• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.80-88
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• 2011

The dental high-speed air turbine handpiece is one of the most popular devices that have been widely used as the main means of cutting tooth structure and restorative material in dentistry. In consideration of usage and marketability of the dental handpiece, it is obviously worthy of investigating it. The goal of this paper is to establish the relationship between the air turbine speed and the supply route inside the handpiece. To do this, the Computational Fluid Dynamics(CFD) tool, Fine$^{TM}$/Turbo is used and the optimal supply route position is suggested from the simulation results. In addition, as an attempt for domestic product, the reverse engineering process of a high speed dental handpiece by 3D X-Ray CT equipment and wire cutting is presented for the Mark II model in NSK. In doing so, the 3D modeling of the handpiece parts is carried out with CATIA V5, and the interference between parts is examined. Finally, the result of performance test for the prototype produced in this research is presented.

• The Journal of Advanced Prosthodontics
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• v.13 no.3
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• pp.136-143
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• 2021

Purpose. This study aimed to evaluate the effect of repeated use of an implant handpiece under an implant placement torque (35 Ncm) and overloading torque condition (50 Ncm) on an output torque. Materials and Methods. Two types of implant handpiece systems (Surgicpro/X-DSG20L [NSK, Kanuma, Japan] and SIP20/CRB46LN [SAESHIN, Daegu, South Korea]) were used. The output torque was measured using a digital torque gauge. The height and angle (x, y, and z axes) of the digital torque gauge and implant handpiece were adjusted through a jig for passive connection. The experiment was conducted under the setting torque value of 35 Ncm (implant placement torque) and 50 Ncm (overloading torque condition) and 30 times per set; a total of 5 sets were performed (N = 150). For statistical analysis, the difference between the groups was analyzed using the Mann-Whitney U test and the Friedman test was used to confirm the change in output torque (α=.05). Results. NSK and SAESHIN implant handpieces showed significant differences in output torque results at the setting torques of 35 Ncm and 50 Ncm (P<.001). The type of implant handpiece and repeated use influenced the output torque (P<.001). Conclusion. There may be a difference between the setting torque and actual output torque due to repeated use, and the implant handpiece should be managed and repaired during long-term use. In addition, for successful implant results in dental clinics, the output torque of the implant handpiece system should be checked before implant placement.

• Journal of Oral Medicine and Pain
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• v.34 no.3
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• pp.237-245
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• 2009

The purpose of this study was to investigate the clinical efficacy of latex cover developed for dental handpiece on contamination of microorganisms during dental treatment and to determine whether it can be an alternative to conventional sterilization such as autoclaving. E. fecaelis was used as a experimental microorganism instead of oral flora. Experimental bowl with 2 cm of rectangular cavity was fabricated for handpiece operating instead of oral cavity. Latex covers ($Orokeeper^{(R)}$, Orobiotech Co., Korea) and several handpieces were used after sterilization by autoclave. Four experiments were performed to evaluate bacterial contamination related with (1) various parts of dental handpiece, (2) swabbing time with alcohol sponge, (3) postoperative air-water spraying time and (4) consecutive use of latex covers without autoclaving. The results show that face of handpiece uncovered with latex cover was severely contaminated than the covered area and that most bacteria were removed by swabbing face and head area of dental hand-piece and by air-water spraying more than 15 seconds nearly up to the level of sterilization. Conclusively it can be suggested that use of latex cover for handpiece during dental procedure, swabbing with alcohol sponge is air-water spraying for more than 15 seconds after use of dental handpiece should be very useful and practical for prevention of cross infection and should be an alternative method for the sterilization of dental handpiece under some difficult situations not being able to sterilize a handpiece with autoclave.

• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.169-178
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• 2015

Purpose: This study was to investigate usage satisfaction of multi type handpiece with equipped air-jet function Methods: The subjects of this study through the survey was conducted for fifty-nine dental technicians in Daegu and Gyeongsangbukdo from the May 7 to 19, after the June 23 to July 4 2014. The survey was about the function and quality through user testing environment by cutting zirconia specimens using appliance for zirconia. The collected date was analyzed by the statistical program SPSS Win Ver 19.0 for the satisfaction of handpiece and control system. To test for significance on each item, p<0.05 had been decided a standard. General characteristics and relationship between the handpiece and control system was performed correlation analysis. Results: The results of this study is as follows. 35 dental technicians had 1~2 years career in zirconia part as the highest 59.3%, 95% of subjects expected that the prospects for the zirconia material have bright prospects. The satisfaction of multi type handpiece and control system design and function showed a significant difference. Subjects satisfied with the design and function of the multi type showed negative correlation with those of Standard. The satisfaction of multi type handpiece showed 3.37 points of air jet, 3.05 points of noise level, 2.69 points of water flow rate, and 1.98 points of cruise function. Sample differences in all parameters showed a statistically higher difference. Conclusion: High-speed cutting mechanism of multi-type is recommended working with zirconia materials and the multi-type unit combined handpiece motor, air-turbine and air-gun will be expected the increase of user due to the high satisfaction of air jet.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.29-32
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• 2008

Dental high-speed air turbine handpieces have been used as a dental cutting tool in clinical dentistry for over 50 years, yet little study has been reported on their flow and performance analysis. Therefore it is necessary to investigate turbine for the performance improvements of an air turbine handpiece. This paper presents pressure on turbine rotor and flow analysis in air turbine handpiece using CFD (computational fluid dynamics). Characteristics on each flow and pressure for four various reflection angles of turbine rotor are presented, and then performance change is analyzed about air turbine handpieces by CFD results.

