Assessment of the internal connection of an angled screw channel system.

Statement Of Problem: The angled screw channel (ASC) design has been well accepted for implant prostheses. However, investigation into the behavior of the ASC connection is sparse.

Purpose: The purpose of this in vitro study was to assess the effect of cyclic loading on the internal connection of an ASC system compared with straight access systems by measuring reverse torque values (RTVs) and using microcomputed tomography (µCT) imaging.

Principles of interdisciplinary orthodontic and restorative treatment.

Dentistry has changed significantly in the last two decades. Interdisciplinary treatment planning strives to deliver the highest quality of care through innovative collaborations among providers and the patient. The complexity of the care and challenges in interdisciplinary team communications are primary hurdles.

An integrated digital workflow for long-term interim combined fixed and removable prostheses.

Interim prostheses are required for the management of complex prosthodontic treatment which sometimes comprises both fixed and removable prostheses in the same arch. The traditional workflow for interim combined fixed and removable prostheses is time consuming and results can be unpredictable. A novel integrated digital workflow was adopted in the management of long-term interim combined fixed and removable prostheses.

Effect of Fiber Reinforcement on the Flexural Strength of the Transitional Implant-Supported Fixed Dental Prosthesis.

Purpose: The aim of this in vitro study was to assess the efficacy of fiber reinforcement to enhance flexural strength of the transitional implant-supported fixed dental prosthesis (TISFDP).

Materials And Methods: One hundred and forty denture acrylic resin plates (64 mm × 12 mm × 5 mm) with two 7 mm diameter holes were fabricated using heat-polymerized type (Lucitone 199) and CAD-CAM prepolymerized type (AvaDent) materials to simulate a chair-side reconstruction of the TISFDP. Specimens were divided into 7 groups (n = 10) according to the airborne-particle abrasion of titanium cylinder (Straumann) surface and locations of fiber reinforcement ribbons (Ribbond-ULTRA).

Effect of airborne-particle abrasion with a novel spherical abrasive on the zirconia surface.

Statement Of Problem: A novel zirconia-alumina composite (ZAC) particle has yet to be studied for airborne-particle abrasion in a bonding protocol for the zirconia surface.

Purpose: The purpose of this in vitro study was to evaluate the shear bond force of resin cement to yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) when using spherical ZAC particles to conduct airborne-particle abrasion and modify the topography of Y-TZP.

Material And Methods: Spherical 30- to 70-μm ZAC particles were fabricated by using a hybrid gel technique.

Effect of the attachments on clinical outcomes of mandibular distal extension implant-supported removable partial dentures: A systematic review.

Statement Of Problem: Healing abutments and attachments have been used for implant-supported removable partial dentures (ISRPDs). However, the effects of these abutments and attachments on the clinical outcomes of the implants and prostheses are elusive because of the lack of standardized research protocols.

Purpose: The purpose of this systematic review was to determine the clinical outcomes of mandibular distal extension ISRPDs with healing abutments and attachments by analyzing qualified studies.

Microcomputed tomography evaluation of cement shrinkage under zirconia versus lithium disilicate veneers.

Statement Of Problem: Computer-aided design and computer-aided manufacturing (CAD-CAM) technology and the improved translucency of recently developed high-strength monolithic zirconia could make them clinically acceptable for veneers if bonding to zirconia was as predictable as to glass-ceramics. Few studies have compared how resin cements behave between glass-ceramic and zirconia veneers before and after polymerization.

Purpose: The purpose of this in vitro study was to evaluate the volumetric polymerization shrinkage of resin cement, marginal discrepancy, and cement thickness before and after polymerization for glass-ceramic and zirconia veneers with light-polymerizing resin cement.

A technique to guide replacement of multiunit abutments supporting an existing implant-supported fixed complete denture.

This article describes a technique for replacing a fractured multiunit abutment (MUA) supporting an existing implant-supported fixed complete denture (ISFCD) with a custom-fabricated abutment alignment device. The angulated MUA threads that receive the prosthetic screw to secure the ISFCD can become stripped, cross-threaded, or, in some patients, the thin metal in this region may fracture. These conditions necessitate the removal and replacement of the angulated MUA.

Assessment of the Adaptation of Interim Crowns using Different Measurement Techniques.

Purpose: To compare the internal fit and marginal discrepancy of acrylic resin interim crowns fabricated by different manufacturing methods, and to test the consistency of measuring marginal discrepancy and internal fit between different measuring techniques.

Materials And Methods: A dentoform mandibular left first molar was prepared for an all-ceramic crown. Thirty-six interim crowns were fabricated and divided into three groups (n = 12): group BAC (Bis-acrylic composite, fabricated manually), group CAM (CAD/CAM polymethylmethacrylate resin, milled), and group 3DP (3D printed methacrylic oligomers, printed).

Assessment of the internal fit and marginal integrity of interim crowns made by different manufacturing methods.

Statement Of Problem: The adaptation of interim crowns made by subtractive and additive manufacturing has not been well investigated.

Purpose: The purpose of this in vitro study was to evaluate the internal fit and marginal discrepancy of interim crowns made by different manufacturing methods.

Material And Methods: A dentoform mandibular left first molar was prepared for a ceramic crown and scanned for the fabrication of 48 stereolithical resin dies and interim crowns.

Effect of layering gingiva-shade composite resin on the strength of denture base polymers.

