Mohamed Madian *, Gehan Allam ** And Amr Abd Al Aziz*** ,

ABSTRACT


Introduction: In Recent Years, Significant Developments Have Been Taking Place In Caries Removal And Cavity Preparation Using Laser In Dentistry. As The Concept Of Laser-use For Cavity Preparation Is Being Widely Adopted In Dentistry, It Is Necessary To Determine The Quality Of Restoration Margins And Also To Assess The Strength Of The Bond Created After Laser Preparation. Resin Modified Glass Ionomer Restorations Have Great And Wide Applications In The Pediatric Field. The Purpose Of This In Vitro Study Was To Compare The Microleakage And Shear Bond Strength Of RMGI Restorations In Samples Prepared By Er:YAG Laser Versus The Conventional Method In Primary Teeth.

Materials and Methods: For Microleakage Test, 30 Primary Teeth Were Selected And Randomly Divided Into Two Groups For Cavity Preparation. Cavities In Group One Were Prepared By High Speed Diamond Bur And Cavities In Group Two Were Prepared With Er:YAG Laser And Cavities Were Restored With RMGI. The Teeth Were Thermocycled For 1000 Cycles, Placed In 2% Methylene Blue For 24h, Sectioned In The Buccolingual Direction And The Degree Of Dye Penetration Was Scored And Examined Under Stereomicroscope. In Shear Bond Strength Test, Another 30 Primary Teeth Were Selected And Randomly Divided Into Two Groups; High Speed Diamond Bur Group And Er:YAG Laser Group, In Which Samples Were Prepared In Both Groups Until Flat Dentin Surface Was Reached. RMGI Restorations Were Adhered To The Samples In Cylindrical Shape And Samples Were Thermocycled For 1000 Cycles. The Shear Bond Strength Of Samples Was After That Measured By A Universal Testing Machine And The Results Of The Two Groups Were Analyzed.

Results: There Was No Statistical Difference In Scores Of Either Microleakage Or Shear Bond Strength Between Laser Group And The Conventional Group (P>0.05). Conclusion: Er:YAG Laser With Its Advantages In Pediatric Dentistry And Excellent Acceptance May Be Suggested As An Alternative Device For Cavity Preparation In Primary Teeth.

Sarah Isaac El Mankabadi, Geraldine Mohamed Ahmed And Heba Ahmed ElAsfouri,

ABSTRACT


Aim: To Compare The Cyclic Fatigue Resistance Of Three Thermomechanically Treated Rotary NiTi Instruments 2Shape (TS; Micro-Mega, Besancon, France), ProTaper Gold (PTG; Dentsply Maillefer, Baillagues, Switzerland) And Vortex Blue (VB; Dentsply; Tulsa Dental Specialties, Tulsa, OK, USA) Under Intracanal Conditions.

Materials and Methods: A Total Of 36 Rotary NiTi Instruments Of TS (25/0.06), PTG (25/0.08) And VB (25/0.06) (n=12) Were Rotated In A Custom Made Model Having A 60? Angle Of Curvature And 5mm Radius Of Curvature Until Fracture Occurred. The Model Was Immersed In An Acrylic Container Filled With 2.5% Sodium Hypochlorite (NaOCl) Solution Set At Intracanal Temperature (35?C ? 2?C). Time To Fracture Was Recorded Followed By Calculating The Number Of Cycles To Failure (NCF). The Length Of The Fractured Segments Was Measured Using A Digital Caliper And Scanning Electron Microscope (SEM) Examination Was Also Performed. The Data Were Statistically Analyzed Using Kruskal-Wallis And Dunn?s Tests With The Significance Level Set At P ? 0.05.

Results: The PTG Group Showed The Highest Statistically Significant NCF Followed By The VB And TS Groups Respectively (P < 0.001). Both The PTG And TS Groups Exhibited No Statistical Significant Difference Regarding The Length Of The Fractured Segment (P > 0.05). However, They Had Statistically Significant Longer Fragment Compared To The VB Group (P < 0.007). SEM Analysis Revealed Typical Features Of Cyclic Fatigue Failure.

