title: [Influence of different ultrasonic irrigation solutions after root canal preparation with ProTaper by machine on micro-hardness of root canal dentin].
abstract: OBJECTIVE
  To develope the influence of different ultrasonic irrigations after root canal preparation with nickel titanium ProTaper on micro-hardness of root canal dentin.
  
  
  METHODS
  Sixty of maxillary anterior teeth with single-canal were collected and randomly divided into 6 groups. Group A was control group, group B was prepared to F3 with nickel titanium ProTaper by machine, group C was ultrasonic irrigated with 3% hydrogen peroxide solution for 1 minute after preparation, group D was ultrasonic irrigated with koutai mouthwash for 1 minute after preparation, group E was ultrasonic irrigated with 17% EDTA solution for 1 minute after preparation, group F was ultrasonic irrigated with distilled water for 1 minute after preparation. The roots were then sectioned horizontally into 3 parts, split longitudinally into halves and examined under a micro Vickers hardness test machine. The data was analyzed by one-way ANOVA and t test with SPSS 17.0 software package.
  
  
  RESULTS
  The micro-hardness of group A was (52.66 ± 1.64) HV,(52.08 ± 1.53) HV and (51.47 ± 2.53) HV. There was no significant difference in all parts of the root canal in group A (P>0.05). The micro-hardness of the apical third of root canal was lower than that of the cervical and middle of root canal in the other groups (P<0.05). In the cervical and middle third of the root canals, the micro-hardness of group E was (44.65 ± 1.33) HV and(42.55 ± 1.12) HV, and there were statistical significances between group E and the other groups (P<0.05). In the apical third of root canal,the micro-hardness of group E was (37.82 ± 1.60) HV, and group C was (44.14±1.73) HV, both of the comparative differences with other groups were statistically significant (P<0.05). There was no significant difference among group B, group D and group F (P>0.05).
  
  
  CONCLUSIONS
  Root canal preparation to F3 with nickel titanium ProTaper by machine can make the micro-hardness of the apical third of root canal decrease. Ultrasonic irrigation with 17% EDTA solution for 1 minute can make the micro-hardness of the root canal decrease ultrasonic irrigation with. Ultrasonic irrigation with 3% hydrogen peroxide can make the micro-hardness of the apical third of root canal decrease. Ultrasonic irrigation with Koutai mouthwash and distilled water for 1 minute have no influence on the micro-hardness of root canal.
authors.affiliation: Department of Endodontics, Shanghai Municipal Hospital for Oral Health. Shanghai 200001, China.E-mail:guojiangli77@163.com.
authors.forename: Jiang-li
authors.initials: JL
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhen
mesh_terms: D003786:Dental Pulp Cavity; D003804:Dentin; D006244:Hardness; D006801:Humans; D009532:Nickel; D012388:Root Canal Irrigants; D018915:Root Canal Preparation / Q000379:methods*; D012390:Root Canal Therapy; D014025:Titanium; D014465:Ultrasonics
chemical_list: D012388:Root Canal Irrigants; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium