Maha Badr, Doaa Heshmat And Hamdy Abo El Fotouh,

ABSTRACT
Background: Implant Assisted Overdenture Can Provide Better Masticatory Force Than Complete Denture But Less Than The Normal Teeth.

Purpose: To Compare Fracture Resistance Of Implant Assisted Overdenture For Different Types Of Denture Base Materials Including Heat Cure Acrylic, Polyamide And Acetal Denture Base Materials To Measure The Magnitude Of The Maximum Force Applied On The Overdenture Immediately Before Fracture.

Materials and Methods: A Completely Edentulous Mandibular Epoxy Resin Cast Was Used For Implant Placement And Overdenture Construction. The Position Of The Two Implants In The Epoxy Resin Cast At The Canine Area Was Marked By A Notch So It Will Be Transferred During Duplication Of Casts To Three Identical Stone Casts To Determine Placement Of Attachments. Construction Of Three Trial Denture Base From Wax Pattern On Three Stone Cast In A Conventional Way. Then Processing Was Occurred Then Testing Them.

Results: The Fracture Resistance Test Results Revealed That The Highest Mean Values Of The Fracture Loads Were Found In The Overdenture With Heat Cured Acrylic Denture Base Material.

Conclusions: The Fracture Pattern Of The Polyamide Denture Base Material Was Less Extensive Than The Overdenture Retained With Acetal And Acrylic.

Reham Samy Elsaid, Nagwa Mohammed Khattab And Mona Nagy Mahmoud ,

ABSTRACT
Background: Although The Warning Signs Of Child Abuse And Neglect Aren?t Always Obvious, Physically Abused Victims Mainly Injured In Head And Neck Areas. Dentist Might Be The Firstperson Who Notice This Type Of Injury And Make A Huge Difference In A Child?s Life.

Aim: This Study Investigated Dentists? Level Of Knowledge, Perception, Attitude & Responsibility Regarding Child Physical Abuse In Some Of Upper Egypt Governorates (Minia, Assuit And Sohag).

Materials and Methods: In A Cross-sectional Study Of 420 Dentists In Minia, Assuit And Sohag A Previously Validated Self-administered Questionnaire Was Distributed, In Both Printed And Electronic Forms From January 2020 To October 2020, To Collect Data On Personal Characteristics, Professional Background, Knowledge, Perception, Attitude And Responsibility Toward Children Who Are Suspected Cases Of Physical Abuse. Descriptive And Analytic Statistics Were Applied. Significancewas Taken Into Consideration At P ? 0.05.

Results: Most Of The Participants Displayed Low Knowledge Score, While Only 12.9% Had High Knowledge Score. The Difference Between The Groups Was Significantin Term Of Statistics (p<0.05). Conclusion: Most Of Dentists In The Three Governorates (Minia, Assuit And Sohag) Have Insufficient Knowledge Level About Diagnosing And Approaching Cases Of Child Physical Abuse

Abdelrahman Al-Duqi, Fatma Abdelgawad And Nevine Waly,

ABSTRACT
Background: White Spot Lesions (WSLs) Usually Occurs As A Side Effect Of Comprehensive Orthodontic Treatment. The Prevalence Of WSLs Is Very High On Debonding Although Many Attempts Are Performed For Prevention. Many Agents Are Frequently Used For The Remineralization Of WSLs Such As Fluoridetoothpastes, Fluoridevarnishes, And Fluoridemouth Rinses. However, These Arrested Lesions May Persist Lifelong, Exhibiting A White Colour, Or Might Become Yellowish Or Dark Brown In Colour As A Result Of Exogenous Stain?s Uptake. Thus, The Present Study Was Designed To Evaluate Postoperative Stain Following Casein Phosphopeptide-amorphous Calcium Phosphate (CPP-ACP) Varnish Versus Tricalcium Phosphate (TCP) Varnish On Postorthodontic WSLs. Methodology: The Study Included Patients Who Developed Multiple Decalcifiedenamel Lesions After Fixedorthodontic Therapy, Exhibiting At Least 2 WSLs In Buccal Surface Of Teeth And No History Of Any Allergy To Fluorideor Other Ingredients In The Varnish. The Study Population Was Divided Equally Into Two Groups Using The (CPP-ACP Varnish And TCP Varnish). The Effect Of Both Materials On Staining The Tooth Surface And Gingivitis Were Evaluated During Follow Up Period.

