Radiographic pattern of inactive occlusal enamel lesions and its relationship with caries progression over 4-5 years

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

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.

Underlying Dentin Shadows (ICDAS 4) in Occlusal Surface of Permanent Teeth Have Low Progression Rate after 1-2 Years

The aim of this prospective cohort study was to assess the radiographic progression of underlying dentin shadows (UDS) on the occlusal surfaces of permanent posterior teeth of adolescents and young adults over 1-2 years and to identify possible risk factors. A total of 149 UDS lesions (from 101 individuals) were included at baseline. Each participant had to present at least one UDS to be considered eligible for the study. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs, performed at baseline and after 1-2 years. The association between possible predictors and UDS progression (defined radiographically as an increase in the radiographic score from baseline to follow-up) was assessed using Weibull regression models. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated. A total of 81 individuals (mean age: 24.0, standard deviation: 8.03) were reexamined after 1-2 years (742 occlusal surfaces, of which 118 were UDS). The overall progression rate was 8.6% after 1-2 years, being 12.6% for UDS without baseline radiolucency and 20% for UDS with baseline radiolucency. The risk analysis showed that UDS without radiolucency at baseline had a similar likelihood of progression (adjusted HR = 1.71, 95% CI = 0.68-4.32, p = 0.26) while UDS with radiolucency at baseline were more likely to progress (adjusted HR = 2.96, 95% CI = 1.06-8.26, p = 0.04) than the reference category (sound occlusal surfaces without radiolucency). These estimates were adjusted for caries prevalence, tooth type, and arch. This study showed low progression rates of UDS after 1-2 years. The presence of radiolucency at baseline was found to predict UDS progression.