Ahmed G. Abdelnabi, Shams W. Amged And Cherif A. Mohsen,

ABSTRACT
Objective The Purpose Of This Study Was To Assess Fracture Strength And Colour Change Of Different Constructed Thicknesses Of Two Different Materials Namely IPS E.max Press And IPS E.max CAD.

Materials and Methods: Thirty Sound Extracted Human Permanent Premolar Teeth (N =30, N = 15 Per Group) Were Occlusaly Sectioned To Expose Underlying Yellow Dentin And Create A Smooth Uniform Surface. Standardized Preparations Of Thirty Disc Of Lithium Disilicate HT A3 Were Studied; They Were Divided Into Two Groups (15 Samples For Each) According To The Process Of Fabrication Into IPS E.max CAD And IPS E.max Press. Each Group Was Subdivided Into Three Groups According To Thickness 0.5mm, 1mm And 1.5mm (5 Samples For Each). Each Sample Was Cemented To Its Represented Tooth Using Adhesive Resin Cement Universal (A2 Shade) And Preserved In Distilled Water For 3 Days. A Digital Spectrophotometer (vita Esayshade) Was Used And CIE LAB Parameters Were Measured And The Average Values Of The Color Differences (?E) Were Calculated. The Samples Then Subjected To Vertical Compression Load Until Failure Using A Universal Testing Machine. Data Were Collected, Tabulated And Statically Analyzed. One Way ANOVA Followed By Pair-wise Tukey?s Post-hoc Tests Were Performed To Detect Significance Between Groups. Student T-test Was Done Between Subgroups. Result: The Results Showed That IPS E.max Press Recorded Higher Color Change (3.436) Than IPS E.max CAD (2.751). Concerned Fracture Resistance Highest Mean Value Was Recorded For The IPS E.max CAD (850.6N) That Higher Than IPS E.max Press (687.133N). (p�0.05). For Both Groups Of Monolithic Lithium Disilicate Glass-ceramic Material With 1.5mm Thickness Recorded Higher Fracture Strength Than Those Monolithic Lithium Disilicate Glass-ceramic Material With 1mm And 0.5mm. Conclusion: IPS E.max CAD Advocated Lower Color Change Compared With IPS E.max Press. And Concerning Fracture Strength, The IPS E.max CAD Advocated Higher Fracture Strength Compared With IPS E.max Press.

Raghda Ashraf Hassan Fayez, Ahmed Nour-Eldin Ahmed Habiband Rasha Mohamed Abdelraouf,

ABSTRACT

Objectives: The Aim Of The Present Study Is To Evaluate The Effect Of An Experimental Bioactive Glass-based Nanopowder Formula (BG-based Formula) Compared To Casein Phosphopeptide-Amorphous Calcium Phosphate Fluoride (CPP-ACPF) On Remineralization Of Experimentally Induced White Spot Lesions (WSL) In Enamel. Methods: Twenty Seven Upper Human Permanent Central Incisors Were Collected, Polished And Randomly Distributed Into Three Groups (I, II And III). WSLs Were Induced In All Teeth. Each Group Was Daily Subjected To The Remineralizing Agents (14 Days); Group I (negative Control) Was Suspended In Artificial Saliva, Group II Was Treated With CPP-ACPF, While Group III Was Treated With The Slurry Of The Experimental BG-based Formula. The Microstructure And Minerals Content Of Enamel Were Examined For Each Group Using SEM And EDXA At The Baseline, After Formation Of The WSL, And After Remineralization.

Results: Group III (the Experimental BG-based Formula) Showed More Regular Deposition Of The Mineral Layer On The Surface. A Subsurface EDXA Profile Of A Sectioned Representative Tooth From Each Group Showed That The Experimental BG-based Formula Was Effective In Surface As Well As Subsurface Remineralization Of WSLs. Whereas, MI GC Tooth Paste Plus (CPP-ACPF) Showed Remineralization Of The Enamel Subsurface More Than The Enamel Surface. Significance: Both CPP-ACPF And The New Experimental BG-based Nanopowder Formula Were Both Effective In Remineralization Of Enamel WSLs, With Less Surface Remineralization In Case Of CPP-ACPF.

Dalia M. Ghalwash, Khaled A. El Gaaly And Amani M. Zaki Abozeid,

ABSTRACT
Bisphosphonates (BPPs) Is A Drug Used In Treatment Of Many Pathological Conditions In Different Doses, Which Could Have Diverse Effects On Implant Success In Patients Receiving It. In This Study The Effect Of Oral Bisphosphonates On Successful Osseointegration Were Evaluated By Comparing The Effect Of High And Standard Doses Of BPPs On Bone Density Around Implants. Methodology: Implants Were Inserted In The Heads Of Femurs Of 25 Rabbits Were Divided Into 3 Groups. One Group Received Standard Dose Of BPPs, Another Group Received High Dose Of BPPs And A Control Group. Bone Density Was Evaluated Around Each Implant Using Radioactive Dating And CBCT. At The End, All Results Were Compared Together And Statistically Analyzed.

