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Biomedical Engineering Online Apr 2020The remineralization approach mechanically occludes the exposed dentinal tubules mechanically, reduces the permeability of dentinal tubules and eliminates the symptoms...
BACKGROUND
The remineralization approach mechanically occludes the exposed dentinal tubules mechanically, reduces the permeability of dentinal tubules and eliminates the symptoms of dentin hypersensitivity. The aim of the present study was to investigate the remineralization of demineralized dentin slices using CPP-ACP combined with TPP, and the research hypothesis was that CPP-ACP combined with TPP could result in extrafibrillar and intrafibrillar remineralization of dentin.
METHODS
Demineralized dentin slices were prepared and randomly divided into the following groups: A (the CPP-ACP group), B (the CPP-ACP + TPP combination group), C (the artificial saliva group), D (the negative control group), and E (the positive control group). Dentin slice samples from groups A, B and C were remineralized and the remineralization effect was evaluated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD).
RESULTS
Treatment with CPP-ACP combined with TPP occluded the dentinal tubules and resulted in remineralization of collagen fibrils. The hydroxyapatite crystals formed via remineralization were found to closely resemble the natural dentin components.
CONCLUSION
CPP-ACP combined with TPP has a good remineralization effect on demineralized dentin slices.
Topics: Caseins; Dentin; Drug Interactions; Humans; Minerals; Polyphosphates
PubMed: 32245476
DOI: 10.1186/s12938-020-0756-9 -
Scientific Reports Oct 2018Hutchinson-Gilford progeria syndrome (HGPS) is a rare accelerated senescence disease, manifesting dental abnormalities and several symptoms suggestive of premature...
Hutchinson-Gilford progeria syndrome (HGPS) is a rare accelerated senescence disease, manifesting dental abnormalities and several symptoms suggestive of premature aging. Although irregular secondary dentin formation in HGPS patients has been reported, pathological mechanisms underlying aberrant dentin formation remain undefined. In this study, we analyzed the mandibular molars of a tissue-specific mouse model that overexpresses the most common HGPS mutation (LMNA, c.1824C > T, p.G608G) in odontoblasts. In the molars of HGPS mutant mice at postnatal week 13, targeted expression of the HGPS mutation in odontoblasts results in excessive dentin formation and pulp obliteration. Circumpulpal dentin of HGPS mutants was clearly distinguished from secondary dentin of wild-type (WT) littermates and its mantle dentin by considering the irregular porous structure and loss of dentinal tubules. However, the dentin was significantly thinner in the molars of HGPS mutants at postnatal weeks 3 and 5 than in those of WT mice. In vitro analyses using MDPC-23, a mouse odontoblastic cell line, showed cellular senescence, defects of signaling pathways and consequential downregulation of matrix protein expression in progerin-expressing odontoblasts. These results indicate that expression of the HGPS mutation in odontoblasts disturbs physiological secondary dentin formation. In addition, progerin-expressing odontoblasts secrete paracrine factors that can stimulate odontogenic differentiation of dental pulp cells. Taken together, our results suggest that the aberrant circumpulpal dentin of HGPS mutants results from defects in physiological secondary dentin formation and consequential pathologic response stimulated by paracrine factors from neighboring progerin-expressing odontoblasts.
Topics: Animals; Cells, Cultured; Cellular Senescence; Dental Pulp; Dentin; Humans; Lamin Type A; Mice; Mice, Transgenic; Mutation; Progeria
PubMed: 30337599
DOI: 10.1038/s41598-018-33764-6 -
Archives of Oral Biology Feb 2020The aim of this study was to evaluate the morphological and chemical effect of in-office and at-home desensitising agents containing sodium fluoride (NaF) on eroded root...
OBJECTIVE
The aim of this study was to evaluate the morphological and chemical effect of in-office and at-home desensitising agents containing sodium fluoride (NaF) on eroded root dentine in vitro.
METHODS
Fifty bovine dentine samples were pre-eroded and randomised into five groups (n = 10): G1 (Control) - milli-Q water; G2 - fluoride varnish containing NaF 22,500 ppm; G3 - desensitising cream containing NaF 9,000 ppm associated with 20% nanohydroxyapatite; G4 - toothpaste with NaF 5,000 ppm associated to tricalcium phosphate; G5 - toothpaste containing NaF 900 ppm and casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF). The specimens were submitted to erosive challenge for three days. The analyses were performed using non-contact profilometry for volumetric (Sa) and linear roughness (Ra) followed by scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS). The data were analysed by Kruskal-Wallis and Wilcoxon tests (α = 0.05).
RESULTS
There was a significant reduction of Ra and Sa for the eroded samples from the G2 and G5 (p < 0.05) after an erosive challenge. The dentine surface topography pattern showed partially or totally occluded dentinal tubules after treatments, except in the control group. The control, G4 and G3 groups showed a reduction in the dentine inorganic content percentage of Ca (Calcium) and P (Phosphorus) minerals.
