Nada Farid Shehab, Reham ElBasty And Hesham Katamish,

ABSTRACT
Statement Of Problem: Veneered Zirconia Restorations Exhibit Very High Modulus Of Elasticity And High Incidence Of Veneer Chipping. Therefore, The Continuous Search For High Strength Esthetic Restorations Is Never Ending.

Purpose: To Evaluate The Fracture Resistance And Mode Of Failure Of Of CAD/CAM Milled PEEK Core Veneered By Milled High Impact Polymer Composite Compared To CAD-On Zirconia Core Veneered By Lithium Disilicate.

Materials and Methods: Fourteen Freshly Extracted Molars Were Mounted In Epoxy Blocks And Uniformly Prepared With A 1.0 Mm Circular Deep Chamfer Finish Line. They Were Divided In To Two Groups According To The Type Of Material (n=7): Group A: Teeth Restored By ZirCAD Core Veneered By E.max-CAD And Group B: Teeth Restored By PEEK BioHPP Core Veneered By HIPC. All Crowns Were Adhesively Cemented. They Were Then Subjected To Thermo-mechanical Aging Using A Chewing Simulator Then Static Compressive Loading Till Failure Using A Universal Testing Machine And Failure Types Were Determined.

Results: PEEK Group Recorded Statistically Non-significant (p>0.05) Higher Fracture Resistance Mean Value (2851.1�241.02 N) Than Zirconia Group (2786�240 N) As Indicated By Unpaired T-test. The Mode Of Fracture In Zirconia Group Was Manifested As Veneer Chipping In Almost All Of The Specimens. All PEEK Specimens Showed Cohesive Failure In Both Core And Veneer Layers Upon Failure.

Conclusions: Within The Limitations Of This Study, It Can Be Concluded That PEEK Veneered By HIPC Can Be Considered A Potential Permanent Crown And Bridge Material With Comparable Results To Veneered Zirconia Restorations.

Michael Emad, Carl Hany And Hesham Katamish,

ABSTRACT
Statement Of Problem: Marginal Inaccuracy Causes A Space Between Restoration And Prepared Tooth, Which Accelerates Cement Dissolution, Leading To Secondary Caries, Pulpal Lesions, Postoperative Sensitivity, Periodontal Disease And Marginal Discoloration. Marginal Gap Should Be Less Than 120�m. Aim Of This Study Is To Evaluate Vertical Marginal Gap Of PEEK (Bio-HPP) Veneered With CAD/CAM Composite Veneer (HIPC) As Compared To Zirconia Veneered With CAD-On Lithium Disilicate Glass Ceramic. And The Effect Of Ageing On The Gap Of Both Restorations.

Materials and Methods: 40 Extracted Molars Were Prepared, Divided Into Two Groups, Control Group (ZR) (n=20), Teeth Restored With IPS E.max ZirCAD Copings Veneered With IPS E.max CAD And Intervention Group (PEEK) (n=20), Teeth Restored With BreCAM BioHPP Copings Veneered With BreCAM.HIPC. Each Specimen Was Photographed Using Leica S8 APO Stereomicroscope Under Magnification 32X And Image Analysis Was Done. Measurements Were Taken Twice Before And After Thermo-mechanical Cycling.

Results: PEEK Group Recorded Higher Gap Mean Values (49.88�7.97um) Than Zirconia (18.39�3.1um). This Was Significantly (p < 0.05) As Confirmed By Mann-Whitney Test, But All Measurements Were Clinically Acceptable. And Thermo-mechanical Cycling Had No Effect Of On Both Groups. Conclusion: PEEK Veneered With Composite Can Be Used Intra Orally For Single Crown Restorations.

Salma K. Rizk, Gihan A. Abd Elrahman, Shaymaa I. Habib And Ahmed G. Hegazi,

ABSTRACT
Objective: This Study Aimed To Evaluate The Effect Of Ethanolic Extract Of Propolis (EEP) Addition On Resin Based Dental Sealant With 10% Concentration As Regard Its Antibacterial Effect On Streptococcus Mutans In Comparison To Fluoride Releasing Sealant And Conventional (fluoride-free) Resin-based Pit And Fissure Sealant. Methodology: A Total Number Of 90 Specimens Were Prepared, Specimens Were Randomly Assigned Into 3 Groups (30 Specimens Per Group). Group I: Resin-based P&F Sealant Containing 10% EEP, Group II: Fluoride Releasing Resin-based P&F Sealant And Group III: Conventional Resin-based P&F Sealant. The Antibacterial Activity Of The Differently Investigated Groups Against Streptococcus Mutans Strain Was Evaluated Using Agar Diffusion Test. This Test Was Conducted After 1,7,14,21 And 30 Days Of Incubation In Artificial Saliva At 37�C To Mimic The Clinical Situation. Data Were Statistically Analyzed. Results Of This Study Showed Statistically Significant Difference Between The Three Investigated Groups After 1, 14, 21and 30 Days. With The Highest Mean Value For The Propolis Containing Group After 1 Day, Followed By The Fluoride Containing Group.

