MATERIAL AND METHODS: The materials were divided into two groups, Fuji IX GIC® (n = 30) and Cention N® (n = 30) and further divided (n = 10) to test three parameters, the fluoride releasing ability, flexural strength, and shear bond strength. Fluoride release was checked using fluoride ion-selective electrode, and flexural strength and shear bond strength were tested using universal testing machine (Intron 3366, UK).
RESULTS: Fluoride release of Fuji IX GIC® was significantly higher compared to that of control Cention N® over a period of 21 days. Flexural strength of Cention N® was significantly higher compared to Fuji IX GIC® and there were no significant differences in shear bond strength of both the materials.
CONCLUSION: From the results of the study, it can be concluded that Cention N® is an alkasite filling material for the complete and permanent replacement of tooth structure in posterior teeth and can be a good alternative when compared to GICs on the basis of their superior mechanical properties.
CLINICAL SIGNIFICANCE: Cention N® is an innovative filling material for the complete and permanent replacement of tooth structure in posterior teeth and can be a good alternative when compared to GICs on the basis of their superior mechanical properties.
MATERIALS AND METHODS: The HVGICs evaluated were Zirconomer [ZR] (Shofu), Equia Forte [EQ] (GC) and Riva [RV] (SDI). Sixty specimens (12mm x 2mm x 2mm) of each material were fabricated using customized Teflon molds. After initial set, the specimens were removed from their molds, finished, measured and randomly divided into 3 groups of 20. Half the specimens in each group were left uncoated while the remaining half was covered with the respective manufacturers' resin coating. The specimens were subsequently conditioned in distilled water, artificial saliva or citric acid at 37°C for 7 days. The uncoated and coated specimens (n=10) were then subjected to dynamic mechanical testing in flexure mode at 37°C with a frequency of 0.1 to 10Hz. Storage modulus, loss modulus and loss tangent data were subjected to normality testing and statistical analysis using one-way ANOVA/Scheffe's post-hoc test and Ttest at significance level p<0.05.
RESULTS: Mean storage modulus ranged from 1.39 ± 0.36 to 10.80 ± 0.86 GPa while mean loss modulus varied from 0.13 ± 0.03 to 0.70 ± 0.14 GPa after conditioning in the different mediums. Values for loss tangent ranged from 39.4 ± 7.75 to 213.2 ± 20.11 (x10 -3 ). Significant differences in visco-elastic properties were observed between mediums and materials. When conditioned in distilled water and artificial saliva,storage modulus was significantly improved when ZR, EQ and RV were uncoated. Significantly higher values were, however, observed with resin coating when the materials were exposed to citric acid.
CONCLUSION: The visco-elastic properties of HVGICs were influenced by both resin coating and chemical environment.
METHODS: Dentin slabs were treated with 0.1% riboflavin-5-phosphate modified (powder added slowly while shaking and then sonicated to enhance the dispersion process) Universal Adhesive Scotch Bond and Zipbond™ along with control (non-modified) and experimental adhesives, photoactivated with blue light for 20s. Hydroxyproline (HYP) release was assessed after 1-week storage. Elastic-modulus testing was evaluated using universal testing machine at 24 h. Resin-dentin interfacial morphology was assessed with scanning electron-microscope, after 6-month storage. 0.1% rhodamine dye was added into each adhesive and analyzed using CLSM. Detection of free amino groups was carried out using ninhydrin and considered directly proportional to optical absorbance. Collagen molecular confirmation was determined using spectropolarimeter to evaluate and assess CD spectra. For molecular docking studies with riboflavin (PDB ID file), the binding pocket was selected with larger SiteScore and DScore using Schrodinger PB software. After curing, Raman shifts in Amide regions were obtained at 8 μm levels. Data were analyzed using Two-way analysis of variance (ANOVA, p ≤ 0.05) and Tukey-Kramer multiple comparison post hoc tests.
RESULTS: At baseline, bond strength reduced significantly (p ≤ 0.05) in control specimens. However, at 6 months' storage, UVA Zipbond™ had significantly higher μTBS. Resin was able to diffuse through the porous demineralized dentin creating adequate hybrid layers in both 0.1%RF modified adhesives in CLSM images. In riboflavin groups, hybrid layer and resin tags were more pronounced. The circular dichroism spectrum showed negative peaks for riboflavin adhesive specimens. Best fitted poses adopted by riboflavin compound are docked with MMP-2 and -9 proteases. Amide bands and CH2 peaks followed the trend of being lowest for control UA Scotch bond adhesive specimens and increasing in Amides, proline, and CH2 intensities in 0.1%RF modified adhesive specimens. All 0.1%RF application groups showed statistically significant (p
METHODS: Experimental adhesives modified with different fractions of dioctadecyldimethyl ammonium bromide quaternary ammonium and riboflavin (QARF) were formulated. Dentine specimens were bonded to resincomposites with control or the experimental adhesives to be evaluated for bond strength, interfacial morphology, micro-Raman analysis, nano-CT and nano-leakage expression. In addition, the antibacterial and biocompatibilities of the experimental adhesives were investigated. The endogenous proteases activities and their molecular binding-sites were studied.
