Prosthodontics and Prosthodontology Commons^™

Digital Assessment Of Subtractive And Additive Cad/Cam Fabrication Methods On The Fit And Accuracy Of Lithium Disilicate Veneers, Basma Refaat Fayad, Islam Heiba Dr, Sara Fikry Dr, Maha Nagy

Dentistry

Objectives: This study compared subtractive and additive fabrication methods regarding their impact on the marginal/internal fit, trueness, and precision of lithium disilicate ceramic veneers. Methods: Laminate veneer preparations on an acrylic tooth were duplicated into twenty-four additively manufactured resin dies. Veneers were digitally designed and fabricated via milling (subtractive) or 3D-printing (additive) (n=12/group). All veneers were scanned. For trueness, the final design served as the reference; for precision, pairwise comparisons were made within each group. For adaptation, the scanned die was the reference. Post-cementation and thermal cycling (10,000 cycles, 5–55°C), marginal adaptation was measured using a digital microscope (×100). Data …

Digital Assessment Of Subtractive And Additive Cad/Cam Fabrication Methods On The Fit And Accuracy Of Lithium Disilicate Veneers, Sara Fikry Elshafei Dr, Islam Heiba Dr, Basma Fayyad, Maha Nagy

Dentistry

No abstract provided.

Effect Of Dynamic Fatigue Loading On The Adaptation And Retention Of Maxillary Single Dentures Reinforced With Digitally Constructed Zirconia And Cobalt–Chromium Frameworks, Ghada Elgindy, Fardos N Rizk, Marwa Ezzat Sabet, Hebatallah Tarek Mohamed

Dentistry

Background. The impact of dynamic fatigue loading on denture adaptation and retention is clinically important. Zirconia and cobalt–chromium (Co–Cr) frameworks enhance denture strength, but their performance under cyclic loading remains unclear. Objectives. The aim of the study was to evaluate the adaptation and retention of maxillary single dentures reinforced with digitally constructed Co–Cr or zirconia frameworks after a simulated 1 year of function. Material and methods. Three types of maxillary single dentures were constructed on maxillary master casts. Group A included maxillary dentures without reinforcement (control group), whereas groups B and C encompassed maxillary dentures reinforced with digitally designed and …

The Effect Of Cementation Load, Unload Time And Storage Time On Film Thickness And Μtbs Durability Of Dual-Cure Resin Cements. An In-Vitro Study, Sara Adel Botros, Abdullah Hassanien, Nader Maher Tadros, Farid Sabry El-Askary, Salvatore Sauro

Dentistry

No abstract provided.

Impact Of Adhesive Curing Mode And Dentin Sealing On Bond Strength Of Cad/Cam Resin Composite, Sara Adel Botros, Mohamed Fouad Haridy, Nermin Mohieldin Abdelmohssen

Dentistry

No abstract provided.

Comparative Evaluation Of Maxillary Partial Denture Frameworks Additively Manufactured With Different 3d Printing Techniques, Basma Refaat Fayad, Islam Heiba Dr, Eman Gamal Abdelghaffar, Ayman Hany Amin

Dentistry

Objectives: To compare the accuracy of fit, surface roughness, and microstructure of cobalt chromium (Co-Cr) maxillary removable partial denture (RPD) frameworks fabricated using direct metal laser melting (DMLS) and selective laser melting (SLM). Methods: A custom Kennedy Class II maxillary partial edentulous resin model was digitally scanned, and a virtual RPD framework was designed. Frameworks were fabricated using DMLS (Co-Cr, n = 8) and SLM (Co-Cr, n = 8), while a control group was produced using a hybrid digital-conventional protocol by lost-wax casting (CAST-Co- Cr, n = 8), in total 24 frameworks. Overall and point comparison adaptation was assessed using …

Effect Of Acid-Containing Drinks On Surface Roughness And Bacterial Accumulation Of Different Types Of Denture Base Materials, Sara Fikry Dr, Ayman Amin, Eman Khedr, Fatma Makkeya

Dentistry

No abstract provided.

