In vivo effects of fluoride, chlorhexidine and zinc ions on acid formation by dental plaque and salivary mutans streptococcus counts in patients with irradiation-induced xerostomia.
Irradiation therapy including major salivary glands may result in xerostomia and enhanced susceptibility to dental caries. The present aim was to assess the ability of mouthrinses with F-, Zn2+, and chlorhexidine (CH), in various combinations, to reduce acidogenic potential of dental plaque and salivary mutans streptococcus counts (SMSC) in 7 patients with xerostomia secondary to irradiation. The patients rinsed twice daily for 3 weeks with the following test solutions: (1) 12 mmol/l NaF (F; control), (2) NaF + 20 mmol/l ZnCl2 (F-Zn), and (3) NaF + 1.1 mmol/l CH (F-CH). Resting periods (F) of varying lengths were incorporated. Acid formation by dental plaque was monitored as plaque pH response to a sucrose mouthrinse, at the end of each test period, 4 h after mouthrinsing with test solution. Plaque pH was measured repeatedly at 2-8 sites in each patient before, and up to 60 min after the sucrose mouthrinse using touch microelectrodes. SMSC were determined using Dentocult SM-Strip mutans. Compared with F, F-CH significantly (P < or = 0.02) reduced acid formation by plaque and SMSC, whereas F-Zn did not affect acid formation or SMSC significantly. Pilot experiments in 4 patients showed mouthrinses with NaF + 0.55 mmol/l CH + 10 mmol/l Zn2+ to be ineffective, whereas NaF + 2.2 mmol/l CH was highly effective, but no better than F-CH. Twice daily mouthrinses with 12 mmol/l NaF in combination with 1.1 mmol/l CH may be an effective regimen to prevent post-irradiation caries.
Giertsen
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Department of Oral Biology, Section of Microbiology, Dental Faculty, University of Oslo, P.O. Box 1052, Blindern, N-0316 Oslo, Norway.
Scheie
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D000328:Adult; D000368:Aged; D002710:Chlorhexidine / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003731:Dental Caries / Q000209:etiology / Q000517:prevention & control*; D003773:Dental Plaque / Q000737:chemistry*; D005260:Female; D005459:Fluorides / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008297:Male; D008875:Middle Aged; D009067:Mouthwashes; D011832:Radiation Injuries; D012469:Salivary Glands / Q000382:microbiology* / Q000473:pathology; D013291:Streptococcus / Q000302:isolation & purification* / Q000472:pathogenicity; D014987:Xerostomia / Q000209:etiology* / Q000517:prevention & control*; D015032:Zinc / Q000494:pharmacology*
D007477:Ions; D009067:Mouthwashes; D015032:Zinc; D005459:Fluorides; D002710:Chlorhexidine