Results: The Study Population Consisted Of 20 Patients Mean Age In Group (I) Was (14.90?0.99) And In Group (II) It Was (14.60?1.37) (15 Females, 5 Males; 194 Affected Teeth). At 6 Months, Postoperative Staining Showed No Statistically Significantdifference Between Both Groups (p=0.350). Postoperative Gingivitis Showed No Statistically Significant Diference Between Both Groups (p=1).

Conclusions: Postoperative Staining Can Occur During Treatment Of WSLs As A Side Effect Of Fluoride Varnish Denoting Remineralization, Or Exogenous Stains

Osama Magdy Monir Mostafa, Nihal Ezzat Sabet And Amira Galal Ismail,

ABSTRACT
The Push-out Bond Strength Of MTA Fillapex And GuttaFlow Bioseal Was Evaluated And Compared After 24 Hours And 7 Days. Forty Single Rooted, Lower Premolars Were Chosen For This Study. The Specimens Were Decoronated, And Prepared Using Protaper Universal Rotary System Till F4 File.Specimens Were Randomly Divided Into Two Equal Groups; Group I (n=20) Was Obturated Using MTA FILLAPEX, While Group II (n=20) Was Obturated Using GuttaFlow Bioseal. Each Group Was Further Subdivided Into Two Subgroups, Where Subgroup 1 (n=10) Was Tested After 24 Hours, And Subgroup 2 (n=10) Was Tested After 7 Days. Samples Within Each Subgroup Were Tested For Push Out Bond Strength Using Universal Bonding Machine. After 24 Hours GuttaFlow Bioseal Showed Statistically Significantlyhigher Median Push-out Bond Strength Than MTA FILLAPEX. While After 7 Days; GuttaFlow Bioseal Showed Statistically Significantlylower Median Push-out Bond Strength Than MTA FILLAPEX. It Was Concluded That MTA FILLAPEX Presented A Better Long-term Push-out Bond Strength Than GuttaFlow Bioseal.

Dena Badr Mahmoud , Nagwa Mohammed Ali Khattab And Ahmed Abdel Hamid Abdel Kader Elheeny ,

ABSTRACT
ABSTRACT
: The Vertical Root Fracture In Endodontically Treated Teethis An Undesired Condition And Usually Results In The Extraction Of Involved Teeth. Thus, The Aim Of Present Study Was To Evaluate The Dentinal Crack Formation Of Wave-One Gold In Comparison With Stainless Steel Hand K Filesafter Root Canal Preparation In Primary Molars Using Scanning Electron Microscope (SEM).

Materials and Methods: Forty Mandibular Primary Molars With Two Separate And Straight Mesial Canals Were Selected And Stored In Distilled Water . The Coronal Portions And Distal Roots Of All Teeth Were Removed Using A Diamond Coated Bur With Water Cooling. The Teeth Were Randomly Divided Into The Following Two Groups (n=20) For Each: Wave-One Gold And Stainless Steel Hand Files.The 20 Specimens Were Cut Perpendicular To The Tooth Axis To Coronal, Middle And Apical Third , And Three Slices Were Obtained From Each Specimen. Scanning Using (SEM) For Each Slice To Determine The Presence Of Cracks. The Absence/presence Of Cracks Was Recorded, And Statistical Analysis Was Performed With IBM? SPSS? Statistics Version 20 For Windows. The Significancelevel Was Set At P < 0.05.