Biomechanicalperformanceofimplant-Tooth-Supportedprostheses:Anumerical3dfiniteelementanalysis, Basma Refaat Fayad, Islam Heiba Dr, Al Hassan Diab

Dentistry

Objective:Toassessthebiomechanicalbehaviourofimplant-tooth-supported(hybrid)pros-theses,comparedwithanimplant-implant-supportedprosthesis,utilisingtwodifferentprostheticmaterials,employingfiniteelementanalysis(FEA).Method:Threedigitalmodels,derivedfromaCBCT-scannededentulousmandible,weredesigned:twohybridconfigurations(M1:distalimplant-firstpremolar;M2:mesialimplant-firstmolar)andanimplant-implant-supportedprosthesis(M3).Abiomechanicalmodellingworkflowwascarriedout(Mimicsforsegmentation,3-Maticforbone/mucosallayerrefinement,ExocadDentalCADandSolidWorksforimplants,abutmentandprosthe-sisintegration,andANSYSformeshingandFEA).Assumingisotropic/elasticmaterialproperties,zirconiaandpolyetherketoneketone(PEKK)wereselectedasprostheticmateri-als.Modelsweresubjectedtoastaticverticalload(100N).vonMisesstressandtotaldefor-mationwereanalysedtoevaluatestructuralresponses.Results:M3demonstratedthemostfavourablebiomechanicalprofile,exhibitingthelowestvonMisesstressmagnitudesalongsidethehighestoveralldeformation.Inhybridmodels(M1,M2),stressmaximawerelocalisedatthepontic−toothconnectorregionsand,inM1-PEKK,reached261MPainthescrew.Corticalboneandpreparedteethexhibitedhigherstressindis-tallyanchoredhybridsystems(M1)comparedtomesiallysupporteddesigns(M2),regardlessoftheprostheticmaterial.Comparativeanalysisrevealedthatzirconia-basedprosthesesgen-eratedhigherstressconcentrationsinbone(≤35MPa)comparedtoPEKK,whereasthePEKKprosthesisitselfexhibitedgreaterstructuraldeformation(70mminM1-PEKK).Conclusion:Hybridimplant-tooth-supportedprosthesescanactasareliablealternativetoimplant-implantonesandeliminatecantileverextensions;however,theiruseshouldbereservedforcarefullyselectedcasestoavoidbiomechanicalincompatibilities.

Evaluation Of Marginal And Internal Fit In Cad/Cam-Fabricated Indirect Restorations, Sara Adel Botros, Mohamed Samy Salama, Hend Sayed Ahmed, Ayman Helmy

Dentistry

No abstract provided.

Effect Of Smoking And Finishing And Polishing Protocol On Color Stability And Surface Roughness Of Resin Composite, Fatma Makkeyah, Mohamed Samy Salama, Sara Adel Botros, Mohamed Shamel, Mahmoud Al Ankily

Dentistry

Purpose To investigate the influence of smoking and finishing and polishing protocol on color stability and surface roughness of resin composite. Materials and methods Seventy-two discs fabricated from supra-nanofilled composite were divided to 6 groups according to: Tobacco Product (Conventional Cigarette/CS and Heated Tobacco/HTP); and Finishing and Polishing Protocol (Control/C, Multi-step finishing system/FS, and Medium-grit abrasive bur + two-step polishing system/ PS). After finishing and polishing, specimens were exposed to a total of 600 cigarettes, divided into 20 each day, simulating 30 days of smoking. Color parameters were detected using a spectrophotometer. Surface roughness (Ra) was measured before and after …

Effect Of Load Removal On Bonding Of Resin Cement To Cad/Cam Composite, Sara Adel Botros, Farid Sabry El-Askary, Nader Maher Tadros, Abdallah Hassanien, Salvatore Sauro

Dentistry

No abstract provided.

