-
Acta Odontologica Latinoamericana : AOL Dec 2022Dentin hypersensitivity (DH) is characterized by rapid, acute pain arising from exposed dental tubules.
UNLABELLED
Dentin hypersensitivity (DH) is characterized by rapid, acute pain arising from exposed dental tubules.
AIM
the aim of this study was to evaluate the roughness, tubule occlusion, and permeability of eroded dentin brushed with different toothpastes.
MATERIALS AND METHOD
ninety bovine teeth were cut into blocks. Thirty hemifaces were protected with varnish and the other sixty were submitted to permeability tests. Specimens were divided into groups according to the dentifrices: without fluoride (WF), sodium fluoride (NaF), and stannous fluoride (SnF2). The blocks were subjected to a 5-day erosive-abrasive protocol. Surface roughness and dentinal tubule occlusion (n=10) were assessed for both control and test hemifaces of the same sample along with permeability analysis (n=20). Two-way RM ANOVA and Tukey's post-hoc test were performed (p≤0.05).
RESULTS
NaF and SnF2 presented higher roughness than WF. The number of open tubules was higher in WF. Permeability was higher in SnF2, but there was no significant difference between WF and NaF.
CONCLUSIONS
both fluoride toothpastes occluded dentinal tubules and increased roughness. NaF toothpaste promoted greater decrease in dentin permeability.
Topics: Animals; Cattle; Toothpastes; Fluorides; Dentin; Dentin Sensitivity; Sodium Fluoride; Permeability; Dentin Permeability
PubMed: 36748742
DOI: 10.54589/aol.35/3/229 -
Journal of Endodontics Nov 2019Odontoblasts produce dentin throughout life and in response to trauma. The purpose of this study was to identify the roles of endogenous Wnt signaling in regulating the...
INTRODUCTION
Odontoblasts produce dentin throughout life and in response to trauma. The purpose of this study was to identify the roles of endogenous Wnt signaling in regulating the rate of dentin accumulation.
METHODS
Histology, immunohistochemistry, vital dye labeling, and histomorphometric assays were used to quantify the rate of dentin accumulation as a function of age. Two strains of Wnt reporter mice were used to identify and follow the distribution and number of Wnt-responsive odontoblasts as a function of age. To show a causal relationship between dentin secretion and Wnt signaling, dentin accumulation was monitored in a strain of mice in which Wnt signaling was aberrantly elevated.
RESULTS
Dentin deposition occurs throughout life, but the rate of accumulation slows with age. This decline in dentin secretion correlates with a decrease in endogenous Wnt signaling. In a genetically modified strain of mice, instead of tubular dentin, aberrantly elevated Wnt signaling resulted in accumulation of reparative dentin or osteodentin secreted from predontoblasts.
CONCLUSIONS
Wnt signaling regulates dentin secretion by odontoblasts, and the formation of reparative or osteodentin is the direct consequence of elevated Wnt signaling. These preclinical data have therapeutic implications for the development of a biologically based pulp capping medicant.
Topics: Animals; Dental Pulp; Dentin; Mice; Odontoblasts; Odontogenesis; Wnt Signaling Pathway; beta Catenin
PubMed: 31522810
DOI: 10.1016/j.joen.2019.07.014 -
Biomolecules Jul 2021Intracellular Ca signaling engendered by Ca influx and mobilization in odontoblasts is critical for dentinogenesis induced by multiple stimuli at the dentin surface....
