• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.3.1-3.10
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• 2019

Objectives: It was the aim of this study to evaluate the effect of cooling water temperature on the temperature changes in the pulp chamber and at the handpiece head during high-speed tooth preparation using an electric handpiece. Materials and Methods: Twenty-eight intact human molars received a standardized occlusal preparation for 60 seconds using a diamond bur in an electric handpiece, and one of four treatments were applied that varied in the temperature of cooling water applied (control, with no cooling water, $10^{\circ}C$, $23^{\circ}C$, and $35^{\circ}C$). The temperature changes in the pulp chamber and at the handpiece head were recorded using K-type thermocouples connected to a digital thermometer. Results: The average temperature changes within the pulp chamber and at the handpiece head during preparation increased substantially when no cooling water was applied ($6.8^{\circ}C$ and $11.0^{\circ}C$, respectively), but decreased significantly when cooling water was added. The most substantial drop in temperature occurred with $10^{\circ}C$ water ($-16.3^{\circ}C$ and $-10.2^{\circ}C$), but reductions were also seen at $23^{\circ}C$ ($-8.6^{\circ}C$ and $-4.9^{\circ}C$). With $35^{\circ}C$ cooling water, temperatures increased slightly, but still remained lower than the no cooling water group ($1.6^{\circ}C$ and $6.7^{\circ}C$). Conclusions: The temperature changes in the pulp chamber and at the handpiece head were above harmful thresholds when tooth preparation was performed without cooling water. However, cooling water of all temperatures prevented harmful critical temperature changes even though water at $35^{\circ}C$ raised temperatures slightly above baseline.

• 대한소아치과학회지
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• 제30권3호
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• pp.431-438
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• 2003

수복 치료과정에서 발생하는 온도증가가 치수조직에 미칠 수 있는 위해효과는 치의학의 오랜 관심사였다. 일반적으로, $5.5^{\circ}C$를 초과하는 치수 내 온도변화는 치수조직 에 비가역적인 손상을 야기할 수 있다. 기존의 할로겐 램프 광중합기와 더불어 최근 시판되고 있는 플라즈마 아크 중합기, LED 중합기를 사용하여 복합레진 중합시 치수강 내 온도증가량을 조사하였다. 한 개의 우식이 없는 치아를 대상으로 V급 와동을 형성하였다. 와동 내에 복합레진(Z250, Shade A2)을 충전한 후, 광중합조건을 달리하여 5군(I군: VIP, 20초 (mode 3), II군: VIP, 20초 (mode 6), III군: Flipo, 3초, IV군: Flipo, 5초 (2-step), V군: Lux-O-Max, 40초)으로 분류하고, 각 조건에 맞게 복합레진을 중합시키면서 치수강 내의 온도측정 단자를 통하여 $37.0^{\circ}C$로부터 증가되는 치수강 내 최대 온도증가량을 측정한 결과 다음과 같은 결론을 얻게 되었다. 1. 모든 군에서 치수강 내 최대 온도 증가량은 치수의 변성을 일으키기 시작하는 경계온도인 $5.5^{\circ}C$ 보다 낮았으며, II군에서 치수강 내 최대 온도증가량이 통계적으로 유의하게 가장 높았다(p<0.05). 또한 Lux-O-Max를 조사한 V군은 다른 군보다 낮은 치수강 내 최대 온도증가량을 나타내었다(p<0.05). 2. VIP로 조사한 두 군을 비교할 경우, 조사강도가 높은 II군이 I군보다 치수강 내 최대 온도증가량이 더 높게 증가하였으며(p<0.05), Flipo로 조사한 III군과 IV군 사이에서는 2-step 조사모드로 5초간 조사한 IV군이 3초간 조사한 III군보다 치수강 내 최대 온도증가량이 더 높게 증가하였다(p<0.05). 3. VIP와 Flipo를 비교할 경우, II군이 III, IV군보다 더 높게 증가하였고, IV군이 I군보다 더 높게 증가하였으나(p<0.05), I군과 III군 사이에는 차이를 보이지 않았다.

