Objective In order to get the current distribution range of Chinese Han population healthy anterior gingival color chroma values,the gingival color value of healthy Han people from the 5 major chinese cities and the effects of gender,age,region and areas on it were investigated.Methods 300 healthy Han people were chosen from 5 major cities,and chroma value of their anterial gingival color were measured and analyzed with MINOLTA CR-321 clorimeter.Results ①There was no significant difference on Chinese Han population healthy anterior gingival color by area(△E 2);② The comparison of anterior gingival color chroma values in different regions shows that:The a* values of attached gingiva between the root of two teeth and distal incisor attached gingiva has no significant difference(0.02P0.05);the b* values of mesial incisor gingival papilla and distal incisor attached gingiva has no significant difference(P0.5);the gingival color chroma values of the rest areas have statistical significant differences(P0.001).The color difference △E between various parts was 2;3.The range of chorma values of Chinese Han population in five major cities was values of L*31.69 ～ 56.77,values of a*3.58～15.66,values of b*1.02～7.83.Conclusion This investigation reveals that there was no significant difference on color by area,while the difference in gingival color by regions was significant.Attached gum group is redder and yellower than in the upper edge of gum group.The range of chorma values of Chinese Han population was values of L*31.69 ～56.77,values of a*3.58 ～ 15.66,values of b*:1.02～7.83.

Objective To examine the repeatability of color measurement of Vita 3D-Master shade guide with MINOLTA CM-700d/600d portable spectrophotometer.Methods The chromatic values of incisal site and cervical site of every piece of the shade guide were measured for three times,the first time it was measured in one day,and the second and third time was respectively measured in the next day. Each measurement of the third time was taken just after the second time before the instrument was moved. All the data were calculated and analysized.Results Compared with each other separately in the three groups,the mean ΔE was smaller than 1.5NBS.Conclusion The repeatability of MINOLTA CM-700d/600d spectrophotometer is very good. And it could satisfy the demands of repeated color measurement.

目的 比较恒磨牙不可复性牙髓炎根管治疗术一次法和失活法的疗效差异.方法 选择门诊接诊的由于深龋引起不可复性牙髓炎的共计169颗患牙,进行根管治疗术.将患牙随机分为二组:对照组使用一次法,试验组采用失活法治疗,比较治疗1周后反应和2年后的疗效.结果 根管治疗一次法在术后1周内出现不适的有7例;失活法术后1周有3例出现不适.2年后复查,根管治疗一次法成功率90.32%,根管治疗失活法成功率94.12%.经统计学处理和分析,P>0.05,一次法和失活法的疗效差异无统计学意义.结论 虽然恒磨牙不可复性牙髓炎根管治疗术一次法与失活法在疗效上差异无统计学意义,但从2年成功率来看,失活法高于一次法.