目的:分析不同温度热塑牙胶充填时牙根表面的温度变化。方法:纳入单根管牙60个,分别截除牙冠并预备根管后,用藻酸盐印模材料均匀包绕各牙根。用B&L热塑系统分别以230、200、180℃的温度进行根管充填,并用热电偶分别测量各牙根上部、根中部、根尖上4mm处的牙根表面温度变化;然后分别在上述3个检测点处截开牙根,并测量其各位置1.0、1.5、2.0mm根管壁厚度的温度变化。结果:230、200℃充填时,部牙根上部表面的温度升高平均值均超过10℃。不同温度充填时,冠部牙根表面温度两两相比P〈0.05;根中和根尖上方4mm处,230℃充填时分别与180、200℃相比P〈0.05。同一充填温度时,牙根表面3个测量点温度升高值两两相比P〈0.05。300、200℃充填时,各部位牙根表面温度升高值1.0、2.0mm组相比P〈0.05;180℃充填时,3种厚度根管壁无统计学差异(P〉0.05)。结论:对于根管壁较薄的牙,应适当降低充填温度。
AIM: To observe the changes of root surface temperature with different root filling temperatures. METHODS: 60 permanent teeth with single canal were used. After crown removal and root canal preparation the teeth were instrumented and subsequently embedded in alginate. 3 holes were made into the alginate at levels the cementoe- namel junction, mid-root, and 4 mm to apex to allow access for the temperature probes. Obturations were made at 180 ℃, 200 ℃ and 230℃respectively, the temperature was measured at each position. Then the teeth were sectioned using a fine sandpaper disk, and the remaining dentin thickness was measured. RESUITS: When the temperature set- tings were 200℃ and 230℃, the temperature rise at the cementoenamel junction exceeded 10℃. At the remaining den- tin thickness of 1 mm group, significant difference in temperature rise was found among the 3 filling temperature settings ( P 〈 0.05) and among the 3 temperature measurement sites (P 〈 0.05 ). When the root canals were obturated at 200℃ or 230℃, significant difference was found in the change of root surface temperature between dentin - thickness 1.0 mm group and 2.0 mm group at the cementoenamel junction (P 〈 0.05). However, when the root canals were obturated at 180℃, no difference was found among the 3 measurement depths (P 〉0. 05). CONCLUSION: Suitable filling temperature should be used for individual tooth.