Journal of Prosthetic Dentistry

STATEMENT OF PROBLEM: Dynamic computer-assisted zygomatic implant surgery (dCAZIS) has been reported to provide clinical efficacy with high accuracy and low risk of complications. However, the learning curve before performing dCAZIS effectively is unknown. PURPOSE: The purpose of this in vitro study was to explore the learning curve of dCAZIS in dentists with different levels of experience in implant dentistry and navigation surgery. MATERIAL AND METHODS: Six senior dental students were randomly divided into 3 groups for initial training (FH-CI group: pretraining on freehand conventional implant surgery; FH-ZI group: pretraining on freehand ZI surgery; DN-CI group: pretraining on conventional implant surgery under dynamic navigation)...

STATEMENT OF PROBLEM: Oral mucormycosis is uncommon in pediatric patients with hematolymphoid diseases. Prosthetic rehabilitation is challenging, and protocols are scarce in the literature. PURPOSE: The purpose of this clinical report and systematic literature review of case reports and case series was to describe the clinicopathologic aspects of oral mucormycosis and the interim prosthetic rehabilitation of an affected infant. MATERIAL AND METHODS: The clinical lesions were ulcerative and necrotic with underlying bone exposure that affected the hard palate...

STATEMENT OF PROBLEM: Maxillary and mandibular scans can be articulated in maximum intercuspal position (MIP) by using an artificial intelligence (AI) based program; however, the accuracy of the AI-based program locating the MIP relationship is unknown. PURPOSE: The purpose of the present clinical study was to assess the accuracy of the MIP relationship located by using 4 intraoral scanners (IOSs) and an AI-based program. MATERIAL AND METHODS: Conventional casts of a participant mounted on an articulator in MIP were digitized (T710)...

With the development of digital dental technologies, a complete digital workflow without using physical casts has become possible. However, for certain clinical and dental laboratory procedures, especially in complex rehabilitation treatments, physically mounted casts in an ideal location in a mechanical articulator are still necessary for treatment planning and restoration fabrication. This technique report describes a digital approach to fabricating a custom transfer plate to cross mount intraoral scan casts from a virtual articulator to the corresponding mechanical articulator...

STATEMENT OF PROBLEM: Evidence on the long-term clinical assessment and longevity of ceramic veneers bonded to different substrates is limited. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the effect of various substrates, including enamel, dentin, or an existing composite resin restoration, on the clinical survival and complication rates of ceramic veneers. MATERIAL AND METHODS: The PubMed, Scopus, and the Cochrane Library electronic databases were searched, and related journals were hand searched without time or language restrictions to identify clinical trials that compared the survival rate and clinical complication rates when bonding ceramic veneers to different tooth substrates...

STATEMENT OF PROBLEM: The impact of different coloring liquid shades and dipping times on the color, transparency, and flexural strength of monolithic zirconia ceramics is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effects of different coloring liquid shades (A2, 3M2, and 5M2) and dipping times (no dipping, 30 seconds, 60 seconds, and 90 seconds) on the color difference (ΔE00 ), relative translucency parameter (ΔRTP00 ), and 3-point flexural strength (σ) of monolithic zirconia ceramics...

STATEMENT OF PROBLEM: Unscrewing the healing abutment can affect the soft tissue integration and apical migration of the biological width, which may compromise the integrity of peri-implant soft tissue. PURPOSE: The purpose of this clinical study was to determine the level of glycosaminoglycan (GAG) detected in the peri-implant crevicular fluid (PICF) between the test group (1-time abutment) and control group (healing abutment) for implant-retained mandibular overdentures...

Implant failure may occur after the delivery of definitive prostheses. Avoiding replacement of a complete arch implant-supported fixed prosthesis becomes a significant challenge when placement of a new implant is necessary. This technical article introduces a protocol to replace a failed implant in situ, effectively rescuing the original prosthesis.

STATEMENT OF PROBLEM: A predictable protocol for accurately scanning implants in a complete edentulous arch has not been established. PURPOSE: The purpose of this clinical study was to investigate the effect of splinting implant scan bodies intraorally on the accuracy and scan time for digital scans of edentulous arches. MATERIAL AND METHODS: This single center, nonrandomized, clinical trial included a total of 19 arches. Definitive casts with scan bodies were fabricated and scanned with a laboratory scanner as the reference (control) scan...

STATEMENT OF PROBLEM: The hydrophobic and bioinert nature of polyetheretherketone (PEEK) implants needs to be addressed for successful osseointegration. PURPOSE: The purpose of this in vitro study was to evaluate the osteoblast cell behavior on PEEK implant surfaces treated with airborne-particle abrasion using different grit size aluminum oxide (Al2 O3 ) particles. MATERIAL AND METHODS: Disk-shaped specimens (n=96) were prepared from medical grade PEEK rods and were distributed into 4 groups (n=24) of untreated PEEK (PEEK 0), airborne-particle abrasion using 50-μm Al2 O3 particles (PEEK 50), airborne-particle abrasion using 110-μm Al2 O3 particles (PEEK 110), and airborne-particle abrasion using 150-μm Al2 O3 particles (PEEK 150)...

