scholarly journals A Chemical Approach to Optimizing Bioactive Glass Dental Composites

2018 ◽  
Vol 98 (2) ◽  
pp. 194-199 ◽  
Author(s):  
S. Aponso ◽  
J.G. Ummadi ◽  
H. Davis ◽  
J. Ferracane ◽  
D. Koley
Keyword(s):  
Bioactive Glass ◽  
Metal Ion ◽  
Volume Fraction ◽  
Dimensional Space ◽  
Resin Composite ◽  
Artificial Saliva ◽  
Basal Medium ◽  
Dental Composites ◽  
Biofilm Growth ◽  
Chemical Microenvironment

The chemical microenvironment surrounding dental composites plays a crucial role in controlling the bacteria grown on these specialized surfaces. In this study, we report a scanning electrochemical microscopy (SECM)–based analytic technique to design and optimize metal ion-releasing bioactive glass (BAG) composites, which showed a significant reduction in biofilm growth. SECM allows positioning of the probe without touching the substrate while mapping the chemical parameters in 3-dimensional space above the substrate. Using SECM and a solid-state H+ and Ca2+ ion-selective microprobe, we determined that the local Ca2+ concentration released by different composites was 10 to 224 µM for a BAG particle size of <5 to 150 µm in the presence of artificial saliva at pH 4.5. The local pH was constant above the composites in the same saliva solution. The released amount of Ca2+ was determined to be maximal for particles <38 µm and a BAG volume fraction of 0.32. This optimized BAG-resin composite also showed significant inhibition of biofilm growth (24 ± 5 µm) in comparison with resin-only composites (53 ± 6 µm) after Streptococcus mutans bacteria were grown for 3 d in a basal medium mucin solution. Biofilm morphology and its subsequent volume, as determined by the SECM imaging technique, was (0.59 ± 0.38) × 107 µm3 for BAG-resin composites and (1.29 ± 0.53) × 107 µm3 for resin-only composites. This study thus lays the foundation for a new analytic technique for designing dental composites that are based on the chemical microenvironment created by biomaterials to which bacteria have been exposed.

scholarly journals Effects of Composites Containing Bioactive Glasses on Demineralized Dentin

2017 ◽  
Vol 96 (9) ◽  
pp. 999-1005 ◽  
Author(s):  
A. Tezvergil-Mutluay ◽  
R. Seseogullari-Dirihan ◽  
V.P. Feitosa ◽  
G. Cama ◽  
D.S. Brauer ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Direct Contact ◽  
Artificial Saliva ◽  
Dry Mass ◽  
Sem Analysis ◽  
Dental Composites ◽  
Bioactive Glasses ◽  
Beneficial Effects ◽  
Before And After ◽  
Demineralized Dentin

The aim of this study was to evaluate the degradation of completely demineralized dentin specimens in contact with a filler-free or 2 ion-releasing resins containing micrometer-sized particles of Bioglass 45S5 (BAG) or fluoride-containing phosphate-rich bioactive glass (BAG-F). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were also used to evaluate the remineralization induced by the experimental ion-releasing resin-based materials. Dentin beams were totally demineralized in H3PO4 (10%) and placed in direct contact with a filler-free (RESIN) or 2 experimental ion-releasing resins (BAG or BAG-F) and immersed in artificial saliva (AS) up to 30 d. Further specimens were also processed and submitted to FTIR and SEM analysis to evaluate the remineralization induced by such ion-releasing resins before and after AS immersion. BAG and BAG-F alkalinized the incubation media. A significant decrease of the dry mass was observed between the specimens of all groups stored for 3 and 30 d in AS. However, the fluoride-containing phosphate-rich bioactive glass incorporated into a resin-based material (BAG-F) showed greater ability in reducing the solubilization of C-terminal cross-linked telopeptide (ICTP) and C-terminal telopeptide (CTX) after prolonged AS storage. Moreover, after 30 d of AS storage, BAG-F showed the greatest remineralizing effect on the stiffness of the completely demineralized dentin matrices. In conclusion, fluoride-containing phosphate-rich bioactive glass incorporated as micrometer-sized filler in dental composites may offer greater beneficial effects than Bioglass 45S5 in reducing the enzyme-mediated degradation and remineralization of demineralized dentin.