Intracellular Ca signaling engendered by Ca influx and mobilization in odontoblasts is critical for dentinogenesis induced by multiple stimuli at the dentin surface. Increased Ca is exported by the Na-Ca exchanger (NCX) and plasma membrane Ca-ATPase (PMCA) to maintain Ca homeostasis. We previously demonstrated a functional coupling between Ca extrusion by NCX and its influx through transient receptor potential channels in odontoblasts. Although the presence of PMCA in odontoblasts has been previously described, steady-state levels of mRNA-encoding PMCA subtypes, pharmacological properties, and other cellular functions remain unclear. Thus, we investigated PMCA mRNA levels and their contribution to mineralization under physiological conditions. We also examined the role of PMCA in the Ca extrusion pathway during hypotonic and alkaline stimulation-induced increases in intracellular free Ca concentration ([Ca]). We performed RT-PCR and mineralization assays in human odontoblasts. [Ca] was measured using fura-2 fluorescence measurements in odontoblasts isolated from newborn Wistar rat incisor teeth and human odontoblasts. We detected mRNA encoding PMCA1-4 in human odontoblasts. The application of hypotonic or alkaline solutions transiently increased [Ca] in odontoblasts in both rat and human odontoblasts. The Ca extrusion efficiency during the hypotonic or alkaline solution-induced [Ca] increase was decreased by PMCA inhibitors in both cell types. Alizarin red and von Kossa staining showed that PMCA inhibition suppressed mineralization. In addition, alkaline stimulation (not hypotonic stimulation) to human odontoblasts upregulated the mRNA levels of dentin matrix protein-1 (DMP-1) and dentin sialophosphoprotein (DSPP). The PMCA inhibitor did not affect DMP-1 or DSPP mRNA levels at pH 7.4-8.8 and under isotonic and hypotonic conditions, respectively. We also observed PMCA1 immunoreactivity using immunofluorescence analysis. These findings indicate that PMCA participates in maintaining [Ca] homeostasis in odontoblasts by Ca extrusion following [Ca] elevation. In addition, PMCA participates in dentinogenesis by transporting Ca to the mineralizing front (which is independent of non-collagenous dentin matrix protein secretion) under physiological and pathological conditions following mechanical stimulation by hydrodynamic force inside dentinal tubules, or direct alkaline stimulation by the application of high-pH dental materials.
Topics: Animals; Calcium; Cell Line; Dentin; Humans; Odontoblasts; Plasma Membrane Calcium-Transporting ATPases; Rats; Rats, Wistar; Tooth Calcification
PubMed: 34356633
DOI: 10.3390/biom11071010 -
BMC Oral Health Dec 2022The use of silver diamine fluoride (SDF) in caries treatment in children has increased despite the disadvantage of causing tooth discoloration. Nanosilver fluoride (NSF)... (Randomized Controlled Trial)
Randomized Controlled Trial
Antibacterial effect and impact on caries activity of nanosilver fluoride and silver diamine fluoride in dentin caries of primary teeth: a randomized controlled clinical trial.
BACKGROUND
The use of silver diamine fluoride (SDF) in caries treatment in children has increased despite the disadvantage of causing tooth discoloration. Nanosilver fluoride (NSF) is a possible alternative. This study aimed to assess the antibacterial effect of NSF and SDF and their impact on the activity of dentin caries in primary teeth.
METHODS
Synthesis and characterization of the physical and biological properties of NSF were conducted. Fifty children aged 4-6 years with dentin caries (active caries corresponding to ICDAS code 5) in deciduous teeth were randomly assigned to treatment by NSF or SDF. Baseline assessment of Streptococcus mutans (S. mutans) and lactobacilli counts as CFU/mL in caries lesions was done, followed by the application of the agents. After one month, microbiological samples were recollected, and lesion activity was reassessed. Groups were compared using Mann-Whitney and Chi-Square tests, while intragroup comparisons were done using Wilcoxon and McNemar tests. Multilevel logistic regression analysis was used to assess the effect of different variables on the outcomes.
RESULTS
There were 130 teeth in 50 children; mean ± SD age = 4.75 ± 0.76 years, 63% were posterior teeth. At the one-month follow-up appointment, both groups showed a significant decrease from baseline bacterial counts. There was a significant difference in the reduction of S. mutans between NSF and SDF (21.3% and 10.5%, respectively, p = 0.002), while not in lactobacilli (13.9% and 6.0%, respectively, p = 0.094). In both groups, there was a significant reduction in the number of active caries from baseline (p < 0.0001) with no significant difference between groups (percentage inactive = 64.4% and 63.4%, p = 0.903). Multilevel regression revealed non-significant differences in S. mutans and lactobacilli counts (AOR 1.281, p = 0.737 and 1.888, p = 0.341, respectively), and in the number of inactive lesions (AOR 1.355, p = 0.731) between groups.
CONCLUSION
The short-term antibacterial efficacy of NSF was similar to that of SDF. In both groups there was a significant reduction of S. mutans and lactobacilli counts in active dentin caries, and two-thirds of the lesions became inactive with no differences between the two interventions. Further research is needed to investigate the long-term efficacy of NSF and its suitability for clinical use in caries management.