Evaluation Of Marginal And Internal Fit In Cad/Cam-Fabricated Indirect Restorations, Mohamed Salama, Sara Adel Botros, Hend Sayed Ahmed

Dentistry

Objectives: This study investigated the effect of marginal adaptation and internal fit of premolar teeth restored with indirect overlays, fabricated from different CAD/CAM materials (lithium-disilicate and composite blocks). Materials and Methods: Twenty-two intact premolars with standardized concave chamfer overlay preparation were divided into two groups (n= 18) Group (A): lithium disilicate blocks and Group (B): composite blocks. All groups cemented with dual cured resin cement. After 24h of storage at 37°C followed by thermocycling. Marginal gap evaluation evaluated using a stereomicroscope at x50 magnification at 4 points at each surface. Specimens were then sectioned mesiodistally to assess internal fit. Statistical …

Effect Of Different Digital Technology On The Adaptation And Retention Of Co-Cr Partial Denture Frameworks, Islam Heiba

Dentistry

Purpose: To evaluate the overall adaptation and retention of class I cobalt-chromium (Co-Cr) removable partial denture (RPD) frameworks using three different computeraided design and computer-aided manufacturing (CAD-CAM) technologies: Indirect wax milling with lost wax technique (LWT), direct milling, and selective laser melting (SLM) technique. Materials and Methods: An educational maxillary stone model (Kennedy class I) was scanned after preparing rest seats to create a resin model. The resin model was scanned, and the RPD framework was digitally designed and saved as a standard tessellation language (STL) file. Twenty-four Co-Cr RPD frameworks were then constructed and divided into three groups (n …

Application Of Different Digital Technology On Partial Denture Frameworks, Islam Heiba, Fardos N Rizk, Marwa Sabet Prof., Shaimaa Mohamed Lotfy A. Prof

Dentistry

AIM or PURPOSE

MATERIALS and METHOD

Efect Of Conventional Cigarette Smoking And Recent Heated Tobacco Products On Cad/ Cam Restorative Materials, Fatma Makkeyah, Omar Elsergany, Mohamed Shamel, Mahmoud Al Ankily

Dentistry

No abstract provided.

The Effect Of Using Two Sintering Cycles On The Optical Properties Of Gradient Multi-Layered Zirconia (In Vitro Study), Fatma Makkeyah, Passent Elghalab, Maged Zohdy, Mostafa Nour

Dentistry

No abstract provided.

Effect Of Acidic Media On Surface Topography And Color Stability Of Two Different Glass Ceramics, Fatma Makkeyah, Nesrine A. Elsahn, Mahmoud Bakr, Mahmoud Al Ankily

Dentistry

No abstract provided.

Effect Of Layer Thickness, Inner Structure, And Implant Angulation On The Accuracy Of 3d Printed Models With Implant Analogs, Omar Elsergany

Dentistry

Objective: This study evaluated the effect of layer thickness, model inner structure, and im- plant angulation on the accuracy of 3D printed models with repositional analogs.

Materials and methods: 126 models designed to receive all-on-4 implant retained fixed den- tal prosthesis were 3D printed. Models were divided into 2 groups (n=63) according to posterior implant angulation (Group 1; 30 ̊ and group 2;45 ̊). The models were then divided into three sub- groups (n=21) according to the printing layer thickness (Group a; 50 μm, group b; 100 μm, and group c; 150 μm). Each subgroup was later subdivided into 3 …

Color Stability And Marginal Adaptation Of Ceramic Veneers Cemented Using Different Composite Resins, Basma Refaat Fayad, Maged Zohdy, Engy Adel Farag, Ghada Hussein

Dentistry

BACKGROUND: The purpose of this study was to compare the color stability and marginal adaption of lithium disilicate veneers before and after thermocycling using various resin composite materials employed as cement. METHODS: Laminate veneer preparation was done on an acrylic tooth according to standardized procedures. The veneer preparations were duplicated into twenty-one dies. The veneers were fabricated from lithium disilicate using the CEREC in Lab system. According to the cement type, the twenty-one die specimens were randomly divided into three equal groups: group I, with light cured adhesive resin cement (N.=7), group II, with owable light cured composite, and group …

Effect Of Two Different Intraoral Polishing Systems On Surface Roughness, Color Stability, And Bacterial Accumulation Of Zirconiareinforced Lithium Silicate Ceramic, Fatma Makkeyah, Dina Mohamed Mostafa, Griffith University - Australia, Mahmoud Al Ankily

Dentistry

No abstract provided.