Conclusions: When Propolis Was Added To Resin-based Sealant, A Pronounced Antibacterial Effect Against Streptococcus Mutans Bacteria Was Evidenced.

Bassant M. El-Fiky, Manal A. El-Sheikh And Rasha M. Hatem,

ABSTRACT

Objectives: The Objective Of This Study Was To Determine The Prevalence Of Anterior Open Bite (AOB) In A Group Of Egyptian Children Methods: The Sample Comprised 115 Participant Aged Between 8 And 10 Years From The Outpatients? Clinic Of Pediatric Dentistry And Dental Public Health Department, Faculty Of Dentistry, Cairo University. Anterior Open Bite Was Assessed. Other Variables Examined Were Normal Overbite, Excessive Overbite And Excessive Overjet.

Results: The Results Showed That 71.2% Had Normal Overbite, 7.8% Had Increased Overbite. Overjet Relationship Was Increased In 44.4%. When Data Were Statistically Analyzed, It Was Evident That There Was No Statistical Significant Difference (P-value > 0.05) In Mean (AOB) Between Boys And Girls Throughout The Whole Study Period.

Conclusions: There Was A Slight Difference Of AOB Between Boys And Girls Where It Was Slight Higher In Girls. There Is No Correlation Between Gender And The Presence Of AOB.

Mariam Salah Mohammad Yassin Alyan, Fatma Ahmed Hamdy El Shehaby And Soad Abd El Moniem Abd El Moniem,

ABSTRACT
Background: Dental Anxiety Is One Of The Major Obstacles That Face The Pediatric Dentist And Interferes With The Delivery Of Optimum Quality Dental Service For Children. That?s Why Pediatric Dentist Should Invest Time And Effort To Control The Children?s Dental Anxiety And Reduce It As Much As Possible Before, During And After The Dental Treatment.

Aim: This Study Was Conducted To Compare Between The Filmed Modelling Technique And The Live Modelling Technique For Management Of Children Dental Anxiety Who Require Simple Filling To The Primary Molars During Their First Dental Visit. Subjects And Methods: A Total Number Of Fifty Four Children Were Allocated And Randomized Into Three Groups, Eighteen Children In Each Group. In The First Visit, Group A The Children Were Subjected To Live Modelling, Group B The Children Were Subjected To Video Modelling And Group C Were Subjected To Tell-Show-Do. In The Second Visit The Children Were Subjected To The Treatment [cavity Preparation And Filling] Both The Oxygen Saturation And The Heart Rate Were Measured Using A Pulse Oximeter.

Results: The Results Of The First Five Questions Of The Facial Image Scale Showed No Statistical Significant Difference While The 6th Question Showed Statistical Significant Difference. The Heart Rate And Oxygen Saturation Showed No Statistical Significant Difference In Their Results Between The Different Behavior Management Groups. Conclusion: Video Modelling And Live Modelling Are Of Equal Effectiveness In Anxiety Control During The Dental Treatment.

Hanaa Salem Moubarak, Tarek Ahmed Essawyand Saher Sayed Mohammed,

ABSTRACT
Potassium Bromate (KBrO3) Is A Strong Oxidizing Agent Involved In Many Food And Cosmetic Industries. It Is Used Mainly As A Flour Improver. This Compound Was Found To Be Toxic To Animal And Human Body Organs And Was Classified As B2 (probable Human) Carcinogen And Health Organizations Started Banning It. However, It Is Still Used In Bakeries In Large Amounts. The Aim Of This Study Was To Investigate The Effect Of KBrO3 Administration On Parotid Gland Of Adult Male Albino Rats. 60 Adult Male Albino Rats Weighting ~ 200 Gm Were Divided Equally Into 3 Groups: Control, Experimental Group I (gp I) And Experimental Group II (gp II). Control Group, Received Distilled Water And The Experimental Gps. Received 62 And 123 Mgkg KBrO3 Respectively Dissolved In Distilled Water Orally On A Daily Basis For 2 And 4 Months. Histopathological Examination Of Specimens In Experimental Groups Revealed Histological Alternations And Dysplastic Changes That Increased As Increasing The Dose And The Duration. Distended Acini With Vacuolated Cytoplasm, Nuclear Changes (hypertrophy, Pleomorphism And Hyperchromatism), Abnormal Mitotic Figures, Dilated Ducts With Thin Atrophied Lining And Stagnant Secretions, Dilated Congested Blood Vessels, Fibrosis And Inflammatory Cell Infiltration Were The Main Histological Changes Observed. Immunohistochemical Results Showed Significant Increase In Immunoreactivity Of PCNA In KBrO3 Treated Groups Compared To The Control Group. In Conclusion KBrO3 Was Proved To Cause A Dose And Time Dependent Carcinogenic Effect On Parotid Salivary Gland Of Adult Male Albino Rats.

