Bacterial leakage in obturated root canals-part 2: a comparative histologic and microbiologic analyses.
OBJECTIVE
In this study, presence of dentin infection in root canals, obturated with 4 techniques submitted to the bacterial leakage test, was evaluated using histologic methods.


METHODS
The canals of palatal roots of 160 molars were instrumented and divided into different groups, according to the obturation technique used (lateral condensation, MicroSeal system, Touch 'n Heat + Ultrafil, and Tagger's hybrid technique) and extent of the remaining obturation material (5 mm and 10 mm). Ten additional roots were used as control samples. The roots were sterilized in ethylene oxide and mounted on a device for evaluation of bacterial leakage using the bacteria Enterococcus faecalis for 120 days. After the leakage test, roots were microscopically analyzed for the presence of dentin infection in the root canals and dentinal tubules.


RESULTS
A total of 154 specimens were analyzed using both methodologies in the experimental groups; 50 root canals (32.4%) showed bacterial leakage at the end of the experimental period, and 118 (76.6%) showed the presence of bacteria in the root canals using the histologic criteria. The lateral condensation technique allowed lower penetration of bacteria in the root canals and dentinal tubules, followed by Touch 'n Heat + Ultrafil, MicroSeal, and Tagger's hybrid technique, which allowed significantly greater penetration of bacteria. Root canals with 10 mm of remaining obturation material presented similar bacterial penetration as root canals with 5 mm.


CONCLUSIONS
Even when an adequate seal of the apical foramen was shown by the absence of turbidity in the bacterial leakage test, E. faecalis dentin infection was present in a high percentage of the root canals after 120 days of root filling exposure to the bacteria. Tagger's hybrid technique presented greater quantity of bacteria in histologic sections than root canals obturated with the other techniques.
Brosco
Viviane Haiub
VH
Postgraduate Student, Department of Endodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil. vivianebrosco@yahoo.com.br
Bernardineli
Norberti
N
Torres
Sérgio Aparecido
SA
Consolaro
Alberto
A
Bramante
Clóvis Monteiro
CM
de Moraes
Ivaldo Gomes
IG
Ordinola-Zapata
Ronald
R
Garcia
Roberto Brandão
RB
D001840:Dental Bonding / Q000379:methods; D019551:Dental Disinfectants / Q000627:therapeutic use; D003763:Dental Leakage / Q000382:microbiology*; D003786:Dental Pulp Cavity / Q000382:microbiology* / Q000473:pathology; D003804:Dentin / Q000382:microbiology / Q000473:pathology; D013293:Enterococcus faecalis / Q000254:growth & development; D005027:Ethylene Oxide / Q000627:therapeutic use; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012389:Root Canal Obturation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013242:Sterilization / Q000379:methods; D013997:Time Factors; D019227:Tooth Apex / Q000382:microbiology / Q000473:pathology
D019551:Dental Disinfectants; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D006171:Gutta-Percha; D012973:Sodium Hypochlorite; D005027:Ethylene Oxide