• Journal of Korean Dental Science
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• 제16권1호
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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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.863-864
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• 2013

• 한국추진공학회지
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• 제13권1호
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• pp.34-42
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• 2009

의료용 고속 에어터빈 핸드피스는 치아 절삭 도구로써 지난 50년 동안 치의학분야에서 사용되어왔으나, 그것에 대한 성능 연구가 많이 없었다. 그래서 수치해석을 이용하여 핸드피스 터빈 형상의 성능 특성을 본 논문에서 연구하였다. 정상상태 방법 중 하나인 프로즌 로터 방식을 이용하여 터빈 블레이드의 위치에 따라 5가지의 경우에서 계산하였다. 형상과 반사각에 따른 터빈 블레이드의 특성을 분석하였다. 계산 결과에 따르면, 터빈 블레이드의 반사각이 증가할 때 토크가 증가하였다.

• Composites Research
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• 제28권4호
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• pp.244-248
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• 2015

When a small gear rotates at a very high speed over 40,000 rpm, frictional heat is generated on the gear surfaces. Thermal deformations and stresses arising from frictional heat may lower the efficiency and fatigue life of the high-speed gear. Especially, such frictional heat has much stronger effects on the performance of millimeter-sized high-speed gears used for surgical and dental hand-pieces, due to a small surface area. An analytical equation was derived to calculate frictional temperature on a mating gear surface and conduction heat transfer analysis was performed. Thermal deformation and contact stresses were then calculated using FEM for gears used for medical hand-pieces. The contact stresses of the meshed gear and pinion increase by 19.4% and 16.4%, respectively, when the frictional thermal deformations are considered.

• Journal of Preventive Medicine and Public Health
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• 제28권4호
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• pp.765-771
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• 1995

치과용 핸드피스에서 발산하는 고주파수의 진동에 의한 일시적 진동감각역치 변화를 관찰하고자 치과위생병 28명을 대상으로 34,000rpm의 low-speed handpiece를 진동기구로 사용하였다. 진동에 폭로시키기 전과 후, 치과의사가 스케일링시 취하는 작업자세에 5분간 폭로시킨 후의 진동감각역치를 청력계기의 골전도진동기를 사용하여 250 Hz에서 그들이 주로 사용하는 손의 제2지두수에서 측정한 결과, 각각 $23.5{\pm}3.5dB,\;30.8{\pm}4.2dB,\;23.7{\pm}4.6dB$로 진동에 5분간 폭로시킨 후의 역치가 폭로 전에 비해 7.3dB의 유의한 증가가 있었다(p<0.001). 진동폭로 전후의 차이에 따른 분포를 보면, 10 dB 내외로 증가한 사람이 71.4%로 대부분이었고 16 dB의 증가가 가장 높았다. 진동 폭로 전의 진동감각역치와 신장, 체중, 체질량 지수와의 상관관계는 각각의 상관계수가 0.0360, -0.1657, -0.2641로 통계적 유의성은 없었으며, 흡연에 따른 차이도 흡연군(N=20)과 비흡연군(N=8)의 진동감 각역치가 각각 23.1 dB, 24.6 dB로 그 차이 가 없었다. 본 연구 결과로 볼 때 핸드피스와 같은 고주파-진동기구를 사용하는 치과의사 및 치과위생사에게서 진동감각역치의 변화가 예상되며, 말초신경병증의 원인이 될 수 있는 작업자세에 의한 장기간의 영향 및 아말감 충전시 사용하는 수은의 영향에 대해서도 연구가 필요할 것으로 생각된다.

• 대한치과기공학회지
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• 제38권3호
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• pp.157-163
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• 2016

Purpose: It is to compare and evaluate the change of the wear rate and phase variation of the Zirconia before and after the sintering after the grinding by a high speed equipment manufactured for the Zirconia. Methods: The specimen of the sintered Zirconia was manufactured as size of $15mm{\times}15mm{\times}2mm$. The grinding has been applied to each of all pieces of each test groups for a minute fit for each condition at same speed of 50,000 rpm by a diamond bur at high speed handpiece with injection of the air and water. For the observation of the surface before and after the sintering of the each test piece, the cross section of it was observed as 100 magnification by a scanning electron microscope after it was coated by PT, and the diffraction analysis was performed by XDR to compare the crystal phase of the Zirconia. The average surface roughness value of all specimens were evaluated. The wear test was performed at room temperature by applying a load of 1kg for 120,000 cycles for the chewing period 6 months. Wear was analyzed for the enamel cusps by measurement of the vertical substance loss with a laser scanner. Conclusion: The phase variation from the tetragonal phase to the monoclinic phase was confirmed in the test group of the pre-sintered Zirconia after the grinding, and the value of the surface roughness and the wear rate was increased in experimental group.

• Journal of Korean Dental Science
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• 제7권1호
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• pp.25-30
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• 2014

Subcutaneous emphysema and pneumomediastinum is a relatively uncommon phenomenon. It may occur secondary to dental treatment using high-speed air turbine handpieces, especially after extraction of tooth. Subcutaneous emphysema is often limited only to the areas of head and neck, but also can involve deeper structures. Thorough examination and conservative treatment of these problems are essential in preventing life-threatening complications such as airway obstruction and mediastinitis. The subject of this report is a 57-year-old woman with subcutaneous emphysema and pneumomediastinum during the extraction of maxillary third molar using high-speed air turbine handpiece. If there isn't any appropriate measure, severe complications may occur. Therefore it is important to be well-informed of proper diagnosis and treatment. This article shall present a case report with literature review.