RESULTS: Modifying the experimental adhesives with QARF did not adversely affect micro-tensile bond strength or the degree of conversion along with the demonstration of anti-proteases and antibacterial abilities with acceptable biocompatibilities. In general, all experimental adhesives demonstrated favourable bond strength with increased and improved values in 1% QARF adhesive at 24 h (39.2 ± 3.0 MPa) and following thermocycling (34.8 ± 4.3 MPa).
SIGNIFICANCE: It is possible to conclude that the use of QARF with defined concentration can maintain bond strength values when an appropriate protocol is used and have contributed in ensuring a significant decrease in microbial growth of biofilms. Incorporation of 1% QARF in the experimental adhesive lead to simultaneous antimicrobial and anti-proteolytic effects with low cytotoxic effects, acceptable bond strength and interfacial morphology.
METHODS: Each alloy was immersed in growth medium for 0-21 days, and the elution was analyzed to detect the released metals. The elution was further used as the treatment medium and exposed to seeded HGFs overnight. The HGFs were also cultured directly to the titanium alloy for 1, 3 and 7 days. Cell viability was then determined.
RESULTS: Six metal elements were detected in the immersion of titanium alloys. Among these elements, molybdenum released from Ti-10Mo-10Cr had the highest concentration throughout the immersion period. Significant difference in the viability of fibroblast cells treated with growth medium containing metals and with direct exposure technique was not observed. The duration of immersion did not significantly affect cell viability. Nevertheless, cell viability was significantly affected after 1 and 7 days of exposure, when the cells were grown directly onto the alloy surfaces.
CONCLUSIONS: Within the limitation of this study, the newly developed β-titanium alloys are non-cytotoxic to human gingival fibroblasts.
MATERIALS AND METHODS: The flexural strength and flexural modulus, following thermal cycling (5000 cycles of 5-55°C) of 3 MCC-reinforced poly methyl methacrylate (PMMA) specimens were compared with the conventional and commercially available high-impact PMMA. The 3 test groups were represented by addition of various weight combinations of MCC and acrylic powders.
RESULTS: All 3 test groups with the addition of MCC demonstrated improved flexural strength and flexural modulus compared to the conventional resin, without and after thermal cycling. The highest mean flexural strength corresponded to the specimens reinforced with 5% MCC followed by 2% MCC.
CONCLUSION: Addition of MCC derived from OPEFB to PMMA may be a viable alternative to the existing, commercially available synthetic reinforced PMMA resins. The potential application of natural fillers in the fabrication of a reinforced denture base resin needs further study.
MATERIALS AND METHODS: Eighty test specimens were fabricated according to the manufacturer's instructions into rectangular test specimens. The hardness and surface roughness were tested, after 6 months of exposure to natural hot and dry weather. The hardness was measured through the International Rubber Hardness Degree (IRHD) scale using an automated hardness tester. The surface roughness was measured using a novel 3D optical noncontact technique using a combination of a light sectioning microscope and a computer vision system. Statistical Package for Social Sciences software SPSS/version 24 was used for analysis and a comparison between two independent variables was done using an independent t test, while more than two variables were analyzed, F test (ANOVA) to be used followed by a post hoc test to determine the level of significance between every two groups.
RESULTS: The hot and dry weather statistically influenced the hardness and surface roughness of MFSEM. Cosmesil M-511 showed the least hardness in test groups while A-2000 showed the hardest material (p < 0.05). A-2000 showed significant changes from rough in case of nonweathered to become smoother in weather followed by A-2186 (p < 0.05). Cosmesil M-511 showed the roughest material.
CONCLUSION: Cosmesil M-511 showed the least hard MFSEM after outdoor weathering while A-2000, the highest and least material showed hardness and surface roughness, respectively.
CLINICAL IMPLICATION: A-2000 had a high IRHD scale hardness. This makes this material more suitable for the replacement of ear and nose defects. Cosmesil M-511 is soft and easily adaptable material that makes the material more appropriate for the replacement of small facial defect with undercut area to be easily inserted and removed. Whilst A-2000 is smoother and finer in test specimens after weathering, Cosmesil M-511 became rougher after weathering.