Yasmin Hefnawy, Jylan Fouad El-Guindy And Lamyaa Khair Allah,

ABSTRACT
The Aim Of This Study: Was To Measure The Fracture Resistance In Endodontically Treated Teeth Restored With Lithium Disilicate Crowns Retained With Fiber Posts And Core Compared To VITASUPRINITY And CERASMART Endocrowns. Statement Of The Problem: The Risks That Increased The Potential Of Tooth Fracture After Endodontic Treatment, The Risks Included Loss Of Tooth Structure, Post Canal Preparation, Post Selection. Endocrowns Were Revealed To Fail More When Fixed To Premolars. The Influence Of Different Crown Material On Fracture Resistance Of Ceramic Crowns Placed On Endodontically Treated Maxillary Premolars Has Not Been Clearly Established. RESEARCH QUESTION: In Endodontically Treated Maxillary Premolars Will Teeth Requiring (VITASUPRINITY) And Hybrid Ceramics (CERASMART) Endo Crowns Provide Better Fracture Resistance Compared To Lithium Disilicate Ceramic Crowns Retained With Glass Fiber Posts? Hypothesis: 1. Endo-crowns Will Have More Fracture Resistance Than Lithium Disilicate Crowns Retained With Fiber Postsand Composite Core. 2. Endocrowns Restoration Made Of VITASUPRINITY Material Would Show More Fracture Resistance Than Endocrowns Made Of Hybrid Ceramics CERASMART. Conclusion: 1. Both VITASUPRINITY And CERASMART Endocrowns Are As Promising As Fiber Post And Composite Core Supported IPS E.max CAD Crowns. 2.Favourable Mode Of Fracture Of VITASUPRINITY, CERASMART Endocrowns And Fiber Post And Composite Core Supported IPS E.max CAD Crowns Since The Fracture Was Mostly Above CEJ ?repairable?. 3. All Fracture Resistance Loads Obtained Were Far Beyond The Maximum Masticatory Forces, Which Can Withstand The Maximum Intraoral Masticatory Forces In The Maxillary Premolar Region.

Rana A. Abdulatif And Cherif A.Mohsen,

ABSTRACT
Objective: The Aim Of This Study Is To Evaluate In An In Vitro Study, The Influence Of Straight And Angulated Implant In Lower First Molar And Upper Central Incisor On The Fracture Resistance And Failure Location Of Zirconia Crowns Fabricated Using CADCAMtechnology.

Materials and Methods: In This Study 20 Casts Were Used , Epoxy Resin Mixed And Loaded In The Sockets, Then Implant Was Loaded And Fixed Into All 10 Missed Lower Molar And 10 Upper Central Incisor. According To Position Of Implants The Samples Divided Into Two Groups Anterior And Posterior. Each Group Divided Into 2 Subgroups (5 Samples Each) According To The Degree Of Abutment Angulation Straight Abutment And 15 Degree Angulation. The Specimens Were Then Subjected To Compressive Loading By Universal Testing Machine (Shimadzu Autograph AG-50kNE, Shimadzu Co., Ltd, Japan) . The Force Required (N) To Cause Fracture Of The Crown, And The Mode Of Failure Were Recorded Using A Classification Designed For The Investigation.

Results: The Mean Values �SD Of Loads At Failure (n -5) For Each Group Were As Follows In Newton (N): Posterior Straight Angle (A- I) 1361.6�245.3-,posterior 15 Angulation,(A-II) 1820.6�168 , Anterior Straight Angulation(B-I) 1117.5�112, Anterior 15 Angulation (B-II) 1435�135.9 0There Was Significant Increase In The Maximum Resistance At Angle 15 Compared With Angle 0 At Anterior E And Posterior Site.(p<0.05). Conclusion: Within The Limitations Of The Invitro Study, The Following Can Be Concluded: (I) Angulation 150 Abutment Increases Fracture Resistance Of The Overlaying CAM-milled Zirconia Single Crowns Than Straight Abutment. (II) All The Values Of Fracture Resistance Obtained In This Study Were Higher Than The Average Of Normal Occlusal Forces . (III) There Was Insignificant Difference Between The Posterior And Anterior Sites At Straight And Angulated.

