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Brazilian Dental Journal 2017This study evaluated the effect of dentin biomodification on the bond strength (BS) and sealing ability (SA) of HEMA-free and multi-mode adhesives after 24 h and 6...
This study evaluated the effect of dentin biomodification on the bond strength (BS) and sealing ability (SA) of HEMA-free and multi-mode adhesives after 24 h and 6 months of water storage. Four adhesives were tested: two multi-mode (Scotchbond Universal - SU, and Prime & Bond Elect - PB) and two HEMA-free (All-Bond 3 - AB, and G-Aenial - GA). Human third molars were selected and dentin was treated with two cross-linking agents (5% glutaraldehyde and 6.5% proanthocyanidin-rich grape seed extract - PACs) for 10 min or kept untreated (control group) (n=6). Teeth were sectioned and prepared for BS test and SA analysis. The SA measurements were taken with the presence of smear layer (minimum permeability), EDTA treatment (maximum permeability), PACs application, adhesive application and after 6 months of water storage. BS data were analyzed by Proc Mixed and Tukey-Kramer test (α=5%). PACs application increased the BS for all adhesives tested at 24 h. However, BS decreased for SU and AB after six months. In general, multi-mode adhesives (SU and PB) did not differ from AB HEMA-free. GA presented the lowest BS values at both times of evaluation. Dentin permeability was reduced after PACs application and remained the same after 6 months, regardless adhesive application. PACs can increase the BS regardless the type of adhesive, however only for PB and GA the BS kept stable after 6-months of water storage. PACs was able to seal the dentin as the minimum permeability and also remained stable after 6 months.
Topics: Dental Cements; Dentin; Humans; Permeability
PubMed: 29211130
DOI: 10.1590/0103-6440201701522 -
Journal of Oral Rehabilitation Oct 2016One of the greatest challenges to modern dentistry is the progressive destruction of tooth material due to chemical erosion. Dental erosion is the loss of dental hard... (Review)
Review
One of the greatest challenges to modern dentistry is the progressive destruction of tooth material due to chemical erosion. Dental erosion is the loss of dental hard tissue, without the action of bacteria, in which demineralisation of enamel and dentine results due to a decrease in intra-oral pH. The aim of this review was to appraise the scientific literature on the factors that can affect intra-oral pH. The review will examine (i) the protective role of human saliva, in terms of its mineral composition, flow rates and buffering systems and (ii) sources of in-mouth acids such as extrinsic acids, which are derived from the diet and environment, as well as intrinsic acids, which are related to disorders of the gastro-oesophageal tract. This review may assist clinicians to identify the risk factors for tooth wear and to recommend adequate preventive measures to patients.
Topics: Dental Enamel; Dentin; Dentin Sensitivity; Diet; Humans; Hydrogen-Ion Concentration; Saliva; Tooth Erosion
PubMed: 27573678
DOI: 10.1111/joor.12429 -
Dental Materials : Official Publication... Aug 2017Infiltration of adhesive on dentin matrix depends on interaction of surface and adhesive. Interaction depends on dentin wettability, which can be enhanced either by...
OBJECTIVES
Infiltration of adhesive on dentin matrix depends on interaction of surface and adhesive. Interaction depends on dentin wettability, which can be enhanced either by increasing dentin surface energy or lowering the surface energy of adhesive. The objective was to examine the effect of dimethyl sulfoxide (DMSO) on demineralized dentin wettability and dentin organic matrix expansion.
METHODS
Acid-etched human dentin was used for sessile drop contact angle measurement to test surface wetting on 1-5% DMSO-treated demineralized dentin surface, and linear variable differential transformer (LVDT) to measure expansion/shrinkage of dentinal matrix. DMSO-water binary liquids were examined for surface tension changes through concentrations from 0 to 100% DMSO. Kruskal-Wallis and Mann-Whitney tests were used to test the differences in dentin wettability, expansion and shrinkage, and Spearman test to test the correlation between DMSO concentration and water surface tension. The level of significance was p<0.05.
RESULTS
Pretreatment with 1-5% DMSO caused statistically significant concentration-dependent increase in wetting: the immediate contact angles decreased by 11.8% and 46.6% and 60s contact angles by 9.5% and 47.4% with 1% and 5% DMSO, respectively. DMSO-water mixtures concentration-dependently expanded demineralized dentin samples less than pure water, except with high (≥80%) DMSO concentrations which expanded demineralized dentin more than water. Drying times of LVDT samples increased significantly with the use of DMSO.
SIGNIFICANCE
Increased dentin wettability may explain the previously demonstrated increase in adhesive penetration with DMSO-treated dentin, and together with the expansion of collagen matrix after drying may also explain previously observed increase in dentin adhesive bonding.