• 한국광학회:학술대회논문집
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• 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.45-48
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• 1990

CO2 laser beam was focused by a ZnSe lens onto the center of the occlusal surface f extracted lower molars. K-type thermocouple was contacted with the pulp chamber and the changes of temperature in the during and after the laser irradiation were measured as function of the power of laser beam, the time of laser irradiation and thickness of the sample. An empirical formula for temperature effect was derived from the measured data.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.43-53
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• 1984

The purpose of this study was to suggest the use of laser energy in the the field of operative dentistry without considerable pulpal damage and significant effects on the dental hard tissue, additionally to find out the methods which could control the temperature rise. The laser beam (CW $CO_2$ laser, output: 6W, beam diameter: 1.5mm) was focused on the center of the occlusal surface of extracted lower molars. A Ge lens (focal length 200mm) was used to focus the primary laser beam. In order to vary the total amount of the same irradiated energy, experimental subjects were devided into three groups: continuously irradiated group, intermittently irradiated group, and water-cooled group after continuous laser irradiation. Temperature changes in the pulp chamber after laser irradiation were measured and recorded by the digital thermometer and recorder. The following results were obtained: 1. Temperatures in the pulp chamber were raised up in the order of the continuously irradiated group, intermittently irradiated group, water-cooled group after continuous laser irradiation. 2. In the continuously irradiated group, the temperature was raised up $1.7^{\circ}C$, $3.8^{\circ}C$, $7.3^{\circ}C$, $17.2^{\circ}C$ after 2, 4, 8, 16 seconds of the irradiation of laser. In the intermittently irradiated group, the changes were $1.2^{\circ}C$, $3.4^{\circ}C$, $6.3^{\circ}C$, $11.1^{\circ}C$, respectively. In the water-cooled group after continuous laser irradiation, the changes were $0.0^{\circ}C$, $0.8^{\circ}C$, $1.6^{\circ}C$, $6.9^{\circ}C$, respectively. 3. The starting time of temperature rise in the pulp chamber had no connection with laser irradiation time.

• 대한치과보철학회지
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• 제14권1호
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• pp.47-54
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• 1976

Pulpal temperature is changed in response for various conditions which were mechanical, thermal, chemical and biological stimuli. This study was performed to determine the pulpal temperature changes which were using air turbine with air-water coolant, water coolant, and conventional dental engine with water coolant and no coolant on 28 canine of dogs. In order to record pulpal temperature, pulp chamber was opened on the labiocervical area of canine. Thermocouple was inserted into pulp chamber and was fixed with filling material(dycal). Changes of pulpal temperature were recorded on the physiograph, which had been standardized temperature degree, through thermocouple to thermistor bridge and carrier preamplifier. The amount of experimental temperature change to that of control was interpreted in the pulpal cavity. The obtained results were as followings: 1. The mean normal temperature was 33.07 centigrade. 2. The temperature was decreased than normal pulpal temperature. It was 12.04 centigrade in reduction by air turbine with air-water coolant, 7.17 centigrade in reduction by air turbine with air coolant, 5.54 centigrade in reduction by conventional engine with water coolant, and 1.26 centigrade in reduction by conventional engine with no coolant. 3. The time for maximal temperature change was 53.3 seconds in reduction by air turbine with air-water coolant, 73.4 seconds in reduction by air turbine with air coolant, 50.9 seconds in reduction by conventional engine with water coolant, and 27.1 seconds in reduction by conventional engine with no coolant. 4.. After reduction was ceased, the recovery time to normal pulp temperature was 287.1 seconds in air turbine with air-water coolant, 189.0 seconds in air turbine with air coolant, 86.9 seconds in conventional engine with water coolant, and 52.9 seconds in conventional engine with no coolant respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.659-661
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• 1989

$CO_2$ laser beam was focused a ZnSe lens onto the center of the occlusal surface of extracted lower molars. K-type thermocouple was contacted with the pulp chamber and the changes of temperature in the pulp chamber during and after the laser irradiation were measured as function of the power of laser beam, the time of laser irradiation and thickness of the sample. An empirical formula for temperature effect was derived from the measured data.

