Abstract Archives

IADR Abstract Archives

Dentine Reactions Subjacent to Natural Enamel Caries - A Facilitated Pathway

Objectives: This study aimed at testing the relationship between natural enamel caries (NEC) and subjacent dentine reactions under stereomicroscopy (SM) and microradiography with contrast solution (MRC) analysis, and also investigating the transport of fluid into dentinal tubes and modification of cariogenic biofilm formed on the NEC surface.
Methods: Five experiments were carried out with proximal NEC lesions of extracted human teeth. Study I, transport of dentinal fluid towards NEC, real-time MRC was used for tracking transport of contrast solution (Thoulet’s) from the pulp chamber to the NEC surface. Study II, NEC surface changes in response to dentinal fluid, real-time optical profilometry of NEC surface after filling pulp chamber with Thoulet’s. Study III, correlation between enamel and dentine reactions in caries process, histological scoring of these reaction under SM and MRC on longitudinal ground sections. Study IV, effect of dentinal fluid on the biofilm matrix formed on the NEC surface, quantification of extracellular polysaccharides (EPS) after application of 2% chlorhexidine in pulp chamber. Study V, analysis of subjacent dentine reactions under microCT with Thoulet’s. Statistics includes one-sample Z-test, T-test, ANOVA, Hedge's g and Cohen H effect size, 95% confidence intervals, and power (Table).
Results: Study I, II and V evidenced a facilitated transport of modified dentinal fluid towards NEC lesions. Study III revealed a decreased proportion of sclerotic dentine and an increased proportion of deep dentine demineralization under MRC compared to SM analysis, based on dentin color and translucency. In study IV, cariogenic biofilm formed in vitro on the NEC surface presented lower amounts of insoluble and soluble matrix polysaccharides when 2% chlorhexidine was applied in the pulp chamber.
Conclusions: In conclusion, this study evidenced that dentine subjacent to NEC is mostly demineralized, providing facilitated pathway for dentinal fluid to penetrate into NEC and alter the composition of the biofilm formed on the NEC surface.
Division: IADR/AADR/CADR General Session
Meeting: 2019 IADR/AADR/CADR General Session (Vancouver, BC, Canada)
Location: Vancouver, BC, Canada
Year: 2019
Final Presentation ID: 2426
Abstract Category|Abstract Category(s): Cariology Research-Demineralization/Remineralization
Authors
  • Garcia De Carvalho, Gabriel  ( Araraquara Dental School - São Paulo State University , Araraquara , São Paulo , Brazil ;  Federal University of Paraíba , João Pessoa , Paraíba , Brazil )
  • De Barros Pinto, Laryssa  ( Federal University of Paraíba , João Pessoa , Paraíba , Brazil )
  • Alves Lira, Maria Luiza  ( Federal University of Paraíba , João Pessoa , Paraíba , Brazil )
  • Cavalcanti, Yuri  ( Federal University of Paraíba , João Pessoa , Paraíba , Brazil )
  • De Andrade Dantas, Eugênia Livia  ( Federal University of Paraíba , João Pessoa , Paraíba , Brazil )
  • Oliveira Vieira, Maria Lúcia  ( Federal University of Paraíba , João Pessoa , Paraíba , Brazil )
  • Sousa, Frederico  ( Federal University of Paraiba , João Pessoa , Paraíba , Brazil )
    • Support Funding Agency/Grant Number: CNPq (Brazilian Ministry of Science, Technology, and Innovation)
    Financial Interest Disclosure: NONE
    SESSION INFORMATION
    Poster Session
    Demineralization/Remineralization II
    Friday, 06/21/2019 , 03:45PM - 05:00PM
    TABLES
    Statistical analysis, results and conclusions.
    StudyProportionp valueEffect sizePower95% CIErrorConclusion
    I (n=56)42.86%<0.00810.5184.3%N/AN/AStatistically different from the expected proportion of 20%.
    II (n=4)N/AN/AN/AN/AN/A1.18μmEach sample presents pronounced changes (outside the error).
    III (n=91)N/A<0.000010.5497.4%0.61-0.22N/AThe distributions of histological
    scores in dentine differed from SM to MRC.
    IV (n=10) - Soluble EPSN/A<0.000236.8%97.8%N/AN/ADentinal fluid subjacent to NEC affected cariogenic biofilm formed on the NEC surface (soluble polysaccharides).
    IV (n=10) - Insoluble EPSN/A<0.00530%90.8%N/AN/ADentinal fluid subjacent to NEC affected cariogenic biofilm formed on the NEC surface (insoluble polysaccharides).
    V (n=10)N/AN/AN/AN/AN/AN/AIn all teeth (100%) used in the in vitro biofilm formation, 3D microCT analysis detected that the radiographic contrast solution infiltrated in the pulp chamber penetrated all the way through the dentine layer and eventually penetrated the body of the NEC (Dichotomous variables, penetrated or not).
    Description of results obtained after statistical analysis for all five studies. Test of normality of data, homogeneity of variances, and priori sample size calculation were also performed, though not described in the table above. CI, confidente interval. EPS, extracellular polysaccharides. N/A, not applicable. NEC, natural enamel caries.
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