de Oliveira Cleide Regina Alves Carrara, Zanin Fátima, Cassoni Alessandra, Rodrigues José Augusto, Silveira Landulfo, Pacheco Marcos Tadeu, Brugnera Aldo
1 University UniVap-IPD , São Paulo, Brazil .
2 Anhembi Morumbi University, São José dos Campos, Brazil .
Photomed Laser Surg. 2017 Oct;35(10):515-519. doi: 10.1089/pho.2016.4233. Epub 2017 Feb 16.
One of the limiting factors of employing laser radiation on dental therapies is the potential of causing thermal injuries to pulp tissues. The purpose of this study was to evaluate intra-chamber temperature increase on extracted human teeth exposed to 670 nm wavelength InGaAlP laser diode radiation.
In vitro intra-chamber temperature measurements of 12 standardized human teeth (incisors, canines, premolars, and molars; n = 3) were taken both before and after laser radiation. A type-K thermocouple fast-response thermocouple wire with a 0.5 mm diameter probe was inserted into the tooth pulp chamber (ICEL-Manaus-brand). The laser device Lasotronic-brand InGaAlP laser diode was used to irradiate tooth enamel, perpendicularly to the external surface for 30 sec, with power of levels of 340, 272, 204, 136, and 68 mW. The measurements were taken at three time points: 0, 30 sec, and 3 min after the laser irradiation. Measurements were repeated 24 h after removal and reinsertion of the probe in the pulp chamber. The temperature gradient (ΔT in °C) was calculated (ΔT = final temperature-initial temperature) for each group. Data of ΔT were statistically analyzed by two-way analysis of variance (ANOVA) at the 95% confidence level and compared by Tukey post hoc test (α = 0.05).
ANOVA showed statistically significant differences to the interaction of factors (p < 0.05). The highest ΔT values obtained were observed to incisors with 340 mW, 272 mW; 204 mW of power (respectively 4.7°C, 4.2°C, and 3.1°C); and canines presented the lowest ΔT (0.8°C-0.3°C) with no influence of power output.
Since the thermal increase was observed in this study, especially in incisors, attention should be paid to avoid pulpal damage.
在牙科治疗中使用激光辐射的限制因素之一是可能对牙髓组织造成热损伤。本研究的目的是评估暴露于670nm波长的InGaAlP激光二极管辐射下的拔除人牙牙髓腔内温度的升高情况。
对12颗标准化人牙（切牙、尖牙、前磨牙和磨牙；n = 3）在激光辐射前后进行牙髓腔内温度测量。将一根直径为0.5mm探头的K型快速响应热电偶丝插入牙髓腔（ICEL-玛瑙斯品牌）。使用Lasotronic品牌的InGaAlP激光二极管装置垂直于牙齿外表面照射牙釉质30秒，功率水平分别为340、272、204、136和68mW。在三个时间点进行测量：激光照射后0、30秒和3分钟。在将探头从牙髓腔取出并重新插入24小时后重复测量。计算每组的温度梯度（ΔT，单位为°C）（ΔT = 最终温度 - 初始温度）。对ΔT数据进行95%置信水平的双向方差分析（ANOVA）统计分析，并通过Tukey事后检验进行比较（α = 0.05）。
ANOVA显示因素间相互作用具有统计学显著差异（p < 0.05）。观察到功率为340mW、272mW、204mW时切牙获得的ΔT值最高（分别为4.7°C、4.2°C和3.1°C）；尖牙的ΔT最低（0.8°C - 0.3°C），且不受功率输出影响。
由于本研究中观察到温度升高，尤其是在切牙中，应注意避免牙髓损伤。
