Biofilm formation in Haas palatal expanders with and without use of an antimicrobial agent: an in situ study.

Orthodontic appliances causes specific alterations in oral environment, including reduction of pH, increase of dental biofilm and elevation of salivary microbial levels, causing an increased risk for dental caries. This study evaluated, using microbial culture and scanning electron microscopy (SEM), the in situ contamination by mutans streptococci (MS) of different surfaces of Haas palatal expanders with and without use of chlorhexidine gluconate mouthrinses (CHX). Thirty-four patients were randomly assigned to two groups (n = 17/group), using placebo (Group I) and 0.12% CHX (Group II-Periogard® ) mouthrinses twice a week. After 4 months, appliances were submitted to microbiological processing and after fragments were analyzed by SEM. Mann-Whitney U test (α = 5%) was used to assess differences between groups on the appliances' different surfaces and to compare the contamination on the free and nonfree surfaces of these components. There was no difference (p = 0.999) between groups regarding the number of MS colonies/biofilms on the nonfree surfaces, which showed intense contamination. However, free surfaces of Group II presented less contamination (p < 0.001) than those of Group I in all appliances' components. Results of the microbial culture were confirmed by SEM. Use of 0.12% CHX was effective in reducing the formation of MS colonies/biofilms on free surfaces of Haas expanders, in situ.

Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study

OBJECTIVES: The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. MATERIAL AND METHODS: Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12 percent chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5 percent significance level. RESULTS: The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. CONCLUSION: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12 percent chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.

Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study.

OBJECTIVES: The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. MATERIAL AND METHODS: Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12% chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5% significance level. RESULTS: The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. CONCLUSION: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12% chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.

Higiene bucal no tratamento ortodôntico: importância da motivação / Oral hygiene in orthodontic treatment: importance of the motivation

Muitos fatores podem influenciar as características físicas, químicas e biológicas da placa bacteriana, favorecendo o desenvolvimento de cáries e doenças periodontais. Um desses fatores seria a colocação de bandas, braquetes e fios ortodônticos na cavidade bucal. O aumento de lactobacillus no meio bucal é diretamente proporcional ao número de dentes envolvidos pelo aparelho ortodôntico. Também tem-se observado aumento na população de estreptococos, de espiroquetas filamentosas e fungiformes. O controle da placa bacteriana por meios mecânicos é considerado um recurso importante para o combate direto de agentes etiológicos das doenças cárie e periodontal. A escovação é o meio mais utilizado e eficaz na conservação de uma boa higiene bucal em pacientes sob tratamento ortodôntico. Além do uso da escova dental tradicional, outros recursos são utilizados para a higiene bucal, tais como escovas ortodônticas, escovas elétricas, unitufo e interdentária, fio dental, palito, irrigação por meio de jatos d'agua, irrigação subgengival com gluconato de clorexidina a 0,12 por cento, tablete para estimulção salivar e agentes químicos (enxaguantes, como por exemplo: plx, peróxido de uréia, flúor, cepacol). Para os prortadores de aparelho ortodôntico fixo, a escovação dental deve ser supervisionada e motivada para ser efetiva no controle da placa bacteriana

O efeito da lesão unilateral do nervo lingual sobre a função gustativa: revisão da literatura / The effect of unilateral lingual nerve damagem on gustatory function: a review

As funções quimio-sensorais do gosto e olfato têm um papel significativo na fisiologia humana. Eles determinam o paladar dos alimentos e bebidas, a seleção de nutrientes para a vida, além de nos advertirem com relação ao fogo, vapores tóxicos e alimentos estragados. Todo indivíduo tem uma experiência diária com a quimio-sensação. A lesão do nervo lingual é um dos problemas mais comuns em cirurgia oral, especialmente durante a remoção do terceiro molar. O trajeto do nervo exibe uma grande variação. As principais causas de lesão do nervo lingual são atribuídas ao tipo de anestesia, o estado da erupção do dente, retração do retalho lingual, remoção óssea e ao operador. Na região do terceiro molar, onde mais frequentemente a lesão pode ocorrer durante a remoção de um dente impactado, as fibras do corda do tímpano poderão ser facilmente identificadas. Devido à sua distribuição no nervo lingual é muito pequena a chance de encontrar as fibras gustatórias e a sua regeneração será dificultada mesmo após a microcirurgia. Após reconstrução microcirúrgica do nervo, o exame clínico tem mostrado que, em contraste à função sensorial dos 2/3 anteriores da língua, a função gustatória não retorna ou ela é inadequada