Aya A. Hamzawy, Omneya M. Wahba And Iman S. ElShamy,

ABSTRACT
Background: Oral Cancer Represents 3% Of All Body Lesion With High Mortality Rate And Poor Prognosis. Lymph Node (LN) Metastasis Is One Of The Most Important Prognostic Factors Related To Survival Of Oral Squamous Cell Carcinoma (SCC). Overexpression Of Metastasis-associated Protein 1 (MTA1) Has Been Demonstrated In A Variety Of Human Cancers And Significantly Associated With The Tumor Size, Lymph Node Metastasis, Clinical Stage, Tumor Invasion, And Prognosis Of These Cancers; However, Its Role In Determining Lymph Node Metastases In Oral SCC Remains Unclear. OBJECTIVES: Detect And Compare The Expression Patterns Of MTA1 Immunohistochemically In Metastasizing And Non-metastasizing Oral SCC. MATERIALS AND METHODS: MTA1 Expression Was Detected Immunohistochemically In 40 Oral SCC Specimens And The Correlation With LN Metastasis Was Evaluated. RESULTS: Upregulation Of MTA1 Nuclear Expression Had A Significant Correlation With LN Metastasis But Not With The Histologic Grade Of The Tumor. CONCLUSIONS: The Present Study Suggests That Increased MTA1 Epithelial Cell-expression At The Invasive Front Reflects Its Potential Role During Invasion And Metastasis. Whereas, Nuclear Expression Of MTA1 Can Be Used A Predictor Of SCC Aggressiveness.

Ragia Mounir , Omniya Abdel Aziz And Khaled Jamal,

ABSTRACT
The Use Of Mineralized Plasmatic Matrix Derived From Autogenous Bone In Grafting Of The Residual Socket (socket Preservation) Aims To Preserve The Bone At The Same Level And To Regenerate New Bone With Better Quality As Compared To Socket Preservation Using Particulate Autogenous Bone Graft. The Goal Of The Present Study Evaluate And Assess The Effectiveness Of Mineralized Plasmatic Matrix (MPM) Versus Autogenous Bone Graft In Socket Preservation In Mandibular Anterior And Premolar Area. Methods:Ten Patients With Total 20 Extraction Sites In Lower Anterior And Premolar Area Who Fulfilled Specific Inclusion Criteria Were Assigned Into Two Groups Group A(Study Group), Group B (control Group). According To The Surgical Technique Used, In Study Group MPM Was Placed In Extraction Sockets Of Mandibular Anterior And Premolar Region, In Control Group Extraction Sockets Were Grafted With Autogenous Bone Graft, After 3 Months And Comparison And Implants Were Placed And Standardized X-ray Was Performed, Three Months Later Another X-ray Was Taken To Compare Crestal Bone Loss In Both Groups.

Results: Bone Loss Was Assessed In Both Group After 3 Months Following Implant Placement And Showed No Significant Difference.

Eman A. S. Khalaf, Laila E. Amin, Ayman M. Nagib And Fatma M.M. Ibrahim,

ABSTRACT
Objective: Chronic Renal Failure Can Elicit A Wide Spectrum Of Oral Manifestations In The Hard And Soft Tissues. Many Studies Have Demonstrated The Efficacy Of Casein Phosphopeptide Amorphous Calcium Phosphate With Fluoride Paste In Promoting Remineralization Of Enamel And Dentin In Vitro. Design: This Study Was Designed To Determine The Effect Of Renal Insufficiency On Patients? Teeth (enamel And Dentin) And Study Biological Effects Of Topical Application Of Fluoride On Extracted Teeth.

Materials and Methods: Twenty Sound Posterior Teeth Were Used, Divided Into 2 Groups, Group I (control Group) And Group II (fluoride Group). Each Group Was Subdivided Into 2 Subgroups; A (control) And B (uremic). All The Specimens Were Scanned By Using Scanning Electron Microscope And Elemental Analysis Of Enamel And Dentin Surfaces Was Tested Using Energy Dispersive Analytical X-ray.

Results: Enamel Of Uremic Teeth Showed Irregular Enamel Surface With Deep Depressions And Pitting. Also, Dentinal Tubules Showed Different Shaped Outlines And Diameter. The Application Of Fluoride Paste Was Significantly Increase In Calcium And Phosphorus Levels.

Conclusions: Chronic Renal Failure Leads To Alteration In The Structure Of Enamel And Dentin With Significant Increase In Mineral Content (Calcium & Phousphrous) When Compared With Healthy Teeth. The Topical Application Of Fluoride Was Effectively Enhanced The Remineralization And Counter Act Demineralization And Erosion.

Tarek Anwar, Ashraf Mokhtar And Hanaa Zaghloul,

ABSTRACT
Statement Of The Problem: Bond Strength Is A Very Important Determinant Of Clinical Success Of Dental Prosthesis. However, With The Introduction Of Hybrid Ceramics, Further Information Is Needed Regarding The Use Of Universal Adhesives As Bonding Agents. Aim Of The Study: To Evaluate The Effect Of Surface Treatments And Universal Adhesives On The Micro-shear Bond Strength Of Hybrid Ceramics.

