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.

365 nm LED laser treatment on beagle for gingival whitening without gum dermabrasion

PURPOSE: Gingival whitening is one of dental treatment purposes which is close to treating aesthetic disorders. Initial gingival whitening treatment was done by dermabrasion using a high power Diode Laser. However, this treatment method cannot be free from any infection or pain after the treatment. Therefore, we have decided to progress gingival whitening treatment using a low power LED laser. MATERIALS AND METHODS: The laser was irradiated on pork meat then the safety of output power, temperature change and skin denaturalization was measured. Bison 365 nm LED laser was irradiated on oral mucosal pigment of a 15 - 20 kg beagle for 15 min for 1 - 2 weeks, one or two times each. Any pigment loss was checked through Hematoxyline-Eosin staining. RESULTS: The melanin pigments at the area of 365 nm LED Laser irradiation were decreased. CONCLUSION: The 365 nm LED Laser proposed in this study is considered to compensate the bleaching effect achieved by either using Diode laser or surgical methods.

The Effect of Cardiac Rehabilitation Exercise Training on Cardiopulmonary Function in Ischemic Cardiomyopathy With Reduced Left Ventricular Ejection Fraction

OBJECTIVE: To observe the effect and safety of cardiac rehabilitation (CR) exercise in ischemic cardiomyopathy and to compare the results between patients with preserved left ventricular ejection fraction (LVEF) and reduced LVEF. METHODS: Patients with ischemic cardiomyopathy with LVEF <50% were included as subjects. The patients were classified into the preserved LVEF (pLVEF; LVEF 41%–49%) group and the reduced LVEF (rLVEF; LVEF ≤40%) group. Patients underwent hourly aerobic exercise training sessions with an intensity of 60%–85% of heart rate reserve, three times a week for 6 weeks. Graded exercise test and transthoracic echocardiogram were performed in all study patients before and after completion of the CR exercise program. RESULTS: After completion of the CR exercise program, both groups (pLVEF, n=30; rLVEF, n=18) showed significant increases in LVEF and VO(2max). In the pLVEF group, LVEF and VO(2max) increased from 45.1%±4.8% to 52.5%±9.6% (p<0.001) and from 24.1±6.3 to 28.1±8.8 mL/kg/min (p=0.002), respectively. In the rLVEF group, LVEF and VO(2max) increased from 29.7%±7.7% to 37.6%±10.3% (p<0.001) and from 17.6±4.7 to 21.2±5.1 mL/kg/min (p<0.001), respectively. Both groups completed their exercise program safely. CONCLUSION: In both groups, patients with ischemic cardiomyopathy who completed a 6-week supervised CR exercise program demonstrated remarkable improvements in cardiopulmonary function. This result implies that neither of the two groups showed higher efficacy in comparison to each other, but we can conclude that CR exercise in the rLVEF group was as effective and safe as that in the pLVEF group.

Comparison of the Effects of 1 Hz and 20 Hz rTMS on Motor Recovery in Subacute Stroke Patients

OBJECTIVE: To compare the low frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) with high frequency (20 Hz) rTMS on motor functional improvement of the affected upper extremity in subacute stroke patients. METHODS: Forty patients with subacute ischemic stroke participated in this study. The first group received 10 sessions of 20 Hz rTMS at ipsilesional M1 area and the other group received 10 sessions of 1 Hz rTMS at contralesional M1 area. Motor training of the hemiparetic hand was conducted after each rTMS train. All the patients received conventional occupational therapy immediately after each rTMS session. Manual function test (MFT), Fugl-Meyer Assessment scale (FMS), Modified Barthel Index (MBI), Brunnstrom recovery stage, and grip strength were used to assess motor function before, at the end of, and one month after the last session of rTMS. RESULTS: No adverse side effects were reported during the course of the experiment using rTMS. No significant difference in motor function of the affected upper extremity was observed between the two groups before rTMS. Significant improvements in MFT, FMS, MBI, and Brunnstrom stage were observed in the both groups at the end of the last rTMS session and one month later (p0.05). CONCLUSION: There was no significant difference in motor function of the affected upper extremity between 1 Hz and 20 Hz rTMS during the subacute period of ischemic stroke. Thus, we cannot conclude which has a greater effect.