scholarly journals Toughening and polymerization stress control in composites using thiourethane-treated fillers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana Paula Piovezan Fugolin ◽  
Ana Rosa Costa ◽  
Lourenco Correr-Sobrinho ◽  
R. Crystal Chaw ◽  
Steven Lewis ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Thermogravimetric Analysis ◽  
Laser Scanning ◽  
Volume Fraction ◽  
Filler Particle ◽  
Laser Scanning Microscopy ◽  
Dental Composites ◽  
Confocal Laser ◽  
Filler Surface ◽  
Silane Layer

AbstractFiller particle functionalization with thiourethane oligomers has been shown to increase fracture toughness and decrease polymerization stress in dental composites, though the mechanism is poorly understood. The aim of this study was to systematically characterize the effect of the type of filler surface functionalization on the physicochemical properties of experimental resin composites containing fillers of different size and volume fraction. Barium glass fillers (1, 3 and 10 µm) were functionalized with 2 wt% thiourethane-silane (TU-Sil) synthesized de novo and characterized by thermogravimetric analysis. Fillers treated with 3-(Trimethoxysilyl)propyl methacrylate (MA-Sil) and with no surface treatment (No-Sil) served as controls. Fillers (50, 60 and 70 wt%) were incorporated into BisGMA-UDMA-TEGDMA (5:3:2) containing camphorquinone/ethyl-4-dimethylaminobenzoate (0.2/0.8 wt%) and 0.2 wt% di-tert-butyl hydroxytoluene. The functionalized particles were characterized by thermogravimetric analysis and a representative group was tagged with methacrylated rhodamine B and analyzed by confocal laser scanning microscopy. Polymerization kinetics were assessed by near-IR spectroscopy. Polymerization stress was tested in a cantilever system, and fracture toughness was assessed with single edge-notched beams. Fracture surfaces were characterized by SEM. Data were analyzed with ANOVA/Tukey's test (α = 0.05). The grafting of thiourethane oligomer onto the surface of the filler particles led to reductions in polymerization stress ranging between 41 and 54%, without affecting the viscosity of the composite. Fracture toughness increased on average by 35% for composites with the experimental fillers compared with the traditional methacrylate-silanized groups. SEM and confocal analyses demonstrate that the coverage of the filler surface was not homogeneous and varied with the size of the filler. The average silane layer for the 1 µm particle functionalized with the thiourethane was 206 nm, much thicker than reported for traditional silanes. In summary, this study systematically characterized the silane layer and established structure–property relationships for methacrylate and thiourethane silane-containing materials. The results demonstrate that significant stress reductions and fracture toughness increases are obtained by judiciously tailoring the organic–inorganic interface in dental composites.

Effect of EPS on biofilm structure and function as revealed by an individual-based model of biofilm growth

2001 ◽  
Vol 43 (6) ◽  
pp. 135-135 ◽  
Author(s):  
J.-U. Kreft ◽  
J. W. Wimpenny
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Structure And Function ◽  
Individual Based Model ◽  
Biofilm Growth ◽  
Rate Dependent ◽  
Binding Forces ◽  
The Individual ◽  
And Function ◽  
Biofilm Structure

We have simulated a nitrifying biofilm with one ammonia and one nitrite oxidising species in order to elucidate the effect of various extracellular polymeric substance (EPS) production scenarios on biofilm structure and function. The individual-based model (IbM) BacSim simulates diffusion of all substrates on a two-dimensional lattice. Each bacterium is individually simulated as a sphere of given size in a continuous, three-dimensional space. EPS production kinetics was described by a growth rate dependent and an independent term (Luedeking-Piret equation). The structure of the biofilm was dramatically influenced by EPS production or capsule formation. EPS production decreased growth of producers and stimulated growth of non-producers because of the energy cost involved. For the same reason, EPS accumulation can fall as its rate of production increases. The patchiness and roughness of the biofilm decreased and the porosity increased due to EPS production. EPS density was maximal in the middle of the vertical profile. Introduction of binding forces between like cells increased clustering.