Samar Saleh Mahmoud, Mohammed Nasser Mohammed Anwar, Omaima Hassan Ghallab And Mokhtar Nagi Ibrahim,

ABSTRACT

Objectives: This Study Was Conducted To Evaluate The Effect Of Different Curing System Of Self-etch Adhesives(SEA) On Shear Bond Strength(SBS) And Nano-leakage(NL) Of A Light-cured And Dual-cured Composite Core Material Methods: For Shear Bond Strength Testing, 150 Bovine Permanent Anterior Teeth Were Used In This Study. Teeth Were Grinding To Expose Super-facial Dentin Layer And Smear Layer Was Subsequently Formed. The Teeth Were Randomly Divided Into Three Experimental Groups (n= 50 Teeth/group) According To Adhesive System Application (A1=self-cured Tokuyama Universal Adhesive,A2=light-cured Futura Bond M+,A3=dual-cured Futura Bond DC). Then Each Group Was Divided Into 2 Sub-groups According To The Applied Core Material (B1=light-cured Xtra Fil Bulk Material,B2=Dual-cured Estecore Material) Each Material Was Used According To Manufacturers? Instructions. Specimens Were Stored In 100% Relative Humidity For 24 Hours. SBS Test Was Run At A Crosshead Speed Of 0.5 Mm/min Using A Universal Testing Machine. For Nano-leakage Testing, 18 Adhesive/resin Tooth Specimens Were Assigned With The Same Groups And Subgroups (n = 3) As For SBS Testing. Specimens Were Evaluated Using SEM Operated In The Backscattered Mode To Detect Dye Penetration. The Bond Strength Data And Nano-leakage Statistical Analysis Were Subjected To One And Two-way ANOVA Followed By Tukey Post Hoc Test. Spearman Rank Order Correlation Coefficient Was Used To Study The Correlation Between Them.

Results: The Results Showed That The Light-cured Adhesive Exhibited The Significant Highest SBS Values And The Lowest NL Followed By Self-cured Adhesive Then Dual-cured. Light-cured Xtrafill Bulk Material Showed Higher SBS Values And NL Values Than Estecore Dual-cured Core Material. A Medium Positive Correlation Was Found Between SBS And NL Readings.

Conclusions: Light-cured 10-MDP Based SEA Remain To Be The Most Efficient System Light Curing Of The Dual Cured Resin Cement Was Crucial To Achieve High SBS Values. Dual-cured Composite Core Material Offers Low Degree Of Nano-leakage. There Was A Positive Direct Correlation Between The Shear Bond Strength And The Degree Of Nano-leakage Of Resin Material.

Nihal Mohamed Darwish , Safa Fathy And Heba Mahmoud Dhmoush,

ABSTRACT
Background: BPs Have Been Widely Used For The Management Of Osteoporosis. Since Tooth Extractions Are Common Dental Procedures In The Elderly, Therefore, It Is More Crucial For Dentists To Understand The Effect Of BPs On Tooth Extraction Wound Healing To Establish Better Informed Postextraction Care. This Study Was Aimed To Assess The Impact Of Oral And The Intravenous Administration Of Bisphosphonates On Bone Healing After Tooth Extraction And Compare The Histopathological And Radiographic Density Of The Alveolar Bone Associated With Both Ways Of Administration.

Materials and Methods: 52 Rats Were Used In The Present Study, Divided Into 3 Groups. Control Group (10 Rats With No BPs Therapy), Oral Group {21 Rats Who Received Oral BPs (Fosamex, 0.21mg/day) And Intraperitoneal Group ( 21 Rats Who Received IV BPs (Zometa, 0.01 Mg IP Injection Once) Then After 1 Week Of Drug Administration, The First Lower Left Molar Of All Groups Was Extracted. Rats Were Killed After 2, 4 And 6 Weeks From Extraction And The Dissected Mandibule Was Evaluated Histologically And Radiographically (table 1).

Results: In The Extraction Side, The IPG Showed More Increase In The Bone Density In The 2 And 4 Week Interval Than The NCG And The OG However, BRONJ Was Significantly Higher In The 6 Week Interval Of The IPG. In The Non- Extraction Side The Area% Of The Bone In The 3 Groups Was Close In The 2 And 4 Week Intervals But Deterioration Of The Bone Condition Was Seen In The OG And The IPG At 6 Week Compared To NCG. Conclusion: IV BPs Show Rapid Initial Increase In The Bone Density More Than The Oral BPs However On The Long Term It Results In Delayed Healing Of Extraction Socket And Decrease Bone Density.

