A feasibility study on the use of an intraoral optical coherence tomography system for scanning the subgingival finish line for the fabrication of zirconia crowns: An evaluation of the marginal and internal fit.

Objectives: This study aimed to evaluate the marginal and internal fit of zirconia crowns were fabricated using scan data from an intraoral optical coherence tomography (OCT) scanner and an intraoral scanner (IOS) for scanning the subgingival finish line.

Methods: An extracted maxillary left central incisor was prepared for a zirconia crown. The prepared tooth was placed in artificial gingiva, created using silicone with a refractive index similar to that of the tooth, ensuring a subgingival depth of 0.

How does the consecutive use of intraoral scanners affect musculoskeletal health? A preliminary clinical study.

Background: Minimizing muscle strain and reducing the risk of musculoskeletal disorders associated with intraoral scanner (IOS) usage require ergonomic awareness, device selection, and workplace adjustments in dental practice. This preliminary clinical study aimed to simulate intraoral scanning tasks using wired and wireless IOSs and assess muscle activation and fatigue for both types.

Materials And Methods: Fourteen participants performed intraoral scanning tasks using wired and wireless IOSs (i700; MEDIT), with weights of 280 g and 328 g, respectively.

Effect of the Inter-Tooth Distance and Proximal Axial Wall Height of Prepared Teeth on the Scanning Accuracy of Intraoral Scanners.

This study aimed to analyze the effect of the height of the proximal axial wall of the prepared tooth and the distance between the adjacent tooth and the prepared tooth on the scan accuracy of intraoral scanners. Ten working casts with maxillary first molars prepared to receive zirconia crowns were randomly obtained from a dental clinic. Each of the 10 casts was scanned using two intraoral scanners (i700; MEDIT and CS3600; Carestream; computer-aided design [CAD] test model, CTM; N = 15 per working cast) 15 times per scanner.

Feasibility of images acquired using smartphone camera for marginal and internal fit of fixed dental prosthesis: comparison and correlation study.

This study aimed to measure marginal and internal fit using images captured with both an optical microscope and a smartphone camera, comparing the fit measurement performance of these devices and analyzing their correlation. Working casts (with 10 posterior and 10 anterior teeth) created to fabricate fixed dental prostheses were used. These working casts were scanned using a desktop scanner (E1) to design an interim crown, and the designed interim crown was fabricated using a three-dimensional (3D) printer.

Prediction of learning curves of wired and wireless intraoral scanners.

This clinical study aimed to predict the learning curve of wireless and wired intraoral scanners (IOSs) and to compare the reduction patterns of working time. Overall, 14 participants were enrolled in the study. The intraoral scanning procedure was repeated four times, each using wireless and wired IOSs (i700; MEDIT).

Effect of Electrocautery and Laser Treatment on the Composition and Morphology of Surface-Modified Titanium Implants.

The purpose of this study was to investigate the effects of different peri-implantitis treatment methods (Er,Cr:YSGG laser, diode laser, and electrocautery) on various titanium implant surfaces: machined; sandblasted, large-grit, and acid-etched; and femtosecond laser-treated surfaces. Grade 4 titanium (Ti) disks, with a diameter of 10 mm and a thickness of 1 mm, were fabricated and treated using the aforementioned techniques. Subsequently, each treated group of disks underwent different peri-implantitis treatment methods: Er,Cr:YSGG laser (Biolase, Inc.

Evaluation of photopolymer resins for dental prosthetics fabricated via the stereolithography process at different polymerization temperatures. Part II: Dimensional accuracy and fracture load of fixed dental prostheses.

Statement Of Problem: Prostheses printed on a 3-dimensional (3D) printer need to undergo the postpolymerization process, which can increase the working time. However, it has been not suggested for reducing workload and improving the properties of prostheses in dental clinical practice.

Purpose: The purpose of this in vitro study was to evaluate how the printing temperature impacts the dimensional accuracy and fracture load of 3D printed fixed dental prostheses (FDPs).

Does an Ergonomic Dentist Stool Design Have a Positive Impact on Musculoskeletal Health During Intraoral Scans and Tooth Preparation?

Purpose: To evaluate the effects of an ergonomic dentist stool design on muscle activity and fatigue in dentists.

