Questionnaire survey for the clinical trial participants who experienced both digital and conventional impression

PURPOSE: The aim of this study was to assess the patients' perception, acceptance, and preference of the difference between a conventional impression and digital impression through questionnaire survey. MATERIALS AND METHODS: Thirteen (6 male, 7 female) subjects who experienced both digital and conventional impression at the same day were enrolled in this study. Conventional impression were taken with polyvinylsiloxane and digital impression were performed using a newly developed intra-oral scanner. Immediately after the two impressions were made, a survey was conducted with the standardized questionnaires consisting of the following three categories; 1) general dental treatment 2) satisfaction of conventional impression 3) satisfaction of digital impression. The perceived source of satisfaction was evaluated using Likert scale. The distribution of the answers was assessed by percentages and statistical analyses were performed with the paired t-test, and P < 0.05 was considered significant. RESULTS: There were significant differences of the overall satisfaction between two impression methods (P < 0.05). Digital impression showed high satisfaction in less shortness of breath and odor to participants compared to conventional impression. The use of an oral scanner resulted in a discomfort of TMJ due to prolonged mouth opening and in lower score of the scanner tip size. CONCLUSION: It was confirmed that the preference for the digital impression using intraoral scanner is higher than the conventional impression. Most survey participants said they would recommend the digital impression to others and said they preferred it for future prosthetic treatment.

Erratum: Comparative study on quality of scanned images from varying materials and surface conditions of standardized model for dental scanner evaluation

No abstract available.

Comparative study on quality of scanned images from varying materials and surface conditions of standardized model for dental scanner evaluation

PURPOSE: The purpose of this study is to evaluate the image acquisition ability of intraoral scanners by analyzing the comprehensiveness of scanned images from standardized model, and to identify problems of the model. MATERIALS AND METHODS: Cast models and 3D-printed models were prepared according to international standards set by ISO12836 and ANSI/ADA no. 132, which were then scanned by model scanner and two different intraoral scanners (TRIOS3 and CS3500). The image acquisition performance of the scanners was classified into three grades, and the study was repeated with varying surface conditions of the models. RESULTS: Model scanner produced the most accurate images in all models. Meanwhile, CS3500 showed good image reproducibility for angled structures and TRIOS3 showed good image reproducibility for rounded structures. As for model ingredients, improved plaster model best reproduced scan images regardless of the type of scanner used. When limited to 3D-printed model, powdered surface condition resulted in higher image quality. CONCLUSION: When scanning structures beyond FOV (field of view) in standardized models (following ISO12836 and ANSI/ADA 132), lack of reference points to help distinguish different faces confuses the scanning and matching process, resulting in inaccurate display of images. These results imply the need to develop a new standard model not confined to simple pattern repetition and symmetric structure.

Survey study on the Preference of Dental Medical Personnel for Dental CAD/CAM Milling Machines / 대한치과보철학회지

PURPOSE: Recently, according to the development of digital technology, computer aided design/computer aided manufacture (CAD/CAM) system is widely used for fabrication of various dental prostheses in the field of dentistry. This study aims to survey the present state and awareness of CAD/CAM system on domestic dental field, and to supply the advice for the application of the new system. MATERIALS AND METHODS: In this questionnaire survey was conducted for a total of 298 dentists, dental hygienist and dental technicians of the whole country including the dental hospital of Seoul National University for two months from November to December, 2016 through mail. RESULTS: The most important purpose to consider when purchasing a dental CAD/CAM milling machine were the performance of the milling machine (64.43%) and the use of milling machine was the highest with 49.33% of manufacturing for dental prosthesis and customized implant abutment. In addition, more than 60% of respondents answered positively about the purchase of new milling machine if the CAD/CAM milling machine was improved to satisfactory performance. CONCLUSION: This survey results show that the improved CAD/CAM milling machine would be play an important role in the dental industry in preparation for digitization and the 4th industrial revolution.

