• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.113-121
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• 2002

Conventional intraoral radiography continues to be the most widely used image modality for the diagnosis of dental caries. But, conventional intraoral radiography has several shortcomings, including the difficulty of exposing and processing intraoral film of consistently acceptable quality. In addition, radiographic retaking that was the result of processing errors, may result in increased discomfort and radiation dose to the patient. Recently, various digital radiographies substitute for conventional intraoral radiography to overcome these disadvantages. The advantages of digital radiography are numerous. One of advantages Is the elimination of processing errors. In addition, the radiation dose for digital system is approximately 20% to 25% of that required for conventional intraoral radiography Another potential advantage of digital imaging is the ability to perform image quality enhancements such as contrast and density modulation, which may increase diagnostic accuracy. The purpose of this study was to compare the diagnostic ability of artificial proximal defects to conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital image(Digora$^{\circledR}$). Artificial defects were made in proximal surfaces of 60 extracted human molars using #1/2, #1, #2 round bur. Five dentists assessed proximal defects on conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital image(Digora$^{\circledR}$). ROC(Receiver Operating Characteristic) analysis and Two-way ANOVA test were used for the evaluation of detectability, and following results were acquired. 1. The mean ROC area of conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital Image(Digora$^{\circledR}$) were 0.6766, 0.7538, 0.6791(Grade I), 0.7176, 0.7594, 0.7361(Grade II), and 0.7449, 0.7608, 0.7414(Grade III), respectively. 2. Diagnostic ability of direct digital image was higher than other image modalities. But, there was no statistically significant difference among other imaging modalities for Grade I, II, III lesion(p>0.05). In conclusion, when direct and indirect digital system are comparable with conventional intraoral radiography. these systems may be considered an alternative of conventional intraoral radiography for the diagnosis of proximal surface caries.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.354-362
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• 2016

PURPOSE. The trueness and precision of acquired images of intraoral digital scanners could be influenced by restoration type, preparation outline form, scanning technology and the application of power. The aim of this study is to perform the comparative evaluation of the 3-dimensional reproducibility of intraoral scanners (IOSs). MATERIALS AND METHODS. The phantom containing five prepared teeth was scanned by the reference scanner (Dental Wings) and 5 test IOSs (E4D dentist, Fastscan, iTero, Trios and Zfx Intrascan). The acquired images of the scanner groups were compared with the image from the reference scanner (trueness) and within each scanner groups (precision). Statistical analysis was performed using independent two-samples t-test and analysis of variance (${\alpha}=.05$). RESULTS. The average deviations of trueness and precision of Fastscan, iTero and Trios were significantly lower than the other scanners. According to the restoration type, significantly higher trueness was observed in crown and inlay than in bridge. However, no significant difference was observed among four sites of preparation outline form. If compared by the characteristics of IOS, high trueness was observed in the group adopting the active triangulation and using powder. However, there was no significant difference between the still image acquisition and video acquisition groups. CONCLUSION. Except for two intraoral scanners, Fastscan, iTero and Trios displayed comparable levels of trueness and precision values in tested phantom model. Difference in trueness was observed depending on the restoration type, the preparation outline form and characteristics of IOS, which should be taken into consideration when the intraoral scanning data are utilized.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.237-242
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• 2012

Purpose: The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. Materials and Methods: One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. Results: The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 $mGycm^2$ (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 $mGycm^2$ (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05). Conclusion: We recommend 3.1 mGy (PED), 87.4 $mGycm^2$ (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.221-230
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• 2015

Recently, traditional impression has been rapidly replaced by digital impression using intraoral scanning. There are more than 7 types of intraoral scanners available in the dental market. It is difficult to make effective strategic choices due to a lack of standards and guidelines for optimal intraoral scanning devices. So far, little has been reported about evaluating the ergonomic aspect of these scanners. This literature review compares current intraoral scanning systems based on different types of handles and suggests the most comfortable, user-friendly intraoral scanners from an ergonomic standpoint.

• Journal of Technologic Dentistry
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• v.41 no.3
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• pp.187-193
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• 2019

Purpose: The purpose of this study was to compare two-dimensional fitness of the monolithic zirconia prosthesis by using different type of scanner. Methods: No. 26 abutment tooth of FDI system was selected for the study. Using the extraoral scanner and intraoral scanner, the abutment tooth was scanned 10 times and the scanned files were saved as STL files. CAD/CAM system was used to produce the monolithic zirconia prosthesis. marginal and internal gap of the monolithic zirconia prosthesis were measured by digital microscope(x160) and applied silicone replica technique was applied. t-test, a statistical software, was used to perform data analysis. Results: Marginal gap $mean{\pm}SD$ of the monolithic zirconia prosthesis was $33{\pm}7.5{\mu}m$ with extra oral scanner and $34.7{\pm}11.1{\mu}m$ with intraoral scanner. axial gap mean was $40.5{\pm}3.5{\mu}m$ with extra oral scanner and $44.6{\pm}11.6{\mu}m$ with intraoral scanner. occlusal gap mean was $110.1{\pm}25.4{\mu}m$ with extra oral scanner and $64{\pm}9.7{\mu}m$ with intraoral scanner. Conclusion: In this study, fabricating zirconia prosthesis with different type of scanner was clinically applicable.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.69-74
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• 2021