Materials And Methods: A total of 14 dentists were recruited, and electrodes were attached to the arm, neck, and shoulder muscles of these dentists according to the surface electromyography (EMG) for the noninvasive assessment of muscles protocol. After measuring the maximal voluntary contraction, eightchannel surface EMG was performed during simulations of two dental procedures (intraoral scanning and tooth preparation) while the dentists were using two types of dentist stools.

A concept to detect a subgingival finish line using an intraoral optical coherence tomography system: A clinical report.

This clinical report introduces an approach for detecting the supragingival finish line by penetrating the teeth and gingival tissue using optical coherence tomography (OCT) technology. This approach was used in 3 patients who underwent tooth preparation with a subgingival finish line. Consequently, the subgingival finish line, typically challenging to discern clearly in intraoral scans, was identifiable in the OCT image.

Evaluation of photopolymer resins for dental prosthetics fabricated via the stereolithography process at different polymerization temperatures-Part I: Conversion rate and mechanical properties.

Statement Of Problem: Improvement in the mechanical properties of 3-dimensional (3D) printed dental prostheses is necessary to prevent wear caused by an antagonist or fracture. However, how different printing temperatures affect their mechanical properties is unclear.

Purpose: The purpose of this in vitro study was to evaluate the mechanical properties of 3D printed parts fabricated at different printing temperatures.

The Impact of Mechanical Debridement Techniques on Titanium Implant Surfaces: A Comparison of Sandblasted, Acid-Etched, and Femtosecond Laser-Treated Surfaces.

This study evaluated the effects of various mechanical debridement methods on the surface roughness (Ra) of dental implants, comparing femtosecond laser-treated surfaces with conventionally machined and sandblasted with large-grit sand and acid-etched (SLA) implant surfaces. The fabrication of grade 4 titanium (Ti) disks (10 mm in diameter and 1 mm thick) and the SLA process were carried out by a dental implant manufacturer (DENTIS; Daegu, Republic of Korea). Subsequently, disk surfaces were treated with various methods: machined, SLA, and femtosecond laser.

In Vitro Biofilm Formation on Zirconia Implant Surfaces Treated with Femtosecond and Nanosecond Lasers.

(1) Background: The purpose of this study was to evaluate how a zirconia implant surface treated with laser technology affects the degree of biofilm formation. (2) Methods: Experimental titanium (Ti) disks were produced that were sandblasted with large grit and acid-etched (T), and they were compared with zirconia (ZrO) discs with a machined (M) surface topography; a hydrophilic surface topography with a femtosecond laser (HF); and a hydrophobic surface topography with a nanosecond laser (HN) (N = 12 per surface group). An in vitro three-species biofilm sample (Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi)) was applied to each disc type, and bacterial adhesion was assessed after 48 and 72 h of incubation using an anaerobic flow chamber model.

Influence of Dental Titanium Implants with Different Surface Treatments Using Femtosecond and Nanosecond Lasers on Biofilm Formation.

This study aimed to evaluate the impact of different surface treatments (machined; sandblasted, large grit, and acid-etched (SLA); hydrophilic; and hydrophobic) on dental titanium (Ti) implant surface morphology, roughness, and biofilm formation. Four groups of Ti disks were prepared using distinct surface treatments, including femtosecond and nanosecond lasers for hydrophilic and hydrophobic treatments. Surface morphology, wettability, and roughness were assessed.

Three-dimensional morphometric analysis of facial units in virtual smiling facial images with different smile expressions.

Purpose: Accuracy of image matching between resting and smiling facial models is affected by the stability of the reference surfaces. This study aimed to investigate the morphometric variations in subdivided facial units during resting, posed and spontaneous smiling.

Materials And Methods: The posed and spontaneous smiling faces of 33 adults were digitized and registered to the resting faces.

Marginal and Internal Fit and Intaglio Surface Trueness of Temporary Crowns Fabricated with Stereolithography, Digital Light Processing, and Milling Technology.

Purpose: To evaluate the fit and trueness of temporary crowns fabricated with 3D printing vs milling technologies and to analyze any existing correlations between fit and trueness.

Materials And Methods: Marginal and internal fit and trueness were evaluated. Groups were compared using Kruskal-Wallis H test (α = .

Trueness of intraoral scanners according to subgingival depth of abutment for fixed prosthesis.