Materials and Methods: Two CAD/CAM Hybrid Ceramics (VITA Enamic (VE) And LAVA Ultimate (LU)) Were Used In This Study. Each Was Cut Into 4 Ceramic Specimens. The 8 Ceramic Specimens Were Divided Into 2 Groups (n=4) According To The Material. Each Group Was Subdivided Into 2 Subgroups (n=2) According To The Surface Treatment; Hydrofluoric Acid Etching (HF) And Sandblasting (SB). Each Subgroup Was Further Divided Into 2 Subgroups (n=1) According To The Universal Adhesive Used; Scotchbond Universal (SbU) And Futurabond U (FbU). Silane Was Applied On All Specimens For 60 Seconds. All Specimens Were Cemented With RelyX-Ultimate Resin Cement Through Microtubules. They Were Then Thermocycled As An Artificial Aging To Simulate The Oral Environment. Micro-shear Bond (?SBS) Test Was Performed On All Thermocycled Specimens Using The Universal Testing Machine.

Results: LU Showed A Higher Statistically Significant ?SBS Value Than VE (P<0.001). HF Showed A Better Statistically Significant ?SBS Value Than SB (P<0.001). No Statistical Significance Was Found Between The Two Tested Universal Adhesives (p=0.060).

Conclusions: 1) Ceramic Microstructure Had A Great Impact On The ?SBS. 2) HF Could Be Considered As A Reliable Surface Treatment Protocol Of Hybrid Ceramics. 3) The Presence Of MDP In The Universal Adhesive Did Not Have A Significant Influence On The Micro-shear Bond Strengths Measured.

AbdelFattah Elhabashy, Mohamed Z. Amer, Wael S. Ahmed And Wael M. Safwat,

ABSTRACT
Problem Statement: Stereolithographic Surgical Guides Were Introduced As An Aid To Overcome Blind Technique Associated With Flapless Implant Placement And To Compensate Surgeon Experience. This Study Was Conducted To Evaluate The Accuracy Of Flapless Placement Of Dental Implants In Posterior Mandible With And Without Using Stereolithographic Surgical Guide. Patient And Method: Twelve Patients, Ten Females And Two Males, Received Sixteen Dental Implants To Replace Missing Mandibular Posterior Teeth. All Patients Were Equally Divided Into Two Groups. In 1st Group, 6 Patients Received 8 Dental Implants Using Stereolithographic Surgical Guide Without Flap Reflection. While, In 2nd Group, 6 Patients Received 8 Dental Implants Using The Conventional Surgical Guide Without Flap Reflection. All Implants Were Subjected To Immediate Loading Within 1 Week. Preoperative And Postoperative CBCT Were Performed For Both Groups To Evaluate Accuracy Of The Actually Placed Implant In The Oral Cavity Compared With The Virtually Planned Implants In The Software. All Patients Were Clinically And Radiographically Assessed At Baseline (T0), After 6 Months (T1), And After 12 Months (T2) Of Follow Up Regarding To Implant Stability, Peri-implant Pocket Depth, Modified Sulcus Bleeding Index, And Marginal Bone Level. Result: All Implants Were Successfully Osseointegrated. There Were No Statistical Significant Differences Between Planned And Placed Implants In Both Groups Regarding To Angular Deviation, Horizontal Deviations At Coronal And Apical Parts, And Vertical Deviations At Coronal And Apical Parts (P= 0.645, 0.721, 0.442, 0.234, 0.328 Respectively). No Significant Differences Were Recorded Between Both Groups Regarding To Stability, (mSBI), And (PPD) At Different Time Intervals Of Follow Up Periods Either At, (T0), (T1), Or At (T2) (P=0.721, 0.798, 0.505 Respectively), (P=0.721, 0.105, 0.721 Respectively), And (P=0.505, 1.000, 1.000 Respectively). Nevertheless, There Were Statistical Significant Differences Between Both Groups Regarding To (MBL) Either At, (T0), (T1), Or At (T2) (P=0.010*, 0.001*, 0.001*respectively). Conclusion: Both Flapless Techniques Either Aided By Stereolithographic Guide Or Aided By Conventional Guide Give Comparable Good Results Without An Additional Superiority Regarding To Accuracy Parameters Of The Implant Inserted In The First Group By Stereolithographic Guide.

