Z250 XT? With No Significant Difference Conclusion: There Was No Statistically Significant Difference In Mean Microleakage Values Of Bioactive Composite ?Activa? And Nanohybrid Composite ?Filtek Z250 XT?.

Angham Ibrahim El-Gendy, Mohamed Farag Ayad And Amany Mohammed Korsel,

ABSTRACT


Purpose: To Evaluate The Fatigue Resistance Of High Translucent Zirconia And Hybrid Ceramic Posterior Occlusal Veneer.

Materials and Methods: Forty Freshly Extracted Human Molars Were Received Standardized Tooth Preparations Replicating A Worn Occlusal Table By Using A Diamond Saw By Removing All Coronal Tooth Structure 4 Mm Occlusal To The CEJs Leaving Exposed Dentin Centrally And Peripheral Enamel. Intra-enamel Indexing Notches Were Created Proximally. The Specimens Were Divided Into 2 Groups Based On Restorative Materials Each Group Included Twenty Teeth For Each Group. Group I: High Translucent Zirconia (Bruxzir Anterior), Group II: Polymer Infiltrated Ceramic (Vita Enamic). The Restoration Thickness Was 1 Mm At The Fossa And 1.5 Mm At The Cusp Tip. The Specimens Were Cemented By Self-etch Resin Cement (Panavia F2.0). Half Of The Specimens Of Each Group(10 Specimen) Were Subjected To Fracture Resistance Test While The Other Half Subjected To Thermocycling (15000 Cycles, 5-55 C, 30 Sec Dwell Time) And Chewing Simulator With A Load 150 N Which Was Applied For 600,000 Cycles To Simulate 2.5 Years With A Loading Frequency 6 HZ. Specimens That Survived Cyclic Loading Were Loaded Until Failure, To Calculate The Residual Fracture Strength After Fatigue. Mean Values For Each Group Were Calculated, And Differences Between The Groups Were Tested For Statistical Significance By Use Of 2-way Analysis Of Variance (ANOVA).

Results: Both Material And Fatigue Test Had Significant Effect On The Fracture Resistance Where (P-value<0.001). According To The Material Type; P-value Was High Significante As The Bruxzir Anterior Had A Higher Mean Of Fracture Resistance Than The Vita Enamic. According To The Fatigue Test For Bruxzir Anterior ,the P-value Was High Significant As The Mean Of The Initial Fracture Resistance Was 2240.60� 139.90 Which Is Higher Than The Mean Of The Specimen After Subjected To Fatigue Test 2019.88 � 132.29. For The Vita Enamic The P-value Was High Significant That The Mean Of The Initial Fracture Resistance Was 744.58 �99.23 Which Is Higher Than The Mean Of The Specimen After Subjected To Fatigue Test 596.45 �81.13. The Coefficient Of Variation Showed That For Bruxzir Anterior The Specimens Lost About 22 % Of Their Initial Fracture Resistance After They Were Subjected To Fatigue While The Vita Enamic Specimens Lost About 19 % Of Their Initial Fracture Resistance. Conclusion: Within Limitations Of This Study, High Translucent Zirconia Posterior Occlusal Veneers Can Resist Cyclic Loading That Represent Several Years In Patient Mouth, The Percentage Of The Loss In The Initial Fracture Resistance Of Both Material After Subjected To Chewing Simulator Was Approximated To Each Other, However More Researches Are Required To Prove The Use Of Polymer Infiltrated Ceramic As Posterior Occlusal Veneers.

Diaa Eldin Abulhassan Mosref, Magdy Mohamed Ali And Mohamed Medhat Kataia,

ABSTRACT


Introduction: The Aim Of The Study Was To Compare Between WaveOne Gold And WaveOne Reciprocating Files Concerning Surface Topography Analysis Using (SEM) And Changes In Canal Curvature Using (CBCT). Methods: A Number Of Extracted Mandibular Molars Were Collected, Their Mesial Roots Were Cut Using Diamond Disk. The Preoperative Angle Of Curvature Was Measured According To Schneider Technique On CBCT Images Scans. Seventy Two (72) Roots With Curvature Angles Ranges From 5o To 45o Were Selected For This Study Then Canal Preparation Was Done Using WaveOne Gold And WaveOne Files. The Angles Of Curvature Were Measured After Instrumentation And Comparison Was Done By Fusion (superimposition) Of The Pre-operative And Post-operative Cone Beam Scans. WaveOne Gold Files And WaveOne Files Were Scanned Using SEM Before And After Preparing 3,6,9 Canals. One Way-ANOVA Was Used To Study The Effect Of Different Groups On Mean Canal Curvature And Measurements Of Canal Transportation. Statistical Analysis Was Performed With IBM? SPSS? Statistics Version 21 For Windows.