CONCLUSION
The fluoride varnish and CPP-ACPF toothpaste were able to prevent morphological changes and were the only materials that showed the Ca and P content increased after treatment. These materials may be promising alternatives in the clinical control of dentin erosion.
Topics: Animals; Cattle; Dentin; Fluorides; Sodium Fluoride; Tooth Erosion; Tooth Root; Toothpastes
PubMed: 31805483
DOI: 10.1016/j.archoralbio.2019.104619 -
Brazilian Dental Journal 2009Permeability involves the passage of fluids, ions, molecules, particulate matter and bacteria into and through a substance or tissue under different and varying...
Permeability involves the passage of fluids, ions, molecules, particulate matter and bacteria into and through a substance or tissue under different and varying conditions. The permeability of the dentin is essential to support the physiology and reaction patterns of the pulp-dentin organ. Nutrients and impulses are transported from the pulp via the odontoblast process and the contents of its tubules maintain the dentin as a vital tissue. However, the main interest of this paper focuses on penetration from the outside towards the pulp rather than from the pulp towards the outside. The present overview centers on the dentinal tubules; how they are formed and how they change as a result of normal and abnormal function, age, and pathological processes and the effect of these processes on the permeability of dentin. Particular attention is focused on the patency of the dentinal tubules.This overview is largely based on the authors own research, clinical insights and active participation in continuing dental education over the last 50 years. It is not a review of the literature related to the permeability of dentin. Rather it presents interpretation of results related to the permeability of dentin based on experience and opinions acquired over a lifetime in dental research.
Topics: Aging; Dental Bonding; Dental Caries; Dental Pulp; Dentin; Dentin Permeability; Dentin Sensitivity; Dentin, Secondary; Dentin-Bonding Agents; Dentinal Fluid; Dentinogenesis; Humans; Hydrostatic Pressure; Odontoblasts; Smear Layer; Tooth Attrition
PubMed: 19466224
DOI: 10.1590/s0103-64402009000100001 -
Environment International Dec 2018Metal exposure alters neurodevelopmental outcomes; little is known about critical windows of susceptibility when exposure exerts the strongest effect.
BACKGROUND
Metal exposure alters neurodevelopmental outcomes; little is known about critical windows of susceptibility when exposure exerts the strongest effect.
OBJECTIVE
To examine associations between dentine biomarkers of manganese (Mn), zinc (Zn) and lead (Pb) and later childhood behaviors.
METHODS
Subjects enrolled in a longitudinal birth cohort study in Mexico City provided naturally shed deciduous teeth. We estimated weekly prenatal and postnatal dentine Mn, Zn and Pb concentrations in teeth using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and measured behavior at ages 8-11 years of age using the Behavior Assessment System for Children, 2nd edition (BASC-2). We used distributed lag models and lagged weighted quantile sum regression to identify the role of individual and combined dentine biomarkers of Mn, Zn and Pb on behavioral outcomes controlling for maternal education and gestational age.
RESULTS
Among the 133 subjects included in this study, prenatal and early postnatal dentine Mn appeared protective against childhood behavioral problems, specifically hyperactivity and attention. Postnatal dentine Mn was associated with increased reporting of internalizing problems, specifically anxiety. At 6 months, a 1-unit increase (unit = 1 SD of log concentration) in Mn was associated with a 0.18-unit (unit = 1 SD of BASC-2 score) increase in internalizing symptoms score and a 0.25-unit increase in anxiety. Postnatal Pb was associated with increasing anxiety symptoms; at 12 months, a 1-unit increase in Pb was associated with a 0.4 unit increase in anxiety symptoms. When examined as a metal mixture, we observed two potential windows of susceptibility to increased anxiety symptoms: the first window (0-8 months) appeared driven by Mn, the second window (8-12 months) was driven by the metal mixture and dominated by Pb. A 1-unit increase in the mixture index was associated with a 0.7-unit increase in SD of anxiety symptoms.
CONCLUSIONS
Childhood behaviors may demonstrate postnatal windows of susceptibility to individual and mixed metal concentrations measured in deciduous teeth. Prenatal dentine Mn may be protective, while excessive early postnatal Mn may increase risk for adverse behaviors. In combination, higher concentrations of Mn, Zn and Pb may have an adverse impact on behavior.
Topics: Air Pollutants; Biomarkers; Child; Child Behavior; Dentin; Environmental Exposure; Humans; Lead; Manganese; Zinc
PubMed: 30205321
DOI: 10.1016/j.envint.2018.08.045 -
Scientific Reports Jun 2020Teeth are a fundamental tool in forensic odontology for identification in a legal context of those individuals who cannot be identified visually or by other means....