• Restorative Dentistry and Endodontics
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• 제14권2호
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• pp.5-19
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• 1989

The purpose of this study was to observe the microleakage of composite resin filling using several glass ionomer cements. The Class V cavities of eighty noncarious human molars were prepared at the cementoenamel juction on the facial and lingual surfaces of each tooth with a No.330 carbide bur in a high speed handpiece. The cavity dimensions were $3.0{\pm}0.5mm$ wide, $2.0{\pm}0.5mm$ high, and $1.5{\pm}0.5mm$ deep and all enamel cavosurface margins were beveled with a No.558 carbide bur in low speed handpiece. The bevel was approximately $45^{\circ}$ and 0.5-1.0mm in width. A total of the 160 cavities was divided into four groups, and then 144 cavities among them were three experimental groups and remaining sixteen cavities were control group. All of the prepared cavities were restored as follows: group 1 : Preparations were restored with there three glass ionomer cements. group 2 : Preparations were restored with a composite resin with three glass ionomer cement bases placed $0.2{\pm}0.1mm$ short of the cavosurface margin. group 3 : Preparations were restored with a composite resin with three glass ionomer cement bases extened to the cavosurface margin. group 4 : As control group, preparations were restored with a composite resin, PALFIQUE. The specimens were then thermocycled in a range of $6^{\circ}C-60^{\circ}C$ and immersed in a bath of 2.0% aqueous basic fuchsin solution for 24 hours. Dye penetration was read on a scale of 0 to 4 by Tani and Buonocore's method. The following conclusions were derived from the results obtained; 1. All groups showed significantly more leakage at the gingival margins than at the occlusal margins(p<0.0005). 2. At the gingival margins, group 1 showed less leakage than group 3(p<0.01) and group 4(p<0.0005), while group 3 exhibited less leakage than group 2(p<0.01) and group 4(p<0.0005). 3. At the occlusal margins, group 4 showed less leakage than group 3(p<0.1) and group 1(p<0.005), while group 3 exhibited less leakage than group 2(p>0.1) and group 1(p<0.025).

• 대한소아치과학회지
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• 제35권4호
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• pp.628-634
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• 2008

최근 치과계에는 교차감염의 문제가 점차 대두되고 있으며, 그 감염경로에는 혈액이나 구강 분비물을 통한 직접접촉과 진료실 장비 등에 의한 간접접촉이 있다. 또한 병원 등 한정된 공간 내에 많은 인원이 수용된 환경에서는 공기 중을 떠다니는 오염물질에 의한 공기 감염에 보다 많은 관심이 모아지고 있으며, 치과 진료실에서는 고속회전 핸드피스에서 발생하는 분무에 의한 감염이 가장 우려되고 있는 상황이다.따라서 본 실험에서는 치과 진료실 내 핸드피스 분무에 의한 공기 중 세균 감염 위험성을 파악하고 실제 진료 시, 감염 방지에 도움을 주는데 그 목적을 두었으며, 다음과 같은 결론을 얻었다. 1. 핸드피스를 사용해 진료한 군 97.4 cfu, 핸드피스를 사용하지 않고 진료한 군 5.6 cfu로 핸드피스를 사용해서 진료한 군에서 박테리아 군집의 수가 높게 나타났으며 통계학적으로 유의한 차이를 보였다(P<0.01). 2. 핸드피스 사용 시 러버댐을 같이 사용한 진료는 22.4 cfu로 러버댐을 사용하지 않고 진료하는 경우보다 박테리아 군집의 수가 낮게 나타났으며,통계학적으로 유의한 차이를 보였다(P<0.01).3. 핸드피스 물 공급원으로 관주용액을 사용한 경우와 증류수를 사용한 경우를 비교 시 관주용액을 사용한 경우 cfu는 22.4 cfu, 증류수의 경우 17.0 cfu로 측정되었으나, 통계학적으로 유의한 차이를 보이지 않았다. (P>0.05). 4. 핸드피스를 사용해 진료하는 경우, 0.5m와 1.5m 거리에서 측정 시 97.4cfu와 22.0 cfu로 0.5m 거리에서 박테리아 군집의 수가 높게 나타났으며 통계학적으로 유의한 차이를 보였다(P<0.01). 또한 원거리에서도 핸드피스 분무에 의해 박테리아가 검출되었다. 5. 박테리아균을 분류한 결과 그램양성 구균의 수가 73.9%로 가장 많은 비중을 보였고, 그램음성 구균, 그램음성 간균, 그램양성 간균의 순이었다.

• 대한치과의사협회지
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• 제56권8호
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• pp.418-422
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• 2018

Subcutaneous emphysema is relatively rare postoperative complication in the oral and maxillofacial region. Most cases reported in maxillofacial area relate to the use of high-speed handpiece. However, in this case, subcutaneous emphysema was caused by compressed air blow performed during suture removal. Cone-Beam Computed Tomography was conducted to evaluate the extent of diffusion bubbles.. In this report, we describe etiology, diagnosis, prevention and management of subcutaneous emphysema in the maxillofacial area.