Hebat-Allah Mostafa Mohamed, Ahmed Mohamed Fayed, Dina Wafik Elkassas And Olfat Sayed Hassanien,

ABSTRACT
The Aim Of This Study Was To Evaluate The Color Stability Of Two Different In-office Bleaching Techniques With The Corresponding Post Bleaching Remineralizing Agent And Nano-hydroxyapatite Paste. Materials And Methods. Twenty-eight Patients Were Divided Into Two Groups (n=14), In Accordance With The Bleaching Agent Applied Either Photo Or Chemo Catalyzed Bleaching Agent (25% And 30% Hydrogen Peroxide), And In Accordance With The Remineralizing Agent Applied After Bleaching Either ACP (control Group) Or Nano-hydroxyapatite Paste. Color Stability Was Assessed Using A Spectrophotometer At Baseline, After Twenty-four Hours, After One Week, After Four Weeks And After 24 Weeks Time Intervals. The Results Were Submitted To Statistical Analysis Using Mann-Whiteny U Test And Friedman?s Test. Results. No Statistically Significant Difference Was Found Between Groups That Received ACP And Nano P In The Photo Catalyzed System, Meanwhile A Statistically Significant Difference Was Found With The Chemo Catalyzed Bleaching System After Nano P Application. Conclusion. Nano P Did Enhance The Color Lightening And Stability Of The Chemo Catalyzed Bleaching System.

Fayrouz Abdel Hassieb, Ashraf Hassan Mokhtar And Tamer Abd El Rehim Hamza,

ABSTRACT
Statement Of The Problem: Fracture Resistance Is Essential For The Long-term Success Of Endocrown Restorations. Recently The Use Of Hybrid Ceramics Had Been Used For Endocrown Fabrication Yet The Studies Comparing Their Fracture Resistance Are Limited. The Purpose Of This In Vitro Study: Was To Compare Fracture Resistance Of Recently Introduced Hybrid Ceramic And Lithium Disilicate Endocrown Restorations Cemented With Two Bonding Approaches.

Materials and Methods: Twenty Extracted Human Maxillary First Molars Were Divided Into Two Equal Groups Of Ten Teeth According To Ceramic Material Used Each Group: Group (E): Ten Teeth Were Prepared To Receive E-max Endocrowns. Group (V): Ten Teeth Were Prepared To Receive Vita-Enamic Endocrowns. Each Group Was Further Subdivided Into Two Groups (n=5) According To Bonding Approach: Sub Group (1) N=5: Endocrowns Cemented With Self-adhesive Rein Cement (Rely-X Unicem). Sub Group (2) N=5: Endocrowns Cemented With Self-etch Adhesive (Futurabond DC 8th Generation) And Self-adhesive Resin Cement (Rely-X Unicem). After Standardized Preparation Of All Samples Fracture Resistance Was Tested Using Universal Testing Machine.

Results: Showed That Ceramic Type Had A Statistically Significant Effect On Mean Fracture Resistance. Cementation Technique And The Interaction Between The Two Variables Had Non-statistically Significant Effect On Mean Fracture Resistance. Since The Interaction Between The Variables Is Non-statistically Significant, So The Variables Are Independent From Each Other.

Conclusions: 1) Lithium-disilicate Endocrowns Showed Higher Fracture Resistance Than Hybrid Ceramics Endocrowns. 2) Futurabond DC In Combination With Rely-X Unicem Increased The Fracture Resistance Of Hybrid Ceramic Endocrowns Approximating Their Performance To Lithium-disilicate Endocrowns.

Heba Talat Mustafa El-Wakeel, Mohamed Galal El-Behiery And Tarek Ibrahim El-Ghareab,

ABSTRACT
The Amount Of Hard Tissue Resorption Following Tooth Extraction Sometimes Jeopardizes Prosthetically Driven Implant Placement; Therefore, There Is Great Interest In Socket Preservation Techniques That May Result In Less Alveolar Bone Loss. For The Most Part, Research Has Focused On The Healing Of Alveolar Sockets And The Ramifications Of Post Extraction Implant Placement. The Alveolar Bone Crest Is Known To Lose Volume During The First 6 Months After Tooth Extraction, Mostly On The Buccal Wall. The Aim Of The Presented Study Is To Evaluate Clinically And Radiographically A New Alternative Technique For Socket Preservation By Placement Of Collagenated Cortico-cancellous Xenograft Over An Intact Buccal Plate After Extraction. Ten Patients Were Selected Who Need Extraction For Non-restorable Single Rooted Teeth Where Atraumatic Extraction Was Performed Using Periotome And Forceps And A Surgical Caliper Was Used To Measure The Buccolingual Dimension At A Midpoint Then A Periosteal Elevator Was Used To Carefully To Create A Pouch On The Buccal Aspect At Midpoint Areas Of The Socket. Prehydrated Collagenated Cortico-cancellous Xenograft, Composed Of 80% Granulated Mix & 20% Collagen Gel?,which Is In A Paste Form Presented In Syringe Was Next Placed In The Pouch Overlying The Buccal Plate With Its Syringe. Clinical And Radiographic Examination Was Done For Each Patient By A Cone Beam C.T (CBCT) At The Pre-determined Follow Up Periods: Immediate Postoperative (base Line) And Four Months Postoperatively. Either Using Cone Beam Or Caliber; There Was No Statistically Significant Change In Mean Bone Width Measurements After 4 Months.