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Tissue Engineering and Regenerative... Feb 2021Autologous platelet concentrates such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) have gained overwhelming popularity in regenerative endodontics.... (Review)
Review
BACKGROUND
Autologous platelet concentrates such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) have gained overwhelming popularity in regenerative endodontics. Clinical evidence reveals the lack of a particular advantage of using PRP or PRF over an evoked blood clot in promoting canal wall thickening and/or continued root development in immature necrotic teeth. Moreover, despite stimulating tissue repair and repopulating the root canals of immature and mature permanent teeth, the new vital tissue may not possess the functional activity of the native pulp tissue.
METHODS
To better understand the origin, nature, and long-term fate of the tissue types found within the pulp space, we critically examine all available histo-/morphological evidence for pulp-dentine complex regeneration using PRP and/or PRF, alone or together with an evoked blood clot, specialised or unspecialised primary cells, and other biomaterials.
RESULTS
Histological data from clinical studies is scant. Reportedly, the inner dentinal surface supports cementum-like tissue formation, but this interface likely deviates in structure and function from the native cementodentinal junction. Presence of bone-like tissue within the pulp space is intriguing since de novo osteogenesis requires closely coordinated recruitment and differentiation of osteoprogenitor cells. Compared to untreated necrotic teeth, an evoked blood clot (with/without PRF) improves fracture resistance. Tooth regeneration using PRF and dental bud cells is unreliable and the constituent neoformed tissues are poorly organised.
CONCLUSION
PRP/PRF fail to demonstrate a significant advantage over an induced blood clot, alone. The true nature of neoformed tissues remains poorly characterised while their response to subsequent insult/injury is unexplored.
Topics: Dentin; Platelet-Rich Fibrin; Platelet-Rich Plasma; Regenerative Endodontics; Wound Healing
PubMed: 33150561
DOI: 10.1007/s13770-020-00291-3 -
Journal of Dental Research Dec 2016Advanced glycation end-products (AGEs) are generated via nonenzymatic glycation of dentinal collagen, resulting in accumulation of AGEs in dentin tissue. Since...
Advanced glycation end-products (AGEs) are generated via nonenzymatic glycation of dentinal collagen, resulting in accumulation of AGEs in dentin tissue. Since accumulated AGEs cause crosslinking between amino acid polypeptides in the collagen molecule and modify mechanical properties of dentinal collagen, the authors assumed that there would be a significant interaction between the generation of AGEs and progression of caries in dentin. To confirm such an interaction, spectroscopic imaging analyses (i.e., nanosecond fluorescence lifetime imaging and second harmonic generation light imaging) were performed in addition to biochemical and electron microscopic analyses in the present study. Seven carious human teeth were fixed in paraformaldehyde and cut longitudinally into 1-mm sections using a low-speed diamond saw for the following analyses. In transmission electron microscopy (TEM) analysis, nondecalcified specimens were embedded in epoxy resin and sliced into thin sections for observation. For the immunohistochemical analysis, the specimens were paraffin embedded after decalcification for 2 wk and sectioned with a microtome. Resultant sections were stained with anti-AGE and anticollagen antibodies. The demineralized specimens were used for spectroscopic analyses without additional treatment. For Western blotting analysis, specimens were separated into carious and sound dentin. Each specimen was homogenized with a bead crusher and an ultrasonic homogenizer and then treated with hydrochloric acid. In carious dentin, the collagen fibers showed an amorphous structure in the TEM image, and the AGEs were localized in the areas of bacterial invasion in the immunostaining image. The total amount of AGEs in carious dentin was higher than in sound dentin in Western blotting. The ultrastructure of type I collagen and total amount of AGEs varied markedly in the dentinal caries region. The fluorescence lifetime was shorter in the carious area than that in the sound areas, indicating an increase of AGEs in the carious area. The increase of AGEs could influence the progression of dentinal caries.
Topics: Blotting, Western; Collagen; Cross-Linking Reagents; Dental Caries; Dentin; Disease Progression; Fluorescence; Glycation End Products, Advanced; Humans; Immunohistochemistry; In Vitro Techniques; Maillard Reaction; Microscopy, Electron
PubMed: 27523626
DOI: 10.1177/0022034516662246 -
Archives of Oral Biology Nov 2020To determine the rate of fluid flow through human dentine due to electroosmosis during iontophoresis of either 2 % lignocaine with epinephrine, Ringer's solution,...