TRIAL REGISTRATION
This trial was prospectively registered on the clinicaltrials.gov registry with ID: NCT05221749 on 03/02/2022.
Topics: Child; Humans; Fluorides; Cariostatic Agents; Dental Caries Susceptibility; Tooth, Deciduous; Fluorides, Topical; Dental Caries; Silver Compounds; Quaternary Ammonium Compounds; Dentin
PubMed: 36585664
DOI: 10.1186/s12903-022-02697-y -
Brazilian Oral Research 2018This study aimed to evaluate the influence of different ethanol concentrations on dentin roughness, surface free energy, and contact angle between AH Plus and the root...
This study aimed to evaluate the influence of different ethanol concentrations on dentin roughness, surface free energy, and contact angle between AH Plus and the root canal dentin. One hundred human maxillary anterior teeth were split longitudinally and 200 dentin specimens were polished to make the surface flatter and smoother. An acrylic bar was positioned between two dentin specimens and impression material was added to create a block, simulating an instrumented root canal space. Specimens were removed from the mold and cleaned in an ultrasonic bath for 10 min. Thereafter, dentin specimens were divided into four groups (n = 50) according to the drying methods used: a) wet: vacuum only, b) paper points: vacuum + absorbent paper points, c) 70% alcohol: 70% alcohol (1 min) + vacuum + absorbent paper points, and d) 100% alcohol: 100% alcohol (1 min) + vacuum + absorbent paper points. A rugosimeter and a goniometer were used to verify the roughness (Ra) and to measure the surface free energy and the contact angle between the AH Plus sealer and the root canal dentin. ANOVA and Tukey tests (α = 0.05) were used for statistical analysis. The 70% and 100% ethanol groups showed significantly decreased roughness as well as increased surface free energy in the root canal dentin when compared to the wet and paper point groups. In addition, ethanol significantly reduced the contact angle between the AH Plus sealer and the root canal dentin. Ethanol solutions (70% and 100%) provide better wettability of AH Plus sealer on dentin surfaces.
Topics: Analysis of Variance; Dental Bonding; Dentin; Epoxy Resins; Ethanol; Humans; Materials Testing; Reproducibility of Results; Root Canal Filling Materials; Surface Properties; Tooth Root; Wettability
PubMed: 29723333
DOI: 10.1590/1807-3107bor-2018.vol32.0033 -
Journal of Dentistry Aug 2020Proanthocyanidins (PACs) are biocompounds mimicking native collagen cross-links. The effective and practical delivery of any biocompound is pivotal for clinical usage....
OBJECTIVES
Proanthocyanidins (PACs) are biocompounds mimicking native collagen cross-links. The effective and practical delivery of any biocompound is pivotal for clinical usage. The aim was to investigate the dentin biomodification and effective formation of dentin-resin biointerfaces of two highly bioactive PAC-rich extracts, Vitis vinifera (Vv) and Camellia sinensis (Cs), delivered using neutral (NP) or acidic (AP) rinse-out primer approaches.
METHODS
The depth of dentin demineralization (optical profilometry), dentin biomodification (apparent modulus of elasticity, collagen auto-fluorescence) and properties of dentin-resin interfaces (microtensile bond strength - μTBS, and micro-permeability) were investigated. NP consisted of either 15% Vv or Cs applied for 60 s after surface etching; while AP contained 15% Vv or Cs in either 35% glycolic acid or tartaric acid applied for 30 s or 60 s. Data were analyzed using ANOVA and post-hoc tests (α = 0.05).
RESULTS
The depth of demineralization was statistically higher when applied for 60 s, regardless of rinse-out primer approach (p < 0.001). Compared to the AP strategy, NP exhibited statistically higher apparent modulus of elasticity, regardless of PAC extract (p < 0.001). Highest μTBS were obtained for NP, which were statistically similar to AP, when applied for 60 s (p < 0.001); both resulted in a dramatic decrease of the interfacial permeability. NP group showed the lowest μTBS (p < 0.001).
CONCLUSIONS
A combination of high bond strength and low micro-permeability can be accomplished using glycolic acid with the mid- and high-PAC oligomer enriched extract (Vv). Cs extract containing mostly catechins and dimeric PACs, was found unsuitable for resin-dentin adhesion despite exhibiting high initial dentin biomodification.