Results: Statistically Significantmore Dentinal Cracks Were Observed In The WOG Group Than In Stainless Steel Hand K ?filesgroup In Terms Of The Total Number Of Dentinal Crack Where (p<0.001).Statistically Significantmore Dentinal Cracks In The Apical Region Were Observed In The WOG Group Than In Stainless Steel Hand K ?files Groups (p=0.02)

Conclusions: Within The Limitations Of The Study, Statistically Significantmore Dentinal Cracks Were Observed In The WOG Group Than In Stainless Steel Hand K ?filesgroup In Terms Of The Total Number Of Dentinal Crack

Sahar Abdel-Nasser Mohammed, Tarik Essawy And Saher Sayed Mohammed,

ABSTRACT
Background: Titanium Dioxide Nanoparticles(TiO2 NPs) Have Been Used In A Wide Variety Of Applications In Our Daily Life. However, The Safety Of Their Exposure Remains Unclear. Objective: Investigating TiO2NPs-induced Alterations In The Rat Submandibular Salivary Gland (SMSG) Using Masson?s Trichrome Stain (MT) & Alpha Smooth Muscle Actin (?-SMA). Methodology: 50 Adult Rats Weighing About ?200-250 Gm Were Divided Into 4 Groups: Group I (control Group), Group II Divided Into 2 Subgroups: Subgroup IIA Received TiO2 NPs A Daily Dose Of 10 Mg/kg/day For 14 Days And Subgroup IIB Received TiO2 NPs A Daily Dose Of 50 Mg/kg/day For 14 Days, Group III Divided Into 2 Subgroups: Subgroup IIIA Received TiO2 NPs A Daily Dose Of 10 Mg/kg/day For One Month And Subgroup IIIB Received TiO2 NPs A Daily Dose Of 50 Mg/kg/day For One Month & Group IV (recovery Group) Received TiO2 NPs A Daily Dose Of 10 Mg/kg/day For One Month & Allowed For One Month Of Recovery After TiO2 NPs Withdrawal. All Animals Were Sac-rificed,SMSG Were Dissected, Specimens Were Prepared And Sections Were Stained With Masson?s Trichrome. Immunohistochemical Detection Of Alpha Smooth Muscle Actin Was Done.

Results: Masson?s Trichrome Sections Of SMSG Of The Current Study Revealed A Dramatically Increasing Of The Amount Of Blue-stained Collagen Fibersfrom Group II To Group III In Compared To Control Group. The Collagen Fibersin Recovery Group Exhibited Degree Of Hyaline Degeneration. Immunohistochemical Results Revealed A Statistically High Significantincrease In ?-SMA Positive Cytoplasmic Immunoreaction Of Myoepithelial Cells In A Time-dependent Manner From Group II To Group IV. Conclusion: TiO2 NPs Could Produce Changes To The Structure Of SMSG. These Changes Were Both Time And Dose Dependent. Also They Were Persistent, Which Did Not Regress After One Month Following Cessation Of Tio2 NPs Intake.

Hanaa Ewas Korany,Wael Huessien Kamel And Dalia Ali Ahmed Moukarab,

ABSTRACT
Objective: The Aim Of This Study Was To Evaluate The Root Canal Transportation Comparing Different Kinematic Motion And Metallargical Compostion Used In Truss Access.Materia & Methods: Eighty Extracted Mandibular Firstmolars Were Collected And Randomly Divided Into Two Main Groups (n=40) According To Access Cavity Type 40 For Conventional Access Cavity And 40 For Truss Access Cavity, Then Every Group Was Subdivided Into 4 Equal Subgroups (n=10) Following Access Cavity Preparation Of All Samples, The Roots Were Vertically Mounted Half-way In Transparent Auto Polymerizing Acrylic Resin Inside A Silicon Mold (10 Cm X 10 Cm) To Fixthem. Group I; Reciproc Blue (size 25, Taper 0.08) .group II; HyflexCM Files(sizes 20,25,30 Taper 0.04), Group III; Endostar E3 Basic Files(size, 30, Taper 0.08, Size 25, Taper 0.06, Size 30, Taper 0.04) And Group IV: Wave One (size 25 Taper 0.08).Pre And Post Instrumentation Scanning For The Root Canals Were Done Via CBCT. Data Were Analyzed Using Kolmogorov-Smirnov And Shapiro-Wilk Tests. Intergroup Comparisons Were Done Using One-way ANOVA Followed By Tukey?s Post Hoc Test, While Intragroup Comparisons Were Done Using One-way Repeated Measures ANOVA Followed By Bonferroni Post Hoc Test.