Topics: Collagen; Dental Bonding; Dental Cements; Dentin; Dentin-Bonding Agents; Dimethyl Sulfoxide; Humans; Surface Properties
PubMed: 28610709
DOI: 10.1016/j.dental.2017.04.018 -
Journal of Dental Research Apr 2017Oligomeric proanthocyanidins (OPACs) are potent and renewable natural bioactives possible to be refined into chemically standardized mixtures for biological...
Oligomeric proanthocyanidins (OPACs) are potent and renewable natural bioactives possible to be refined into chemically standardized mixtures for biological applications. Herein, we found that multiscale interactions of OPACs with the dentin matrix create tight biointerfaces with hydrophobic methacrylate adhesives on wet surfaces. An enriched mixture of OPACs, with a known phytochemical profile, was produced from grape seed crude extract ( Vitis vinifera; enriched grape seed extract [e-GSE]) and applied to dentin matrices to determine changes to the mechanical properties and biodegradability of the dentin matrix and favorable resin adhesion mechanisms. Methods included a 3-point flexural test, quantification of hydroxyproline (collagen solubilization), static and dynamic nanomechanical analyses, resin-dentin microtensile bond strength, and micropermeability at the adhesive interface. The e-GSE-modified dentin matrix exhibited remarkably low collagen solubilization and sustained the bulk elastic properties over 12 mo. Tan δ findings reveal a more elastic-like behavior of the e-GSE-modified dentin matrix, which was not affected by H-bond destabilization by urea. Dentin-methacrylate biointerfaces with robust and stable adhesion were created on e-GSE-primed dentin surfaces, leading to a dramatic decrease of the interfacial permeability. Standardized OPAC mixtures provide a new mechanism of adhesion to type I collagen-rich tissues that does not rely on hydrophilic monomers. The bioadhesion mechanism involves physicochemical modifications to the dentin matrix, reduced tissue biodegradation, and bridging to methacrylate resins.
Topics: Collagen; Cross-Linking Reagents; Dental Bonding; Dentin; Dentin-Bonding Agents; Elasticity; Grape Seed Extract; Humans; Materials Testing; Methacrylates; Molar; Proanthocyanidins; Surface Properties; Tensile Strength; Vitis
PubMed: 27927886
DOI: 10.1177/0022034516680586 -
Dental Materials : Official Publication... Jan 2022This study investigated the chemical and structural changes in the mineral phase and collagen of dentin during application of a mild universal adhesive. Particular...
OBJECTIVE
This study investigated the chemical and structural changes in the mineral phase and collagen of dentin during application of a mild universal adhesive. Particular attention was paid to the role of isopropanol and changes in water molecules.
METHODS
In vitro application of the mild universal adhesive on dentin with two established etching modes (self-etch and etch-and-rinse) was studied using solid state nuclear magnetic resonance spectroscopy.
RESULTS
It was evidenced that the etch-and-rinse mode leads to a decrease of the inorganic apatite and a reorganization of the residual mineral phase with a low amount of adhesive phosphate monoesters calcium salt formed, compared to the self-etch mode. In contrast, the adhesive interacts very similarly to the level of dentin collagen in both protocols, with a strong decrease in the amount of the free water molecules induced by the presence of isopropanol as the adhesive solvent, but without significant changes in the initial collagen structure. For both modes, the adhesive acrylates monomers remain mobile and can infiltrate the collagen.
SIGNIFICANCE
Understanding the molecular interactions between dentin and adhesive solutions is a major challenge for designing products that lead to the formation of ideal dentin resin hybrid layer. Notably, one point considered essential is the presence of unbound water which, over time, is associated with a hydrolytic degradation of the organic matrix. Isopropanol, as an adhesive solvent, leads to a decrease in the amount of the less stable water molecules while the water molecules strongly attached to the collagen are retained, thus preserving the collagen structure.
Topics: 2-Propanol; Dental Bonding; Dental Cements; Dentin; Dentin-Bonding Agents; Magnetic Resonance Spectroscopy; Materials Testing; Resin Cements; Solvents; Tensile Strength
PubMed: 34736760
DOI: 10.1016/j.dental.2021.10.001 -
The Journal of Adhesive Dentistry Nov 2022To evaluate the microtensile bond strength (μTBS) and silver nitrate uptake (SNU) of three universal adhesives used in etch-and-rinse (ER) and self-etch (SE) modes on...
PURPOSE
To evaluate the microtensile bond strength (μTBS) and silver nitrate uptake (SNU) of three universal adhesives used in etch-and-rinse (ER) and self-etch (SE) modes on dry, wet, and oversaturated dentin surfaces after 24 h and 1 year of water storage. The morphology of the hybrid layer (MHL) and the degree of conversion (DC) were also evaluated.