CLINICAL SIGNIFICANCE
This study provides a new conceptual delivery of PAC-mediated dentin biomodification and conservative dentin surface etching using rinse-out primers. The strategy requires a specific combination of PAC source, α-hydroxy acid, and application time.
Topics: Catechin; Collagen; Dental Bonding; Dentin; Dentin-Bonding Agents; Materials Testing; Proanthocyanidins; Resin Cements; Surface Properties; Tensile Strength
PubMed: 32360320
DOI: 10.1016/j.jdent.2020.103354 -
Acta Biomaterialia Jan 2022Aging is a physiological process with profound impact on the biology and function of biosystems, including the human dentition. While resilient, human teeth undergo wear...
Aging is a physiological process with profound impact on the biology and function of biosystems, including the human dentition. While resilient, human teeth undergo wear and disease, affecting overall physical, psychological, and social human health. However, the underlying mechanisms of tooth aging remain largely unknown. Root dentin is integral to tooth function in that it anchors and dissipates mechanical load stresses of the tooth-bone system. Here, we assess the viscoelastic behavior, composition, and ultrastructure of young and old root dentin using nano-dynamic mechanical analysis, micro-Raman spectroscopy, small angle X-ray scattering, atomic force and transmission electron microscopies. We find that the root dentin overall stiffness increases with age. Unlike other mineralized tissues and even coronal dentin, however, the ability of root dentin to dissipate energy during deformation does not decay with age. Using a deconstruction method to dissect the contribution of mineral and organic matrix, we find that the damping factor of the organic matrix does deteriorate. Compositional and ultrastructural analyses revealed higher mineral-to-matrix ratio, altered enzymatic and non-enzymatic collagen cross-linking, increased collagen d-spacing and fibril diameter, and decreased abundance of proteoglycans and sulfation pattern of glycosaminoglycans . Therefore, even in the absence of remodeling, the extracellular matrix of root dentin shares traits of aging with other tissues. To explain this discrepancy, we propose that altered matrix-mineral interactions, possibly mediated by carbonate ions sequestered at the mineral interface and/or altered glycosaminoglycans counteract the deleterious effects of aging on the structural components of the extracellular matrix. STATEMENT OF SIGNIFICANCE: Globally, a quarter of the population will be over 65 years old by 2050. Because many will retain their dentition, it will become increasingly important to understand and manage how aging affects teeth. Dentin is integral to the protective, biomechanical, and regenerative features of teeth. Here, we demonstrate that older root dentin not only has altered mechanical properties, but shows characteristic shifts in mineralization, composition, and post-translational modifications of the matrix. This strongly suggests that there is a mechanistic link between mineral and matrix components to the biomechanical performance of aging dentin with implications for efforts to slow or even reverse the aging process.
Topics: Aged; Dentin; Extracellular Matrix; Humans; Minerals; Proteoglycans; Tooth Root
PubMed: 34740855
DOI: 10.1016/j.actbio.2021.10.051 -
Brazilian Dental Journal Oct 2015The aim of this study was to evaluate the effect of hydrogen peroxide whitening on fluorescence and color of bovine enamel and dentin. Twenty five dentin discs and 25...
The aim of this study was to evaluate the effect of hydrogen peroxide whitening on fluorescence and color of bovine enamel and dentin. Twenty five dentin discs and 25 enamel discs, with 6 mm diameter and 1 mm thick, were obtained. Direct fluorescence (spectrofluorophotometry) and color (spectrophotometry) were assessed. After fluorescence and color baseline measurements, specimens were immersed in a 35% hydrogen peroxide (HP) solution for 1 h. This procedure was repeated after 7 days. Final fluorescence and color measurements were performed after the second immersion. Chemical characterization of 5 additional specimens was also performed. Data were submitted to repeated analysis of variance and Tukey's test for fluorescence and unpaired t-test for color and chemical components (p<0.05). Fluorescence decreased significantly in dentin specimens after whitening. Enamel presented lower fluorescence than dentin at baseline, but this parameter did not decrease after whitening. Color changes were observed for both substrates, with significantly greater whitening effect in dentin (ΔE=10.37) (p<0.001). Whitening by hydrogen peroxide induced significant decrease in fluorescence of tooth dentin and promoted significant color changes in dentin and enamel with more accentuated outcomes in dentin.