Results: It Was Found That ?WaveOne Gold? File System Has Recorded Lower Statistically Significant Degree Of Canal Transportation After Instrumentation Than The ?WaveOne? File System (p<0.05), Also There Was Statistically Significant Effect Of Canal Curvature On The Degree Of Canal Transportation After Instrumentation (p>0.05), As There Was Statistically Significant Difference In Canal Transportation In Both Subgroups (?5?-25?? And ?25?-45??). SEM Analysis Showed A Range Of Defects Detected On ?both Files? In Their New As Well As In Their Used Condition. Defects As Strips, Debris, Pitting Micro-fracture, Cracks, Corrosion, Fretting And Scrapping. Conclusion: It Was Found That WaveOne Gold Reciprocating File Is Superior In Preserving Canal Curvature Than WaveOne File

Mennatalla A. Mehena, Mohammed N. Anwar And Farid S. El-Askary,

ABSTRACT


Purpose: The Purpose Of This Study Was To Evaluate The Effect Of Bonding Protocols And Resin Cement Type On Push-out Bond Strength Of Fiber Reinforced Composite Post To Radicular Dentin.

Materials and Methods: A Total Of 72 Human Lower Premolar Teeth Were Randomly Assigned To 6 Groups (n=12) According To The Two Experimental Factors Being Investigated (bonding Protocol And Type Of Resin Cement). After Decoronation And Pulps Extirpation, The Post Spaces Were Prepared. Adhesive Was Applied On Radicular Dentin And Cured Following The Bonding Protocols Investigated (according To Manufacturer Recommendation Curing Time, Doubling The Manufacturer Recommendation Curing Time And Co-curing). Resin Cement Was Injected Inside The Root Canal And The Post Was Inserted And Either Light Cured For 40s (dual-cure Resin Cement) Or Left To Cure Chemically (chemical-cured Resin Cement). After 24 Hours, Each Root Was Sliced Into Three Slices. Each Slice Was Subjected To Push-out Bond Strength Test At A Crosshead Speed 0.5 Mm/min. ANOVA And Student T-test Were Used To Analyze The Data.

Results: Two-Way ANOVA Revealed That Neither The Bonding Protocol Nor The Type Of Cement Had Significant Effect On Push-out Bond Strength (P=0.408 And P=0.089 Respectively); While Their Interaction Showed Significant Effect On Push-out Bond Strength (P<0.0001). Conclusion: The Effect Of Curing Protocol Is Dependent On The Type Of Cement. In All Bonding Protocols, The Type Of Cement Has An Influence On The Bonding Of Fiber Post To Root Canal Dentin.

Reema A. Al-Eryani, Ghada A. El-Baz, Wael M. Abd-Alkhalek, Essam M. Abd-Allahand Mohamed Sherif M. Salah El-Din,

ABSTRACT
Aim Of The Study: To Study The Variations In Some Salivary Parameters (pH, Ca2+, SIgA, And Lysozyme) And Their Influence On Dental Caries Status In Egyptian And Yemenis Asthmatic Children. Subjects And Methods: This Study Was Carried Out On Two Hundred Children Of Both Sexes With Age Ranged From 6-10 Years. The Cases Were Divided Into Two Main Groups; One Hundred Children From Egypt And One Hundred Children From Yemen. Each Group Was Subdivided Into Two Subgroups; Fifty Children Asthmatic And Fifty Children Healthy. Dental Caries Was Assessed For Each Child According To WHO Criteria (1997) For Detection Of Caries Using DMFS For Permanent Dentition. Saliva Samples Were Collected From Each Child To Measure: PH, Ca2+, SIgA, And Lysozyme. The Correlation Between Different Salivary Parameters And Dental Caries In Permanent Dentition Was Evaluated.

Results: Asthmatic Children Showed No Significant Differences In All Studied Variables Between Egyptian And Yemeni Children. While For Healthy Children, Egyptians Showed Statistically Significant Higher Mean PH Level And Lower Mean Ca2+ And Lysozyme Levels Than Yemeni Children. In Comparing Between Asthmatic And Healthy Children, Egyptian Asthmatic Children Showed Statistically Significant Lower Mean PH Level And Higher Mean Ca2+, SIgA, And Lysozyme Levels Than Healthy Children. Regarding Yemeni Asthmatic Children, There Were Statistical Significant Higher Mean PH And Lysozyme Levels And Lower DMFS Score Than Healthy Children. Egyptian Healthy Children Showed A Statistically Significant Positive Correlation Between DMFS Score And SIgA Levels. Regarding Yemeni Asthmatic Group, There Was A Statistically Significant Positive Correlation Between DMFS Score And SIgA And Negative Correlation Between DMFS Score And Ca2+ Level. While The Yemeni Healthy Children Showed A Positive Correlation Between DMFS Score And SIgA. ROC Curve Analysis Showed That Saliva Samples Of Children With Lysozyme Above 5.80 Ng/ml And 4.66ng/ml For Egyptian And Yemenis Respectively, Can Be Suspected For Asthma With Accuracy Of 66% And 64% In Both Groups Respectively. Conclusion: Salivary Analysis Revealed An Overall Altered Salivary Composition In Children With Asthma, Indicating A Compromised Oral Environment In These Patients And Suggesting Salivary Analysis As An Additional Diagnostic Tool For Allergic Diseases.