MATERIALS AND METHODS
Human molars were divided into 36 groups according to combinations of the following variables: (i) universal adhesives (Ambar Universal APS [AMB], Prime&Bond Active [PBA], Scotchbond Universal Adhesive [SBU]), (ii) adhesive strategies (ER or SE), (iii) moisture level (dry, wet, or oversaturated dentin surface), and (iv) storage time (24 h or 1 year). After restoration, the specimens were sectioned into resin-dentin sticks and tested for μTBS and SNU according to storage time. For MHL, the specimens were sectioned and evaluated after 24 h using SEM. DC was evaluated using FTIR. ANOVA and Tukey's test were used for statistical analyses (5%).
RESULTS
When 24-h vs 1-year data were compared, there was a significant decrease in μTBS and an increase in SNU values for the majority of experimental groups (p < 0.0001). On dry (ER) and oversaturated (ER and SE) dentin, AMB showed higher μTBS than did PBA (p < 0.00001). No significant decrease in μTBS was observed when universal adhesives were applied in the SE mode to dry dentin (p > 0.05). Regarding SNU, at all moisture levels, AMB showed lower SNU values than SBU (p < 0.001). Regarding MHL, SBU showed several imperfections when applied to oversaturated dentin in comparison with AMB and PBA. Regarding DC, when dentin was kept dry or was oversaturated, AMB showed a higher DC than PBA (p < 0.0001).
CONCLUSION
The behavior of the different universal adhesives evaluated did not vary when applied to wet or dry dentin. However, the results with oversaturated dentin were dependent on the universal adhesive. Independent of the moisture level and the universal adhesive evaluated, significant degradation of the bonding properties occurred after 1 year of water storage, with the exception of universal adhesives applied to dry dentin in the SE strategy.
Topics: Humans; Dentin-Bonding Agents; Dental Bonding; Composite Resins; Dental Cements; Dentin; Dental Leakage; Tensile Strength; Materials Testing; Resin Cements; Water; Adhesives
PubMed: 36346400
DOI: 10.3290/j.jad.b3559027 -
Journal of Endodontics Jan 2020This study aims to develop and characterize the regenerative potential of an atelopeptidized treated dentin matrix xenograft using in vitro and in vivo models.
INTRODUCTION
This study aims to develop and characterize the regenerative potential of an atelopeptidized treated dentin matrix xenograft using in vitro and in vivo models.
METHODS
Freshly extracted bovine dentin was pulverized into 250- to 500-μm particles and demineralized with 17% EDTA for 1, 7, and 13 days. The samples were atelopeptidized with pepsin. The degree of demineralization and the effect of atelopeptidization were assessed using field emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy, respectively. The expression of dentin matrix acidic phosphoprotein 1, dentin sialophosphoprotein, and osteopontin was evaluated in dental pulp stem cells using quantitative real-time polymerase chain reaction. The samples were then implanted intramuscularly in rats for 30 days, and the inflammatory cells were quantified histologically.
RESULTS
Field emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy revealed an exposed tubular structure of dentin after 1 and 7 days of demineralization. Fourier transform infrared spectroscopy confirmed the absence of amide peaks at 1260 to 1640/cm after atelopeptidization. The dental pulp stem cell expression of dentin matrix acidic phosphoprotein 1 and dentin sialophosphoprotein increased in all compared with the untreated control group (P < .05). The maximum expression rates were observed for the 1-day demineralized and atelopeptidized group. The 1-day demineralized group elicited the highest inflammatory response compared with the 7- or 13-day demineralized groups (P < .001). Atelopeptidization significantly decreased the inflammatory response only in the 1-day demineralized dentin group (P < .05).
CONCLUSIONS
Atelopeptidization of 1-day demineralized dentin xenograft preserved the collagen structure, minimized the immune reaction, and provided sufficient regenerative potential.
Topics: Animals; Cattle; Dental Pulp; Dentin; Heterografts; Microscopy, Electron, Scanning; Peptides; Rats; Tissue Engineering
PubMed: 31759677
DOI: 10.1016/j.joen.2019.10.005 -
Clinical Oral Investigations Mar 2018The objective of this study was to evaluate the biomechanical properties of dentin and the microtensile bond strength (μTBS) performed before or after radiotherapy (RT).
OBJECTIVES
The objective of this study was to evaluate the biomechanical properties of dentin and the microtensile bond strength (μTBS) performed before or after radiotherapy (RT).
