Numerical Modelling of Tooth Enamel Subsurface Lesion Formation Induced by Dental Plaque

Abstract

Using a one-dimensional mathematical model that couples tooth demineralisation and remineralisation with metabolic processes occurring in the dental plaque, two mechanisms for subsurface lesion formation were evaluated. It was found that a subsurface lesion can develop only as the result of alternating periods of demineralisation (acid attack during sugar consumption) and remineralisation (resting period) in tooth enamel with uniform mineral composition. It was also shown that a minimum plaque thickness that can induce an enamel lesion exists. The subsurface lesion formation can also be explained by assuming the existence of a fluoride-containing layer at the tooth surface that decreases enamel solubility. A nearly constant thickness of the surface layer was obtained with both proposed mechanisms. Sensitivity analysis showed that surface layer formation is strongly dependent on the length of remineralisation and demineralisation cycles. The restoration period is very important and the numerical simulations support the observation that often consumption of sugars is a key factor in caries formation. The calculated profiles of mineral content in enamel are similar to those observed experimentally. Most probably, both studied mechanisms interact in vivo in the process of caries development, but the simplest explanation for subsurface lesion formation remains the alternation between demineralisation and remineralisation cycles without any pre-imposed gradients.

In vitro studies of the antimicrobial effect of non‐thermal plasma‐activated water as a novel mouthwash

“…Streptococcus mutans is a gram‐positive, facultative anaerobic bacterium and the most important cariogenic agent for the development process of dental caries . Actinomyces viscosus is a common gram‐positive bacterium in the oral cavity and the primary colonizer of human tooth surfaces, which plays an important role in plaque formation and growth . Porphyromonas gingivalis is associated with aggressive periodontitis and is implicated as a significant pathogen in human periodontal diseases .…”

In silico modelling to differentiate the contribution of sugar frequency versus total amount in driving biofilm dysbiosis in dental caries

“…The earliest presentation of caries is the occurrence of white spots on the tooth surface, resulting from high environmental acidity that drives demineralisation 7 . We used the minimum pH at the enamel surface, measured over a time interval including at least one glucose pulse, as our metric of plaque cariogenicity, in the absence of explicit enamel de- and remineralisation reactions 19 , 20 . The pH after t = 60d of glucose pulsing is plotted in Fig.…”

“…Values refer to those used unless otherwise stated. Label Parameter Value Based on h plaque Biofilm thickness 250 μm 41 h saliva Thickness of the saliva layer 250 μm Assumed X , Y System box width, breadth 500 μm Assumed Glucose half-saturation for A 0.4 g/L 19 Glucose half-saturation for NA 0.1 g/L 19 Optimal [H + ] for A 10 −5 mol 19 Optimal [H + ] for NA 10 −7 mol Estimated based on 25 Glycolysis base rate (A, NA) 5/h 42 f Fraction of total for [polyGl] 1% Estimated based on 20 Y Growth factor 0.1 42 Y EPS EPS production factor 0.04 Assumed Death rate for A at neutral pH 3 × 10 −3 /h 43 Death rate for NA at neutral pH 6 × 10 −3 /h 43 …”

“…mathematical descriptions of the biochemical processes solved on a computer, which provide a rapid assaying capability that can be used to guide subsequent experiments. In silico oral biofilm models are typically coarse-grained descriptions that do not permit the biofilm composition to evolve in time 17 – 20 . Recently, a two-dimensional cellular automata model based at the level of cell aggregates was developed to investigate competition in growing S. gordonii-P. gingivalis biofilms 21 but clinical predictions for caries were not considered.…”

The Application of the Logistic Equation Model to Predict the Remineralization Characteristics of Desensitizing Paste

“…Essentially, using numeral tools, Ilie et al [17] assumed that it is possible to fashion out a controlled environment to address the challenges of long time period needed to effectively study the biological process. In the last decade, a different mathematical model has been proposed by various scholars to investigate dental hard tissues, most nevertheless, focus largely on dental caries, and tooth demineralization process [17–19]. Despite the numerous models developed to study dental tissues, there is limited evidence that suggests the use of a mathematical model to predict the remineralization potentials of desensitizing agents on dentin tubules.…”