Best-Fit Algorithm Influences on Virtual Casts' Alignment Discrepancies.

Purpose: To measure the influence of best-fit (BF) algorithms (entire dataset, 3 or 6 points landmark-based, or section-based BF) on virtual casts and their alignment discrepancies.

Material And Methods: A mandibular typodont was obtained and digitized by using an industrial scanner (GOM Atos Q 3D 12M). A control mesh was acquired.

Implant-Abutment Discrepancy Before and After Acrylic Resin Veneering of Complete-Arch Titanium Frameworks Manufactured Using Milling and Electron Beam Melting Technologies.

Purpose: To assess the implant-abutment discrepancy of complete-arch frameworks manufactured using milling and additive electron beam melting (EBM) technologies, before and after acrylic resin veneering application.

Materials And Methods: A definitive implant cast with six implant replicas was digitized using a laboratory scanner. A software program was used to design an implant-supported framework which was manufactured using milling (M group) and EBM (EBM group) technologies (n = 10).

Effect of milled and lithography-based additively manufactured zirconia (3Y-TZP) on the biological properties of human osteoblasts.

Statement Of Problem: Lithography-based additively manufactured (AM) zirconia has been used to fabricate dental implants and custom barriers for guided bone regeneration procedures. However, studies on the effect of AM zirconia on the biological properties of human osteoblasts are lacking.

Purpose: The purpose of this in vitro study was to compare the effect of milled and lithography-based AM zirconia on the biological properties of normal human osteoblasts (NHOsts), as well as to compare the chemical composition between the milled and lithography-based AM 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) zirconia.

Chemical Composition and Flexural Strength Discrepancies Between Milled and Lithography-Based Additively Manufactured Zirconia.

Purpose: To evaluate the chemical composition, flexural strength, and Weibull characteristics of milled and lithography-based additively manufactured (AM) zirconia.

Materials And Methods: A virtual design of a bar (25×4×2 mm) was completed using a software program. The standard tessellation language file was used to manufacture all the specimens: 3Y-TZP zirconia (Priti multidisc ZrO monochrome) milled (M group) and 3Y-TZP zirconia (LithaCon 3Y 210) lithography-based AM (CeraFab System S65 Medical) (AM group) bar specimens (n = 20).

Influence of base design on the manufacturing accuracy of vat-polymerized diagnostic casts: An in vitro study.

Statement Of Problem: Vat-polymerized casts can be designed with different bases, but the influence of the base design on the accuracy of the casts remains unclear.

Purpose: The purpose of the present in vitro study was to evaluate the influence of various base designs (solid, honeycombed, and hollow) with 2 different wall thicknesses (1 mm and 2 mm) on the accuracy of vat-polymerized diagnostic casts.

Material And Methods: A virtual maxillary cast was obtained and used to create 3 different base designs: solid (S group), honeycombed (HC group), and hollow (H group).

Multipurpose application of custom, rigid, clear matrix for fabricating trial restorations, tooth preparation guides, and interim veneers.

Interim veneers present an esthetic and functional challenge for restorative dentists. Moreover, inadequate fit or trauma to the soft tissue during their fabrication or subsequently may affect soft-tissue health and stability and lead to bleeding that will compromise the adhesive cementation of the definitive ceramic veneers. This article describes a technique for the atraumatic fabrication of interim veneers with a custom, rigid, clear matrix designed for multipurpose use during the patient's restorative care.

Physical characterization of 3 implant systems made of distinct materials with distinct surfaces.

Statement Of Problem: Dental implants undergo various surface treatments. Studies that have characterized their surface and subsurface by using the same methods are scarce.

Purpose: The purpose of this study is to physically characterize the surface and subsurface of implant systems made of commercially pure (cp) titanium (Ti) grade (gr) 4 and Ti alloy gr 23 and to evaluate whether airborne-particle abrasion and acid etching is an appropriate surface treatment for Ti alloy gr 23.

Cementation of Zirconia-Based Toothborne Restorations: A Clinical Review.

As the demand for esthetics in dentistry has increased over the years, zirconia-based restorations have been successfully used as alternatives to metal-ceramic restorations. A reliable marginal seal is among the factors that are vital to the clinical success of a dental restoration. One advantage of zirconia-based restorations is that the cementation process is generally simpler and more efficient compared to the delivery/cementation of other all-ceramic systems.

Effect of hydrothermal treatment on light transmission of translucent zirconias.

Statement Of Problem: Studies of the light transmission of translucent zirconias after hydrothermal treatment are limited.

Purpose: The purpose of this in vitro study was to evaluate the effect of hydrothermal treatment on the light transmission of translucent zirconias for monolithic restorations.

Material And Methods: Four commercially available zirconia products, BruxZir Anterior Solid Zirconia (BruxAnt, BA), Lava Plus High Translucency (LPHT), Katana Zirconia Super Translucent (KST), and Katana Zirconia Ultra Translucent (KUT) were assessed and 1 type of lithium disilicate, e.

Assessing the feasibility of yttria-stabilized zirconia in novel designs as mandibular anterior fixed lingual retention after orthodontic treatment.

Introduction: The purpose of this study is to explore the feasibility of yttria-stabilized zirconia (Y-TZP) in fixed lingual retention as an alternative to stainless steel.

Methods: Exploratory Y-TZP specimens were milled to establish design parameters. Next, the specimens were milled according to ASTM standard C1161-13 and subjected to 4-point flexural tests to determine material properties.

Prospective cohort clinical study assessing the 5-year survival and success of anterior maxillary zirconia-based crowns with customized zirconia copings.

Statement Of Problem: Studies evaluating anterior zirconia-based crowns are limited.

Purpose: The purpose of this prospective cohort clinical study was to assess the efficacy of zirconia-based anterior maxillary crowns with 0.3-mm customized copings at the cervical third and anatomical design elsewhere for up to 5 years of service.

Influence of aging on flexural strength of translucent zirconia for monolithic restorations.

Statement Of Problem: Concern has been raised with regard to the low-temperature degradation (LTD) of translucent yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) for monolithic zirconia restorations.

Purpose: The purpose of this in vitro study was to assess the LTD behavior of 4 commercially available translucent Y-TZP materials by accelerated aging specimens in steam at 134°C, 0.2 MPa.

A comparative evaluation of the translucency of zirconias and lithium disilicate for monolithic restorations.

Statement Of Problem: Studies comparing the translucency of zirconias and lithium disilicates are limited.

Purpose: The purpose of this in vitro study was to measure the translucency of recently developed translucent zirconias and compare them with lithium disilicate.

Material And Methods: Five types of zirconia, Prettau Anterior (Zirkonzahn GmbH), BruxZir (Glidewell Laboratories), Katana HT, Katana ST, and Katana UT (Kurary Noritake Dental Inc), and 1 type of lithium disilicate, e.

Assessment of reliability of CAD-CAM tooth-colored implant custom abutments.

Statement Of Problem: Information is lacking about the fatigue resistance of computer-aided design and computer-aided manufacturing (CAD-CAM) tooth-colored implant custom abutment materials.

Purpose: The purpose of this in vitro study was to investigate the reliability of different types of CAD-CAM tooth-colored implant custom abutments.

Material And Methods: Zirconia (Lava Plus), lithium disilicate (IPS e.

Effect of accelerated aging on the fracture toughness of zirconias.

Statement Of Problem: Low temperature degradation (LTD) of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) is of concern.

Purpose: The purpose of this in vitro study was to assess the effect of accelerated aging on the Vickers hardness and fracture toughness of a newly developed Y-TZP and 2 primary Y-TZPs.

Material And Methods: Two primary 3 mol% Y-TZP, Lava (LA), Everest Zirconium Soft (EV), and a new 3 mol% Y-TZP, ZirTough (NZ) were assessed.

Clinical efficacy of polyvinyl siloxane impression materials using the one-step two-viscosity impression technique.

Statement Of Problem: Impression making is a challenging clinical procedure for both patients and dentists.

Purpose: The purpose of this clinical study was to compare a recently introduced fast-setting polyvinyl siloxane (PVS) impression material with heavy body/light body (HB/LB) combination (Imprint 4; 3M ESPE) (experimental group) with a conventional PVS impression material with HB/LB combination (Imprint 3; 3M ESPE) (control group), using the 1-step 2-viscosity impression technique.

Material And Methods: Two definitive impressions (1 of each material combination) were made of 20 crown preparations from 20 participants.

In vitro evaluation of accuracy and precision of automated robotic tooth preparation system for porcelain laminate veneers.

Statement Of Problem: Controlling tooth reduction for porcelain laminate veneers (PLVs) in fractions of millimeters is challenging.

Purpose: The purpose of this study was to assess an automated robotic tooth preparation system for PLVs for accuracy and precision compared with conventional freehand tooth preparation.

