Antimicrobial action of chlorhexidine digluconate in self-ligating and conventional metal brackets infected with Streptococcus mutans biofilm

Ana Paula Dias, Marco Aurélio Benini Paschoal, Rafael Soares Diniz, Lucas Meneses Lage, Letícia Machado Gonçalves Department of Dentistry, CEUMA University, São Luis, Maranhão, Brazil Objectives: The objectives of this study were to assess the adherence of Streptococcus mutans biofilms grown over conventional ligature (CL) or self-ligating (SL) metal brackets and their bacterial viability after 0.12% chlorhexidine (CHX) digluconate treatment. Materials and methods: The sample consisted of 48 metallic orthodontic brackets divided randomly into two groups: CL (n=24) and SL brackets (n=24). S. mutans biofilms were grown over the bracket surface (96 h) and treated with CHX (positive control) or 0.9% phosphate-buffered saline (PBS) (negative control) for 1 min each. Quantitative analysis was assessed by colony-forming units, and fluorescence microscopy was performed aiming to illustrate the outcomes. The tests were done in triplicate at three different times (n=9). Data were analyzed using ANOVA and Tukey test (P<0.05). Results: There were significant differences in brackets’ biofilm formation, being CL largely colonized compared with SL, which was observed by colony-forming unit counting (P<0.05) and microcopy images. Significant reduction in the viability of S. mutans was found in both brackets treated with CHX compared to PBS (P<0.05). Conclusion: The antimicrobial activities of CHX were similar for CL and SL brackets (P>0.05). In conclusion, a lower colonization was achieved in SL brackets and S. mutans biofilms were susceptible to CHX treatment to both studied brackets. Keywords: biofilm, chlorhexidine, orthodontic brackets, Streptococcus mutan

Hiperplasia nodular focal múltipla do fígado: subtipo misto hiperplásico/adenomatoso

Focal Nodular Hyperplasia is a benign lesion of the liver, which usually presents with one or two localizations. We report the uncommon case of a 51-year-old female who presents with right upper quadrant pain that worsened in the previous month, without association with feeding. Four hepatic lesions were evidenced at Computerized tomography, the largest being of 8 cm in diameter, of atypical behavior. She was submitted to hepatic segmentectomy of the segment III. The pathologic diagnosis returned focal nodular hyperplasia mixed hyperplastic and adenomatous sub-type. The patient had a good postoperative evolution and is in ambulatory follow-up

Carcinoma verrucoso: uma variante clínico-histopatológica do carcinoma espinocelular Verrucous carcinoma: a clinical-histopathologic variant of squamous cell carcinoma

O carcinoma verrucoso é uma rara e indolente forma do carcinoma espinocelular descrita por Ackerman em 1948. Sua localização preferencial é a cavidade oral. Clinicamente manifesta-se como lesão verrucosa, de progressivo e lento crescimento e bom prognóstico. O tratamento de escolha é a exérese cirúrgica, devendo o paciente ser regularmente acompanhado devido ao risco de recorrências.<br>Verrucous carcinoma is a rare and indolent variant of the squamous cell carcinoma described by Ackerman in 1948. The oral cavity is a most common site. Clinically, it presents most often as a slow-growing verrucous lesion. The prognosis is good. Treatment of choice is surgery. Patients require frequent reevaluation because recurrences may occur