Introduction. Microbial biofilms have constituted an extremely serious problem for dental professionals. The presence of microbial biofilms has been evidenced by electron microscopy techniques on the surface of all materials used in dentistry, but the best were found on the surface of dental alloys.
Aims. The constitution of microbial strains collection isolated from dental plaque. We studied the development of monospecific biofilms on dental alloys, in order to establish the influence of the physical and chemical structure of the alloys with the dynamics of experimental biofilms.
Material and methods. The analysis of bacterial diversity of dental plaque samples was realised with: optic microscope, scanning electronic microscope, determination of bacterial loading, identification of the most important bacterial species and genus after cultivating and isolation in anaerob and aerob media and also automatic identification with VITEK systems. Were tested the patogenity and the virulent status and also the resistance of the cells with no adherence and of the cells included in artificial developed biofilms on dental alloys. Selected materials were: noble alloys (gold-palladium and gold-platinum alloys); seminoble alloys (silver-palladium alloys) and stainless alloys (cobalt-chromium, nikel-chromium alloys).
Results. Dental plaque has a great structural complexity (there are, in the same time: spiral bacterium, fungus, some gram positive morphological type). Tested strains have a high capacity of adherence on dental alloys above mentioned, even after 24 hours of incubation. The bacteria are more resistant in adhered state comparing with initial condition.
Conclusions. Repartition of the selected monospecifc microbial biofilms on dental alloys is determined by antiseptic potential of the alloys components: the development on stainless alloys of much more thicker biofilms than seminoble and noble alloys. Microbial biofilms appeared preferentially in surface irregularities, with on flat surfaces bacteria formed a continuous layer
