Mona M. Abdulrahman, Maha W. Elkerdawy And Ahmed A. Fayyadsity,

ABSTRACT
Aim Of The Study: This Invitro Study Was Carried Out To Investigate The Effect Of Locator And Ball Attachments On Peri-implant Stresses Induced During Loading Of Implant Retained Unilateral Total Maxillectomy Obturator.

Materials and Methods: A Cast Obtained From An Impression Of An Edentulous Patient With Total Hemi-maxillectomy To Simulate The Real Situation. Three Dummy Implants, In Conjunction With Ball Attachment Were Inserted Within The Acrylic Model. The Acrylic Model Was Prepared To Receive The Strain Gauges That Were Attached To The Buccal And Mesial Surface Of Each Implant. A Universal Testing Machine Was Used To Apply Standardized Static Load Unilaterally On The Right First Molar Vertically On Implant Side, Then On The Left First Molar On Defect Side. A Strain Meter Was Used To Assess The Strains Induced By Each Applied Load. After Completing Micro-strain Measurements For The Ball And Socket Attachments, They Were Replaced By The Locator Attachments.

Results: Locator Attachment System Showed Lower Micro Strain Values Than The Ball Attachment System When Used To Retain Obturator In Unilateral Total Maxillectomy Defects.

Mai N A Zaki Norhan A El Dokky And Soad A Abdel Moniem,

ABSTRACT
Controlling Pain In Pediatric Dental Patients Instills A Positive Behavior Towards Dental Treatment. This Study Was Conducted To Compare The Perceived Pain During The Injection Of Alkalinized 2% Lidocaine With Epinephrine 1:100000 Using 8.4% Sodium Bicarbonate And That Perceived During The Injection Of Conventional Lidocaine With Epinephrine 1:100000 In Pediatric Dental Patients. Twenty-five Healthy Children From Both Sexes With Age Range Of 5-9 Years Old Were Enrolled In This Study. Each Child Received Two Anesthetic Infiltration Injections On Two Separate Appointments, Once With Commercial Lidocaine With Epinephrine 1:100000 And Once With Lidocaine With Epinephrine 1:100000 Alkalinized By 8.4% Sodium Bicarbonate Solution Using Insulin Syringes By A Ratio Of 9:1. Pain Was Evaluated Using The Faces Pain Scale ? Revised By Showing The Scale To The Child After Each Injection And Asking Him/her To Choose A Face That Best Described His/her Feeling. It Was Concluded On Comparing Pain Perceived During Anesthetic Injection In Right And Left Sides Of Each Child, There Was A Statistical Significant Difference (P-value = 0.015) Between Buffered And Unbuffered Anesthesia. In Conclusion, Buffered Anesthesia Induces Less Pain Than Unbuffered Anesthesia In Children When Used In Infiltration Technique. Pain Perception Is Neither Affected By Age Nor Gender In Children.

Mohammed Mamdouh And Cherif Adel Mohsen,

ABSTRACT
Objectives. The Aim Of This Study Is To Evaluate The Influence Of Various Surface Treatments To Fibre Posts On The Microtensile Bond Strength With Different Composite Resins. Methods. Seventy Glass Fibre Posts Will Be Used In The Study. Posts Are Randomly Picked And Divide Into Five Groups Of 14 Each, Depending On The Post Surface Pretreatment To Be Performed. These Pre-treatments Include: Immersion In 20% Hydrogen Peroxide For 10 Min At Room Temperature And Silanization For 60 S (gp1), Immersion In 10 % Hydrogen Peroxide For 20 Min At Room Temperature And Silanization For 60 S (gp2), Immersion In 4% Hydrofluoric Acid Gel For 60s And Silanization For 60 S (gp3), Silanization Of The Post Surface For 60 S And Application Of The Bonding Agent (gp4), Silanization Of Post Surface For 60 S Only (gp5, Control Group). After Treatment, Two Posts Were Randomly Selected From Each Group To Evaluate The Morphological Aspect Of The Post Surface With Scanning Electron Microscopy. The Remaining Posts In Each Group Were Divided Into Five Subgroups Of Five Posts Each, Which Differed In The Type Of Composite Resin Used For The Core Build-up. Post-core Strength Was Calculated And The Differences Among Experimental Groups Were Analyzed With One And Two-way Anova And The Tukey Test (� =0.05). Results. The Post-core Strengths Achieved In Groups 4 And 1 Were Significantly Higher (P < 0.05), Than Those Of Groups 3, 5 And 2. The Post-core Strength In Group 2 Was Significantly Lower (P < 0.05) Than All Other Groups.