OBJECTIVE
To determine the rate of fluid flow through human dentine due to electroosmosis during iontophoresis of either 2 % lignocaine with epinephrine, Ringer's solution, epinephrine, or distilled water.
DESIGN
Experiments were carried out on 24 intact extracted human premolars. Dentine was exposed at the tip of the buccal cusp. The cavity was filled with one of the test solutions and the pulp cavity, with Ringer's solution at a pressure of 11 mm Hg. Fluid flow through the dentine was measured using a capillary connected to the pulp cavity. Current was passed between a stainless-steel electrode in the cavity and one in the pulp cavity. The results were analysed using repeated measures, three-way ANOVA, with Bonferroni pairwise comparisons where this showed a significant effect.
RESULTS
The current passed produced a significant flow of fluid through the dentine but neither the composition of the test solution nor etching had a significant effect on the flow. During iontophoresis of 2 % lignocaine with epinephrine for example, currents of 0.2, 0.4, and 0.6 mA applied with the cavity electrode as anode produced inward flow rates of 2.25 ± 0.87, 5.00 ± 1.62, 8.60 ± 1.97 (mean ± s.d.) nL/s/mm² respectively, and applying the currents in the opposite direction caused outward flows of 0.76 ± 0.72, 1.00 ± 1.01, 1.12 ± 1.18 nL/s/mm² respectively.
CONCLUSIONS
It is concluded that electroosmosis can be produced in human dentine, it can enhance the effect of iontophoresis in transporting charged molecules through dentine, particularly large molecules, and it could also enable uncharged molecules to be carried through dentine into the pulp.
Topics: Dentin; Electroosmosis; Epinephrine; Humans; In Vitro Techniques; Iontophoresis; Lidocaine
PubMed: 32905886
DOI: 10.1016/j.archoralbio.2020.104885 -
The Journal of Clinical Pediatric... 2016Study the topographic features of dentin after caries removal with a chemomechanical agent (Papacarie) compared with the conventional drilling method. (Comparative Study)
Comparative Study
AIM
Study the topographic features of dentin after caries removal with a chemomechanical agent (Papacarie) compared with the conventional drilling method.
STUDY DESIGN
The sample included 7 exfoliated and extracted primary teeth with carious dentin lesions, not reaching the pulp. Each tooth was sectioned longitudinally through the center of the carious lesions into two halves. The teeth were then divided into two groups according to the method of caries removal. Following caries removal, dentin topography and the cut section were examined using the scanning electron microscope.
RESULTS
Papacarie produced an irregular, porous, rough and globular dentin appearance. The dentin surfaces were generally free of smear layer, visible bacteria and the dentinal tubules were opened. The dentin cut surfaces showed patent dentinal tubules with open orifices. The drilling method created a smooth and amorphous surface with a continuous smear layer occluding the dentinal tubules. Numerous bacteria were also observed. The cut dentin surfaces showed patent dentinal tubules with their orifices plugged with smear layer.
CONCLUSIONS
Papacarie produced a rough and porous surface with partial or complete removal of the smear layer and opened dentinal tubules, while the drill produced a smooth surface with uniform smear layer occluding the dentinal tubules.
Topics: Bacteria; Collagen; Dental Caries; Dental Cavity Preparation; Dental High-Speed Equipment; Dentin; Humans; Microscopy, Electron, Scanning; Papain; Porosity; Smear Layer; Tooth, Deciduous
PubMed: 27805895
DOI: 10.17796/1053-4628-40.6.472 -
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 -
Dental Materials : Official Publication... Jan 2015To use the Kubelka-Munk theory to evaluate the scattering (S), absorption (K) and transmittance (T) of non-colored and colored dental zirconia systems and human (HD) and...
OBJECTIVES
To use the Kubelka-Munk theory to evaluate the scattering (S), absorption (K) and transmittance (T) of non-colored and colored dental zirconia systems and human (HD) and bovine (BD) dentins.
