Publications by authors named "Myoung-Uk Jin"

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

(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.

View Article and Find Full Text PDF

: The purpose of this study is to observe the usefulness of autogenous tooth transplantation by examining the cumulative survival rate according to the period of auto-transplanted teeth as pre-implant treatment. : This study was conducted on 111 patients who visited Kyungpook National University Dental Hospital and underwent autogenous tooth transplantation between November 2008 and January 2021 (about 13 years). The cumulative survival rate of autogenous tooth transplantation according to the causes of extraction of the recipient tooth (caries, periapical lesion, crack, crown fracture, periodontitis) and condition of opposing teeth (natural teeth vs.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Statement Of Problem: Various strategies for intraoral scanners (IOSs) can be used to scan the oral cavity. However, research on the scan range that can be clinically is lacking.

Purpose: The purpose of this in vitro study was to compare the 3-dimensional (3D) distortion of complete arch scans as part of the scan strategy and analyze the clinically recommended scan range.

View Article and Find Full Text PDF

Objectives: To evaluate the efficacy of a brush-off patch containing 3.0% hydrogen peroxide, which is a new over-the-counter (OTC) product for tooth whitening, and determine the optimal protocol for use.

Materials And Methods: We performed an in vitro study using hydroxyapatite specimens and a clinical trial involving 140 volunteers.

View Article and Find Full Text PDF

Purpose: Hydroxyapatite treated with recombinant human bone morphogenetic protein-2/Hydroxyapatite (rhBMP-2/HA) or bovine bone was applied on extraction sockets for alveolar ridge preservation, and the results were compared with respect to clinical and histological bone formation.

Materials And Methods: This was a prospective, randomized controlled clinical trial performed on 20 implant placement sites (10 in the experimental and 10 in the control group). rhBMP-2/HA was applied on extraction sockets in the experimental group and bovine bone on those of the control group.

View Article and Find Full Text PDF

Introduction: The aim of this study was to evaluate the root canal shaping effect of 2 nickel-titanium rotary instruments with offset mass of rotation compared with an instrument with a conventional centered mass of rotation.

Methods: Thirty-six extracted human mandibular first molars with 2 independent mesial canals and 1 oval distal canal were selected and divided equally into 3 groups for instrumentation with ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Revo-S (RS; Micro-Mega, Besançon, France), and ProTaper Universal (PTU, Dentsply Maillefer) systems (n = 12). For apical preparation, PTN X2 (#25/0.

View Article and Find Full Text PDF

This study evaluated the anatomical profile of the mesial root canals of the Burmese mandibular first molar with Vertucci's type IV canal configuration (VT4) using microcomputed tomography analysis. Seventy-five mesial roots of extracted mandibular first molars were scanned and evaluated. Fourteen middle mesial canals (MMCs) were observed in the specimens; each specimen had an average of 1.

View Article and Find Full Text PDF

Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region.

View Article and Find Full Text PDF

Objectives: The purpose of this study was to evaluate the proximity of the mandibular molar apex to the buccal bone surface in order to provide anatomic information for apical surgery.

Materials And Methods: Cone-beam computed tomography (CBCT) images of 127 mandibular first molars and 153 mandibular second molars were analyzed from 160 patients' records. The distance was measured from the buccal bone surface to the root apex and the apical 3.

View Article and Find Full Text PDF

Purposes: The potent stem cell homing factor stromal cell-derived factor-1 (SDF-1) actively recruits mesenchymal stem cells from circulation and from local bone marrow. It is well established that bone morphogenetic protein-2 (BMP-2) induces ectopic and orthotopic bone formation. However, the exact synergistic effects of BMP-2 and SDF-1 in ectopic and orthotopic bone regeneration models have not been fully investigated.

View Article and Find Full Text PDF

Objectives: Dentistry has been identified as one of the most stressful work environments. Knowledge of modifiable work-environment factors related to job stress could lead to a strategy and policy to provide a better work environment for dentists. The aims of this study were to examine the degree and distribution of burnout and to determine the factors associated with burnout subscale of Korean dentists.

View Article and Find Full Text PDF

Background: There is increasing evidence that peripheral glutamate signaling mechanism is involved in the nociceptive transmission during pathological conditions. However, little is known about the glutamate signaling mechanism and related specific type of vesicular glutamate transporter (VGLUT) in the dental pulp following inflammation. To address this issue, we investigated expression and protein levels of VGLUT1 and VGLUT2 in the dental pulp and trigeminal ganglion (TG) following complete Freund's adjuvant (CFA) application to the rat dental pulp by light microscopic immunohistochemistry and Western blot analysis.

View Article and Find Full Text PDF

Maxillary lateral incisors usually exhibit a single root with a single canal. However, maxillary lateral incisor teeth with unusual morphology of root canal system are frequently reported. These cases of variable root canal anatomy can be treated well by nonsurgical endodontic methods.

View Article and Find Full Text PDF

Purpose: The purpose of this study was to to analyze the effect of Type 2 diabetes on tooth mortality, implant treatment and prosthetic status.

Materials And Methods: 275 Type 2 diabetics and 300 non-diabetics, aged 40-80 years were selected for analysis. The assessment of number of teeth, missing teeth, fixed prostheses (bridge pontics), implants using panoramic radiographs and dental records were carried out.

View Article and Find Full Text PDF

THE OBJECTIVE OF THIS ARTICLE WAS TO PRESENT TWO NONODONTOGENIC CONDITIONS THAT MAY MIMIC ODONTOGENIC TOOTHACHE: trigeminal neuralgia and burning mouth syndrome. Two cases are presented in which one is related to the upper left second premolar and the other is related to the upper left first molar. Both showed pain when chewing.

View Article and Find Full Text PDF

Closure of interdental spaces using proximal build-ups with resin composite is considered to be practical and conservative. However, a comprehensive approach combining two or more treatment modalities may be needed to improve esthetics. This case report describes the management of a patient with multiple diastemas, a peg-shaped lateral incisor and midline deviation in the maxillary anterior area.

View Article and Find Full Text PDF

The transient receptor potential ankyrin 1 (TRPA1) is implicated in the mechanical and cold hyperalgesia following inflammation and nerve injury. Its expression has been presumed to be confined to primary afferent terminals. Here, we show that TRPA1 is expressed in astrocytes in the superficial laminae of the rat trigeminal caudal nucleus by use of electron microscopic immunoperoxidase and immunogold labeling techniques.

View Article and Find Full Text PDF