Yazici A Rüya, Khanbodaghi Azita, Kugel Gerard
Department of Conservative Dentistry, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
J Contemp Dent Pract. 2007 May 1;8(4):19-26.
Several new techniques and materials for in-office bleaching have been introduced recently. The aim of this in vitro study was to measure the temperature increase in the pulp chamber of extracted teeth produced by the Zoom! in-office bleaching system and to investigate the influence of this light in conjunction with the bleaching gel on pulp temperature rise.
Ten extracted, caries-free, unrestored human maxillary central incisor teeth were used for the study. The root of each tooth was cut approximately 2-3 mm apical to the cementoenamel junction (CEJ), and the apical orifice of the root canal was enlarged. The remaining pulp tissue was removed and the empty pulp chamber was filled with a heat sink compound. A thin K-type thermocouple was inserted into the pulp chamber through the cut root area. The root surfaces of the teeth were partially submerged in a water bath during the testing procedure at 37 degrees C. A whitening gel containing 25% hydrogen peroxide was applied to the buccal surfaces of all ten teeth and exposed to a Zoom! activation light for twenty minutes for three times; this was designated as Group I. The same teeth were then exposed with the Zoom! light for the same time period without the application of the bleaching gel and designated as Group II. The intrapulpal temperature pre-treatment (baseline) and the temperature increase during treatment was measured for both treatment groups.
There was a statistically significant difference between the two groups (p=0.003). Application of the Zoom! light in conjuction with the application of bleaching gel produced a greater temperature rise than did the light alone. The mean temperature rise for Group I (light and bleaching gel) was 1.11 degrees C (0.18 degrees C) and 1.01 degrees C (0.12 degrees C) for Group II (light alone) at the end of a five-minute exposure.
The Zoom! light either used with or without bleaching gel showed no significant increase in the intrapulpal temperature of teeth when used for the recommended exposure time.
近期已引入了几种用于诊室漂白的新技术和材料。本体外研究的目的是测量使用Zoom！诊室漂白系统时，离体牙牙髓腔内的温度升高情况，并研究该光照与漂白凝胶联合使用对牙髓温度升高的影响。
选取10颗拔除的、无龋、未修复的人上颌中切牙用于本研究。将每颗牙的牙根在牙骨质牙釉质界（CEJ）根尖约2 - 3毫米处切断，并扩大根管根尖孔。去除剩余的牙髓组织，用散热化合物填充空的牙髓腔。通过切断的牙根区域将一根细的K型热电偶插入牙髓腔。在测试过程中，牙齿的根面部分浸入37摄氏度的水浴中。将含25%过氧化氢的美白凝胶涂覆在所有10颗牙齿的颊面，并暴露于Zoom！激活光下20分钟，共3次；此为第一组。然后将相同的牙齿在不使用漂白凝胶的情况下暴露于Zoom！光下相同时间段，作为第二组。测量两个治疗组的牙髓内温度预处理（基线）和治疗期间的温度升高。
两组之间存在统计学显著差异（p = 0.003）。与单独使用光照相比，联合使用Zoom！光和漂白凝胶导致的温度升高更大。在5分钟暴露结束时，第一组（光照和漂白凝胶）的平均温度升高为1.11摄氏度（0.18摄氏度），第二组（仅光照）为1.01摄氏度（0.12摄氏度）。
当按照推荐的暴露时间使用时，无论是否与漂白凝胶一起使用，Zoom！光均未显示出牙齿牙髓内温度有显著升高。