Commercial Dental Composite: Determination of Reaction Advancement and Study of the Migration of Organic Compounds

2005 ◽  
Vol 13 (3) ◽  
pp. 223-234
Author(s):  
C. Sanglar ◽  
M. Defay ◽  
H. Waton ◽  
A. Bonhomme ◽  
S. Alamercery ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Aqueous Media ◽  
Dental Composite ◽  
Dental Composites ◽  
Hydrophilic Monomer ◽  
Methacrylate Monomers ◽  
Urethane Dimethacrylate ◽  
Hydrolysis Of

This work on organic dental composites was undertaken to determine the role of residual reactive methacrylate functions at the end of the photopolymerization cycle, and to investigate the fate of the residual monomers and oligomers in organic (ethanol) and aqueous (water and artificial saliva) media. The results show that all the methacrylate monomers present in dentine migrate into ethanol (about 1% (w/w)). In aqueous media on the other hand, only the most hydrophilic monomer (UDMA) migrates (0.05% (w/w)) into water and 0.03% into artificial saliva (pH = 9). This desorption in the three media is accompanied by the hydrolysis of monomers, leading to the formation of monohydrolyzed urethane dimethacrylate (UDMA) and bis-phenyl glycidyl dimethacrylate (BISGMA); UDMA and BISGMA are completely hydrolyzed in artificial saliva. The alkalinity of the milieu apparently favours the hydrolysis of methacrylate functions.

Effect of Baicalein on Matrix Metalloproteinases and Durability of Resin-Dentin Bonding

2018 ◽  
Vol 43 (4) ◽  
pp. 426-436 ◽  
Author(s):  
J Li ◽  
B Chen ◽  
N Hong ◽  
S Wu ◽  
Y Li
Keyword(s):  
Matrix Metalloproteinases ◽  
Bonding Strength ◽  
Resin Composite ◽  
Artificial Saliva ◽  
Adhesive System ◽  
Inhibitory Effect ◽  
Dentin Bonding ◽  
Microtensile Testing ◽  
Etch And Rinse

SUMMARY Objective: In an attempt to increase resin-dentin bonding quality, this study used baicalein as a preconditioner in an etch-and-rinse adhesive to evaluate its effect on matrix metalloproteinases (MMPs) and adhesive durability. Methods: As a MMP inhibitor and potential collagen cross-linking agent, baicalein was used as a preconditioner in an etch-and-rinse adhesive system. The degree of conversion was evaluated by Fourier-transform infrared spectroscopy. EnzChek gelatinase/collagenase assay kits were then used to detect the MMP inhibitory effect of different concentrations of baicalein (0.1, 0.5, 2.5, and 5.0 μg/mL) on dentin powders. During in vitro bonding procedures, flat dentin surfaces on sound third molars were preconditioned with 2.5 μg/mL baicalein after being acid-etched; this step was followed by continuation of adhesive processes and build-up of resin composite. After resin-dentin stick preparation, bonding strength, failure mode, and interface nanoleakage were respectively evaluated via microtensile testing, stereomicroscopy, and field emission scanning electron microscopy either immediately or after storage in artificial saliva for three or six months. Data were analyzed by two-way analysis of variance and Tukey test (α=0.05). Results: Baicalein at a concentration of 0-5.0 μg/mL did not influence the conversion of adhesives. However, it inhibited the activities of dentin-bond gelatinase and collagenase, especially at a concentration of 2.5 μg/mL, while effectively increasing microtensile bonding strength and decreasing nanoleakage in vitro, both immediately and after aging. Conclusions: Baicalein used as preconditioner in an etch-and-rinse adhesive system has an anti-MMP function and effectively improves resin-dentin bonding durability in vitro, which has potential value in clinical bonding procedures.

