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Dental Materials : Official Publication... Jul 2019This study introduced the potential and proof-of-concept of high intensity focused ultrasound (HIFU) technology for dentin-surface treatment for resin-dentin bonding...
OBJECTIVE
This study introduced the potential and proof-of-concept of high intensity focused ultrasound (HIFU) technology for dentin-surface treatment for resin-dentin bonding without acid-aided demineralization. This new strategy could provide a way to enhance interface-integrity and bond-durability by changing the nature of dentin-substrate; bonded-interface structure and properties; and minimizing denuded-collagen exposure.
METHODS
The interaction between HIFU waves and dentin-surface in terms of structural, mechanical and chemical variations were investigated by SEM, TEM, AFM, nano-indentation and Raman-analysis. The bonding between HIFU-treated dentin and two-step, etch-and-rinse, adhesive was preliminary explored by characterizing dentin-bound proteases activities, resin-dentin interfacial morphology and bond-durability with HIFU exposure at different time-points of 60, 90 and 120 s compared to conventional acid-etching technique.
RESULTS
With the increase in HIFU exposure-time from 60-to-120 s, HIFU waves were able to remove the smear-layer, expose dentinal-tubules and creating textured/rough dentin surface. In addition, dentin surfaces showed a pattern of interlocking ribbon-like minerals-coated collagen-fibrils protruding from the underlaying amorphous dentin-background with HIFU exposure for 90 s and 120 s. This characteristic pattern of dentin-surface showing inorganic-minerals associated/aligned with collagen-fibrils, with 90-to-120 s HIFU-treatment, was confirmed by the Raman-analysis. HIFU-treated specimens showed higher nano-indentation properties and lower concentrations of active MMP-2 and Cathepsin-K compared to the acid-etched specimens. The resin-dentin bonded interface revealed the partial/complete absence of the characteristic hybrid-layer formed with conventional etch-and-rinse bonding strategy. Additionally, resin-infiltration and resin-tags formation were enhanced with the increase in HIFU exposure-time to 120 s. Although, all groups showed significant decrease in bond-strength after 12 months compared to 24 h storage in artificial saliva, groups exposed to HIFU for 90 s and 120 s showed significantly higher μTBS compared to the control acid-etched group.
SIGNIFICANCE
The implementation of HIFU-technology for dental hard-tissues treatment could be of potential significance in adhesive/restorative dentistry owing to its ability of controlled, selective and localised combined tissue alteration/ablation effects.
Topics: Acid Etching, Dental; Dental Bonding; Dentin; Dentin-Bonding Agents; Materials Testing; Microscopy, Electron, Scanning; Resin Cements; Surface Properties; Tensile Strength
PubMed: 31003759
DOI: 10.1016/j.dental.2019.04.001 -
Dental Traumatology : Official... Aug 2014To analyze the expression and distribution of Small Integrin-Binding LIgand N-linked Glycoproteins (SIBLINGs) in reparative dentin (RepD).
AIM
To analyze the expression and distribution of Small Integrin-Binding LIgand N-linked Glycoproteins (SIBLINGs) in reparative dentin (RepD).
METHODOLOGY
Cavities on the mesial surfaces of rat molars were prepared to expose the pulp, and a calcium hydroxide agent was applied to cap the exposed pulp. The molars with pulp capping were extracted at postoperative 1, 2, and 4 weeks. The immunolocalization of four SIBLINGs, dentin matrix protein 1 (DMP1), dentin sialoprotein (DSP), bone sialoprotein (BSP), and osteopontin (OPN) in RepD, was analyzed in comparison with reactionary dentin (ReaD) and primary dentin (PD).
RESULTS
At two weeks after operation, the region of the exposed pulp formed a layer of reparative dentin bridge sealing the communication between the cavity and pulp chamber. Dentinal tubules in RepD were more irregular in shape and fewer in number than PD. At postoperative 2 and 4 weeks, RepD had lower levels of DMP1 and DSP than PD. BSP and OPN were present in RepD, but not in PD. RepD showed certain similarities to ReaD in the expression of SIBLINGs.