Teeth are a fundamental tool in forensic odontology for identification in a legal context of those individuals who cannot be identified visually or by other means. Dentine presents physiological exchanges of in trace elements after a period of mineralization and several factors can affect its concentration. The aim of this study was to investigate the concentration of 25 trace elements in the coronal dentine according to sex and type of tooth to determine their relationship with age. A total of 25 trace elements were analyzed in 150 human coronal dentine. Teeth were classified into three age groups, sex and tooth type. The trace elements were grouped as potentially toxic or essential. Inductively Coupled Plasma-Mass Spectrometry and Atomic Emission Spectroscopy were used. The toxic and essential elements were detected in the following order of concentration: Al > Pb > Sn > Li > As > Cd and Ca > P > Mg > Na > S > K > Sr > Zn > Ba > Fe > B > Ti > Mn > Cr > Ni > Cu > Co > Se > V. Our findings show an increase in the concentration of toxic (Pb, Li and Sn) and essential (B, Ba, K, Sr, S and Mg) elements in coronal dentin related to the age of the teeth, regardless of sex. The concentrations of Pb and K in dentin of molars and premolars are the elements that best relate their variations with age. In view of our results, the analysis of these trace elements in dentin in combination with other types of techniques could be established as an element to consider in age dating studies in different forensic situations.
Topics: Adult; Aging; Dentin; Female; Humans; Ions; Male; Middle Aged; Spectrum Analysis; Tooth; Trace Elements
PubMed: 32561784
DOI: 10.1038/s41598-020-66472-1 -
International Journal of Nanomedicine 2021The dentin exposure always leads to dentin hypersensitivity and/or caries. Given the dentin's tubular structure and low mineralization degree, reestablishing an...
BACKGROUND
The dentin exposure always leads to dentin hypersensitivity and/or caries. Given the dentin's tubular structure and low mineralization degree, reestablishing an effective biobarrier to stably protect dentin remains significantly challenging. This study reports a versatile dentin surface biobarrier consisting of a mesoporous silica-based epigallocatechin-3-gallate (EGCG)/nanohydroxyapatite delivery system and evaluates its stability on the dentinal tubule occlusion and the () biofilm inhibition.
MATERIALS AND METHODS
The mesoporous delivery system was fabricated and characterized. Sensitive dentin discs were prepared and randomly allocated to three groups: 1, control group; 2, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) group; and 3, the mesoporous delivery system group. The dentin permeability, dentinal tubule occlusion, acid and abrasion resistance, and biofilm inhibition were determined for 1 week and 1 month. The in vitro release profiles of EGCG, Ca, and P were also monitored.
RESULTS
The mesoporous delivery system held the ability to sustainably release EGCG, Ca, and P and could persistently occlude dentinal tubules with acid and abrasion resistance, reduce the dentin permeability, and inhibit the biofilm formation for up to 1 month compared with the two other groups. The system provided prolonged stability to combat oral adverse challenges and served as an effective surface biobarrier to protect the exposed dentin.
CONCLUSION
The establishment of the dentin surface biobarrier consisting of a mesoporous delivery system indicates a promising strategy for the prevention and the management of dentin hypersensitivity and caries after enamel loss.
Topics: Acids; Adsorption; Biofilms; Calcium; Caseins; Catechin; Cell Death; Colony Count, Microbial; Dental Pulp; Dentin; Humans; Nanoparticles; Nitrogen; Permeability; Phosphorus; Porosity; Silicon Dioxide; Streptococcus mutans
PubMed: 33948084
DOI: 10.2147/IJN.S290254 -
PloS One 2016The present study evaluated the effectiveness of a dicalcium and tetracalcium phosphate-based desensitizer in reducing dentin permeability in vitro. Dentin fluid flow...
The present study evaluated the effectiveness of a dicalcium and tetracalcium phosphate-based desensitizer in reducing dentin permeability in vitro. Dentin fluid flow was measured before and after treatment of dentin with patent dentinal tubules using 1 or 3 applications of the dicalcium and tetracalcium phosphate containing agent TeethmateTM (TM) and comparing the results with two sodium fluoride varnishes VellaTM (VLA) and VanishTM (VAN), after storage in artificial saliva for 24 h, 48 h and 7 days. Significant differences were observed among the 4 methods employed for reducing dentin permeability (p < 0.001) and the 3 post-treatment times (p < 0.001). VLA and VAN never achieved 50% permeability reductions consistently in any of the 3 time periods. Only the calcium phosphate-based desensitizer applied for 3 times consistently reduced dentin permeability by 50% after 24 h. When applied once, the permeability reduction of TM increased progressively over the 3 time periods. After 7 days, only one and three applications of the calcium phosphate-based desensitizer consistently reduced dentin permeability by more than 50%. Permeability reductions corresponded well with scanning electron microscopy examination of dentinal tubule orifice occlusion in dentin specimens treated with the agents. Overall, the dicalcium and tetracalcium phosphate-based desensitizer is effective in reducing dentin permeability via a tubule occlusion mechanism. The ability of the agent to reduce dentin permeability renders it to be potentially useful as a clinical dentin desensitizing agent, which has to be confirmed in future clinical studies. By contrast, the two sodium fluoride varnishes are not effective in dentin permeability reduction and should be considered as topical fluoride delivering agents rather than tubular orifice-blocking agents.