scholarly journals Risedronate Effects on the In Vivo Bioactive Glass Behavior: Nuclear Magnetic Resonance and Histopathological Studies

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Siwar Mosbahi ◽  
Hassane Oudadesse ◽  
Claire Roiland ◽  
Bertrand Lefeuvre ◽  
Lotfi Slimani ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Bioactive Glass ◽  
Volume Fraction ◽  
Chemical Reactivity ◽  
Femoral Condyle ◽  
Mineral Density ◽  
Nuclear Magnetic

The present study aimed to enhance the anti-osteoporotic performance of bioactive glass (46S6) through its association with bisphosphonate such as risedronate with amounts of 8, 12, and 20%. Obtained composites have been called 46S6-8RIS, 46S6-12RIS, and 46S6-20RIS, respectively. In vitro and in vivo explorations have been carried out. Bioactive glass and risedronate association has been performed by adsorption process. Structure analyses have been carried out to evaluate and to understand their chemical interactions. Solid Nuclear Magnetic Resonance (NMR) has been employed to study the structural properties of obtained biocomposite. The spectra deconvolution showed the appearance of a species (Q4) in the biocomposites 46S6-8RIS, 46S6-12RIS, and 46S6-20RIS indicating their successful chemical association. In vitro experiments showed the enhancement of the chemical reactivity of the composites 46S6-xRIS compared to the pure bioactive glass. In fact, the silicon liberation after 30 days of immersion was 50 ppm for pure bioactive glass 46S6, and 41, 64, and 62 from 46S6-8RIS, 46S6-12RIS, and 46S6-20RIS, respectively. Based on the in vitro results, 46S6-8RIS was implanted in the femoral condyle of an ovariectomized rat and compared with implanted pure glass in the goal to highlight its anti-osteoporotic performance. After 60 days, implanted group with 46S6-8RIS showed the increase in bone mineral density (BMD with 10%) and bone volume fraction (BV/TV with 80%) and the decrease in trabecular separation (Tb/Sp with 74%) when compared to that of 46S6 group. These results are confirmed by the histopathological analyses, which showed the bone trabeculae reconnection after the 46S6-8RIS implantation. Chemical analyses showed the reduction in silicon (Si) and sodium (Na) ion concentrations, and the rise in calcium (Ca) and phosphorus (P) ion levels, which was explained by the dissolution of biocomposite matrix and the deposition of hydroxyapatite layer. Histomorphometric results highlighted the risedronate effect on the antiosteoporotic phenomenon. Obtained results showed good behavior with only 8% of introduced risedronate in the glass matrix.

scholarly journals Crystal growth on bioactive glass sputter-coated alumina in artificial saliva

2013 ◽  
Vol 32 (5) ◽  
pp. 775-780 ◽  
Author(s):  
Masahiro IIJIMA ◽  
Masanori HASHIMOTO ◽  
Naohisa KOHDA ◽  
Susumu NAKAGAKI ◽  
Takeshi MUGURUMA ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Bioactive Glass ◽  
Artificial Saliva

Hydrolytic Degradation of Dental Composites

2014 ◽  
Vol 614 ◽  
pp. 113-117 ◽  
Author(s):  
Codruta Sarosi ◽  
Aurora Antoniac ◽  
Cristina Prejmerean ◽  
Ovidiu Cristian Pastrav ◽  
Dan Patroi ◽  
...  
Keyword(s):  
Fourier Transforms ◽  
Artificial Saliva ◽  
Hydrolytic Degradation ◽  
Alcoholic Solution ◽  
Dental Composites ◽  
Infrared Analysis ◽  
Halogen Lamp ◽  
Distilled Water ◽  
Dental Restorations ◽  
Ft Ir

This study evaluated the hydrolytic degradation of two experimental (C1, C2) and two commercial composite (Tetric EvoCeram and Premise) prepared to be used in dental restorations. Two experimental composites and two commercial composites were undergoing hydrolytic degradation in three different medium: distilled water, artificial saliva and alcoholic solution (50/50). The samples were investigated immediately after polymerisation with halogen lamp Optilux 501 and after 33 days of immersion in all three medium, using Fourier transforms infrared analysis (FTIR). FT-IR spectra of samples from the same composite immersed in distilled water, artificial saliva and alcoholic solution, revealed mostly reducing the intensity of the characteristic peaks of Si-O-Si bond less Tetric composite immersed in artificial saliva, which peak intensity remains unchanged.