CONCLUSIONS
The reduced levels of DMP1 and DSP may be associated with the decreased number of dentinal tubules in RepD. The expression of BSP and OPN in RepD indicates that the odontoblast-like cells were attempting to produce a hard tissue at a very rapid pace. These findings suggest that in response to the surgical injury, the newly differentiated odontoblast-like cells altered their synthesis of the dentinogenesis-related proteins and produced a hard tissue that is an intermediate between dentin and bone.
Topics: Animals; Dentin; Glycoproteins; Immunohistochemistry; Integrins; Ligands; Molar; Rats; Rats, Wistar
PubMed: 24502800
DOI: 10.1111/edt.12093 -
Journal of Dental Research Jul 2013The aim of this study was to investigate the diffusion dynamics of 25% hydrogen peroxide (H2O2) through enamel-dentin layers and to correlate it with dentin's structural...
The aim of this study was to investigate the diffusion dynamics of 25% hydrogen peroxide (H2O2) through enamel-dentin layers and to correlate it with dentin's structural alterations. Micro-Raman Spectroscopy (MRS) and Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) were used to measure the spectra of specimens before and during the bleaching procedure. H2O2 was applied to the outer surface of human enamel specimens for 60 minutes. MRS measurements were performed on the inner surface of enamel or on the subsurface dentin. In addition, H2O2 diffusion dynamics from outer enamel to dentin, passing through the dentin-enamel junction (DEJ) was obtained with Raman transverse scans. FTIR-PAS spectra were collected on the outer dentin. MRS findings revealed that H2O2 (O-O stretching µ-Raman band) crossed enamel, had a more marked concentration at DEJ, and accumulated in dentin. FTIR-PAS analysis showed that H2O2 modified dentin's organic compounds, observed by the decrease in amides I, II, and III absorption band intensities. In conclusion, H2O2 penetration was demonstrated to be not merely a physical passage through enamel interprismatic spaces into the dentinal tubules. H2O2 diffusion dynamics presented a concentration gradient determined by the chemical affinity of the H2O2 with each specific dental tissue.
Topics: Adolescent; Adult; Amides; Biochemical Phenomena; Carbon; Child; Color; Dental Enamel; Dentin; Diffusion; Humans; Hydrogen; Hydrogen Peroxide; Microspectrophotometry; Oxygen; Photoacoustic Techniques; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Time Factors; Tooth Bleaching Agents; Young Adult
PubMed: 23632810
DOI: 10.1177/0022034513488893 -
Journal of Dentistry May 2015Understanding morphological changes and mineral content of tooth hard tissues may influence dental treatment. In this study, the effect of Type 1 Diabetes Mellitus...
OBJECTIVES
Understanding morphological changes and mineral content of tooth hard tissues may influence dental treatment. In this study, the effect of Type 1 Diabetes Mellitus (T1DM) on tooth structure was examined.
METHODS
Experimental T1DM was induced in 3-week old male Wistar rats (n=10) by a single dose of 60mg/kg body weight of Streprozotocin. All rats were injected with calcein twice during the experiment and sacrificed at the age of 7 weeks old. Micro-computed tomography (micro-CT) was used to determine the mineral density and thickness of enamel and dentine. Also, a histomorphometery study was conducted to detect the rates of dentine mineral apposition and formation. The examined area was in the crown analogue of the rat mandibular incisor parallel to the long axis of the mesial surface of the first molar. All results were compared using Students' t-test (p<0.05).
RESULTS
Results showed that the enamel and dentine thickness were significantly reduced (hypoplasia) and there was a significant reduction of the rate of dentine mineral apposition and formation, while there was no significant effect of the T1DM condition on the mineral density of enamel and dentine.
CONCLUSIONS
T1DM has a detrimental influence on the formation of enamel and dentine in the early growth stage.
CLINICAL SIGNIFICANCE
T1DM condition may alter treatment planning of orthodontic treatment as it is associated with decreased enamel and dentin thickness that may affect teeth size and their resistance to caries.
