Prediction of the learning curves of 2 dental CAD software programs

Statement of problem

Dental clinical procedures are being replaced by digital workflows. Therefore, the time necessary to learn dental computer-aided design (CAD) software to achieve a change in the digital workflow should be evaluated.

A microcomputed tomography evaluation of the marginal fit of cobalt-chromium alloy copings fabricated by new manufacturing techniques and alloy systems

Statement of problem

Although new digital manufacturing techniques are attracting interest in dentistry, few studies have comprehensively investigated the marginal fit of fixed dental prostheses fabricated with such techniques.

Oral tuberculosis mimicking a traumatic denture ulcer

Tuberculosis (TB) of the oral cavity may be overlooked in the differential diagnosis of oral lesions and can be misdiagnosed and managed incorrectly. A 66-year-old man with complete dentures presented with a nonhealing mucosal ulcer in the upper lip. Despite the treatments performed by a local medical clinic, the ulcerative lesion on the denture-bearing area had not improved over 5 months. A partial excisional biopsy was performed to investigate further. Histopathologic examination revealed granulomatous inflammation caused by TB, and a chest radiograph showed consolidation and cavitation of the upper lobes. The patient was diagnosed with pulmonary TB. This clinical report describes the management of oral TB mimicking a traumatic denture ulcer in a patient with long-term complete denture use.     

Effects of image and education on the precision of the measurement method for evaluating prosthesis misfit

Statement of problem

Various methods for measuring prosthesis misfit have been suggested. Although the cross-sectional images between the crown and abutment are used to evaluate the misfit, the effects of the image and the observer’s knowledge on the precision of measurement are unknown.

A technique for verifying the accuracy of the virtual mounting of digital scans against the actual occlusal contacts

The digital scans of dentate arches can be mounted from a virtual interocclusal record to expedite the fabrication of dental prostheses. However, the virtual mounting may develop an occlusal error when combined with less than ideally scanned data and an algorithm that matches poorly. This article describes a method of verifying the accuracy of virtual mounting against the actual occlusal contacts marked with colored articulating paper.     

Integration of intraoral digital scans with a 3D facial scan for anterior tooth rehabilitation

This article describes a digital technique that combines intraoral digital scans with a 3-dimensional facial scan to predict the outcome of prosthodontic treatment of anterior teeth at the treatment planning phase. This approach may increase patient acceptance of the definitive treatment, as the altered facial appearance is visualized with definitive prosthodontic restorations, thereby improving communication before treatment begins.     

Fabricating a reduction guide for parallel guiding planes with computer-aided design and computer-aided manufacturing technology

Preparing appropriate guiding planes is essential for the success of a removable partial denture. Owing to the difficulty of determining the location and dimension of proximal reduction, establishing optimal guiding planes may challenge even skilled clinicians. This article introduces a digital workflow for fabricating a reduction guide to establish parallel guiding planes.     

Fabrication of a complete,removable dental prosthesis from a digital intraoral impression for a patient with an excessively tight reconstructed lip after oral cancer treatment: A clinical report

This clinical report describes the management of a patient who had an excessively tight reconstructed lip because of oral cancer surgery and postoperative radiotherapy. The presented technique used an intraoral scanner for a preliminary impression and computer-aided design and computer-aided manufacturing (CAD-CAM) technology for preliminary laboratory procedures. This digital impression technique may reduce patient discomfort.     

Biomechanical analysis of 4 types of short dental implants in a resorbed mandible

Statement of problem

Short implants have been increasingly used in the aging society. However, studies which explain the difference of stress distribution according to different connections in short implant treatment are scarce.

Recording an accurate maxillomandibular relationship by adding vertical stops to the occlusal rims

Complete denture fabrication includes accurate recording of the maxillomandibular relationship to ensure the functional requirements of occlusion and minimize the traumatic effects on the residual alveolar ridges. However, errors may occur when the occlusal rims have uneven and nonuniform occlusal contacts. The technique described is a straightforward method for recording an accurate silicone centric relationship record with dome-shaped baseplate wax added as vertical stops on the occlusal surface of the mandibular occlusal rim.     

Assessment of the trueness and tissue surface adaptation of CAD-CAM maxillary denture bases manufactured using digital light processing

Statement of problem

Limited information is available evaluating the trueness and tissue surface adaptation of computer-aided design and computer-aided manufacturing (CAD-CAM) maxillary denture bases fabricated using digital light processing (DLP).

Retention and wear behaviors of two implant overdenture stud-type attachments at different implant angulations

Statement of problem

Implant angulation should be considered when selecting an attachment. Some in vitro studies have investigated the relationship between implant angulation and changes in the retention force of the stud attachment, but few studies have evaluated the effect of cyclic loading and repeated cycles of insertion and removal on the stud attachment.

In vitro assessment of cutting efficiency and durability of zirconia removal diamond rotary instruments

Statement of problem

Recently, zirconia removal diamond rotary instruments have become commercially available for efficient cutting of zirconia. However, research of cutting efficiency and the cutting characteristics of zirconia removal diamond rotary instruments is limited.

A digital implant custom tray fabrication method using the design process for simulating the position of the impression copings and 3D printing technology

The technique described allowed an implant custom tray to be fabricated referencing the location of connected impression copings. The technique uses dental computer-aided design (CAD) software and 3D printing technology. The method controls the thickness of the impression material around the impression copings, improving the impression-making process.     

A digital technique for fabricating an interim implant-supported fixed prosthesis immediately after implant placement in patients with complete edentulism

The conversion of a denture into an interim implant-supported, screw-retained restoration has become the standard method for immediate interim restoration in patients with complete edentulism. The most critical steps of the denture conversion process are the creation of appropriate denture access holes to prevent displacement of the denture by the interim cylinders and removal of the denture flanges to facilitate both good esthetics and accessibility for oral hygiene after the denture is connected to the interim cylinders. This article presents a digital technique for designing and fabricating an interim implant-supported, fixed prosthesis for edentulous patients. The interim prosthesis has cylinder access holes that are digitally prefabricated and a denture flange part that is designed to be easily sectioned. This technique facilitates more straightforward and efficient immediate restoration for edentulous patients after implant placement.     

Recording the trajectory of mouth opening and closing for the fabrication of an occlusal splint

Various attempts have been made to transfer the transverse hinge axis and mandibular movement pattern to the mechanical articulator and to fabricate dental prostheses with the fewest errors. However, the occlusal adjustment of a dental prosthesis is always necessary to ensure a precise intraoral fit even when the facebow transfer technique is used in the cast mounting procedure. This is because the true hinge axis is not obtained when the facebow is applied to a patient who exhibits a variable mandible movement pattern rather than a single rotational axis. This technique merges facial scanning data and digital data obtained from a diagnostic cast based on measurements of several landmarks of the anterior teeth and makes it possible to design a dental prosthesis while considering the mandibular opening and closing movements of the patient. This technique could be used to design prosthetic restorations, occlusal splints, and intermediate splints for orthognathic surgery and for complete mouth rehabilitation when changes in vertical dimensions are needed.     

Treatment of a mandibular discontinuity defect by using a fibula free flap and an implant-supported fixed complete denture fabricated with a PEKK framework: A clinical report

This clinical report describes the rehabilitation of a patient with a history of mandibulectomy that involved the use of a fibula free flap and an implant-supported fixed complete denture. A recently introduced material, polyetherketoneketone (PEKK), was used as the framework material for the prosthesis, and the treatment produced favorable esthetic and functional results.