Accuracy And Surface Roughness Of Co-Cr Partial Denture Frameworks With Different Digital Fabrication Methods, Islam Heiba

Dentistry

Statement of problem. Traditional removable partial denture (RPD) manufacture is being phased out in favor of computer-aided design and computer-aided manufacturing (CAD-CAM) techniques and rapid prototyping (RP), which provide more efficient methods of producing RPD frameworks. However, studies comparing the accuracy and surface roughness of these approaches on RPD frameworks are still scarce. Purpose. The purpose of this in vitro study was to evaluate the accuracy and surface roughness of class I cobalt chromium (Co-Cr) removable partial denture frameworks digitally constructed using 2 different CAD-CAM technologies: direct milling (DM) and selective laser melting (SLM). Material and methods. An educational maxillary …

Build Angle Effect On 3d-Printed Dental Crowns Marginal Fit Using Digital Light- Processing And Stereo-Lithography Technology: An In Vitro Study, Omar Elsergany

Dentistry

Background The effect of 3D printing technology and build angle on the marginal fit of printed crowns is unclear. The objective of this research was to use digital light processing (DLP) and stereo-lithography (SLA)-based 3D printing to construct single restorations with varied build angles and to analyze the crowns′ marginal fit.

Methods A prepared resin first molar was scanned utilizing an optical scanner. Three build orientations were used to construct the specimens: 0, 45, and 90o. DLP and SLA technology were used to produce the casting patterns. A digital microscope was used to measure the marginal gaps. The effect of …

Adaptation Of Conventional Versus Digitally Fabricated Auricular Prosthesis: A Randomized Clinical Trial, Sara Fikry, Fatma Mohei El Mogei Dr, Mohamed El Khashab Prof, Amal Rekabi Prof

Dentistry

Aim: This study aimed to compare digitally fabricated auricular prostheses to conventional prostheses, regarding adaptation to defect site in patients with auricular defects.

Subjects and methods: Fifteen patients were recruited for auricular prosthetic reconstruction. Endosseous implants were placed, then patients were assigned into two groups. In control group, ear models were processed on stone cast obtained from conventional impression. In intervention group, computed tomography and optical scanning were combined to obtain a virtual model with digital analogues over which ear models were designed and printed. Ear models of both groups were seated, and adaptation was measured on the patient using …

The Effect Of Two Sintering Cycles And Aging On Biaxial Flexural Strength Of Strength Gradient Multi-Layered Zirconia (An Vitro Study), Passent Hm El Galab, Maged Zohdy, Fatma Makkeyah, Mustafa Noor

Dentistry

No abstract provided.

Enhanced Periodontal Ligament Stem Cell Viability And Osteogenic Differentiation On Two Implant Materials: An Experimental In Vitro Study, Sara Fikry, Shereen Nader Dr, Engy Farag Dr

Dentistry

Background: Surface roughness of dental implants impacts the survival of adult periodontal stem cells and rate of differentiation. This research was conducted to test how human periodontal ligament stem cells behaved on yttria stabilized tetragonal zirconia polycrystals and polyetheretherketone (PEEK) discs with different surface topographies. Methods: Discs roughening was prepared by sandblasting. Stem cells were cultivated on zirconia discs with a polished surface, PEEK discs with a polished surface, sandblasted zirconia discs and sandblasted PEEK discs. Cells viability was assessed after 24, 48, 72 hours. Scanning electron microscopy was used to examine the adherence and attachment of cells. Osteoblastic differentiation …

Effect Of Different Span Lengths With Different Total Occlusal Convergences On The Accuracy Of Intraoral Scanners, Omar Elsergany

Dentistry

Purpose: The aim was to assess the effect of span lengths and total occlusal

convergence (TOC) on the accuracy of intraoral scanners .

