In vitro effect of low-level laser therapy on typical oral microbial biofilms

• Autor(a) principal: Basso, Fernanda G.
• Data de Publicação: 2011
• Outros Autores: Oliveira, Camila F. [UNESP], Fontana, Amanda [UNESP], Kurachi, Cristina, Bagnato, Vanderlei S., Spolidório, Denise M. P. [UNESP], Hebling, Josimeri [UNESP], de Souza Costa, Carlos A. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S0103-64402011000600011; http://hdl.handle.net/11449/73110
• topic: Biofilm; Candida albicans; Low level laser therapy; Streptococcus mutans; coloring agent; diagnostic agent; succinate dehydrogenase; tetrazolium; thiazole derivative; thiazolyl blue; biofilm; comparative study; diode laser; fungus hyphae; growth, development and aging; human; instrumentation; low level laser therapy; materials testing; methodology; microbial viability; microbiological examination; microbiology; mouth; mycology; organismal interaction; radiation dose; radiation exposure; radiation response; scanning electron microscopy; temperature; time; ultrastructure; Bacteriological Techniques; Biofilms; Coloring Agents; Dose-Response Relationship, Radiation; Humans; Hyphae; Laser Therapy, Low-Level; Lasers, Semiconductor; Materials Testing; Microbial Interactions; Microbial Viability; Microscopy, Electron, Scanning; Mouth; Mycology; Radiation Dosage; Succinate Dehydrogenase; Temperature; Tetrazolium Salts; Thiazoles; Time Factors

The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms - SSB and DSB - were exposed to laser doses of 5, 10 or 20 J/cm 2 from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species.