Conclusions: The Gold Treatment Had The Highest Cyclic Fatigue Resistance Followed By The Blue Treatment. The T.wire Technology Of The TS System Showed The Lowest Resistance To Cyclic Fatigue.

Manhal Gamal El-Din Ali*, Nagwa Mohmmad Ali Khattab* And Ahmad Abdel Hamid Elheeny,

ABSTRACT
Objective: The Aim Of This Study Is To Evaluate The Effectiveness?of Two Herbal Extracts; Ginger And Rosemary Compared To 2% Sodium Fluoride On The Enamel Surface Of Extracted Human Premolars Regarding Surface Microhardness, Surface Topography And Mineral Content.

Materials and Methods: 120 First Premolars Were Collected And Divided Into 6 Groups. The Herbal Extracts Were Prepared To Merge Teeth In And The Demineralization Remineralization Cycle Start For 3 Weeks. The Evaluation Was Done By Vickers Micro-hardness Test And Environmental Scanning Electron Microscope. Statistical Analysis: Mean And Standard Deviation Of Microhardness And Minerals Content (continuous Data) After Testing The Normality Of Data. Normally Distributed Data Were Compared Of Different Groups Using One-way Analysis Of Variance. For All Tests P-value Of 0.05 Or Less Was Considered For Statistical Significance And Confidence Interval Was 95%. Result: The Mean Differences Between Control And Experimental Groups Was Not Statistically Significant. Ca Mass Has Significant Difference Between Ginger And NaF, Ginger And Artificial Saliva, While There Was No Statistical Significance In P Mass Percentage. Teeth Were Examined At Magnification Of 1000 With ESEM. Fig2 (a) Shows Normal Enamel Prisms? Ends With Few Surface Deposit And No Surface Enamel Roughness. Fig 2 (b) Shows Severe Surface Roughness Of The Enamel With No Surface Deposits. In Fig.2 (c), (d), (e) The Enamel Nearly Regained Its Original Surface With Normal Enamel Prisms? Ends And No Surface Roughness.

Conclusions: From This Laboratory Research, It Can Be Concluded That Ethanolic Ginger And Rosemary Have Comparable Remineralization Effect To Sodium Fluoride.

,

Radwa Mohamed Nagieb, Mona Riad And Mohamed Mostafa,

ABSTRACT


Aim: The Aim Of This Study Was To Evaluate The Effect Load Cycling On Fracture Resistance Of A New Bioactive Restorative Material (ACTIVA) And Compared With Nano Resin Composite Materials.

Materials & Methods: A Total Of 60 Upper Premolars Were Used In The Study. They Were Divided Into Two Groups Of 30 Specimens Each According To Type Of Restorative Materials. (Group A1) Was Restored By Bioactive Restorative Material (ACTIVA), And (group A2) Was Restored By Nano Hybrid Composite Restorative Material (Filtek Z250 XT). Each Group Was Divided Into 2 Subgroups Of 15specimens According To The Number Of Received Load Cycles That Represent 24 Hours (T1) And 3 Months (T2). Mesio-Occluso-Distal (MOD) Cavities Were Prepared In All The Specimens With A 2?0.2 Mm Pulpal Depth, 1.5?0.2 Mm Gingival Width, 2?0.2 Mm Axial Height. Adhesive System As Well As Composite Resin Application Was Done According To Manufacturer?s Instructions. After Cavity Preparation And Restoration Fracture Resistance Test Were Done Using The Universal Testing Machine (Instron Model 3345 Ingland). Samples Were Secured To The Lower Fixed Compartment Of Testing Machine By Tightening Screws. Fracture Test Was Done By Compressive Mode Of Load Applied Occlusally Using A Metallic Rod With Round Tip (3.6 Mm Diameter) Attached To The Upper Movable Compartment Of Testing Machine Traveling At Cross-head Speed Of 0.5mm/min. The Load Required To Fracture Was Recorded In Newton.