Results: BPPs Affected Bone Quality Close To And Far From The Implant Differently According To The Dose. Higher Doses Of BPPs Were Associated With Better Contact Osseointegration, While Standard Doses Were Associated With Better Distant Oasseointegration. Conclusion: Standard Doses Of BPPs Therefore Have Better Effect On The Quality Of Bone Surrounding Implants. So, Together With Obviously Having Less Side Effects, The Standard Doses Of Oral BPPs Could Be Considered Superior To High Doses In Achieving Our Optimum Goals Of Successful Osseointegration With Minimum Undesirable Side Effects.

Noura. Mokhtar ; Samir. Zidan And Ashraf. Taher,

ABSTRACT
Statement Of The Problem: When Dental Ceramic Materials Are Exposed To The Oral Environment, They May Undergo Physicochemical Alterations. The Incidence Of Repeated Forces During Chewing Results In Stress Concentration, And Thermal Variations Induce Fatigue Of The Materials. Thus, Restorations Are Prone To Catastrophic Failure When Subjected To Stress. Efforts To Enhance The Service Life Of All-ceramic Materials Have Been Undertaken To Improve Their Strength (s) And Fracture Toughness (KIC).

Purpose: The Aim Of This Study Was To Evaluate The Fracture Toughness And Hardness Of Vita Suprinity CAD/ CAM With And Without Cyclic Loading And Thermocycling.

Materials and Methods: A Total Of 24 Vita Suprinity Plates Of 3mm Thickness Were Cut By An Isomet Cutting Machine. All The Specimens Were Sintered And Then Auto-glazed According To Manufacturer?s Instructions. All Specimens Were Stored In Distilled Water At 37oC For 24 Hours In Sealed Containers In Incubator. Half Of The Specimens Were Exposed To Thermal Cycling With Number Of Cycles Was 500 Cycle , Dwell Times Were 25 S. In Each Water Bath With A Lag Time 10 S. And The Low-temperature Point Was 5 0C). The High Temperature Point Was 55 0C,and Also Were Exposed To Cyclic Loading In Chewing Simulator Machine In Which Twelve Specimens Of Experimental Ceramic Group Were Exposed To The Mouth-motion Fatigue At Load Of 50 N For 20,000 Cycles With A Frequency Of 1.6 Hz. The Other Half Was Left Without Any Aging Procedures. Surface Hardness And Fracture Toughness Were Measured Before And After Storage Where The Surface Hardness Was Measured Through Vicker?s Indentation By Using This Equation. HV=1.854 P/d2. Fracture Toughness Was Calculated By The Indentation Method Through This Equation. KIC = 0.016(E/H) 0.5 (P/c1.5).

Results: It Was Found That: Aging Procedure Affected On Vickers Hardness Mean Value Significantly. It Was Found That The Highest Mean Value Of Hardness Recorded At Baseline Then After Water Storage While The Lowest Mean � SD Value Of Hardness Recorded After Thermo-mechanical Aging. The Difference Was Statistically Significant. It Was Found That Aging Procedure Affected On Fracture Toughness Mean Value Non-significantly. It Is Found That The Highest Mean Value Of Fracture Toughness Recorded At Baseline Then After Thermo-mechanical Aging While The Lowest Mean � SD Value Of Fracture Toughness Recorded After Water Storage. The Difference Was Statistically Significant.

Conclusions: From The Findings Of Our Study, Ageing Procedure With Thermocycling And Cyclic Loading Negatively Affected The Surface Hardness And Cause Non-significant Increase In The Fracture Toughness Of Vita Suprinity.