Topics: Animals; Dental Enamel; Dentin; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Fluoresceins; Incisor; Male; Mandible; Molar; Random Allocation; Rats; Rats, Wistar; Tooth Calcification; Tooth Crown; Tooth Root; X-Ray Microtomography
PubMed: 25681642
DOI: 10.1016/j.jdent.2015.01.005 -
Journal of Oral Pathology & Medicine :... May 2010The present study was designed to study the effect of beta-aminopropionitrile (beta-APN), present in Lathyrus sativus grass pea consumed in drought prone areas, on...
BACKGROUND
The present study was designed to study the effect of beta-aminopropionitrile (beta-APN), present in Lathyrus sativus grass pea consumed in drought prone areas, on dentin of the continuously erupting rat incisors.
METHODS
Eighteen adult male rats were used. In the experimental group (18 rats), lathyrism was induced by a once daily subcutaneous administration of beta-APN for 40 days. The maxillary and mandibular incisors were examined ultrastructurally and morphometrically.
RESULTS
The mean number of patent tubules, the mean area, perimeter and the area percent of the tubules were analyzed. Ultrastructurally, the dentinal tubules of both coronal and radicular dentin in the lathyritic group were narrower or even obliterated compared with those in the control. The coronal and radicular dentin of the lathyritic group exhibited an irregular lattice of non-mineralized small branching collagen fibrils obliterating the dentinal tubules. The mean number of patent tubules in the control and lathyritic groups revealed an insignificant difference. The mean area of the tubules showed a statistically significant difference in lathyritic radicular dentin (P = 0.0353). The percentage of the total surface area of the dentinal tubules significantly decreased in the radicular dentin of the lathyritic group (P = 0.024).
CONCLUSIONS
These findings indicated a deleterious effect of lathyrism on dentin, with a possible negative impact on developing teeth integrity.
Topics: Aminopropionitrile; Animals; Collagen; Dentin; Dentin Dysplasia; Dentinogenesis; Injections, Subcutaneous; Lathyrism; Male; Microscopy, Electron, Scanning; Rats
PubMed: 20202086
DOI: 10.1111/j.1600-0714.2009.00877.x -
Dental Materials : Official Publication... Oct 2013The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin-dentin bond durability, as well as potential functional mechanisms behind the...
OBJECTIVE
The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin-dentin bond durability, as well as potential functional mechanisms behind the effect.
METHODS
Microtensile bond strength (μTBS) was evaluated in extracted human teeth in two separate experiments. Dentin specimens were acid-etched and assigned to pre-treatment with 0.5mM (0.004%) DMSO as additional primer for 30s and to controls with water pre-treatment. Two-step etch-and-rinse adhesive (Scotchbond 1XT, 3M ESPE) was applied and resin composite build-ups were created. Specimens were immediately tested for μTBS or stored in artificial saliva for 6 and 12 months prior to testing. Additional immediate and 6-month specimens were examined for interfacial nanoleakage analysis under SEM. Matrix metalloproteinase (MMP) inhibition by DMSO was examined with gelatin zymography. Demineralized dentin disks were incubated in 100% DMSO to observe the optical clearing effect.
RESULTS
The use of 0.5mM DMSO had no effect on immediate bond strength or nanoleakage. In controls, μTBS decreased significantly after storage, but increased significantly in DMSO-treated group. The control group had significantly lower μTBS than DMSO-group after 6 and 12 months. DMSO also eliminated the increase in nanoleakage seen in controls. 5% and higher DMSO concentrations significantly inhibited the gelatinases. DMSO induced optical clearing effect demonstrating collagen dissociation.
SIGNIFICANCE
DMSO as a solvent may be useful in improving the preservation of long-term dentin-adhesive bond strength. The effect may relate to dentinal enzyme inhibition or improved wetting of collagen by adhesives. The collagen dissociation required much higher DMSO concentrations than the 0.5mM DMSO used for bonding.
