Effects of chlorhexidine and sodium hypochlorite on the microhardness of root canal dentin.
OBJECTIVE
The purpose of this study was to evaluate the effects of endodontic irrigants on the microhardness of root canal dentin.


METHODS
Thirty extracted single-rooted human teeth were used. The crowns were sectioned at the cementoenamel junction. Each root was transversely sectioned into cervical, middle, and apical segments, resulting in 90 specimens. The 3 sections of each root were separately mounted in an individual silicon device with acrylic resin. The specimens were randomly divided into the following 3 groups (n = 30), according to the irrigant solution used: (1) group 1, control (saline solution); (2) group 2, 2% chlorhexidine gluconate solution; and (3) group 3, 1% sodium hypochlorite (NaOCl). After 15 minutes of irrigation, dentin microhardness was measured on each section at 500 microm and 1000 microm from the pulp-dentin interface with a Vickers diamond microhardness tester in Vickers hardness number (VHN).


RESULTS
Data obtained were analyzed using analysis of variance and the Tukey test (5%). Specimens irrigated with 2% chlorhexidine (group 2) or 1% NaOCl (group 3) presented lower values of dentin microhardness, with significant difference in relation to the control group (P < .05).


CONCLUSIONS
It could be concluded that chlorhexidine and NaOCl solutions significantly reduced the microhardness of root canal dentin at 500 microm and 1000 microm from the pulp-dentin interface.
Oliveira
Luciane Dias
LD
Department of Oral Biosciences and Diagnosis, School of Dentistry, Paulista State University-UNESP, Sao Jose dos Campos, Sao Paulo, Brazil.
Carvalho
Cláudio Antonio Talge
CA
Nunes
Willian
W
Valera
Marcia Carneiro
MC
Camargo
Carlos Henrique Ribeiro
CH
Jorge
Antonio Olavo Cardoso
AO
D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001641:Bicuspid; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003786:Dental Pulp Cavity; D003804:Dentin / Q000187:drug effects*; D006244:Hardness / Q000187:drug effects; D006801:Humans; D012388:Root Canal Irrigants / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D018709:Statistics, Nonparametric
D000891:Anti-Infective Agents, Local; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite; C010882:chlorhexidine gluconate; D002710:Chlorhexidine