2种侧压器进入弯曲根管的深度及充填质量的比较

目的 比较镍钛（NiTi）侧方加压器和不锈钢（SS）侧方加压器进入不同程度弯曲根管的深度和根充质量。方法 选择40颗离体弯曲单根管的下颌前磨牙，依据根管弯曲度将其分为小于等于20°和大于20°。采用机用镍钛ProFile器械预备根管，测定2种侧压器进入有主牙胶尖根管的深度，并采用冷牙胶侧方加压充填技术充填根管，在距根尖2 mm和4 mm处对根管作水平片切，记录图像并分析根管中牙胶面积的百分比（PGP）。结果 在弯曲度大于20°的根管中，NiTi侧压器进入根管的深度及根尖2 mm处PGP均大于SS侧压器（P<0.05）；在弯曲度小于等于20°的根管中，二者的差异无统计学意义（P>0.05）。采用不同侧压器充填的根管距根尖4 mm处的PGP的差异均无统计学意义（P>0.05）。结论 NiTi侧压器在严重弯曲根管中较SS侧压器能获得较好的进入深度及充填质量。

Comparison of Penetration and Obturation Density Using Nickel-titanium and Stainless-steel Spreader in Curved Canals

OBJECTIVE: To compare the initial penetration depth of nickel-titanium (NiTi) and stainless-steel (SS) spreader during lateral compaction and the quality of the seal in curved canals. METHODS: Forty extracted mandibular premolars with a single curved canal were divided into two groups: no more than 20 degrees and more than 20 degrees based on degree of curvature. All canals were instrumented using a rotary instrumentation technique. NiTi and SS spreaders were used to obturate the canals containing a master cone while the penetration depths were measured. Horizontal sections were cut in 2 and 4 mm from the apex and photographed under stereomicroscope. The percentage of gutta-percha-filled are (PGP) of cross-sections was measured using an image analysis program. RESULTS: In canals of more than 20 degrees, the penetration depths and PGP of 2 mm from the apex of NiTi spreaders were higher than SS spreader. In canals of no more than 20 degrees, there were no significant difference between them (P > 0.05). At 4 mm from the apex, there was no significant difference between two groups. CONCLUSION: NiTi spreaders has a higher penetrated depth and obturation density than SS spreaders in severed curved canals.