Analysis of temperature changes and sterilization effect of diode laser for the treatment of peri-implantitis by wavelength and irradiation time

PURPOSE: We compared the effects of newly developed diode laser (Bison 808 nm Diode laser) on the treatment of peri-implantitis with conventional products (Picasso 810 nm Diode laser) by comparing the surface temperature of titanium disc and bacterial sterilization according to laser power. MATERIALS AND METHODS: The titanium disc was irradiated for 60 seconds and 1 – 2.5 W using diode laser 808 nm and 810 nm. The surface temperature of the titanium disc was measured using a temperature measurement module and a temperature measurement program. In addition, in order to investigate the sterilizing effect according to the laser power, 808 nm laser was irradiated after application of bacteria to sandblasted large-grit acid-etched (SLA) and resorbable blast media (RBM) coated titanium discs. The irradiated disks were examined with scanning electron microscopy. RESULTS: Both 808 nm and 810 nm lasers increased disk surface temperature as the power increased. When the 810 nm was irradiated under all conditions, the initial temperature rise rate, the descending rate, and the temperature change before and after was higher than that of 808 nm. Disk surface changes were not observed on both lasers at all conditions. Bacteria were irradiated with 808 nm, and the bactericidal effect was increased as the power increased. CONCLUSION: When applying these diode lasers to the treatment of peri-implantitis, 808 nm which have a bactericidal effect with less temperature fluctuation in the same power conditions would be considered safer. However, in order to apply a laser treatment in the dental clinical field, various safety and reliability should be secured.

Study on application to the field of dentistry using optical coherence tomography (OCT) / 대한치과보철학회지

PURPOSE: This paper describes the basic principles and the feasibility of the field of dental diagnosis of optical coherence tomography (OCT) used in diverse field of medical diagnosis. MATERIALS AND METHODS: In this review, the research data of OCT were searched from PubMed, medical journal and related papers. RESULTS: Generally, OCT is non-invasive and is possible to secure an excellent spatial resolution and real-time images of biological microstructure. CONCLUSION: This review discusses not only the basic principles of operation, types, advantages, disadvantages of OCT but also the future applications of OCT technology and their potential in the field of dental diagnosis.

Study on methodology for the assessment of internal and marginal adaptation on fixed dental prosthesis

This article is to review various methods used to investigate internal and marginal adaptation of fixed dental prostheses, and to summarize a merit, worth, and limitation of each method, using some results of previous studies. The methods of measuring internal and marginal gap are divided into two categories in this study; in vivo and in vitro. In vivo methods are clinical evaluations, including exploration, radiography, and impression technique. In vitro methods are laboratory evaluations such as direct view, cross-sectioning, and silicone replica technique using microscope. Measuring by micro computed tomography (CT) or profilometer is also in vitro methods. In recent years, the development of scanning systems is able to analyze 3-dimensional internal and marginal space in detail. As measuring and analyzing technology become more advanced, the ability to thoroughly examine crown adaptation is becoming both simpler and more efficient.

Dural Arteriovenous Malformations

We have experienced 3 cases of dural arteriovenous malformation(AVM). Among them, 2 cases were traumatic and one case was congenital origin. The need for careful preoperative definition of all feeding vessels by selective cerebral angiography is stressed. Most frequent arterial feeders were the tentorial, middle meningeal, occipital artery and meningeal branches of vertebral artery. A complete neuroradiological investigation was essential for adequate treatment. Common symptoms were headache and troublesome tinnitus aurium. More serious neurological deficiencies may occur as result of disturbance in cerebral hemodynamics. Direct shunting of arterial blood into the transverse and sigmoid sinus caused a considerable increase of the sagital sinus pressure and elevation of intracranial pressure(ICP). ICP decreased following obliteration of dural AVM by muscle embolization with ligation of external carotid artery in one case. Operative isolation of the transverse sinus and sigmoid sinus by craniectomy or craniotomy and dural section is considered by far the most successful treatment. Purpose of this communication is, therefore, to describe the clinical and radiological features and various types of surgical procedure in 3 cases with dural AVM.