Topics: Animals; Cattle; Color; Dental Enamel; Dentin; Fluorescence; Hydrogen Peroxide; Spectrometry, Fluorescence
PubMed: 26647938
DOI: 10.1590/0103-6440201300249 -
Journal of Conservative Dentistry : JCD 2021The aim of this study was to compare the effects of herbal irrigants with conventional irrigants on microhardness and flexural strength of root dentin.
AIM
The aim of this study was to compare the effects of herbal irrigants with conventional irrigants on microhardness and flexural strength of root dentin.
MATERIALS AND METHODS
Sixty extracted permanent maxillary canines were selected. Decoronated roots were sectioned longitudinally into buccal and lingual segments to get 120 specimens. These were embedded in auto polymerizing acrylic resin and further grounded with fine emery papers under distilled water. Of these, 100 root segments without any defects were selected, further divided into four test groups and a control group according to the irrigants used ( = 20). Group 1: 2.5% Sodium hypochlorite, Group 2: Miswak stick extract, Group 3: Cashew leaves extract. Group 4: Mango leaves extract and Group 5: Normal saline (control). All specimens were treated with 5 ml of each irrigant for 10 minutes and rinsed immediately. Dentin microhardness was measured with a Vickers indenter, and the flexural strength test was done using a universal testing machine. The data were analyzed using one-way ANOVA and the intergroup comparison by student -test.
RESULTS
The experimental groups showed a significant reduction in microhardness values when compared with the control group. Intragroup comparison among experimental groups, herbal irrigants showed the least reduction in microhardness values at cervical, middle, and apical thirds. When compared to the control group, the flexural strength values decreased significantly with experimental groups.
CONCLUSION
Within the limitation of this study, it was concluded that herbal irrigants were least detrimental to root dentin microhardness when compared with conventional irrigant. But the flexural strength was equally reduced by both conventional and herbal irrigants.
PubMed: 34475686
DOI: 10.4103/JCD.JCD_426_20 -
Clinical Oral Investigations Aug 2021Matrix metalloproteases (MMPs) are a family of enzymes that operate a proteolytic activity at the level of the extracellular matrix. MMPs are regulated by tissue...
OBJECTIVES
Matrix metalloproteases (MMPs) are a family of enzymes that operate a proteolytic activity at the level of the extracellular matrix. MMPs are regulated by tissue inhibitors of metalloproteinases (TIMPs) that can ubiquitously bind different enzyme forms. The study aims to identify a morfo-functional association between TIMP-1 and MMP-2 and -9 in human dentin.
MATERIALS AND METHODS
Proteins were extracted from demineralized human sound dentin powder and centrifuged to separate two aliquots with different molecular weights of proteins, higher and lower than 30 kDa. In each aliquot, the evaluation of the presence of TIMP-1/MMP-2 and TIMP-1/MMP-9 was performed using co-immunoprecipitation/immunoblotting analysis. The distribution of TIMP-1, in association with MMP-2 and -9, was investigated using a double immunohistochemical technique. Furthermore, the activity of TIMP-1 was measured by reverse zymography, where acrylamide gel was copolymerized with gelatin and recombinant MMP-2.
RESULTS
Co-immunoprecipitation/immunoblotting analysis showed the association TIMP-1/MMP-2 and TIMP-1/MMP-9 in human sound dentin. Electron microscopy evaluation revealed a diffuse presence of TIMP-1 tightly associated with MMP-2 and -9. Reverse zymography analysis confirmed that TIMP-1 present in human dentin is active and can bind different MMPs isoforms.
CONCLUSIONS
The strict association of TIMP-1 with MMP-2 and -9 in situ appeared a constant finding in the human sound dentin.
CLINICAL RELEVANCE
Considering the role of TIMP-1, MMP-2, and MMP-9 within the connective tissues, clinically applicable protocols could be developed in the future to increase or decrease the level of TIMPs in human dentin to regulate the activity of MMPs, contributing to reduce caries progression and collagen degradation.
Topics: Dentin; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinases; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinases
PubMed: 33569677
DOI: 10.1007/s00784-021-03819-6