STATEMENT OF PROBLEM: Additive (AM) and subtractive (SM) manufacturing have become popular for fabricating occlusal devices with materials of different chemical compositions. However, knowledge on the effect of material and antagonist type on the wear characteristics of occlusal devices fabricated by using different methods is limited. PURPOSE: The purpose of this in vitro study was to evaluate the effect of material and antagonist type on the wear of occlusal devices fabricated by using conventional manufacturing, AM, and SM...

STATEMENT OF PROBLEM: The outcome of photopolymerized 3-dimensional (3D) printing is influenced by the methods used for postprinting cleaning, yet information on postprinting cleaning is sparse. PURPOSE: The purpose of this in vitro study was to assess the cleaning efficiency and surface and mechanical properties of 3D printed resin according to postprinting cleaning methods. MATERIAL AND METHODS: Specimens were fabricated from a 3D model using resin materials (NextDent C&B MFH and DIOnavi-P...

STATEMENT OF PROBLEM: The type of veneer preparation is often chosen according to the patient's tooth structure and occlusion. Taking biomechanics into account in this decision-making process provides the clinician with more technical information on how to improve the clinical longevity of restorations. However, biomechanical analyses of veneer preparation designs are sparse. PURPOSE: The purpose of this 3-dimensional (3D) finite element analysis with microcomputed tomography (µCT) data obtained from realistic models was to assess the influence of different preparations for ceramic and composite resin veneers on restoration and resin layer stress distribution...

STATEMENT OF PROBLEM: Evidence comparing the survival of zirconia crowns with metal-ceramic crowns is sparse. Knowledge of their survival and a comparison of their clinical outcomes would improve clinical decision making. PURPOSE: The purpose of this university-based study was to compare the survival, failures, biological and technical complications encountered with zirconia and metal-ceramic crowns restored and followed up over a similar period. MATERIAL AND METHODS: This retrospective chart review consisted of 403 patients treated at the University of Toronto, Faculty of Dentistry, predoctoral dental clinic in whom zirconia (n=209) and metal-ceramic (n=306) crowns were inserted between September 2015 and July 2016 and followed for up to 7 years...

STATEMENT OF PROBLEM: The clinical complications, success, and survival rates of indirect restorations delivered with the immediate dentin sealing protocol are unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to find and collect evidence on the clinical complication, success, and survival rates of indirect restorations delivered with immediate dentin sealing. MATERIAL AND METHODS: Electronic databases were searched for clinical studies on immediate dentin sealing up to December 2023, without language or time limitations...

Precise reproduction of the preoperatively designed 3-dimensional (3D) implant position is key to seating a prefabricated restoration and restoring esthetics. Static and dynamic computer-aided implant surgery (CAIS) based on the fusion of 3D imaging files have been used to improve implant accuracy. However, both techniques have shortcomings that can be remedied by a robotic system. This clinical report describes the immediate placement of an implant in the anterior esthetic zone by using an autonomous dental implant robotic system (ADIR)...

STATEMENT OF PROBLEM: Infants with a cleft palate often experience middle ear disease, a condition of great significance, and early prosthetic management of these infants is essential. However, any correlation between prosthetic palatal obturation and middle ear function is unclear. PURPOSE: The purpose of this clinical trial was to assess whether prosthetic palatal obturation with a feeding appliance prevented or improved middle ear problems in infants with a cleft lip and palate...

High-quality impressions and accurate occlusal relationship records are essential for the success of complete dentures. A custom impression tray and interim complete denture base fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) are introduced, enhancing the ability to obtain precise definitive impressions and accurate jaw relation records and improving complete denture treatment.

STATEMENT OF PROBLEM: The alignment of 3-dimensional (3D) files involves selecting a reference area before performing a local best fit alignment during the digital scan superimposition and is essential for comparing digital scans. Scan alignment relies on both reference area location and the alignment algorithm. However, a consensus on the impact of different reference areas on intraoral scanning accuracy is lacking. PURPOSE: The purpose of this in vitro study was to assess the impact of 3 superimposition reference areas on the accuracy of 3 intraoral scanners for a partially dentate maxilla...

The replacement of an obturator prosthesis using conventional methods has multiple issues. Standard tessellation language files generated from the superimposition of an accurate intraoral scanning of the maxillary defect and direct data acquisition of the existing hollow bulb obturator can facilitate the precise design of the prosthesis, requiring only minor adjustments. Rapid prototyping manufacturing techniques seem to ensure precise control of the integrity of the prosthetic component completion. The success of the technique is the simplicity and repeatability of designing and fabricating a retrievable and easily repairable obturator...