The use of a composition that comprises a non-pathogenic, hydrogen-peroxide producing bacterial species or strain for whitening teeth, treating stained teeth, dental caries, periodontitis, oral bacterial infections, oral wounds, Candida or fungal overgrowth, halitosis and xerostomia-induced dental caries. The bacteria can be Lactobacillus, Bifidobacteria, viridans Streptococcus, Leuconostoc, Pediococcus or Lactococus. The composition can further comprise the lactate dehydrogenase-deficient mutans Streptococcus species S. rattus.
