Determination of Root Canal Cleanliness by Different Irrigation Methods and Morphometric Analysis of Apical Third.
The aim of this study was to determine the root canal area before and after the instrumentation 1 mm short of the apical foramen by clinical and cone beam computed tomography (CBCT) methods, and to evaluate the cleanliness of the apical region in mesiodistal flattened teeth by using optical microscopy.



Forty-two human single-canal mandibular incisors were instrumented using the Free Tip Preparation technique up to three, four or five instruments from the initial. Cone beam computed tomography scans were acquired of the samples before and after root canal preparation (RCP). Irrigation was performed by conventional or hydrodynamic means, using 2.5% sodium hypochlorite. The samples were prepared for observation under an optical microscope. Images were digitally obtained, analyzed and the results were submitted to statistical analysis (two-way ANOVA complemented by Bonferroni's post-test).



There was no significant difference between the studied anatomical areas with both CBCT and clinical methods. There were no differences between irrigation methods. It was verified differences between instrumentation techniques. Instrumentation with four instruments from the initial instrument determined a significant increase in the contact area when compared to preparation with three instruments, but RCP with 5 instruments did not result in a better cleanliness.



The analysis with CBCT was not capable to determine the precise shape of surgical apical area comparing to the clinical method.



Both the conventional and hydrodynamic irrigation techniques were not able to promote root canals debris-free. The instruments action in root canal walls was proportional to the number of instruments used from the initial apical instrument.
Department of Restorative Dentistry, Ribeirao Preto Dental School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
Fábio Heredia
FH
Seixas
Department of Stomatologic Sciences, School of Dentistry Federal University of Goias, Goiania, GO, Brazil.
Carlos
C
Estrela
Department of Oral Diagnosis, School of Dentistry, University of Cuiaba, Cuiaba, MT, Brazil.
Mike Reis
MR
Bueno
Department of Restorative Dentistry, Ribeirao Preto Dental School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
Manoel Damião
MD
Sousa-Neto
Department of Restorative Dentistry, Ribeirao Preto Dental School, University of Sao Paulo, Ribeirao Preto, SP, Brazil, Phone: +55-16-360024792, e-mail: jdpecora@gmail.com.
Jesus Djalma
JD
Pécora
D054893:Cone-Beam Computed Tomography / Q000379:methods; D003722:Dental Alloys; D003786:Dental Pulp Cavity; D003804:Dentin; D004867:Equipment Design; D006801:Humans; D007180:Incisor; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000379:methods*; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods*; D016369:Smear Layer / Q000517:prevention & control; D012973:Sodium Hypochlorite; D013499:Surface Properties; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
D003722:Dental Alloys; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite
Anatomic diameter; Cone beam computed tomography; Endodontic; Root canal cleaning; Rotary instrumentation.