Material And Methods: Twenty maxillary central incisor tooth models were divided into 2 groups.

Effect of Tooth-Colored Restorative Materials on Reliability of Heat-Pressed Lithium Disilicate.

Purpose: Restorative material selection in complete mouth rehabilitation is an important factor in long-term management of potential technical complications. The aim of this study was to evaluate in vitro the reliability (fracture resistance) of lithium disilicate fatigued with different restorative materials.

Materials And Methods: A step-stress accelerated life-testing model was used.

Effect of hydrothermal degradation on three types of zirconias for dental application.

Statement Of Problem: Concern has been expressed with regard to hydrothermal aging of yttria-stabilized tetragonal zirconia polycrystalline.

Purpose: The purpose of this study was to assess the accelerated aging characteristics of a new yttria-stabilized tetragonal zirconia polycrystalline material and 2 commercially available yttria-stabilized tetragonal zirconia polycrystalline materials by exposing specimens to hydrothermal treatments in steam at 134°C, 0.2 MPa, and at 180°C, 1.

The rehabilitation of an edentulous mandible with a CAD/CAM zirconia framework and heat-pressed lithium disilicate ceramic crowns: a clinical report.

This clinical report describes a complete arch, implant-supported prosthesis with a zirconia framework and monolithic lithium disilicate crowns. The design of the computer-aided design/computer-aided manufacturing zirconia framework with cemented crowns with screw access is useful in facilitating retrievability and adequate fit, and may reduce the likelihood of porcelain chipping.

A simplified technique for recording an implant-supported ovate pontic site in the esthetic zone.

Implant-supported fixed dental prostheses present an esthetic challenge, especially when an ovate pontic site has been progressively developed during the guided soft-tissue healing process with an interim restoration. This article describes a technique for an accurate capturing of the molded ovate pontic site of an implant-supported fixed dental prostheses and for transferring it to the definitive cast, which facilitates the dental ceramist's ability to design and fabricate an ovate pontic with adequate intaglio contours.

An in vitro study of the effect of different restorative materials on the reliability of a veneering porcelain.

Statement Of Problem: Implant-supported, porcelain veneered restorations experience a greater rate of porcelain fracture than tooth-supported restorations. For completely edentulous patients, one approach to minimizing porcelain fracture is to use acrylic resin in the mandible, although its efficacy is unknown.

Purpose: The purpose of this study was to evaluate the reliability of a veneering porcelain fatigued with different restorative materials in vitro.

Selection patterns of dietary foods in edentulous participants rehabilitated with maxillary complete dentures opposed by mandibular implant-supported prostheses: a multicenter longitudinal assessment.

Statement Of Problem: Documentation of long-term changes in food intake is lacking for those treated with a maxillary complete denture opposed by a mandibular, screw-retained, implant-supported fixed prosthesis.

Purpose: The purpose of this study was to evaluate the selection patterns of dietary foods over 5 years for edentulous participants treated in a multicenter prospective clinical trial that compared cast alloy versus laser-welded titanium frameworks of an implant-supported prostheses opposed by maxillary complete dentures to rehabilitate edentulous participants.

Material And Methods: The study assessed data from a multicenter prospective clinical trial that followed edentulous participants from an initial baseline of wearing existing complete dentures to implant placement, restoration with a mandibular implant-supported prosthesis opposed by a maxillary complete denture, to follow-up assessment of these treatments over 5 years.

An in vitro comparison of photogrammetric and conventional complete-arch implant impression techniques.

Statement Of Problem: Conventional impression techniques for recording the location and orientation of implant-supported, complete-arch prostheses are time consuming and prone to error. The direct optical recording of the location and orientation of implants, without the need for intermediate transfer steps, could reduce or eliminate those disadvantages.

Purpose: The objective of this study was to assess the feasibility of using a photogrammetric technique to record the location and orientation of multiple implants and to compare the results with those of a conventional complete-arch impression technique.

In vitro assessment of three types of zirconia implant abutments under static load.

Statement Of Problem: Although various zirconia abutments have been introduced, insufficient data exist regarding the maximum load capacity of internal tri-channel connection zirconia implant abutments with various implant-abutment interfaces.

Purpose: The purpose of this in vitro study was to compare the maximum load capacity of 3 different types of internal tri-channel connection zirconia abutments and to assess their mode of failure.

Material And Methods: The study investigated 3 groups (n=20) of zirconia implant abutments with different implant-abutment interfaces.