Topics: Calcium Phosphates; Dentin; Dentin Desensitizing Agents; Dentin Permeability; Dentin Sensitivity; Humans; In Vitro Techniques; Materials Testing; Microscopy, Electron, Scanning; Molar, Third; Saliva, Artificial
PubMed: 27359118
DOI: 10.1371/journal.pone.0158400 -
The Journal of Organic Chemistry Feb 2017The structurally complex oligomeric proanthocyanidins (OPACs) are promising biomimetic agents, capable of strengthening the macromolecular backbone of teeth via...
The structurally complex oligomeric proanthocyanidins (OPACs) are promising biomimetic agents, capable of strengthening the macromolecular backbone of teeth via intermolecular and intermicrofibrillar cross-linking. This study establishes analytical methods capable of determining the absolute configuration of the catechin-type monomeric units of underivatized OPACs. This preserves the capacity of their biological evaluation, aimed at understanding the inevitably stereospecific interactions between the OPACs and dentin collagen. Guided by dental bioassays (modulus of elasticity, long-term stability), two new trimeric and tetrameric A-type OPACs were discovered as dentin biomodifiers from pine (Pinus massoniana) bark: epicatechin-(2β→O→7,4β→8)-epicatechin-(2β→O→7,4β→8)-catechin (5) and epicatechin-(2β→O→7,4β→8)-epicatechin-(2β→O→7,4β→6)-epicatechin-(2β→O→7,4β→8)-catechin (6), respectively. Combining 1D/2D NMR, HRESIMS, ECD, H iterative full spin analysis (HiFSA), and gauge-invariant atomic orbital (GIAO) δ calculations, we demonstrate how C NMR chemical shifts (diastereomeric building blocks (A-type dimers)) empower the determination of the absolute configuration of monomeric units in the higher oligomers 5 and 6. Collectively, NMR with ECD reference data elevates the level of structural information achievable for these structurally demanding molecules when degradation analysis is to be avoided. Considering their numerous and deceptively subtle, but 3D impactful, structural variations, this advances the probing of OPAC chemical spaces for species that bind selectively to collagenous and potentially other biologically important biomacromolecules.
Topics: Dentin; Humans; Molecular Conformation; Pinus; Proanthocyanidins
PubMed: 28098463
DOI: 10.1021/acs.joc.6b02161 -
Scientific Reports Sep 2023Dentin hypersensitivity is an oral health concern affecting a large percentage of the world's adult population. Occlusion of the exposed dentinal tubules is among the...
Dentin hypersensitivity is an oral health concern affecting a large percentage of the world's adult population. Occlusion of the exposed dentinal tubules is among the treatment options available, and silver diammine fluoride (SDF) is an occluding agent used for interrupting or dampening the stimulus of the dental pulp nerves that produce pain. In addition to dentin permeability testing, the evaluation of desensitizing agents occluding dentinal tubules strongly relies on microscopic techniques, such as scanning electron microscopy (SEM). Limitations of SEM are that it provides only surface images that lack detailed information on the depth of penetration and amount of material present within the treated specimen, and it is prone to sample preparation artifacts. Here, we present high-resolution X-ray computed tomography (nano-CT) as a potential method for investigating dentin specimens with occluded tubules. We studied human dentin treated with SDF as an exemplary dentinal occlusion treatment option. We evaluated the silver deposits formed on the dentin surface region near the dentinal tubules and in the tubular regions using cross-section SEM, Energy Dispersive X-ray (EDX) analysis, and nano-CT. The resulting images obtained by SEM and nano-CT had comparable resolutions, and both techniques produced images of the tubules' occlusion. Nano-CT provided three-dimensional images adequate to quantitate tubule size and orientation in space. Moreover, it enabled clear visualization of dentinal tubules in any virtual plane and estimation of the amount and depth of occluding material. Thus, nano-CT has the potential to be a valuable technique for evaluating the occluding effects of virtually any material applied to dentinal tubules, supporting deciding between the best occluding treatment options.
Topics: Adult; Humans; Tomography, X-Ray Computed; Artifacts; Microscopy, Electron, Scanning; Dentin
PubMed: 37741849
DOI: 10.1038/s41598-023-42805-8