Raneen Ahmed Gohar; Omaima Mohamed Safwat And Shereen Hafez Ibrahim,

ABSTRACT
Objective: This Study Was Conducted To Evaluate The Change In The Mineral Content And Ultra-morphological Picture Of Enamel Bleached With Bleaching Agent Comprising And Not Comprising Fluoride.

Materials and Methods: A Total Number Of 14 Intact And Freshly Extracted Human Central Incisors Were Used In This Study. Each Tooth Was Divided Into Three Equal Thirds Of Enamel And Dentine Blocks. The Middle Third Is Assigned For For B0 (control Group), The Mesial Third Is Assigned For B1 (bleaching Without Fluoride) While The Distal Third Is Assigned For B2 (bleaching With Fluoride). Each Group Further Divided Into Two Subgroups According To PH Cycle (C). Where C1 Represents No PH Cycle And C2 Represents PH Cycle. Elemental And Ultramorphological Analysis Were Done For All Specimens In All Groups And Subgroups For Sound Unbleached Enamel, After Bleaching Procedure (under Manufacturer Instructions) And After PH Cycle. Quantitative Energy Dispersive X-ray Spectroscopy Elemental Analysis Was Performed On The Enamel Surface To Determine The Elemental Levels (%) Of Calcium (Ca), Phosphorus (P). The Calcium (Ca) And Phosphorus (P) Contents Were Evaluated In Weight Percent (wt. %) And The Mean Ca/P Ratios Were Calculated. The Ultra-morphological Analysis Was Done Using The Environmental Scanning Electron Microscope. One Image Was Obtained From The Center Of Each Enamel Surface Specimen With Magnification Of 4000X. Data Were Collected, Tabulated And Statistically Analyzed.

Results: Quantitative Energy Dispersive X-ray Spectroscopy Elemental Analysis Showed A Statistical Significant Difference Among The Three Groups (control, Bleaching Without Fluoride And Bleaching With Fluoride) In Ca Wt % And P Wt % While It Showed No Significant Difference Among Three Groups After Performing PH Cycle. However, Ca/P Ration Showed No Significant Difference Among The Three Groups But Showed A Significant Difference After Performing PH Cycle. SEM Photomicrographs Showed Morphological Changes In Enamel Surface After Bleaching With No Fluoride As Increase In Porosity, Erosion Giving Etching Like Appearance, While In Bleaching Comprising Fluoride The Morphologic Changes Were Minimal With Surface Discontinuity. After PH Cycle, Bleached Enamel Tends To Return Back To The Normal.

Conclusions: Bleaching Had An Equally Adverse Effect On Both Calcium And Phosphorous Content Of Dental Enamel. The Incorporation Of Fluoride In The Bleaching Agents Lessened Its Demineralizing Effect Also Caused Minimal Morphologic Changes In The Enamel Surface. The Incorporation Of Fluoride In The Bleaching Agent Enhanced The Remineralizing Capacity Of Artificial Saliva During PH Cycling Also Helped The Enamel Surface To Return Back To The Normal.

Walid Ahmed Ghanem, Naglaa Ali Mostafa And Amira Adel Hasanin,

ABSTRACT
Objective: The Aim Of This Study Was To Evaluate The Degenerative Effect Of Two Different Techniques On Condylar Cartilage Of Rabbits. Material And Methods:Twenty Seven Young Male New Zealand White Rabbits(3-4 Months Old) Were Randomized Into Three Equal Groups, Group I Control Group, Group II Unilateral Mandibular Posterior Teeth Extraction Was Done, While Group III Unilateral Forced Mandibular Hypermobility Was Induced. Three Animals Of Each Group Were Sacrificed After1,2and 3 Months Postoperatively And The Tested Temporomandibular Joints Sections Were Prepared For Immunohistochemical Analysis.The Expression Of Collagen Type II Degradation And IL-1? Were Quantified By Quantitative Histomorphometry.

Results: Interleukin-1? Reaction Measured By Histomorphometric Analysis Showed Increase In Average Area Percentage Among The Three Groups Throughout Study Intervals.IL-1?expression Was Significantly Increase In Mandibular Hypermobility Group (GP III)than Extraction Group (GPII)and Control Group(GP I) Respectively. Collagen Type II Degradation Reaction Measured By Histomorphometric Analysis Showed Increase In Average Area Percentage Among The Three Groups Throughout The Study Intervals.Collagen Type II Expression Was Significantly Higher In Mandibular Hypermobility (GP III) Than Extraction(GPII)while The Lowest In Control (GP I).There Was Significant Difference Between The Width Of The Articular Cartilage Of The Groups After One,two And Three Months.The Articular Width Was Thicker In Control Group (GPI),than Extraction Group(GPII) And The Lowest Thickness In Mandibular Hypermobility Group (GPIII). Conclusion: IL-1? Expression Is Directly Proportion With Collagen Type II Degradation On Articular Cartilage Degeneration.The Degenerative Effect Of Mandibular Hypermobility Has More Deleterious Rate On Condylar Cartilage Than That Of Unilateral Loss Of Posterior Teeth.

