RESUMO
Objective:To compare the quality of the canal isthmus retropreparation among three ultrasonic retrotips.Methods:120 maxillary bicuspid teeth with 2 canals and an isthmus were randomly assigned to 3 groups(n =40).The canal isthmus were retro-preparated by ultrasonic Ni-Ti tip RE2,diamond tip Berutti and #25K file respectively.The quality of cavity margin,the number and type of the micro-cracks were evaluated by SEM.Data were statistically analysed by Kruskal Wallis Test of SPSS 13.0.Results:The cavity margin quality of ultrasonic Ni-Ti tip RE2 group was superior to that of other 2 groups(P =0.003);The number of micro-crack in Ni-Ti tip RE2 group was less than that of other 2 groups(P =0.003).The type of micro-cracks has no significant difference among the 3 groups(P =0.830).Conclusion:Ultrasonic Ni-Ti tip RE2 is feasible in the canal isthmus retropreparation.
RESUMO
Objective: To investigate the expression of LL37 in oral lichen planus (OLP) lesions. Methods: 25 OLP and 7 health controls were included in this study. IHC and RT-PCR methods were used to detect the LL37 expression on protein level and mRNA level. T-test was used for data analysis. Results: Positive staining of LL37 was found in all the samples in cytoplasm of epithelium cells using IHC method, and mostly in prickle and basal layers. But the reaction intensity in health control was weak, compared to the strong signal in OLP group(P<0.05). The expressions of LL37 mRNA in OLP were significantly higher than those in health controls(P<0.05). Conclusion: The expression of LL37 on normal oral mucosa suggests that it may play a role in maintaining the health of oral mucosa as a part of innate immunity. The up-regulation of LL37 under inflammation status might participate in the immunopathological development of OLP.
RESUMO
Objective:To compare the quality of root-end preparation quantitatively between ultrasonic retrotips and traditional slow-speed handpiece. Methods: 27 maxillary second bicuspid teeth with two canals and an isthmus were randomly assigned to 3 groups.Root-end preparations were made respectively using ultrasonic diamond tip Berutti and niti tip RE2, ultrasonic 40~#K file and slow-speed handpiece with No.2 round bur. Image processing and analysis system were used to measure the preoperation and postoperation parameters for further evaluating the difference between the two techniques. Results: The cutting volume of ultrasonic instruments was less than slow-speed handpiece(P<0.000 1). Conclusion: Ultrasonic instrument is better in the root-end preparation than traditional slow-speed handpiece.
RESUMO
Objective:To compare the quality of root-end preparation quantitatively between ultrasonic retrotips and traditional slow-speed handpiece.Methods:27 maxillary second bicuspid teeth with two canals and an isthmus were randomly assigned to 3 groups.Root-end preparations were made respectively using ultrasonic diamond tip Berutti and niti tip RE2,ultrasonic #40K file and slow-speed handpiece with No.2 round bur.Image processing and analysis system were used to measure the preoperation and postoperation parameters for further evaluating the difference between the two techniques.Results:The cutting volume of ultrasonic instruments was less than slow-speed handpiece(P