METHODS
Two zirconia systems were used: ZC- ZirCAD (Ivoclar Vivadent) and LV-LAVA (3M ESPE). Specimens from each ceramic system were divided into 3 groups (n=5): ZC1 and LV1 (non-colored); ZC2 and LV2 colored to shade A1, and ZC3 and LV3 colored to shade A3. Five human and bovine anterior teeth were flattened and polished through 1200 grit SiC paper to expose the superficial buccal dentin. All samples were prepared to a final thickness of 0.5 mm. Diffuse reflectance was measured against white and black backgrounds, using a spectroradiometer in a viewing booth with D65 illuminant and d/0° geometry. S and K coefficients and T were calculated using Kubelka-Munk's equations. Data was statistically analyzed using Kruskal-Wallis, Mann-Whitney tests, and VAF coefficient.
RESULTS
Spectral distributions of S, K and T were wavelength dependent. The spectral behavior of S and T was similar to HD (VAF≥96.80), even though they were statistically different (p≤0.05). The spectral behavior of K was also similar to HD, except for LV1 (VAF=38.62), yet all ceramics were statistically different from HD (p≤0.05). HD and BD showed similar values of S and T (p>0.05).
SIGNIFICANCE
The dental professional should consider the optical behavior differences between the zirconia systems evaluated and the human dentin to achieve optimal esthetics in restorative dentistry.
Topics: Animals; Cattle; Ceramics; Color; Dentin; Esthetics, Dental; Humans; Optics and Photonics; Scattering, Radiation; Zirconium
PubMed: 25499249
DOI: 10.1016/j.dental.2014.11.012 -
Ultrastructural Pathology May 2020To evaluate the sealing effects of different Chinese herbal medicines on dentinal tubules, and to provide a reference for the clinical treatment of dentin...
BACKGROUND AND OBJECTIVES
To evaluate the sealing effects of different Chinese herbal medicines on dentinal tubules, and to provide a reference for the clinical treatment of dentin hypersensitivity.
METHODS
Forty dentin slices prepared by freshly extracted bovine mandibular central incisors were randomly assigned to procyanidins, tannic acid, gallic acid, naringin, epigallocatechin gallate (EGCG), glycyrrhizic acid, paeonol, and blank groups. Dentin slices in each Chinese herbal medicine group were treated three times a day, each for 5 min, and then immersed in a remineralization solution for the rest of the time. Dentin slices in the blank group were directly immersed in the remineralization solution for 7 days. The dentinal tubule sealing effect was observed under the scanning electron microscope (SEM).
RESULTS
SEM results showed that the dentinal tubules were almost completely open in the blank group, which was mostly open in the gallic acid, EGCG, glycyrrhizic acid, and paeonol groups, and were sealed in procyanidins, tannic acid, and naringin groups. Significant differences were detected in mean area, mean diameter of dentinal tubules, and mean plugging rate of dentinal tubules between the remaining Chinese herbal medicine groups and blank group ( < .05). Among them, the dentinal tubule sealing effect of procyanidins, tannic acid, and naringin was obvious.
CONCLUSION
The findings suggested that procyanidins, tannic acid, and naringin can effectively seal dentinal tubules, which provided a basis for clinical treatment of dentin hypersensitivity.
Topics: Animals; Cattle; Dentin; Drugs, Chinese Herbal; Microscopy, Electron, Scanning
PubMed: 32241201
DOI: 10.1080/01913123.2020.1749198 -
Acta Histochemica Feb 2018Matrix metalloproteinases (MMPs) such as gelatinases are differentially expressed in human tissues. These enzymes cleave specific substrates involved in cell signaling,...
Matrix metalloproteinases (MMPs) such as gelatinases are differentially expressed in human tissues. These enzymes cleave specific substrates involved in cell signaling, tissue development and remodeling and tissue breakdown. Recent evidences show that gelatinases are crucial for normal dentin development and their activity is maintained throughout the entire tooth function in the oral cavity. Due to the lack of information about the exact location and activity of gelatinases in mature human dentin, the present study was designed to examine gelatinolytic levels in sound dentin. In situ zymography using confocal microscopy was performed on both mineralized and demineralized dentin samples. Sites presenting gelatinase activity were identified throughout the entire biological tissue pursuing different gelatinolytic levels for distinct areas: predentin and dentinal tubule regions presented higher gelatinolytic activity compared to intertubular dentin. Dentin regions with higher gelatinolytic activity immunohistochemically were partially correlated with MMP-2 expression. The maintenance of gelatinolytic activity in mature dentin may have biological implications related to biomineralization of predentin and tubular/peritubular dentinal regions, as well as regulation of defensive mechanisms of the dentin-pulp complex.