Materials and methods: Two typodont acrylic teeth models were prepared to receive

fixed dental prostheses with three different span lengths. Span 1: between maxillary

canines; span 2: between maxillary second premolars; and span 3: between maxillary

In recent years, the employment of digital techniques in

1–4

(CAD–CAM). Obtaining a digital scan using an intrao-

ral scanner (IOS) is the first step of this digital workflow.

This technique, when compared to traditional impression

techniques, has shown exceptional accuracy …

Enhanced Human Periodontal Ligament Stem Cell Viability And Osteogenic Differentiation On Two Implant Materials: An Experimental In Vitro Study, Engy Adel Ahmed Farag, Sara Fikry Dr, Shereen N. Raafat

Dentistry

Background: Surface roughness of dental implants impacts the survival of adult periodontal stem cells and rate of differentiation. This research was conducted to test how human periodontal ligament stem cells behaved on yttria stabilized tetragonal zirconia polycrystals and polyetheretherketone (PEEK) discs with different surface topographies.

Methods: Discs roughening was prepared by sandblasting. Stem cells were cultivated on zirconia discs with a polished surface, polyetheretherketone (PEEK) discs with a polished surface, sandblasted zirconia discs and sandblasted polyetheretherketone (PEEK) discs. Cells viability was assessed after 24, 48, 72 hours. Scanning electron microscopy was used to examine the adherence and attachment of cells. …

Effect Of Overlay Material Type And Design On Fracture Resistance Of Mod Cavities In Molars. (In-Vitro Study), Sara Adel Botros, Mohamed Fouad Haridy, Shaimaa Gad

Dentistry

Objective: To evaluate the influence of restoration material type (CAD/CAM lithium disilicate blocks and reinforced composite blocks) and restoration design on fracture resistance of molars with MOD cavities. Methods and Materials: A total of 54 sound human molars were divided into 2 groups (n=9) according to: 1) material type: lithium disilicate CAD/CAM blocks and reinforced composite CAD/CAM blocks; 2) restoration design: overlay with intra-coronal extension or without intra-coronal extension. Additional 18 samples were assigned to positive control group (sound molars, n=9) and negative control group (unrestored MOD cavities, n=9). Standardized MOD cavities were prepared with occlusal width 3 mm, cavity …

Effect Of Different Digital Impression Techniques On The Trueness Of Post Space Scans With Fixed Cervical Diameter, Omar Elsergany

Dentistry

Objective: The aim of this study was to measure the trueness of post space impression by 2 digital impression techniques: Impression Scanning (IS) and Model Scanning (MS) with cervical diameter 3 millimeters. Materials and methods: Fourteen freshly extracted single rooted lower second premolars were endodontically treated using Wave-One single file technique. Then mounted in acrylic blocks parallel to long access using a dental surveyor 2mm above the CEJ, drills in sequence 1.4 and 1.6 millimeter then diamond stone with 3 millimeter diameter were used for teeth preparation with a standardized depth of 8mm. Teeth were scanned by reference scanner InEos5 …

Effect Of Different Polishing Systems On Surface Roughness And Color Stability Of Lithium Disilicate Ceramics, Mahmoud Al Ankily, Fatma Makkeyah

Dentistry

Objective: This study aimed to investigate the effect of two polishing systems on the surface roughness and color stability of lithium disilicate ceramic. Materials and Methods: Forty disc-shaped lithium disilicate samples were constructed and cemented into a cavity prepared onto the labial surface of freshly extracted bovine teeth; The samples were divided into four groups (10 samples per group); C: Control, SS: Scaling only, SE: Scaling followed by polishing using Eve Diapro lithium disilicate polishers, SD: Scaling followed by polishing using Diatech ShapeGuard ceramic polishing plus kit. The surface roughness was measured before scaling, after scaling and finally after the …