Hajar A. Sayed, Mohammed N. Anwar And Omaima H. Ghallab,

ABSTRACT


Purpose: This In Vitro Study Investigated The Effect Of Two Application Protocols Of Two Remineralizing Agents On The Shear Bond Strength Of Resin Composite To Artificially Caries-affected Dentin As Well As The Micro Hardness, And Scanning Electron Microscope.

Materials and Methods: A Total Of 72 Anterior Bovine Teeth Were Extracted From Sacrificed Bovine Jaws. The Labial Surface Was Ground Flat To Remove Enamel And Expose An Area Of Nearly 7?5mm Diameter Of Dentin. The Flat Dentin Was Treated By 10% Of Citric Acid To Create Caries Affected Dentin. Samples Were Divided Into The Two Main Groups 24 Sample In Each According To The Remineralizing Agent (Remin Pro And MI Paste Plus). Each Main Group Was Then Divided Into Two Subgroups, 12 Samples In Each According To The Time Of Application Of Remineralizing Agents (7 Days And 14 Days). In Addition, There Are Two Control Groups 12 Samples Each; Positive Control: Sound Dentin And Negative Controls: Artificially Caries Affected Dentin.

Results: The Positive Control Showed The Highest Value Of Bond Strength And Microhardness Among Groups And The Negative One Showed The Lowest Value. Over A 7days Period, The Application Of Both MI Paste Plus And Remin Pro Caused Significantly Greater Improvement Of Mechanical Properties; Shear Bond Strength And Microhardness Of Caries Affected Dentin (p�0.05). In Contrast, Increase The Period Of Application To 14 Days Led To Decrease The Mechanical Properties Less Than That Of 7days. MI Paste7 And Remin Pro 7 Days Higher Than That Of 14 Days With Statistical Significance Between Them. But, There Was No Statistical Significance Between Two Pastes In 14 Days In Both Tests.

Conclusions: The Demineralization Process Through Acid Application Has A Negative Influence On The Mechanical Properties Of Dentin; Shear Bond Strength And Microhardness, Remineralization Of Caries Affected Dentin Showed Positive Influence On Both Shear Bond Strength And Microhardness And Seven Days Is The Optimum Time For CAD Remineralization.

Alaa A. Khodair, Mohsen H. Abi El Hassan And Rasha Haridy,

ABSTRACT
Objective: This Study Was Carried Out To Evaluate The In Vitro Three-body Wear Resistance Of The Recently Introduced Ormocer-based (Ceram X One Universal) And POSS (Artiste) Nanohybrid Resin Composites Which Have Different And Novel Chemistries Of Their Resin Matrices Compared To A Nanohybrid Resin Composite With Conventional Methacrylate-based Resin Matrix (Filtek Z250 XT).

Materials and Methods: The Specimens Were Divided Into Three Main Groups (n=14) According To The Type Of Resin Composite Material. Each Group Was Further Subdivided Into Two Main Subgroups (n=7) Where Each Subgroup Was Subjected To Wear Cycles Representing Different Aging Intervals Which Were: 250000 Cycles/specimen Equivalent To Three Months And 500000 Cycles/specimen Equivalent To Six Months, The Wear Test Was Done By ACTA Chewing Simulator. Wear Assessment Was Done Using Contact Stylus Digital Profilometer (Talysurf CLI 2000, Taylor-Hobson Precision, Leicester, England) For Measuring Vertical Loss.

Results: Showed Significant Differences In Vertical Substance Loss Between The Three Restorative Materials After 250000 Cycle Equivalent To Three Months And After 500000 Cycle Equivalent To Six Months (P< 0.001). The Highest Vertical Substance Loss Was Observed For Di-functional Methacrylate-based Resin Composite (Artiste) (after 250000 Cycle Equivalent To Three Months, And After 500000 Cycle Equivalent To Six Months). The Lowest Vertical Substance Loss For The Restorative Materials Was Detected For Methacrylate-based Resin Composite (Filtek Z250 XT) (after 250000 Cycle Equivalent To Three Months, And After 500000 Cycle Equivalent To Six Months). Conclusion: 1) Methacrylate-based Resin Composite Without Any Modification In Its Organic Matrix Yielded The Highest Wear Resistance Among The Tested Resin Composite Materials. 2) The Modification In The Organic Matrix Of Resin Composite Material, Did Not Improve The Wear Resistance. 3) Load Cycling, Thermocycling, And PH Cycling Have Adverse Effects On The Mechanical And Physical Properties Of All Tested Materials.