Results: Regarding Root Canal Transportation: There Was A Significantdifference Between Files:coronal And Middle:-Endo Star E3 Had The Highest Value,while Apical: Reciproc Blue Had The Highest One. HyflexCM Fileshad The Lowest Value Middle And Apical While,coronal: Wave One Had The Highest One. Regarding Centric Ratio: There Was A Significantdifference Between Different Groups: Coronal And Middle: Hyflexfileshad The Highest Value, While Apical: Wave One Had The Highest One. On The Other Hand, Wave One Had The Lowest Values Middle And Apical, While, Coronal:-Reciproc Blue Had The Lowest One.Conclusion: Truss Access Affect Root Canal Transportation And Centralization Of Both Full Rotation And Reciprocation Files With Diferent Metallurgy.

Seif Eldin Mohamed Mounir, Lamia Sayed Kheiralla And Rana Mahmoud Sherif,

ABSTRACT
Statement Of Problem: Fixed Prosthodontic Dentistry Owns Many Updates Including Preparation Design, Luting Cements And A Great Variety Of Restoration Materials. One Of The Most Important Factors Influencingthe Success Rate And Longevity Of The Fixedrestoration Is The Preparation Design Including Many Parameters Specially The Convergence Angle Of The Tooth And How It Is Affecting The Retention Of The Restoration. The Type Of The Crown Material Which Is Shifted To High Esthetic Option Represented In All Ceramic Restorations With Variety Of Types And Techniques Of Manufacturing. Also We Cannot Forget The Leading Role Of The Luting Cement In The Success Rate Of The Fixedrestorations Which Is Its Main Function Is To Retain The Restoration In Place For Life Time Depending On Either Conventional Cements Or Self-adhesive Cements Or The Recent Bioactive.Aim Of Study: To Assess The Efficacyof Convergence Angle On The Retention Of E-max Restoration Bonded With Adhesive Bioactive Cement Vs Adhesive Resin Cements.Methodology: In This In Vitro Study, 40 Sound, Sterilized, Freshly Extracted Human Molar Teeth Free Of Caries, Cracks And Fractures Are Collected From The MIU Bank. Teeth Will Be Machine Milled By Surveyor At Standardized Degree Of Taper 10? Or 20?. Teeth Will Be Divided According To Different Degree Of Taper Into Two Main Groups; Group (1) 10? (n=20) And Group (2) 20? (n=20). E-max Crowns Will Be Constructed According Manufacturer Recommendations, And Then Each Group Will Be Further Subdivided Into Two Subgroups According To The Type Of Luting Agent Used For Cementation; Subgroup (C) E-max Crowns Will Be Cemented Using Ceramir Cement (n=10) And Subgroup (R) E-max Crowns Will Be Cemented Using RelyX Ultimate Adhesive Resin Cement (n=10). Universal Instron Testing Machine Will Be Used For Evaluation Of Retention Of Each Cemented Crown. Values Will Be Expressed In (N), The Investigators Will Code The Samples Into Numbers & Randomize Them Using Computer Guided Randomization. Two-way Analysis Of Variance (ANOVA) Will Be Used To Study The Effect Of Convergence Angle, Cement Type And Their Interaction On Mean Retention Force. The Significance Level Will Be Set At ? 0.05

Results: Among The Two Cement Types (Ceramir & RelyX Ultimate); Teeth Prepared With 10 Degrees Of Convergence Angle Showed Statistically Significantlyhigher Mean Retention Bond Strength Than Those Prepared With 20 Degrees Convergence Angle, While Among The Two Degrees Of Convergence Angle (10o & 20o); Crowns Cemented With RelyX Ultimate Cement Showed Statistically Significantly Higher Mean Retention Bond Strength Than Those Cemented With Ceramir Cement.Conclusion: Increasing The Convergence Angle To 20o Decreased The Retention Of E-max Crowns Significantl, The Mean Retentive Strength Of E-max Crowns Prepared With Two Convergence Angles; 10o & 20o And Cemented With Ceramir Bioactive Cement Was Less Than That Of Crowns Cemented With RelyX Ultimate Resin Cement.

