Fluorescence and bacterial microbiome of dentin in deep carious lesions Public Deposited

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  • March 19, 2019
  • Trippe, Leslie
    • Affiliation: School of Dentistry, Department of Operative Dentistry
  • Purpose: To determine if the presence or absence of fluorescence as clinically detected by fluorescence–aided caries excavation (FACE) correlates with dentin bacterial microbiome diversity, as assessed by 16S rRNA amplicon sequencing and to compare and contrast traditional tactile dentin caries detection with fluorescence. Materials and Methods: Unidentified, extracted human, carious teeth considered discarded waste were obtained from a dental facility. Providers unrelated to the research study supplied the teeth - NHSR (Not Human Subjects Research). Included teeth had a carious lesion two-thirds into the dentin, verified by a radiograph (post extraction), and fluoresce red using FACE technology (SIROInspect,Sirona, Bensheim Germany). Fluorescing carious dentin was assessed using the traditional visual-tactile method, and comparisons made before and after cavity preparation. Red fluorescing (RF) sites were sampled with a sterile spoon excavator, and dentin characteristics evaluated clinically via traditional visual/tactile methods. Once RF dentin was removed, a second sample of carious dentin with pink fluorescing (PF) dentin was obtained with a sterile spoon excavator. After excavation with sterile round burr to non-fluorescing (NF) dentin, the dentin characteristics were evaluated again by visual-tactile method, and a third sample was collected with a new sterile slow speed round burr. Samples were transported on dry ice for analysis of bacterial microbiome to the UNC Microbiome Core Facility. Results: Out of 134 extracted teeth collected, 21 fit the inclusion criteria, yielding 61 samples which were subsequently analyzed. RF samples had a higher number of observed OTUs (Operational Taxonomic Units), at 154, followed by PF 109 and (NF) 100. Regarding tactile assessments: RF carious dentin was primarily ‘soft’, but also had readings of ‘leathery’ or ‘hard’ tactically, and the NF dentin was assessed as ‘hard’ 100% of the time by both examiners. The rank correlation chi-squared statistic for the association of fluorescence and tactile was highly statistically significant (p < 0.001) for each examiner strongly suggesting an association between fluorescence and tactile assessment. However, approximately one-third of the tactile assessments of hard dentin still displayed some level of fluorescence, either PF or RF. Conclusion: The sampled fluorescing (RF, PF) and NF carious dentin layers displayed diverse bacterial taxa that varied in the proportion of bacterial species. Tactile assessments correlated with RF, PF and NF approximately two-thirds of the time, as one-third of the time hard dentin displayed fluorescence.
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  • In Copyright
  • Preisser, John
  • Boushell, Lee
  • Azcarate-Peril, Andrea
  • Zandona, Andrea
  • Master of Science
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2017

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