Results: There Was No Statistical Significant Difference Between Both Tested Materials. The Fracture Resistance Means Values Significantly Influenced By The Number Of Cycles Applied (P < 0.05).

Conclusions: Cyclic Loading Affects The Fracture Resistance Of Tested Materials And Both Materials Can Be Successfully Used To Restore Class II Carious Lesions.

Ahmed Abosheashea Mekawy, Maged Negm And Heba El-Asfouri ,

ABSTRACT
Objective: This Study Was Conducted To Measure The Fracture Resistance Of Endodonticaly Treated Single Rooted Teeth Filledwith Two Different Endodontic Sealers, Prepared With Step-back Technique With Or Without Recapitulation In Presence Or Absence Of Posts.

Materials and Methods: A Total Of 80 Freshly Extracted Sound Human Premolars Were Selected For This Study, Teeth Were Randomly Divided Into Two Equal Groups According To Step Of Preparation Technique With Recapitulation And Without Recapitulation. Each Group Was Divided Into Two Sub-groups According To The Type Of Sealer Used MTA PLUS Sealer And Endosequence Sealer. Each Sub-group Was Divided Into Two Sub-groups According To Presence Or Absence Of Post. Teeth Then Embedded Into Acrylic Resin And Mounted On A Computer Controlled Materials Testing Machine To Detect Fracture Resistance Values.

Results: MTA Plus And Without Post Showed The Lowest Significantmean Fracture Resistance, While The Highest Statically Significantmean Fracture Resistance Was For With Recapitulation, Endosequence And With Post.

Conclusions: Step-back Technique With Recapitulation In Preparation Of The Root Canals Of Endodontically Treated Teeth Can Be Applied To Gain Reinforcement Of The Root. Combination Between Dental Post Insertion And Root Canal Obturation By Bioceramic Based Sealers Provides Proper Protection For The Tooth Against Unfavorable Root Fracture.

Ahmed Magdy Sabrah, Amany Hassan Abd El Ghany And Fady Hessain El Sayed ,

ABSTRACT


Aim: Evaluation Of Gingival Biotypes And Width Of Keratinized Gingiva Of Anterior Teeth In Adults With Abnormal Skeletal Jaw Relations. Methodology: This Cross-sectional Study Included 182 Orthodontic Patient With Skeletal Class II And Skeletal Class III Pattern (74 Males, 108 Females) Who Applied For Orthodontic Treatment In Faculty Of Dentistry, Cairo University Starting From November 2018 October 2019. They Were Included Based On Wit;s Appraisal Measured On Lateral Cephalometric Radiograph Taken As A Record For Orthodontic Treatment. They Were Further Divided Into Six Groups Based On Vertical Growth Pattern According To Facial Axis Angle. Gingival Biotypes For The Anterior Teeth Have Been Determined Either Thick Biotype Or Thin Biotype Using Probe Transparency Method. Width Of Keratinized Gingiva Has Been Measured For Each Anterior Tooth Using Digital Caliper.

Results: The Results Of This Study Have Showed Statistical Significantdecrease In The Percentage Of Thin Gingival Biotypes In Upper Anterior Teeth In Skeletal Class II Patients With Hyperdivergent Growth Pattern. Also There Was A Statistical Significantincrease In The Distribution Of Thin Gingival Biotypes In Lower Anterior Teeth In Skeletal Class II Patients With Normal Vertical Growth Pattern And Skeletal Class III Patients With Hyperdivergent Growth Pattern. Width Of Keratinized Gingiva Of Anterior Teeth Seems Not To Be Correlated With Different Skeletal Sagittal And Vertical Malocclusion Patterns. Conclusion: Thin Gingival Biotype Is More Distributed In Lower Anterior Teeth In Skeletal Class II Patients With Normal Growth Pattern And Skeletal Class III Patients With Hyperdivergent Growth Pattern. Thick Gingival Biotype Is More Prevalent In Upper Anterior Teeth In All Skeletal Malocclusion Groups With The Most Prevalence In Skeletal Class II Patients With Hyperdivergent Growth Pattern

Osama T. Ali , Cherif A. Mohsen And Raiesa M, Hashem,

Objective: The Purpose Of This Study Was To Evaluate Two Different Methods Of Surface Treatment; Conventional And Simplifiedof Three Different Dental Ceramic Materials On Micro-shear Bond Strength (MSBS).