MATERIAL AND METHODS
Dentin chemical composition (infrared spectroscopy-FTIR), SEM images, and mechanical properties (Vickers microhardness-VHN and elastic modulus-E) were evaluated comparing no irradiated and irradiate dentin (n = 5). RT was defined by application of 72 Gy (1.8 Gy daily, 5 days per week, during 8 weeks) with sample immersed in distilled water. μTBS evaluated three groups (n = 10): NI-no irradiated; IB-irradiation before restoration; and IA-irradiation after restoration. Resin-dentin sticks (1.0 mm) were obtained and submitted to μTBS. Analysis of the bonding interface was made by confocal microscopy.
RESULTS
After RT, percentage ratio of FTIR analysis showed increased absorption for all bands. SEM image showed a disorganized dentin structure. Two-way ANOVA showed increased VHN (p = 0.005) and decreased E (p < 0.001). For μTBS, one-way ANOVA and Duncan test showed significant differences among groups (p = 0.018). IB group presented the lowest bond strength values.
CONCLUSIONS
RT alters the absorption bands and SEM images showed a disorganization of the dentin structure. Mechanical properties were changed with increased VHN and decreased E. μTBS was affected by the radiotherapy and restoration period (before or after).
CLINICAL RELEVANCE
RT causes changes that contribute to increased risk of tooth decay. Restorative treatments can be performed using adhesive procedures, but it is preferable to be performed before of the irradiation protocol, to guarantee better adhesive properties to restoration.
Topics: Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Elastic Modulus; Hardness Tests; Humans; In Vitro Techniques; Materials Testing; Microscopy, Confocal; Microscopy, Electron, Scanning; Molar, Third; Resin Cements; Spectrophotometry, Infrared; Surface Properties; Tensile Strength
PubMed: 28776096
DOI: 10.1007/s00784-017-2165-4 -
Stomatologiia 2023Dentinal fluid is very close in its physical and mechanical properties and composition to blood plasma, which makes it a potentially aggressive biological environment...
BACKGROUND
Dentinal fluid is very close in its physical and mechanical properties and composition to blood plasma, which makes it a potentially aggressive biological environment for modern adhesive systems. An in-depth study of the physiological processes of the functioning of tooth dentin remains relevant in order to solve problems associated with its artificial restoration.
PURPOSE OF THE STUDY
Study using computer simulation speed of movement and pressure distribution of dentinal fluid in the dentinal tubule of the tooth to assess the possibilities of their regulation.
MATERIAL AND METHODS
To model the distribution of flow velocity and pressure of dentinal fluid in the dentinal tubule, the finite element method (Fluent ANSYS computer program) was used.
RESULTS
Immediately behind the spherical tip of the odontoblast, there is a rapid increase in the hydraulic diameter of the flow section of the dentinal tubule, and, accordingly, a decrease in capillary pressure, while the tip of the odontoblast creates a large local hydraulic resistance. The resulting distribution of pressure drop in the damaged dentinal tubule is consistent with the fact that fluid movement is due, to a greater extent, to the capillary effect rather than the inlet pressure into the dentinal tubule.
CONCLUSION
By changing the length of the odontoblast process, it is possible to influence the parameters of the hydrodynamics of dentinal fluid in the space of the dentinal tubule.
Topics: Humans; Dentin; Dentinal Fluid; Computer Simulation; Hydrodynamics
PubMed: 38096387
DOI: 10.17116/stomat20231020625 -
Journal of Dental Research Jul 2023Water residue and replacement difficulty cause insufficient adhesive infiltration in demineralized dentin matrix (DDM), which produces a defective hybrid layer and thus...
Water residue and replacement difficulty cause insufficient adhesive infiltration in demineralized dentin matrix (DDM), which produces a defective hybrid layer and thus a bonding durability problem, severely plaguing adhesive dentistry for decades. In this study, we propose that the unique properties of a highly hydrated interface of the porous DDM can give rise to 1 new type of interface, confined liquid water, which accounts for most of the residue water and may be the main cause of insufficient infiltration. To prove our hypothesis, 3 metal ions with increasing binding affinity and complex stability (Na, Ca, and Cu) were introduced respectively to coordinate negatively charged groups such as -PO, -COO abundant in the DDM interface. Strong chelation of Ca and Cu rapidly released the confined water, significantly improving penetration of hydrophobic adhesive monomers, while Na had little effect. A significant decrease of defects in the hybrid layer and a much decreased modulus gap between the hybrid layer and the adhesive layer greatly optimized the microstructure and micromechanical properties of the tooth-resin bonding interface, thus improving the effectiveness and durability of dentin bonding substantially. This study paves the way for a solution to the core scientific issue of contemporary adhesive dentistry: water residue and replacement in dentin bonding, both theoretically and practically.
Topics: Water; Dental Bonding; Dentin-Bonding Agents; Resin Cements; Dentin; Materials Testing; Microscopy, Electron, Scanning; Surface Properties
PubMed: 37029657
DOI: 10.1177/00220345231161006