• 대한소아치과학회지
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• 제31권1호
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• pp.85-91
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• 2004

연구목적은 복합레진 중합 광원에 따른 치수강 온도 변화를 관찰하는 것이었다. 연구에 사용된 광중합기는 일반 플라즈마아크 광중합기, 저발열 플라즈마 아크 광중합기, 저출력 할로겐 광중합기, 저출력 LED 광중합기, 고출력 LED 광중합기의 다섯 개이었다. K-type thermocouple 온도계를 사용하여, 중합기 light guide tip에서의 온도를 측정하고, 잔존 상아질 두께가 1mm가 되도록 형성한 유구치 와동에 상아질 접착제만 도포한 군, ionomer glass를 함유한 base 또는 calcium hydroxide를 함유한 base를 0.5mm두께로 이장한 군에서 각각 레진 충전 전과 후의 치수강내 온도를 측정하였다. 중합기 light guide tip에서 측정한 온도는 일반 플라즈마가 $52.94^{\circ}C$로 가장 높았고, 저출력 LED가 $26.14^{\circ}C$로서 가장 낮았다. 레진충전 전의 치수강내 온도는 고출력 LED가 $41.60{\sim}43.34^{\circ}C$로 가장 높았고, 저출력 LED는 $36.50{\sim}36.76^{\circ}C$로서 가장 낮았다. 레진 충전 후의 치수강내 온도는 고출력 LED가 $40.22{\sim}40.94^{\circ}C$로 가장 높았고, 저발열 플라즈마와 저출력 LED는 온도 상승이 없었다. Base의 사용은 부분적인 열 차단 효과가 있었다.

• 한국광학회지
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• 제1권2호
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• pp.210-216
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• 1990

본 연구에서는 레이저와 치아조직과의 상호작용에 대한 연구의 일환으로, $CO_2$ 레이저의 발진파장인 $10.6\mu\textrm{m}$의 레이저 빔 조사시에 일어나는 치아의 온도변화를 조사하기 위하여 $CO_2$ 레이저 발진장치를 제작하여 여러 가지 조사 에너지, 조사시간에 대하여 발거된 치아의 치수강의 온도변화를 측정 분석하였다. 측정한 data를 분석하여 최대 상승온도 $\DeltaT_m$를 추정할 수 있는 다음과 같은 실용적인 경험식을 얻었다. $\DeltaT_m=\alphaP\Delta\tauexp(-\betad)$$ 여기서 P는 레이저의 출력(W)이고 $\Delta\tau$는 조사시간(sec), d는 치아의 두께(mm)이다.

• Restorative Dentistry and Endodontics
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• 제39권3호
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• pp.155-163
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• 2014

Objectives: Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Materials and Methods: Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results: The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p < 0.05). Filtek P90 induced higher temperature rise during polymerization than Ceram.X and Beautifil II under demineralized dentin (p < 0.05). The temperature rise under demineralized dentin during Filtek P90 polymerization exceeded the threshold value ($5.5^{\circ}C$), with no significant differences between the DCs of the test materials (p > 0.05). Conclusions: Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

• 한국치위생학회지
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• 제14권4호
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• pp.585-591
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• 2014

Objectives : The purpose of this study was to investigate of the color change, tooth surface and intra-pulpal temperature of tooth bleaching by light activation Methods : Forty-eight extracted bovine teeth were immersed into a tea solution for 24 hours. The specimens were randomly divided into four groups(n=15):(G1) 15% HP + without light activation, (G2) 15% HP + light activation, (G3) 25% HP + without light activation, (G4) 25% HP + light activation. All specimens were bleached for 15 minutes three times. The spectrophotometer (CM-2600d, Konica Minolta, Osaka, Japan) was used including before bleaching, immediately after bleaching, 1 week, 1 and 3 months after the end of bleaching. The temperature rise were measured in the pulpal chamber and tooth surface with a digital thermocouple thermometer(Termopar Digital Multimeter, Tektronix DMM916, USA). Between the tested time points, the specimens were stored in distilled water. The data were analyzed by ANOVA, t-test and Tukey's post hoc test set at 0.05. Results : There was no significant color change by the use of light after the bleaching treatment(p>0.05). The dental bleaching treatments of teeth with 15% HP and 25% HP did not seem to be more effective when light source was used. There was no difference in color stability between groups within three month(p>0.05). There was an increase in tooth surface and pulp temperature, but it was not sufficient to cause damage to the pulp. Conclusions :The use of light activation has no obvious effective impact on the tooth bleaching effect.