Materials and Methods: 120 Resin Cement Cylinder-shaped Samples (1mm In Diameter And 2 Mm In Height) Were Fabricated, 5 On Each Ceramic Disc (a Total Of 24 Ceramic Discs Were Used With 10 X14 Mm? Surface Area & Height Of 2 Mm), Samples Were Divided According To The Type Of Ceramic Plate Used Into 3 Groups (each Group N = 40), Group I: Resin Cement Samples Cemented On Lithium Disilicate Plate .? IPS E.max Cad?, Group II: Resin Cement Samples Cemented On Hybrid Ceramic Plate ?Vita Enamic? And Group III: Resin Cement Samples Cemented On Zirconia Reinforced Lithium Silicate Plate ?Celtra Duo?. Each Group Was Subdivided Into 2 Subgroups According To The Technique Of Ceramic Surface Treatment (each Subgroup N = 20), Subgroup I (Conventional Technique Using HF+S), Subgroup II (Simplifiedtechnique Using Monobond Etch & Prime). Then Each Subgroup Was Divided Into Two Classes (10 Samples Each), Class I Tested For Micro Shear Bond Strength (MSBS) Without Thermocycling, Class II Tested After Thermocycling. Resin Cement Was Mixed And Then Light-cured According To The Manufacturer?s Instructions. MSBS Tests Were Carried Out Using Universal Testing Machine (Instron USA). The Data Were Collected, Tabulated, And Statistically Analyzed.

Results: It Was Found That For Emax, The Conventional Technique (50.1?6.5) Showed Higher Values Of MSBS Than The Simplifiedtechnique (42.3?10.5) Before Thermocycling While The Values Were (40.7?9.3) For Conventional And (37.6?5.6) For Simplifiedafter Thermocycling Without A Significantdifference. For Vita Enamic, The Simplifiedtechnique (38?3.7) Showed Higher Values Of MSBS Than The Conventional Technique (29.8?3.7) Before Thermocycling While The Values Were (32?4.5) For Simplifiedand (25.2?5.8) For Conventional After Thermocycling With A Significantdifference. For Celtra Duo, The Simplifiedtechnique (50.6?5.7) Showed Higher Values Of MSBS Than The Conventional Technique (41.6?9.4) Before Thermocycling While The Values Were (36.3?4.5) For Conventional And (21.1?5) For Simplifiedafter Thermocycling With A Significantdifference. The Difference Between Groups Was Statistically Tested By Independent Samples T-test P Value < 0.05 Conclusion: Monobond Etch & Prime Has Shown Better Results To HF Acid And Silane Regarding Vita Enamic And Celtra Duo. It Can Be Safely Used Without Affecting The Clinical Performance Of The Restorations. For Emax: The Conventional Technique Using HF Acid And Silane Has Shown Better Results, Though Not Statistically Significant. Thermocycling Was Responsible For Bond Strength Decreases In All Groups, Regardless Of The Materials Or The Technique Of Surface Treatment.