Topics: Dental Cements; Dentin; Dimethyl Sulfoxide; Materials Testing; Nanotechnology
PubMed: 23942144
DOI: 10.1016/j.dental.2013.07.014 -
Microscopy Research and Technique Oct 2013The aim of this study was to evaluate the effect of final irrigation protocols (17% EDTA, BioPure MTAD, SmearClear, and QMiX) on microhardness and erosion of root canal...
The aim of this study was to evaluate the effect of final irrigation protocols (17% EDTA, BioPure MTAD, SmearClear, and QMiX) on microhardness and erosion of root canal dentin. Fifty roots were sectioned transversely at the cement-enamel junction and each root was sectioned horizontally into 4-mm-thick slices. The samples were divided into five groups (n = 10) according to the final irrigation protocol: G1: distilled water (control group); G2: 17% EDTA; G3: BioPure MTAD; G4: SmearClear; and G5: QMiX. The dentin microhardness was then measured with a load of 25 g for 10 s. Initially, the reference microhardness values were obtained for the samples without any etching. The same samples were then submitted to the final irrigation protocols. A new measure was realized and the difference between before and after the procedures was the dentin microhardness reduction. In sequence, the specimens were submitted to SEM analysis to verify the dentinal erosion. The Kruskal Wallis and Dunn tests (α = 5%) were used to compare the results. The dentin microhardness decreased for all final irrigation protocols. There was no significant difference between groups 2, 3, 4, and 5 (P > 0.05), but this groups presented significant dentin microhardness reduction than G1 (P < 0.05). In G2, occurred the highest incidence of dentinal erosion (P < 0.05). 17% EDTA, BioPure MTAD, SmearClear, and QMiX promoted significant dentin microhardness reduction. Dentinal tubules erosion was promoted by 17% EDTA.
Topics: Cuspid; Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Surface Properties
PubMed: 23897860
DOI: 10.1002/jemt.22268 -
Archives of Oral Biology Oct 2017Enterococcus faecalis is a gram-positive facultative anaerobic bacterium, which is present in 30-89% of teeth with postendodontic treatment failures. E. faecalis is...
OBJECTIVE
Enterococcus faecalis is a gram-positive facultative anaerobic bacterium, which is present in 30-89% of teeth with postendodontic treatment failures. E. faecalis is capable of penetrating dentinal tubules and surviving as a monoculture after conventional endodontic therapy, indicating that it is resistant to commonly used endodontic disinfection protocols. Different E. faecalis strains have shown resistance to several antibiotics, and have been associated with both dental pathology and systemic infections. The aim of this study was to evaluate the efficacy of a genetically engineered bacteriophage to disinfect dentin infected with antibiotic resistant strains of E. faecalis.
METHODS
Extracted human dentin root segments were cemented into sealable two-chamber devices, fabricated from syringe needle caps to form in vitro infected-dentin models. The models were inoculated with an overnight suspension of either E. faecalis V583 (vancomycin resistant strain) or E. faecalis JH2-2 (fusidic acid and rifampin resistant, vancomycin sensitive strain). After 7days of incubation at 37°C, a suspension of a genetically engineered phage, ϕEf11/ϕFL1C(Δ36)P, was added to the root canal of each infected dentin segment, and the incubation was continued for an additional 72-h. Dentin was harvested from the walls of each root canal and assayed for the residual titer of E. faecalis cells.
RESULTS
The recovered E. faecalis titer was reduced by 18% for the JH2-2 infected models, and by 99% for the V583 infected models.
CONCLUSION
Treatment: of E. faecalis-infected dentin with bacteriophage ϕEf11/ϕFL1C(Δ36)P consistently resulted in a decrease in the residual bacterial population of both vancomycin-sensitive and resistant strains.