Hend Khaled Samir, Mervat Rashed, Dalia Moheb And Samah Awad,

ABSTRACT
The Lack Of The Normal Values Of Physiologic Tooth Mobility For Healthy Maxillary Permanent Central Incisors With Closed Apex For Children In The Egyptian Population Urged The Need To Conduct This Study. The Periotest M Device Was Used Because Of Its So Many Merits As The Reliability& Unbiased Results. It Was The Latest Wireless Device That Was User Friendly & Could Be Easily Accepted By The Children. The Total Sample Size Was 377 Children (164 Males & 213 Females) In The Pre Pubertal Period (9-13 Years Old) To Exclude The Hormonal Influence On The Readings. The Upper 2 Central Incisors For Each Child Were Tested, Giving A Total Of 754 Teeth Tested In This Study. These Values Can Be Extremely Beneficial In Early Diagnosis Of Certain Diseases Or Problems Of The Periodontium In Pediatric Dentistry. In Traumatic Dental Injuries, Using The Periotest Can Help In Monitoring The Progress Of The Treatment Of Traumatized Teeth & The Duration Of The Splint. In Addition This Could Allow The Operators To Be More Certain About The Line Of Treatment Offered To The Traumatized Teeth. The Study Was Able To Find The Numbers To Answer The Aim Of The Study. The Results Showed That Gender Affected The Scores Of The Periotest Significantly At The Age 12.5 Years In The Studied Sample. There Was A Negative Significant Correlation Between Age And Average Periotest Reading For Males & An Insignificant Correlation Between Age And Average Periotest Reading For Females In The Studied Sample.

Mohamed M Abielhassan, Khaled M Ezzat And Geraldine M Ahmed,

ABSTRACT
The Purpose Of This Randomized, Double-blind, Controlled Study Was To Assess The Effect Of Antibiotic Premedication On Pre Treatment And Post Opertive Pain After Endodontic Treatment. Forty Two Patients With Symptomatic Irreversible Pulpitis Were Randomized And Allocated To Experimental And Placebo Groups Where The Experimental Group Received The Antibiotic Premedication. Degree Of Pain Was Measured By The Number Of Analgesics Needed In Addition To A Four Step Pain Scale Before Initiation Of Endodontic Treatment And At Time Intervals Of 6, 12, 24, 48 And 96 Hours. We Found That No Statistical Significant Difference Was Detected At The Pretreatment Time Interval. Statistical Significant Difference Was Groups After 24 Hours Of Endodontic Treatment Where The Experimental Group Reported Less Degree Of Post Operative Pain Than The Placebo Group. No Statistical Significance Difference Detected At Other Time Intervals. We Concluded That Antibiotic Premedication Could Be Prescribed To Lessen The Degree Of Post Operative Pain After Endodontic Treatment.

Yasmin A. Youssef , Noha S. Abu-Taleb And Hany M. Omar,

ABSTRACT

Objectives: To Evaluate The Effect Of Using Two Different Voxel Sizes (0.4mm And 0.2mm) On The Accuracy Of Cone Beam Computed Tomography In The Detection Of Simulated Mandibular Condylar Erosions.

Materials and Methods: Twelve Dry Human Mandibles (24 Condyles) Were Selected And Simulated Erosions Were Drilled On The Five Condylar Surfaces (superior, Anterior, Posterior, Medial And Lateral Surfaces). The Mandibles Were Scanned With PlanmecaPromax 3D Mid CBCT Machine Usingnormal And High Resolution Protocols (voxel Sizes: 0.4mm And 0.2mm Respectively).

Results: Regardingthe CBCT Normal Resolution Protocol(voxel Sizes: 0.4mm) The Sensitivity Of Detection Of The Simulated Defects Ranged From 87.05% To 94.96% And The Accuracy Values From 88.9% To 95.86% Among The Observers. However, Higher Values Were Found With The High Resolution Protocol (voxel Sizes: 0.2mm) Where The Sensitivity Values Increased To The Range Of 93.53% To 97.84% And Also Did The Accuracy Values With Range Of 94.44% To 98.15%.The Percentage Agreement Between Both Protocols Were 97.53% And 93.21% For The Two Observers. Conclusion: Despite The Higher Sensitivity And Diagnostic Accuracy Values Of The CBCTsmaller Voxel Size Protocol, Both Protocols Were Comparable In The Detection Of The Simulated Mandibular Condylar Erosions.

Ahmed T. Farag, Sherine E. Taha And Randa Y. Abdel-Gawad,

ABSTRACT
The Mesio-distal Crown Diameter Of Teeth Is An Important Factor Which Affects The Alignment Of Teeth In The Bony Arches And The Development Of Occlusion During Transition Of The Dentition. This Study Was Concerned With The Mesio-distal Width And Dental Arch Dimensions In Egyptian Children In Rural Areas Of Al Giza Governorate Which Will Be Helpful To Overcome Obstacles Which May Be Faced In Different Fields Of Dentistry (orthodontics, Pedodontics, Prosthodontics And Oral Surgery).
Objectives: Determine The Combined Mesio-distal Width Of The Permanent Mandibular Incisors And That Of The Maxillary And Mandibular Canines And Premolars In A Group Of Egyptian Children In Rural Areas Of Al Giza Governorate. And To Find The Correct Relationship Of The Total Mesiodistal Widths Of Teeth Under Study. Methods: A Sample Of 280 Egyptian Childeren With An Age Range From 12-15 Years Attending Schools In Rural Areas Of Al Giza Governorate. The Children Were Referred From These Schools (Almansorya, Berkash, Nekla And Abdelsamad?s) To The Local Medical Health Unit In Al Giza Governorate To Be Examined.