Reema A. Al-Eryani, Ghada A. El-Baz, Wael M. Abd-Alkhalek, Essam M. Abd-Allah And Mohamed Sherif M. Salah El-Din,

ABSTRACT
Aim Of The Study: To Study The Variations In Some Salivary Parameters (pH, Ca2+, SIgA, Lysozyme) And Their Influence On Dental Caries Status In Egyptian And Yemenis Asthmatic Children. Subjects And Methods: This Study Was Carried Out On Two Hundred Children Of Both Sexes With Age Ranged From 6-10 Years. The Cases Were Divided Into Two Main Groups; One Hundred Children From Egypt And One Hundred Children From Yemen. Each Group Was Subdivided Into Two Subgroups; Fifty Children Asthmatic And Fifty Children Healthy. Dental Caries Was Assessed For Each Child According To WHO Criteria (1997) For Detection Of Caries Using Defs For Primary Dentition. Saliva Samples Were Collected From Each Child To Measure: PH, Ca2+, SIgA, And Lysozyme. The Correlation Between Different Salivary Parameters And Dental Caries In Primary Dentition Was Evaluated.

Results: Asthmatic Children Showed No Significant Differences In All Studied Variables Between Egyptians And Yemenis. While For Healthy Children, Egyptians Showed Statistically Significant Higher Mean PH Level And Defs Score And Lower Ca2+ And Lysozyme Levels Than Yemeni Children. In Comparing Between Asthmatic And Healthy Children, Egyptian Asthmatic Children Showed Statistically Significant Lower Mean PH Level And Higher Mean Ca2+, SIgA, And Lysozyme Levels Than Healthy Children. Yemeni Asthmatic Children Showed Statistically Significant Higher Mean PH And Lysozyme Levels Than Healthy Children. Concerning Defs, All In Egyptian Or Yemeni Children As Well As The Whole Sample; Asthmatics Showed Lower Mean Defs Scores Than Healthy Children. There Was A Statistically Significant Negative Correlation Between Defs Score And Lysozyme Level In Egyptian Asthmatics. Egyptian Healthy Showed A Negative Correlation Between Defs Score And PH Level And Positive Correlation With Ca2+ Level. Concerning Yemeni Asthmatic Group, There Was A Statistically Significant Positive Correlation Between Defs Score And SIgA And Negative Correlation Between Defs Score And Lysozyme. While For Yemeni Healthy Children, There Was A Statistically Significant Positive Correlation Between Defs Score And PH Level. ROC Curve Analysis Showed That Saliva Samples Of Children With SIgA Above 271.0 �g/ml And 304.0 �g/ml For Egyptian And Yemenis Respectively, Can Be Suspected For Asthma With Accuracy Of 68% And 64% In Both Groups Respectively. Conclusion: Salivary Analysis Revealed An Overall Altered Salivary Composition In Children With Asthma, And Suggesting Salivary Analysis As An Additional Diagnostic Tool For Allergic Diseases.

Arzaq Sami Abdulrazzaq, Mohamed Abdul Magied Katamish And Amr Amin Ghanem,

ABSTRACT
Objective: The Aim Of This Study Was To Evaluate The Effect Of Mesenchymal Stem Cells In Healing Of Segmental Bony Defects.

Materials and Methods: The Study Was Conducted On Sixteen Skeletally Mature New Zealand Rabbits Weighing 2 To 2.5 Kg. An Approximately 5 Mm Segmental Defect Was Created In The Tibia Of The Animals After The Fixation Of The Tibia With Plate And Screws. We Injected MSCs Into The Defects In The Study Group While The Defects Of The Rabbits Of The Control Group Were Left Empty. All Of The Animals Were Sacrificed On Postoperative Day 22. Digital Radiodensitometric Analysis, Histologic And Histomorphometric Examinations Were Performed On The Harvested Tibia. The Data Were Statistically Analyzed.

Results: There Was Highly Significant Difference Between MSCs Group And Control Regarding Bone Density, Trabecular Bone Thickness And Area Percentage Of Osteoid Tissue. Conclusion: MSCs Showed Promising Results In Improving The Healing Of Segmental Bone Defects In Macroscopic And Microscopic Levels.