Background In inferomedially rotated zygomatic fractures sticking in the maxillary sinus, it is often difficult to achieve complete reduction only by conventional intraoral reduction. We present a new intraoral reduction technique using a Kirschner wire and its clinical outcome. Methods Among 39 inferomedially impacted zygomatic fractures incompletely reduced by a simple intraoral reduction trial with a bone elevator, a Kirschner wire (1.5 mm) was vertically inserted from the zygomatic body to the lateral orbital rim in 17 inferior-dominant rotation fractures and horizontally inserted to the zygomatic arch in nine medial-dominant and 13 bidirectional rotation fractures. A Kirschner wire was held with a wire holder and lifted in the superolateral or anterolateral direction for reduction. Following reduction of the zygomaticomaxillary fracture, internal fixation was performed. Results Fractures were completely reduced using only an intraoral approach with Kirschner wire reduction in 33 cases and through an additional lower lid or transconjunctival incision in six cases. There were no surgical complications except in one patient with undercorrection. Postoperative 6-month computed tomography scans showed complete bone union and excellent bone alignment. Four patients experienced difficulty with upper lip elevation; however, these problems spontaneously resolved after manual tissue lump massage and intralesional steroid (Triamcinolone) injection. Conclusions We completely reduced infraorbital rim fractures, zygomaticomaxillary buttresses, and zygomaticofrontal suture fractures in 84% of patients through an intraoral approach alone. Intraoral Kirschner wire reduction may be a useful option by which to obtain effective and powerful reduction motion of an inferomedially rotated zygomatic body.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.72-82
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• 2008

Various surgical approaches in the mandibular condyle fracture have been reported and many advantages of intraoral reduction were also introduced. But there are still controversies about surgical method of condylar fractures up to date. To establish the surgical approach protocol of condylar fracture, from May 2001 to December 2004, total 65 patients with 74 fractures of the mandibular condyle were reviewed during 2 years, retrospectively. All cases were classified according to the treatment considering factors, such as the level of fracture, degree and direction of displacement of fractured segment, patient’s age and gender, surgical approach methods, and their complications. Especially, advantages and surgical limitations of extraoral surgical approach, such as direct reduction and fixation via submandibular approach, Nam’s method, and endaural approach, were compared with those of intraoral surgical approach, such as direct intraoral reduction with transbuccal fixation or right angle driver system, and intraoral reinsertional approach after extraoral fixation of fractured fragment. The guidelines of surgical approach of condylar fracture based on our clilnical retrospective experiences and literature reviews can be suggested.

• The korean journal of orthodontics
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• v.48 no.4
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• pp.262-267
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• 2018

The aim of this study was to test the clinical application of an intraoral scanner for serial evaluation of orthodontic tooth movement. The maxillary dentitions of eight patients with fixed orthodontic appliances were scanned using an intraoral scanner at the beginning of treatment (T0), and at 1 month (T1), 2 months (T2), 3 months (T3), and 4 months (T4) after T0. The serial digital models were superimposed on the palatal surface as a reference area, and the linear and angular changes of the central incisors, canines, and first molars were evaluated. The intraclass correlation coefficient and method errors showed that this method was clinically acceptable. Various types of orthodontic tooth movements, including minute movements, could be observed every month. The intraoral scanner and digital superimposition technique enabled the serial evaluation of orthodontic tooth movement without taking serial impressions and/or acquiring radiographs.

• Korean Journal of Computational Design and Engineering
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• v.21 no.3
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• pp.296-305
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• 2016

This paper proposes a framework to automatically align Dental range image captured by depth sensors like the Microsoft Kinect. Aligning dental images by intraoral scanning technology is a difficult problem for applications requiring accurate model of dental-scan datasets with efficiency in computation time. The most important thing in dental scanning system is accuracy of the dental prosthesis. Previous approaches in intraoral scanning uses a Z-buffer ICP algorithm for fast registration, but it is relatively not accurate and it may cause cumulative errors. This paper proposes additional Alignment using the rough result comes after intraoral scanning alignment. It requires that Each Depth Image of the total set shares some overlap with at least one other Depth image. This research implements the automatically additional alignment system that aligns all depth images into Completed model by computing a network of pairwise registrations. The order of the each individual transformation is derived from a global network and AABB box overlap detection methods.

• The Journal of the Korean dental association
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• v.52 no.6
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• pp.354-362
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• 2014

With the development of digital dentistry, various intra-oral scanners which acquire intraoral image without conventional impression taking and stone pouring steps have been introduced. Fixed dental prostheses such as inlay, onlay, crown, and bridge fabricated by CAD/CAM technique combined with digital impressions is getting popular due to the recent rapid progress of digital impression taking system. In comparison with traditional prosthetic procedure, the advantages of intraoral image acquiring and CAD/CAM technique are as follows; the omission of conventional impression materials, reduced workflow step, and increased efficiency by online communication with clinic and laboratory. This review article covers some opinions about the suitable scanning procedures for the various prosthodontic treatments and the utilization of digital intraoral scanner and CAD/CAM system.