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Monogr Oral Sci ; 29: 30-37, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33427216


More than 700 microbial species inhabit the complex environment of the oral cavity. For years microorganisms have been studied in pure cultures, a highly artificial situation because microorganisms in natural habitats grow as complex ecologies, termed biofilms. These resemble multicellular organisms and are characterized by their overall metabolic activity upon multiple cellular interactions. Microorganisms in biofilms express different genes than their planktonic counterparts, resulting in higher resistance to antimicrobials, different nutritional requirements, or creation of a low redox potential allowing the growth of strictly anaerobic bacteria in the presence of oxygen. Multiple in vitro biofilm models have been described in the literature so far. The main emphasis here will be on multispecies biofilm batch culture models developed in Zurich. The standard 6-species supragingival biofilm model has been used to study basic aspects of oral biofilms such as structure, social behavior, and spatial distribution of microorganisms, or diffusion properties. Numerous parameters related to the inhibition of dental plaque were tested illustrating the high reliability of the model to predict the in vivo efficiency of antimicrobials. Modifications and advancements led to a 10-species subgingival model often combined with human gingival epithelial cells, as an integral part of the oral innate immune system, eliciting various cell responses ranging from cytokine production to apoptosis. In conclusion, biofilm models enable a multitude of questions to be addressed that cannot be studied with planktonic monocultures. The Zurich in vitro biofilm models are reproducible and reliable and may be used for basic studies, but also for application-oriented questions that could not be addressed using culture techniques. Oral biofilm research will certainly lead to a more realistic assessment of the role of microorganisms in the oral cavity in health and disease. In this respect, substantial progress has been made, but there is still more to explore.

Biofilmes , Boca , Gengiva , Humanos , Plâncton , Reprodutibilidade dos Testes
J Esthet Restor Dent ; 32(4): 416-423, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32277866


OBJECTIVE: The aim of this study was to evaluate and compare surface roughness, gloss, and color change of dental enamel after being brushed with toothpastes containing diamond powder and traditional abrasives. MATERIALS AND METHODS: Seventy enamel slabs were derived from 70 bovine incisors. The slabs were brushed with six different toothpastes and artificial saliva as a negative control. The specimens were then stained with black tea mixed with citric acid (3 days, pH = 4) and again brushed with the same toothpastes. Ra (contact profilometer), gloss (glossmeter), and color (CIE L* a* b* system) values were measured after each step. RESULTS: Emoform-F Diamond (contains diamond powder and traditional abrasives) offered significantly the best improvement of Ra and gloss values after the first brushing sequence and the best recovery of the brightness of enamel after staining and second brushing sequence (P < .05). AMC 2.5 (contains only diamond powder as abrasive) was not able to offer such improvement. CONCLUSION: Diamond powder as an additional abrasive in toothpastes could be able to offer a further improvement of Ra , gloss, and color values of enamel.

Diamante , Cremes Dentais , Animais , Bovinos , Cor , Esmalte Dentário , Propriedades de Superfície , Escovação Dentária