Time-dependent nanoindentation behavior of high elastic modulus dental resin composites

2010 ◽  
Vol 25 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Yijun Wang ◽  
Isabel K. Lloyd
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Resin Composite ◽  
Acrylic Resin ◽  
Resin Matrix ◽  
Resin Composites ◽  
Dental Resin ◽  
Elastic Plastic ◽  
High Elastic Modulus ◽  
Continuous Stiffness Measurement

Nanoindentation and the viscous-elastic–plastic (VEP) model developed by Oyen and Cook for lightly filled thermoplastic polymer composites were used to characterize the elastic modulus, hardness, and viscoelastic response of a new high elastic modulus dental resin composite. The VEP model was used because loading rate studies indicated a viscous component in the loading/unloading response of our highly filled, thermosetting acrylic resin composites. Increasing the volume fraction of our high modulus filler increased the elastic modulus and hardness and decreased the viscous response in our composites. Coupling the filler and resin matrix with a commercial coupling agent like Metaltite or MPTMS (3-methacryloxypropyltrimethoxysilane) that ionically bonds to the filler and covalently bonds to the matrix decreases the viscous response and increases the hardness of the composite. The coupling agents did not affect the elastic modulus. The ability of the VEP model to predict load–displacement trajectories and the correlation of the elastic modulus and hardness values determined from the VEP model with those from the direct continuous stiffness measurement mode nanoindentation measurements indicate that the VEP model can be extended to highly filled, thermosetting systems. This is valuable since the potential to predict elastic, plastic, and viscous contributions to behavior should be valuable in the design and understanding of future highly filled resin composite systems.

scholarly journals Effect of Toothbrushing-mouthrinse-cycling on Surface Roughness and Topography of Nanofilled, Microfilled, and Microhybrid Resin Composites

2014 ◽  
Vol 39 (5) ◽  
pp. 521-529 ◽  
Author(s):  
EM da Silva ◽  
CUF de Sá Rodrigues ◽  
DA Dias ◽  
S da Silva ◽  
CM Amaral ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Resin Composite ◽  
Artificial Saliva ◽  
Filler Particle ◽  
Three Dimensional ◽  
Resin Composites ◽  
Topographic Analysis ◽  
Before And After ◽  
Multifactor Analysis ◽  
Post Hoc

SUMMARY The purpose of this study was to evaluate the influence of toothbrushing-mouthrinse-cycling (TMC) on the surface roughness and topography of three resin composites with different filler particle systems (Z350, nanofilled [Nf]; Durafill, microfilled [Mf], and Empress Direct, microhybrid [Mh]). Twenty specimens of each resin composite (8.0 mm diameter and 2 mm height) were randomly divided into four groups (n=5) according to the mouthrinses: alcohol-free (Plax – P) and alcohol-containing (Listerine – L and Plax Fresh Mint – PM) and artificial saliva (control – AS). The specimens were submitted to TMC for nine weeks. A surface roughness tester and a three-dimensional profilometer were used to measure the roughness (Ra) and the topography (Sa) before and after TMC. The data were analyzed by multifactor analysis of variance and Tukey post hoc test (α=0.05). In all media, Mh presented greater roughness than Mf (p&lt;0.05). The highest value of roughness was presented by Mh immersed in L (p&lt;0.05). The lowest values of roughness were presented by Mf (p&lt;0.05). The three resin composites presented the highest roughness after immersion in mouthrinses containing alcohol (PM and L) (p&lt;0.05). For the three resin composites, the increase in roughness was noticeable after the fifth week. Topographic analysis showed that the smoothest surfaces were present after immersion in AS.

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