This study aimed to compare the trueness of intraoral scanners (IOSs) according to the subgingival finish line depth of tooth preparation for fixed prostheses. The prepared maxillary right first molar was fabricated by using ceramic material. A computer-aided design (CAD) reference model (CRM) of the abutment was obtained by using a contact scanner.

Comparison of Osseointegration of Dental Implants Placed in Rabbit Tibia Using Two Dental Laser and Implant Handpiece Systems.

The present study aimed to confirm the usefulness of a multi-laser handpiece system currently under development. Implants were placed in the tibia of rabbits using a conventional separate laser-implant handpiece system (control group; SurgicPro+; NSK, Kanuma, Japan and Epic 10; Biolase, Irvine, CA, USA) and a multi-laser handpiece system (experimental group; BLP 10; Saeshin, Daegu, Korea). Implants were placed in left and right tibias of five rabbits using a conventional laser-implant handpiece system and a multi-laser handpiece system (N = 5 per group).

A Comparative Immunohistochemical Study of Wound Healing after Dental Diode Laser Treatment in the Rat Oral Mucosa.

This study aimed to examine the differences in healing patterns using two types of diode laser devices (laser A and laser B) and a steel scalpel for periodontal surgery through histological and immunohistochemical methods. Twenty 12-week-old male rats were assigned to three groups (3, 7, and 14 days). Square-shaped erosion wounds (2 × 2 mm2 diameter) were created on the hard palate of each rat.

Comparison of Wear of Interim Crowns in Accordance with the Build Angle of Digital Light Processing 3D Printing: A Preliminary In Vivo Study.

The aim of this study is to evaluate the wear volume of interim crowns fabricated using digital light processing 3D printing according to the printing angle. A total of five patients undergoing the placement of a single crown on the mandibular molar were included. Interim crowns were fabricated directly in the oral cavity using the conventional method.

How Does the Use of an Intraoral Scanner Affect Muscle Fatigue? A Preliminary In Vivo Study.

The purpose of this study was to evaluate muscle activation and fatigue in the operator during tooth preparation and intraoral scanning by simulating these tasks in two types of dental unit chair systems (UCS). Six participants were recruited, and the above tasks were simulated. Electrodes were placed on the skin over five types of muscles (arm, neck, and shoulder muscles), and the maximal voluntary contraction (MVC) was measured.

Dental diagnosis for inlay restoration using an intraoral optical coherence tomography system: A case report.

Patients: The patient was a 32-year-old man who underwent amalgam restoration of the mandibular right second molar. An amalgam restoration fracture was diagnosed by intraoral optical coherence tomography (OCT), and pulp exposure was examined during cavity preparation. Subsequently, a definitive ceramic restoration was fabricated, and the marginal fit in the oral cavity was evaluated using the OCT system.

Impact of scanning strategy on the accuracy of complete-arch intraoral scans: a preliminary study on segmental scans and merge methods.

Purpose: This study investigated the accuracy of full-arch intraoral scans obtained by various scan strategies with the segmental scan and merge methods.

Materials And Methods: Seventy intraoral scans (seven scans per group) were performed using 10 scan strategies that differed in the segmental scan (1, 2, or 3 segments) and the scanning motion (straight, zigzag, or combined). The three-dimensional (3D) geometric accuracy of scan images was evaluated by comparison with a reference image in an image analysis software program, in terms of the arch shape discrepancies.

Satisfaction Factors with a Dental Unit Chair System in South Korea: A Dentist's Perspective.

This study aimed to survey users’ satisfaction with a dental unit chair in order to highlight the elements affecting the dentist’s satisfaction. The questionnaire items were drawn up with seven components that constitute a dental unit chair, including the light, patient seat, foot controller, water fountain and cuspidor, monitor, bracket table and controller, and dentist chair. With these questionnaire elements, a pilot experiment was conducted to test the reliability, and reliability analysis was conducted.

Effect of Different Software Programs on the Accuracy of Dental Scanner Using Three-Dimensional Analysis.

This in vitro study aimed to evaluate the 3D analysis for complete arch, half arch, and tooth preparation region by using four analysis software programs. The CAD reference model (CRM; N = 1 per region) and CAD test models (CTMs; N = 20 per software) of complete arch, half arch, and tooth preparation were obtained by using scanners. For both CRM and CTMs, mesh data other than the same area were deleted.