• Tribology and Lubricants
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• v.23 no.5
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• pp.240-247
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• 2007

The design process of the dental handpiece is described. The parameters of the high speed air turbine are estimated. The effect of supply hole on the stiffuess and damping of the air bearing for handpiece is studied numerically. The Reynolds equation is solved by using the divergence formulation and the perturbation method. The test rig is built and the test procedure is developed for the turbine rotational speed measurement by using Fourier transform of noise generated by the turbine during steady operation.

• Journal of Korean society of Dental Hygiene
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• v.5 no.2
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• pp.219-233
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• 2005

This study was conducted on 185 workers at 73 dental clinics and university hospitals in Daegu to investigate the actual prevention of infection and vaccination against B-type hepatitis among dental workers. 1. According to the result of medical examination, only 35 out of 144 (24%) dental clinic workers had periodic health examination while 7 out of 9 (78%) university hospital workers did. 2. In a survey on vaccination against B-type hepatitis, 52 workers aged 29 or younger (96.3%), 38 dental hygienists (51.9%) and 44 dental workers at dental clinics (81.5%) have not had any vaccination against B-type hepatitis. The rest appeared to have had vaccination or be aware that they had antibody against B-type hepatitis without having to have any vaccination. 3. According to the result of a survey on the existence of antibody by job, 42 (56%) of dental hygienists, 15 (20%) of assistant nurses, 12 (16%) of medical assistants and 6 (8%) of dental technicians did not know whether or not they had antibody. This suggests that all types of dental workers except dental hygienists have low awareness of whether or not they have antibody. 4. In a survey on the relation between general characteristics of subjects and the sterilization of dental equipment, alcohol disinfection of high speed handpiece and low speed handpiece was most common among dental workers aged 29 or younger, and all of those aged over 40 used autoclave. By position, alcohol disinfection was used most commonly for high-speed handpiece. antiseptic solution deposition for disposable suction lips, and autoclaving for impression. By workplace, dental workers at university hospitals used autoc1aving most frequently for high/low speed handpiece while those at dental hospitals and dental clinics used alcohol disinfection most frequently and even some respondents replied that they did not disinfect. For metal cups, workers at dental clinics and dental hospitals did not use any sterilizing method while those at university hospitals used autoclaving. For disposable suction tips, workers at dental clinics used antiseptic solution deposition and those at dental hospitals used alcohol disinfection but some respondents replied that they did not disinfect. For metal suctions and impression trays, autoclaving was most common in all workplaces but some dental clinics replied that they did not disinfect impression trays. According to work experience, alcohol disinfection was most common for high/low speed handpiece. For disposable suction tips, dental workers with 3 years' or shorter work experience, those with 3~6 years' experience and those with 9~12 years' experience used antiseptic solution deposition most commonly, and many of those with 6~9 years replied that they did not disinfect. The results of this study stated above suggest that systematic education is necessary for all dental workers for enhancing th eir awareness of B-type hepatitis and the prevention of infection. Moreover, dental workers are required to make efforts to prevent infection with B-type hepatitis voluntarily and actively.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.80-86
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• 2023

We report two rare cases of extensive bilateral subcutaneous emphysema that occurred during ordinary dental procedures. An air-driven high-speed handpiece, routinely used in dental procedures may cause subcutaneous emphysema when high pressure air is introduced into the loose connective tissues below the dermal layer. The first case occurred with surgical extraction of the lower third molar. The air introduced into the fascial spaces near the surgical field spread to the contralateral spaces, as well as the neck and chest areas. The second case also showed extensive bilateral subcutaneous emphysema caused by the introduction of compressed air from the handpiece during crown preparation without any invasive procedure. Cases where the emphysema extends beyond the treatment site to involve the contralateral cervicofacial areas have been rarely reported. Predicting the occurrence of subcutaneous emphysema is difficult, so it is important to exercise caution during routine dental treatment. If significant bilateral cervicofacial swelling is suspected to be due to subcutaneous emphysema, prompt diagnosis with securing the patient's airway will be necessary.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.1
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• pp.34-42
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• 2009

High-speed air turbine handpieces have been used as a dental cutting tool in clinical dentistry for over 50 years, but little study has been reported on their performance analysis. Therefore, the effect of turbine blade shape on performance characteristics of dental air turbine handpiece were studied using CFD in this paper. Computations have been performed for five different positions of turbine blade by using frozen rotor method that is one of steady-state method. The characteristics of turbine blade for shapes and reflection angles were analyzed. As a result of the computation, torque is increased by increasing the reflection angle of turbine blade.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.5-8
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• 2008

In this paper, the effect of turbine shape on the flow characteristics and performance of dental air turbine handpiece were studied using CFD. Computations have been performed for many different cases of the angle between the center-line of nozzle and turbine rotor by using frozen rotor method that one of steady-state method. The characteristics of turbine rotor for three different types (flat, concave, gull) were analyzed. Additionally, the turbine rotor of gull type that has better performance than others was computed for other reflected angles.