Results: In This Study The Results Showed That The Teeth Size Of Male Subjects Was Slightly Larger Than That Of The Female Subjects. There Was No Statistical Significant Difference In The Mean Of Mesiodistal Tooth Width Between Right And Left Sides For Almost All Teeth Under Study. And A Positive Correlation Exists Between The Sum Of The Mesiodistal Width Of Upper Right Canine And Premolars & The Sum Of The Mesiodistal Width Of The Lower Incisors Among Both Genders Combined. Conclusion: The Mesiodistal Width Of Upper And Lower Canines And Premolars Can Be Predicted By Measuring The Mesiodistal Width Of Lower Incisors, Clinicians Can Rely On The Meisodistal Tooth Width Of One Side If The Contra Lateral Was Missing And Separate Data Regarding Sex While Treating Egyptian Children Has To Be Used.

Moustafa Mohammed Sayed, Nagawa Mohammed Ali Khattab And Wael Hamada Ahmed,

ABSTRACT
Background: Several Medicaments Have Been Used In Pulpotomy Procedures Of Primary And Young Permanent Teeth With The Objective To Maintain Pulp Vitality And Promote Healing Of The Pulp Remnants. Aim Of Study The Aim Of This Study Was To Evaluate The Histological Response Of Pulpotomized Dental Pulp In Dogs To Biodentine And Portland Cement.

Materials and Methods: The Study Included 72 Teeth On 3 Apparently Healthy Adult Mongrel Dogs, It Was Classified Into 2 Groups According To The Tested Material. Group 1: Included 36 Teeth Capped By Biodentine, Group 2: Include 36 Teeth Capped By Portland Cement. The Hard Tissue Formation Over 1, 2, 3 Months Periods Were Recorded.

Results: Histopathological Analysis Showed Complete Dentinal Bridge Formation. Layers Of Well-arranged Odontoblast And Odontoblast-like Cells Were Found To Form Tubular Dentin Under The Osteodentin. Statistical Analysis Showed No Significant Differences Between The Biodentine And Portland Cement Experimental Groups During The Observation Period. Although All Specimens Of Both Groups Showed Formation Of Dentine Bridge, The Dentine Bridge Formed By Biodentine Was Of Better Quality Than Portland Cement Conclusion: Within The Limitation Of The Current Study Biodentine Was Superior To Portland Cement In Terms Of Better Quality Of Dentine Bridge.

Abdel Monem Tawfik Gadallah, Eman Abdel Salam Youssef And Enas Ebrahim Gamil Elzeny,

ABSTRACT
Background: Pedicle Flap Design Is Reported To Enhance Wound Healing And Decrease Incidence Of Dry Socket. However, Limited Data Are Available In The Literature About Its Effect Following The Removal Of Impacted Mandibular Third Molar.

Purpose: To Compare The Post-operative Complications Of The Traditional Triangular Flap And The Pedicle Flap After Surgical Extraction Of Mandibular Third Molars.

Materials and Methods: This Study Was Conducted On Forty Impactions Presented In Twenty Patients With Bilateral Impacted Mandibular Third Molars, Divided Into Two Equal Groups; Group A: The Study Group, In Which Pedicle Flap Design Was Performed And Group B: The Control Group, In Which Triangular Flap Was Performed. Postoperative Pain Was Evaluated Using Visual Analogue Scale (VAS) On 2nd And 7th Postoperative Days, Swelling Was Evaluated On 2nd And 7th Day Postoperatively Using Tape For Measurement Of Two Facial Dimensions, Trismus On 2nd And 7th Days Postoperatively By Using Digital Vernier Was Evaluated Calipers, Wound Dehiscence And Dry Socket Were Evaluated On 2nd And 7th Postoperative Day. Result: There Was No Significant Difference Between The Two Flap Designs Regarding Postoperative Swelling, Trismus And Pain. The Wound Dehiscence Was Lower In The Pedicle Flap Group Compared To The Triangular Flap Group As Recorded In Second Day (P<0.001) And Seventh Day (P=0. 01). The Dry Socket Was Lower In The Pedicle Flap Group Compared To The Triangular Flap Group As Recorded In Second Day(P=0.047) While No Statistical Significance Difference Between Both Groups In The Seventh Day (P=0. 102). Conclusion: There Is No Significant Difference Between The Pedicle Flap Design And The Triangular Flap Regarding Postoperative Pain, Trismus And Swelling After Impacted Third Molar Surgery. However, This Study Reported That Pedicle Flap Design Had Lower Incidence Of Wound Dehiscence And Dry Socket.