Mahmoud. A. Radwan, Nadia. A. Abbas And Mohamed. F. Abdalla,

ABSTRACT
Aim Of The Study: In Vivo Study Was Conducted To Compare The Effect Of Two Different Denture Base Materials (rapid Heat Cure Acrylic Resin And Modified Rapid Heat Cure Acrylic Resin With Titanium Dioxide Nanoparticles) On The Biting Force Of The Maxillary Complete Denture.

Materials and Methods: Twenty Patients With Completely Edentulous Maxilla Were Randomly Selected According To Inclusion And Exclusion Criteria, Primary Impressions Were Made Using Irreversible Hydrocolloid, Secondary Impressions Were Made Using Green Stick Compound As A Border Molding Material And Zinc Oxide/eugenol As A Final Wash Impression Material Then The Master Casts Were Duplicated Using Duplicating Silicone, Both Dentures Were Processed In Boiling Water For 20 Minutes, Each Patient Received Two Dentures; Rapid Heat Cured Acrylic Denture Base And Modified Rapid Heat Cured Acrylic Denture Base With Titanium Dioxide Nanoparticles Then Biting Force Was Measured Using I Load Star Sensor .

Results: Showed That There Was No Statistically Significant Difference Between The Two Types Of Denture Base Materials

Marzaban N.N., Nawwar A.A. And Zayet M.K.,

ABSTRACT
Objective: To Assess The Sensitivity, Specificity And Diagnostic Accuracy Of Cone Beam Computed Tomography (CBCT) Scans With Three Different Voxel Sizes In The Detection Of Vertical Root Fracture In Endodontically Treated Teeth Restored With Glass Fiber Post. Methodology: Seventy Six Extracted Single Rooted Teeth Were Used After Root Canal Treatment And Fiber Post Cementation For All Of Them. Vertical Root Fracture Was Induced In Thirty Eight Teeth Of The Sample. All The Sampled Teeth Were Imaged By CBCT With Voxel Sizes: 0.15, 0.2 And 0.4 Mm. Three Oral Radiology Specialists Examined The Scans.

Results: The Voxel Sizes 0.15 And 0.2 Mm Recorded 100% Sensitivity Value, While 0.4mm Had The Lowest Sensitivity (92.1%). Voxel Size 0.4 Mm Had Statistically Significantly Higher Specificity Than The Voxel Sizes: 0.15 And 0.2 Mm. No Statistical Significant Difference In Specificity Or Diagnostic Accuracy Between The Voxel Sizes: 0.15 And 0.2 Mm. While, 0.4 Mm Had Statistically Significantly Lower Diagnostic Accuracy (96.1%) Than The Other Voxel Sizes. Very Good Inter-observers? Agreement For Voxel Sizes 0.15 And 0.2 Mm Were Obtained. The Lowest Inter-observers? Agreement Was That For Voxel Size 0.4 Mm. Conclusion: For Detection Of Vertical Root Fractures In Endodontically Treated Teeth Restored With Fiber Posts, The Voxel Sizes 0.15 And 0.2 Mm Provide The Highest Diagnostic Accuracy With Optimum Spatial Resolution And Reasonable Radiation Doses.

Nora Mohamed Salah Sayed Mohamed, Kalid Atef El Hayes, Nermeen Hassanien And Nancy El Gendy,

ABSTRACT


Aim: Was To Compare Between The Levels Of Tumor Necrosis Factor Alpha In Synovial Fluid In Single Needle Versus Double Needles Arthrocentesis .

Materials & Methods: This Study Included 12 Joints In 8 Female Patients Having, Internal Derangement Of The Temporomandibular Joint (TMJ) With Anterior Disc Displacement With Reduction. Patients Were Divided Into Two Equal Groups, Group I And Group II. Each Joint In Each Group Underwent Arthrocentesis Using Single Needle In Group I And Double Needle In Group II. The Synovial Fluid Of Both Groups Was Analyzed To Assay TNF A Level.

Results: Results Revealed .that Single Needle Arthrocentesis Is Better Than Double Needle Arthrocentesis In Treatment Of Disc Displacement With Reduction But Both Of Them Are Effective.