[Antimicrobial action of dental materials used in operative dentistry: a review].
This is a review of the literature about the antimicrobial action of dental materials used in operative dentistry. There are referred to the usefulness of the antimicrobial action of dental materials, and to the methods used by the investigators for the study of the antimicrobial properties. The methods used were: the examination of the in vitro antimicrobial action of the materials against several microbes, The in vivo antimicrobial action of the materials against the microbes that are enclosed underneath them in dental cavities, where some carious material was left on the floor of the cavities. Some other methods, as so as the adsorption of microbes on the experimental materials, in vivo and in vitro. There are presented the results of a lot of investigators for the antimicrobial action of dental amalgams, composite resins, silicate cements, glass-ionomer cements, zinc-phosphate, zinc oxide-eugenol and polycarboxylate cements, calcium hydroxide bases and also for varnishes and liners, since the time of Miller (1890) up to now. From these researches we can come to the following conclusions: 1) All dental materials have some antibacterial activities against several microbes when they are freshly mixed. Their action reduces with the past of time. 2) The responsible antibacterial factors are unknown. May be more than one factors. 3) In clinical practice it is not known what material is better, because the conditions are different from tooth to tooth and from mouth to mouth. 4) More researchers are necessary for this purpose because the antibacterial properties must be regarded as a part of the other biological properties of dental materials and the recurrent caries may be inhibited because of the antibacterial properties of filling and base materials.