Dentin decontamination using chloramine T prior to experiments involving bacteria.
OBJECTIVE
This study aims to investigate the importance of ISO11405 recommended storage regime for extracted teeth in surface disinfectant chloramine T (chlT) prior to use in biofilm or in vitro caries studies involving microorganisms. ChlT may be absorbed into dentin and undergoes breakdown with organic material.


METHODS
Extracted roots were stored in chlT (2 days), rinsed and transferred to distilled deionised water. HPLC at regular intervals determined chlT elution. At 4 weeks roots were boiled in water and eluent assessed with HPLC. ChlT breakdown (+/-organic material) over time was monitored with HPLC. ChlT minimum inhibitory/bactericidal concentration (MIC/MBC) against Lactobacillus acidophilus was evaluated using L. acidophilus broth and chlT serial dilutions.


RESULTS
No significant increase in chlT elution was detected between 2h and 4 weeks (ANOVA, Tukeys, p>0.05), although levels tended to increase with time. ChlT detected in water was 0.005%, corresponding to 0.05% in dentin. After boiling (4 weeks) chlT breakdown products in water corresponded to 0.015% in dentin. MIC/MBC of chlT against L. acidophilus was 0.031%.


CONCLUSIONS
ChlT breakdown is accelerated by organic material. L. acidophilus is highly sensitive to chlT. ChlT readily leaches from dentin but rinsing does not reduce chlT concentration below MIC/MBC. Low levels of chlT may remain but will probably be in a less active form. Teeth disinfected in chlT for use in research involving bacteria must be stored in distilled water for at least 2h to reduce chlT concentration below MBC, although longer will give greater elution and breakdown.
Rolland
Sarah L
SL
School of Dental Sciences, Framlington Place, Department of Restorative Dentistry, University of Newcastle, Newcastle upon Tyne NE2 4BW, UK. s.l.rolland@ncl.ac.uk
Carrick
Thomas E
TE
Walls
Angus W
AW
McCabe
John F
JF
D002700:Chloramines / Q000378:metabolism / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D015169:Colony Count, Microbial; D003666:Decontamination / Q000379:methods*; D019551:Dental Disinfectants / Q000378:metabolism / Q000494:pharmacology; D003804:Dentin; D003806:Dentin Permeability; D006801:Humans; D007778:Lactobacillus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D019188:Organ Preservation Solutions / Q000378:metabolism / Q000493:pharmacokinetics; D013449:Sulfonamides / Q000378:metabolism; D014050:Toluene / Q000031:analogs & derivatives / Q000378:metabolism; D014105:Tosyl Compounds / Q000378:metabolism / Q000494:pharmacology; D000096926:Benzenesulfonamides
D002700:Chloramines; D019551:Dental Disinfectants; D019188:Organ Preservation Solutions; D013449:Sulfonamides; D014050:Toluene; D014105:Tosyl Compounds; C016300:chloramine-T; C025417:4-toluenesulfonamide; D000096926:Benzenesulfonamides