Statement Of Problem: Acrylic resin denture base materials, fabricated with either a traditional technique or computer-aided design and computer-aided manufacturing (CAD-CAM) technique, layered with different thicknesses of gingiva-shade composite resin may affect the strength of the definitive prostheses and have not been investigated.

Purpose: The purpose of this in vitro study was to assess the flexural strength of acrylic resin denture base materials modified by layering different thicknesses of gingiva-shade composite resin.

Material And Methods: Two denture acrylic resins, heat-polymerized type (Lucitone 199) and CAD-CAM prepolymerized type (AvaDent) polymethyl methacrylate (PMMA) resin, were used as the base materials.

Fracture resistance of cingulum rest seats in CAD-CAM tooth-colored crowns for removable partial denture abutments.

Statement Of Problem: The prevalent use of computer-aided design and computer-aided manufacturing (CAD-CAM) for tooth-colored ceramic materials has led to several case reports and retrospective clinical studies of surveyed crowns used to support removable partial dentures. How the specific contour of a cingulum rest seat affects the fracture resistance of these CAD-CAM tooth-colored materials is unknown.

Purpose: The purpose of this in vitro study was to compare the fracture resistance of monolithic CAD-CAM tooth-colored mandibular canine-surveyed ceramic crowns with cingulum rest seats of different designs.

Thermal cracks of implant-based zirconia four-unit restorations: A fractographic analysis of two restorations fractured during production.

Two zirconia-based 4-unit restorations intended for the same patient fractured during the veneering process even though the prolonged cooling protocol recommended by the manufacturers was used. Fractographic analyses revealed that both restorations fractured as a result of thermal shock, but at different times during production. Further investigation is necessary to optimize the firing protocols for large zirconia-based restorations and avoid fracture due to thermal shock.

Comparison of Fit of Dentures Fabricated by Traditional Techniques Versus CAD/CAM Technology.

Purpose: To compare the shrinkage of denture bases fabricated by three methods: CAD/CAM, compression molding, and injection molding. The effect of arch form and palate depth was also tested.

Materials And Methods: Nine titanium casts, representing combinations of tapered, ovoid, and square arch forms and shallow, medium, and deep palate depths, were fabricated using electron beam melting (EBM) technology.

Marginal discrepancy dimensions of single unit metal crowns fabricated by using CAD-CAM-milled acrylate resin polymer blocks or a conventional waxing technique.

Statement Of Problem: Because crowns with open margins are a well-known problem and can lead to complications, it is important to assess the accuracy of margins resulting from the use of a new technique. Currently, data regarding the marginal fit of computer-aided design and computer-aided manufacturing (CAD-CAM) technology to fabricate a complete gold crown (CGC) from a castable acrylate resin polymer block are lacking.

Purpose: The purpose of this in vitro study was to compare marginal discrepancy widths of CGCs fabricated by using either conventional hand waxing or acrylate resin polymer blocks generated by using CAD-CAM technology.

The influence of lip form on incisal display with lips in repose on the esthetic preferences of dentists and lay people.

Statement Of Problem: Information is lacking for viewer preferences for incisal display with lips in repose.

Purpose: The purpose of this online survey was to establish measurement parameters to classify and define a lip form and to evaluate the influence of lip form on dentists' and laypersons' preferences for the amount of incisal display with lips in repose.

Material And Methods: Computer-generated male and female models were created using 3 different lip forms each, straight, moderate, and high.

Comparison of margin discrepancy of complete gold crowns fabricated using printed, milled, and conventional hand-waxed patterns.

Statement Of Problem: The recent application of printing for the fabrication of dental restorations has not been compared and evaluated for margin discrepancy (margin fit) with restorations fabricated using milling and conventional hand-waxing techniques.

Purpose: The purpose of this in vitro study was to evaluate and compare margin discrepancy of complete gold crowns (CGCs) fabricated from printed, milled, and conventional hand-waxed patterns.

Material And Methods: Thirty crown patterns were produced by each of 3 different methods: printed by ProJet DP 3000, milled by LAVA CNC 500, and hand waxed, then invested and cast into CGCs.

Effects of chlorine-based and quaternary ammonium-based disinfectants on the wettability of a polyvinyl siloxane impression material.

Statement Of Problem: Polyvinyl siloxane (PVS) impression materials must be cold disinfected before cast pouring to prevent cross-contamination among personnel and patients. However, disinfection may affect the ability of PVS impression materials to provide bubble-free stone surfaces because of the removal of surfactants.

Purpose: The purpose of this in vitro study was to compare the water contact angles of a PVS impression material treated with either a quaternary ammonium-based (QAB) (DisCide Ultra) or a chlorine-based (CLB) (Dispatch) disinfectant for various exposure times.

Complete denture fabrication with CAD/CAM record bases.

One of the primary goals of new materials and processes for complete denture fabrication has been to reduce polymerization shrinkage. The introduction of computer-aided design and computer-aided manufacturing (CAD/CAM) technology into complete denture fabrication has eliminated polymerization shrinkage in the definitive denture. The use of CAD/CAM record bases for complete denture fabrication can provide a better-fitting denture with fewer postprocessing occlusal errors.

Orthodontic single tooth intrusion with a removable interocclusal device: A clinical report.

Interdisciplinary therapy was used to treat a patient missing a single posterior tooth opposing an extruded tooth. The simple technique used a removable interocclusal device and elastic band for orthodontic intrusion over a 2-month period after implant placement in the opposing arch to aid in prosthetic site development. This approach was designed to increase the interocclusal space needed to restore the implant, obtain a more consistent occlusal plane, and improve esthetics.