Topics: Anti-Bacterial Agents; Bacteriophages; Dental Pulp Cavity; Dentin; Drug Resistance, Microbial; Enterococcus faecalis; Genetic Engineering; Humans; In Vitro Techniques; Vancomycin Resistance
PubMed: 28646693
DOI: 10.1016/j.archoralbio.2017.06.005 -
Adhesion of 4-META/MMA-TBB resin to heated dentin: effects of pre-treatments with FeCl3 and/or HEMA.Dental Materials Journal Mar 2003The purpose of this study was to compare the tensile bond strengths (TBSs) and failure mode of 4-META/MMA-TBB resin to 60 degrees C-heated and unheated bovine dentin,... (Comparative Study)
Comparative Study
The purpose of this study was to compare the tensile bond strengths (TBSs) and failure mode of 4-META/MMA-TBB resin to 60 degrees C-heated and unheated bovine dentin, especially to investigate the influence of ferric chloride contained in citric acid pre-conditioning. In addition, the effect of HEMA priming for heated dentin was also evaluated. The TBSs to heated dentin were significantly lower than those to unheated dentin. Adhesive failures were observed in most specimens of the heated and HEMA-non primed group. HEMA application to heated dentin significantly increased the TBSs in each acid conditioning, which were also significantly higher than those of the unheated and ferric chloride-contained citric acid-conditioned group. It was clarified that heating dentin decreased the bond strength without HEMA priming even if the dentin surfaces were acid conditioned with 10-3, while HEMA priming after acid conditioning recovered the bond strength.
Topics: Acid Etching, Dental; Acrylic Resins; Adhesiveness; Adhesives; Animals; Boron Compounds; Cattle; Chlorides; Dental Bonding; Dental Restoration Failure; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Ferric Compounds; Hot Temperature; In Vitro Techniques; Materials Testing; Methacrylates; Methylmethacrylates; Polyhydroxyethyl Methacrylate; Resin Cements; Tensile Strength
PubMed: 12790291
DOI: 10.4012/dmj.22.1 -
Journal of Dentistry Jan 2015Conventionally, caries excavation is performed until only hard dentine remains, while more selective and reliable criteria might be available. We aimed at systematically... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Conventionally, caries excavation is performed until only hard dentine remains, while more selective and reliable criteria might be available. We aimed at systematically comparing the effects of using different excavation criteria via network meta-analysis.
SOURCES
Electronic databases were searched for randomised or non-randomised clinical trials (RCTs/NRCTs) evaluating excavation of cavitated lesions.
DATA
Criteria were divided into six groups: Excavation until pulpo-proximal dentine on the cavity floor was (1) either hard on probing, (2) slightly softened on probing, (3) not stainable by caries-detector-dye, or until (4) self-limiting polymer burs, (5) fluorescence-assisted devices or (6) chemo-mechanical gels indicated termination of the excavation. Evaluation of risk of complications, risk of pain/discomfort, excavation time, and number of remaining bacteria were then undertaken using Bayesian network meta-analysis.
STUDY SELECTION
28 studies (19 RCTs, 9 NRCTs) with 1782 patients (2555 lesions), most of them investigating primary teeth, were included. Risk of complications was highest when excavating until only non-stainable dentine remained, and lowest when not attempting to remove all softened dentine. Risk of pain significantly decreased if self-limiting chemo-mechanical excavation or fluorescence-assisted lasers were used instead of excavating until all dentine was hard. When not attempting to remove all softened dentine, the time required for excavation was shortest, whilst the greatest number bacteria remained.
CONCLUSIONS
Not attempting to remove all softened or stainable dentine might reduce the risk of complications. Data regarding self-limiting excavation is insufficient for definitive conclusions. Excavation criteria should be validated against clinically relevant outcomes.
CLINICAL SIGNIFICANCE
Given current evidence, dentists might not need to attempt excavation until only hard dentin remains in proximity to the pulp. Instead, their choice of excavation criterion or method should be guided by clinical requirements and outcomes.
Topics: Bayes Theorem; Clinical Trials as Topic; Dental Care; Dental Cavity Preparation; Dental Pulp Cavity; Dentin; Humans; Network Meta-Analysis; Pain; Tooth, Deciduous
PubMed: 25456612
DOI: 10.1016/j.jdent.2014.10.004