Samah Lotfy Abd-Elmoula Korshom, Ebtesam Abd Khalek EI-Zefzaf , Sahar Fawzy Ghoraba , And Sahar Mohey Eldin Hazzaa ,

Oral Lichen Planus (OLP) Is A Chronic Inflammatorycondition Implicating T Cell-mediated Cytotoxicity, And Involving Oral Mucosal Surfaces.Aim Of Work: To Evaluate Clinically And Immunologically The Effect Of Diode Laser Versus Topical Corticosteroid Mouthwash In The Management Of Patients With Atrophic-erosive OLP.Materials And Method: 20 Patients Suffering From OLP Were Randomly Assigned Into 2 Group. Group I: Ten Patients Received LLLT By Using Diode Laser Irradiation 808 Nm Wave Length, Group II: (Control Group) Ten Patients Treated By Topical Corticosteroids Consisting Of Dexamethasone Mouthwash For 5 Minutes, Followed 30 Minutes Later By A Mouth Rinse With 30 Drops Of Nystatin (100,000 Unites) For 5 Minutes. The Evaluation Was Assessed Clinically Via Measuring Pain Score And Size Of Lesion And Lesion Recurrence, And Immunologically By Measuring IL-6 Cytokine Level In Saliva.

Results: Corticosteroids Group Showed Better Pain Reduction Than LLLT, With No Statistically Significantdifference In The Mean Value Level Of IL-6 Level At Base Line, But At 4th Week, 1st Month, 2nd Month And 3rd Month Results Revealed Statistically Significantdifference Between G I And GII (p? 0.05).Conclusion: The Results Have Shown That LLLT Was Effective In Management Of Atrophic - Erosive OLP And It Can Be Considered As An Alternative Treatment. However, Traditional Corticosteroid Therapy Showed Better Results.

Doaa Abdel Aziz Elbedewy*, Wedad Mohammed Etman, Thuraia Mohammed Genaid And Olfat Gaballah,

ABSTRACT
Objective: The Purpose Of This Experimental Study Was To Treat Induced Demineralized Coronal Dentin Using Biomimetic Material.

Materials and Methods: A Total Of 6 Healthy Dogs Were Used In This Study. The 2nd & 3rd Upper And Lower Incisors Were Used Representing The Tested Groups. The Labial Enamel Was Removed, And Exposed Dentin Surfaces Of All Experimental Specimens Were Acid Etched. Specimens In Group I Were Treated By Agarose Hydrogel Mineralization System, While In Group II They Were Subjected Only To Oral Saliva. The Hydrogels Were Applied To The Dentin Surfaces For 5 Hours. This Procedure Was Repeated Twice Weekly With 3 Days Intervals. Two Dogs Were Used For Each Of The Three Test Periods Of Material Application (15, 30 And 45 Hours). Before Scarifying The Dogs, The Lower Left 2nd & 3rd Incisors Were Extracted Representing Control Specimens. The Morphology And The Chemical Composition Of All Dentin Surfaces Were Investigated By Using Scanning Electron Microscope Coupled With Energy Dispersive X-ray Spectrometry, And All Data Were Collected And Subjected To Statistical Analysis Using SPSS Version 20. Comparisons Between The Tested Groups And The Controls Were Conducted Using One- Way ANOVA.

Results: SEM Images Of Sound Dentin Revealed The Smear Layer Was Covering And Occluding Some Of The Dentinal Tubules In The Control Group. The Images Of Group I After 15 Hours Of Treatment Revealed The Deposition Of Some Minerals On The Walls Of The Opened Dentinal Tubules Occluding Some Of Them, And EDAX Analysis Presented A Significantincrease In (Ca) Value From (23.08) To (25.92). These Images Still Seen After 30 Hours, While After 45 Hours The Images Showed That Almost The Tubules Were Partially Obliterated With Enamel Prism-like Structures. In Group II, Images Showed Opened & Partially Occluded Dentinal Tubules, And The EDAX Analysis Showed Significantincrease In (P) Value From (7.91) To (11.58). The Previous Findingalso Found After 30 Hours And Subjecting The Teeth For 45 Hours To Oral Saliva The Images Showed Fully Opened Dentinal Tubules With A Significant Increase In (Ca) Value From (6.90) To (14.51).

Conclusions: Group I Resulted In Partially Obliterated Dentinal Tubules With Enamel Prism-like Structures, While The Oral Saliva In Group II Was Not Effective Enough To Treat Dentin Erosion Currently.