Topics: Adolescent; Dentin; Gelatinases; Humans; Immunohistochemistry; Microscopy, Confocal; Young Adult
PubMed: 29373132
DOI: 10.1016/j.acthis.2017.12.008 -
International Journal of Nanomedicine 2024This study was to investigate a novel antibacterial biomimetic mineralization strategy for exploring its potential application for root canal disinfection when...
OBJECTIVE
This study was to investigate a novel antibacterial biomimetic mineralization strategy for exploring its potential application for root canal disinfection when stabilized cerium oxide was used.
MATERIAL AND METHODS
A biomimetic mineralization solution (BMS) consisting of cerium nitrate and dextran was prepared. Single-layer collagen fibrils, collagen membranes, demineralized dentin, and root canal system were treated with the BMS for mineralization. The mineralized samples underwent comprehensive characterization using various techniques, including transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), selected-area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and micro-CT. Additionally, the antimicrobial properties of the BMS and the remineralized dentin were also analyzed with broth microdilution method, live/dead staining, and SEM.
RESULTS
Cerium ions in the BMS underwent a transformation into cerium oxide nanoparticles, which were deposited in the inter- and intra-fibrillar collagen spaces through a meticulous bottom-up process. XPS analysis disclosed the presence of both Ce (III) and Ce (IV) of the generated cerium oxides. A comprehensive examination utilizing SEM and micro-CT identified the presence of cerium oxide nanoparticles deposited within the dentinal tubules and lateral canals of the root canal system. The BMS and remineralized dentin exhibited substantial antibacterial efficacy against E. faecalis, as substantiated by assessments involving the broth dilution method and live/dead staining technique. The SEM findings revealed the cell morphological changes of deceased E. faecalis.
CONCLUSION
This study successfully demonstrated antibacterial biomimetic mineralization as well as sealing dentinal tubules and lateral branches of root canals using cerium nitrate and dextran. This novel biomimetic mineralization could be used as an alternative strategy for root canal disinfection.
Topics: Dental Pulp Cavity; Dentin; Disinfection; Dextrans; Cerium; Microscopy, Electron, Scanning; Collagen; Anti-Bacterial Agents
PubMed: 38179219
DOI: 10.2147/IJN.S441060 -
Oral Health & Preventive Dentistry 2018To evaluate the efficacy of Clinpro XT in reducing dentin permeability and the stability of this effect after different acid challenges.
PURPOSE
To evaluate the efficacy of Clinpro XT in reducing dentin permeability and the stability of this effect after different acid challenges.
MATERIALS AND METHODS
Sixty-five roots of extracted human third molars were used. From each tooth, one dentin specimen was prepared and connected to a fluid filtration system to measure the dentin permeability after each of the following steps: sample preparation; treatment with 37% phosphoric acid; application of Clinpro XT; three acid challenges. Specimens were randomly assigned to 5 groups (n = 13) according to the acidic solution applied: Coca-Cola, natural lemon juice, wine vinegar, white wine and Red Bull energy drink. An additional 10 third molars were used to evaluate the degree of occlusion of the dentinal tubules and the surface roughness.
RESULTS
Clinpro XT statistically significantly reduced dentin permeability after just a single application. No statistically significant increase in dentin permeability could be detected after three consecutive challenges. The application of Clinpro XT promotes the occlusion of dentinal tubules and reduces the surface roughness.
CONCLUSION
The Clinpro XT is effective in reducing dentin permeability. This effect persists even after acid challenges.
Topics: Acids; Beverages; Composite Resins; Dentin; Dentin Permeability; Humans; Microscopy, Electron, Scanning; Pit and Fissure Sealants; Tooth Erosion
PubMed: 30175331
DOI: 10.3290/j.ohpd.a40956