Azza M. Osama Ali, Amr Helmy Moustafa El Bolok, Safaa Marzouk Tohamy And Hanan Eid Gamal,

ABSTRACT
Background: Apigenin Has Effective Cytotoxic Anticancer Properties And Was Used For Treatment Of Variety Of Malignancies. The Aim Of The Study Is To Investigate The Effect Of Apigenin (Apig) And Apigenin Loaded Nanoparticles (Apig NPs) On Squamous Cell Carcinoma Cell Line (HEP-2). Material & Method: Treatment Of Cell Line (HEp-2) By Different Concentrations Of Apig And Apig NPs Was Done To Assess The Viability Of The Treated Cells To Determine The Percentages Of Viable Cells That Was Monitored Using MTT Assay.

Results: The Mean Viability Percentage Of Apig Treated Cells (in Relation To Control Cells) Decreases From 103.69% To 14.41% As Apig Concentration Increased From 1.22 To 2500 MM With An IC50 Of 51.46 MM And Apig NPs Decreased The Cells Viability From 98.11% To 12.25% As Apig NPs Concentration Increased From .24 MM To 500 MM With An IC50 Of .89. Morphometric Analysis Showed A Decrease In Nuclear Area Factor (NAF) Which Is An Indicator Of Apoptosis As Concentrations Increased. The Results Were Statistically Significant. Conclusion: Apig And Apig NPs Have A Significant Anticancer Effect On Hep-2 Cell Line. Abbreviations: Apigenin (Apig), Loaded Nano Particles (NPs), Nuclear Area Factor (NAF), Squamous Cell Carcinoma (SCC)

Ahmed Y. El-Refaay, Manal R. Hassan And Raiesa M. Mohammed,

ABSTRACT
Objective: The Purpose Of This Study Was To Assess Fracture Resistance Of Endocrown Of Premolars Constructed Of Two Different Materials Namely IPS E.max CAD And Hybrid Ceramic Compared To Conventional Post And Core And IPS E.max Full Coverage Crown. Materials And Methods : Thirty Sound Extracted Human Single Rooted Premolars (N =30) Were Endodontically Treated. Standardized Preparations Were Done With 5 Mm Intracoronal Extensions Into The Pulp Chamber And Divided Into 3 Groups Of Each (n=10). Group A: Specimens Involved Endodontically Treated (ET) Premolars Restored With Glass Fiber Posts Cemented With Rely X Cement, Composite Cores Were Built Up And IPS E.max CAD Full Coverage Crowns (control Group) .Group B: Specimens Involved ET Premolars Restored With Hybrid Ceramic Vita Enamic Endocrown. Group C: Specimens Involved ET Premolars Restored With IPS E.max CAD Endocrown. Each Group Was Subdivided Into Two Sub-groups According To Marginal Design, 5 Specimens With 1.5 Mm Ferrule And 5 Specimens Without Ferrule. Specimens Were Subjected To Thermal Cycling (5000 Cycles) And Fatigue By Cyclic Loading (75,000 Cycles) In Order To Simulate A Clinical Service Time Of 6 Months And Were Mounted In A Universal Testing Machine(instron) And Then They Subjected To Vertical Compression Load Until Failure. Data Were Collected, Tabulated And Statically Analyzed). Two-way ANOVA Used To Show The Effect Of Different Groups And Design On Fracture Resistance (N) Followed By Multiple Comparison With Bonferroni Correction. Chi-square Test Used To Show The Effect Of Different Groups And Design For Failure Mode Analysis. Result: The Highest Fracture Resistance Mean Value Was Recorded For E.max CAD Endocrown With Ferrule Group (1409.62�255.01 N) While The Lowest Fracture Resistance Mean Value Was Recorded For E.max Crown Without Ferrule Group (723.48�43.46 N). Difference Between Different Treatment Modalities And Different Marginal Design Preparation Was Significant (p<0.05) While Difference Between Different Materials Was Insignificant. Conclusion:1.The Deep Chamfer Finish Line Marginal Design Increases The Fracture Resistance Of Endocrowns Than Butt-joint Marginal Design.2. Endocrowns With Sufficient Ferrule Were Found To Be A Successful Mean Of Restoring Mutilated Endodontically Treated Single Rooted Premolars.3.VITA ENAMIC And E.max CAD Endocrowns Are Better Than Fiber Post And Core Supported E.max CAD Crowns In Terms Of Fracture Resistance .