Biofilm dysbiosis and caries activity: a surface or an individual issue?

Abstract Objective This study aimed to analyze the functional profile of supragingival biofilm from sound (CAs), active (CAa), and inactive (CAi) enamel caries lesions from caries-active individuals to provide insights into the diversity of biological processes regarding biofilm dysbiosis. Methodology A metatranscriptome analysis was performed in biofilm samples collected from five caries-active individuals. Total RNA was extracted, and the microbial cDNAs were obtained and sequenced (Illumina HiSeq3000). Trimmed data were submitted to the SqueezeMeta pipeline in the co-assembly mode for functional analysis and further differential gene expression analysis (DESeq2). Results Bioinformatics analysis of mRNAs revealed a similar functional profile related to all analyzed conditions (CAa, CAi, and CAs). However, active and inactive surfaces share up-regulated genes (gtsA; qrtT; tqsA; pimB; EPHX1) related to virulence traits that were not overrepresented in sound surfaces. From a functional perspective, what matters most is the individual carious status rather than the surface condition. Therefore, pooling samples from various sites can be carried out using naturally developed oral biofilms but should preferably include carious surfaces. Conclusion Metatranscriptome data from subjects with caries activity have shown that biofilms from sound, arrested, and active lesions are similar in composition and function.

The role of Candida albicans in root caries biofilms: an RNA-seq analysis

Abstract Objective This study sought to analyze the gene expression of Candida albicans in sound root surface and root caries lesions, exploring its role in root caries pathogenesis. Methodology The differential gene expression of C. albicans and the specific genes related to cariogenic traits were studied in association with samples of biofilm collected from exposed sound root surface (SRS, n=10) and from biofilm and carious dentin of active root carious lesions (RC, n=9). The total microbial RNA was extracted, and the cDNA libraries were prepared and sequenced on the Illumina Hi-Seq2500. Unique reads were mapped to 163 oral microbial reference genomes including two chromosomes of C. albicans SC5314 (14,217 genes). The putative presence of C. albicans was estimated (sum of reads/total number of genes≥1) in each sample. Count data were normalized (using the DESeq method package) to analyze differential gene expression (using the DESeq2R package) applying the Benjamini-Hochberg correction (FDR<0.05). Results Two genes (CaO19.610, FDR=0.009; CaO19.2506, FDR=0.018) were up-regulated on SRS, and their functions are related to biofilm formation. Seven genes ( UTP20 , FDR=0.018; ITR1 , FDR=0.036; DHN6 , FDR=0.046; CaO19.7197 , FDR=0.046; CaO19.7838 , FDR=0.046; STT4 , FDR=0.046; GUT1 , FDR=0.046) were up-regulated on RC and their functions are related to metabolic activity, sugar transport, stress tolerance, invasion and pH regulation. The use of alternative carbon sources, including lactate, and the ability to form hypha may be a unique trait of C. albicans influencing biofilm virulence. Conclusions C. albicans is metabolically active in SRS and RC biofilm, with different roles in health and disease.

Fechamento de diastema com resina composta direta: relato de caso clínico / Diastema closure with direct composite restorations: a case report

Com a evolução dos materiais restauradores adesivos diretos e das técnicas restauradoras minimamente invasivas, é possível realizar o fechamento de diastemas inter incisivos superiores de maneira efetiva e estética em uma única sessão. O presente trabalho consiste em um relato de caso clínico que aborda o clareamento dental e o fechamento de diastema entre os dentes 11 e 21 de um paciente jovem. Previamente ao procedimento restaurador foi realizado clareamento de consultório em todos os dentes com peróxido de hidrogênio 35%. Então, o planejamento restaurador foi auxiliado por modelos de estudo associado ao enceramento diagnóstico.A técnica restauradora de eleição foi a resina composta direta com o auxílio de uma matriz/guia de silicona para a confecção das faces palatinas das restaurações. Após o acabamento e polimento, obteve-se a reanatomização dos incisivos centrais com a eliminação do diastema. O tratamento realizado baseado no clareamento dental seguido por restaurações diretas de resina composta foi eficaz na solução estética do sorriso, atingindo a expectativa do paciente e dentro dos princípios de máxima preservação dos tecidos dentais.

After the evolution of restorative adhesive materials and minimal invasive restorations, it ispossible to close a maxilar interincisal diastema in an effective and aesthetical way, performingit in only one session. This clinical case report approaches a teeth bleaching and diastema closurewith composites between teeth 11 and 21, of a young male patient. The elective restorative technique was direct composite restoration with a silicon putty matrix to make the shape of thelingual surfaces of the restorations. Before the restoration procedure, it was performed “in office”bleaching technique, in addition to the case planning with the assistance of a wax-up. The tooth whitening therapy followed by direct composite restorations was effective, contributing to clinical success, esthetic and patient´s satisfaction.