Abstract. The purpose of this study was to assess photodynamic antimicrobial chemotherapy (PACT) via irradiation, using a low power laser associated with a photosensitization dye, as an alternative to remove cariogenic microorganisms by drilling. Remaining dentinal samples in deep carious lesions on permanent molars (n = 26) were treated with 0.01% methylene blue dye and irradiated with a low power laser (InGaAIP -indium gallium aluminum phosphide; λ = 660 nm; 100 mW; 320 Jcm − 2 ; 90 s; 9J). Samples of dentin from the pulpal wall region were collected with a micropunch before and immediately after PACT and kept in a transport medium for microbiological analysis. Samples were cultured in plates of Brucella blood agar, Mitis Salivarius Bacitracin agar and Rogosa SL agar to determine the total viable bacteria, mutans streptococci and Lactobacillus spp. counts, respectively. After incubation, colony-forming units were counted and microbial reduction was calculated for each group of bacteria. PACT led to statistically significant reductions in mutans streptococci (1.38 log), Lactobacillus spp. (0.93 log), and total viable bacteria (0.91 log). This therapy may be an appropriate approach for the treatment of deep carious lesions using minimally invasive procedures. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

LFpen readings present low correlation with approximal caries lesion depth and low reproducibility, especially in white-spot lesions. Therefore, the device could not be a suitable method for monitoring non-cavitated approximal caries lesion in primary molars.

Objective The purpose of this research was to follow the radiolucent area (pixels) in the furcation area and the behavior of the endodontically treated deciduous molars with different simplified echniques. MethodsThe treatments were performed without the duct instrumentation using relative isolation and two drugs were applied, as follows: G1: GuedesPinto paste (GP) was used and for comparison of the initial radiographic image, analysis of variance was used after 6 and 12 months of each group and Tukey spost-hoc test. T-Student test was used for comparison between groups. Results There was a reduction of radiolucent area after 6 (p<0.01) and 12 months (p<0.01) in the teeth treated with CTZ paste. In the teeth treated with PG there was not reduction of radiolucent area after 12 months. (p= 0,09). ConclusionAlthough the clinical signs were similar in both groups after 12 months of follow up, only teeth treated with CTZ showed reduction of radiolucent area in the furca area after 6 and 12 months.Indexing terms: Primary tooth. Public health. Pulpectomy. RESUMO ObjetivoA proposta da pesquisa foi acompanhar a area radiolúcida (pixels) na região de furca e a resposta clínica de molares decíduos tratados endodonticamente com diferentes tecnicas simplificadas. MétodosOs tratamentos foram executados sem instrumentação dos condutos e com isolamento relativo, utilizando-se dois medicamentos: G1:Pasta Guedes-Pinto (PG) e G2: Pasta CTZ (CTZ) no preenchimento da câmara pulpar . As áreas radiolúcidas na região de furca dos molares decíduos obtidas das radiografias antes, após 6 meses e 12 meses do tratamento endodôntico foram analisadas no programa Image Tool 3.0 por 2 examinadores cegos. Para analisar a calibração entre os examinadores foi utilizado o teste Kappa e para comparação da imagem radiográfica inicial, após 6 e 12 meses de cada grupo foi utilizado a Análise de Variância e o teste complementar de Tukey. O teste T Student foi usado para comparação entre os grupos. ResultadosA redução da área radiolúcida inicial após 6 (p<0,01) e 12 meses (p<0,01) foi observada somente com o uso da pasta CTZ. O emprego da pasta Guedes não resultou em diminuição da área radiolúcida após 12 meses de acompanhamento (p=0,09). ConclusãoA resposta clínica foi semelhante em ambos os grupos, porém apenas os dentes tratados com a pasta CTZ apresentaram redução da área radiolúcida na região da furca após 6 e 12 meses de acompanhamento.Termos de indexação: Dente decíduo. Saúde Pública. Pulpectomia.

ABSTRACT

The purpose of this in vitro study was to compare the effects of a self-etch adhesive system and neodymium:yttrium-aluminum-garnet (Nd:YAG) laser application on the dentinal permeability of the furcation area of primary molars. After endodontic access, 39 extracted human deciduous molars were divided into three groups: control group (CG), no treatment; adhesive group (AG), self-etching adhesive was applied to the furcation area; laser group (LG), specimens were irradiated with Nd:YAG laser. To evaluate dentin permeability of the furcation area, we immersed the specimens in 0.5 % methylene blue dye for 4 h. Then, they were longitudinally sectioned into two halves and photographed. The images were analyzed by two qualified evaluators using TpsDig software to calculate the percentage of the dye penetration area in comparison with the total furcation area. Additional analyses by scanning electron microscopy (SEM) were performed. The analysis of variance (ANOVA), complemented by Student's t-test, showed that mean dye penetration in the LG was statistically significant lower than that in all the other groups (P < 0.05). The SEM analysis showed mostly dentinal tubules obliterated by smear layer in the CG; in the AG the smear layer was modified by the adhesive, and, in the LG, melted surfaces were observed. It can be concluded that the Nd:YAG laser was capable of reducing the dentinal permeability of the furcation area of deciduous molars.