Mohamed G. Hussein And Cherif A. Mohsen,

ABSTRACT
Objective: The Purpose Of This Study Was To Investigate Microleakage Ofdifferent Lithium Disili-cate Occlusal Veneers Designs With Different Tooth Preparations.Material And Method: Fifty-six Extracted Human Mandibular Molars Were Collected With Rela-tively Comparable Size And Standardization Done By Diamond Saw And It Will Receive .6mm Lithium Disilicate Occlusal Veneers. Specimens Will Be Divided Into Two Main Groups, Each Of These Groups Contains 28 Samples (group A&B), The Firstgroup Represents Occlusal Veneers With 1.0 Ml With Radial Shoulder Finishline Design Includes Axial Surfaces For A2 Ml Length, While The Second Grou-prepresents Occlusal Veneers Preparation Without Finishline. Each Main Group Will Be Subdivided Into 2 Subtypes Groups (A1, A2, B1, B2), Each Subtype Group Contains 14 Samples, The Firstsubtype Group Will Receive A Buccal Groove, While The Second Subgroup Will Be Without Grooves. Each Sub-group Will Be Divided Into 2 Classes (7samples) According To The Type Of Test It Will Be Subjected To: Microleakage, Bond Strength.

Results: Microleakage Results Measured In Millimeter(mm) Showing Mean Values And Standard Deviations(SD) For All Veneers Design Groups As Function Of Preparation Designs Are Summarized In Table(3). It Was Found That There Was No Dye Penetration Recorded For All Preparation Design Groups.

Conclusions: All Tested Occlusal Veneer Designs Luted In Acorrect Procedures With A Standardized Adhesive System Showed Nearly No Microleakage

Arsany Emil Amin Khellah, Mohammed Khashaba, Nesrine Mohammad Khairy And Mohamed Atef,

ABSTRACT


Aim: The Study Aimed To Assess Clinical Implant Stability & Pink Esthetic Score In The Socket Shield Technique With Immediate Temporization In The Maxillary Esthetic Zone.Methodology: Fourteen Patients Were Randomly Selected From The Outpatient Clinic Of The Implantology Department. They Were Treated With Immediate Implant Placement With Socket Shield Technique And Immediate Temporization In The Maxillary Anterior Region. The Patients Were Assigned To Be Treated Using 30 Titanium Implants.

Results: Means No Visual Change Of Bone Level From Preoperative And Post 6 Months X-ray, Mean PES Immediately Postoperative Was 10.1 + 1.4 That Increased To 11.6+1.4 Six Months Postoperative The Difference Was Statistically Significant( ? 0.05) , Mean Stability Immediately Postoperative Was 56.3+3.9 That Increased To 69.5+4.7 Six Months Postoperative The Difference Was Statistically Significant ( ? 0.05)Conclusion: Socket Shield Technique With Immediate Temporization Is A Viable Option For Immediate Replacement Of Teeth In The Esthetic Zone, Overcoming Dimension Bone Changes After Extraction And Soft Tissue Contour. The Contact Between The Rough Titanium Surface And The Tooth Surface In Immediate Implant Placement Simultaneously With Partial Extraction Therapy Technique Does Not Affect Implant Stability Or Osteointegration. Long Term Follows Up Studies Are Required To Confirmthe Long Term Stability Of The Technique. The Main Factor In Implant Placement Is The Proper Prosthetic Position, Either Contact Or Not With The Shield.