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Aim: To investigate the null hypothesis that neither the surface conditioning (collagen, serum, saliva) of hydroxyapatite (HA) discs, nor the biofilm age (3 days vs. 21 days) has a significant effect on the cellular and matrix composition of biofilms, using Enterococcus faecalis as the model organism. Methodology: Sterile HA discs were conditioned with collagen, saliva or serum, and inoculated with E. faecalis to form 3‐day and 21‐day‐old biofilms. Unconditioned discs served as controls. The biofilms were analysed using culture‐dependent and independent (confocal microscopy and biochemical analysis) methods, to determine the colony‐forming units and the biofilm matrix composition (polysaccharides and proteins), respectively. Statistical analyses were performed using appropriate parametric and nonparametric tests (P = 0.05). Results: Collagen conditioning significantly increased the number of CFUs in the 21‐day biofilms, compared to the 3‐day biofilms (P < 0.05). Although the biochemical analysis revealed that surface conditioning had no significant effect on the total carbohydrate content in the 21‐day biofilms, confocal microscopic analysis revealed that collagen and saliva conditioning selectively increased the polysaccharide content of 21‐day biofilms, compared to the 3‐day biofilms (P < 0.05). Conclusions: The results of this study raise an important methodological concern that the substrate conditioning substances and biofilm age differentially influence the cellular and extracellular matrix components of E. faecalis biofilms. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) has been known to play vital roles in regulating growth and various metabolic processes. In recent years, the association between Mg and tumorigenesis has raised more and more attention. However, the effects of Mg on the progression of head and neck carcinoma (HNC), as well as the mechanism behind it, remain undefined. In this study, the roles of Mg in tumorigenic activities were tested in CAL27 and FaDu cells as well as in a xenograft tumor model in nude mice. We demonstrated that a moderate increase in extracellular Mg contributed to the proliferation, migration, and invasion of 2 HNC cell lines, while the addition of Mg in drinking water promoted the growth of xenograft tumors in mice without altering their serum Mg levels. Moreover, TRPM7, a major Mg transporter, was shown to be essential for the tumorigenic activities of HNC and the Mg-induced promotive effects on HNC cells and was further shown to be associated with the activation of AKT/mTOR (mammalian target of rapamycin) signaling. In a preliminary clinical study, we determined the Mg ion concentrations in the stimulated saliva from 72 patients with nasopharynx carcinoma and 12 healthy individuals. Our data revealed that the salivary Mg levels of subjects with nasopharynx carcinoma were significantly higher than those of the healthy controls. This is correlated with our finding showing TRPM7 to be overexpressed in tumor tissues harvested from 9 patients with HNC. Therefore, we can conclude that salivary Mg level, within a certain range, could act as a risk factor for the progression of HNC, which involves the activation of AKT/mTOR signaling pathways through the TRPM7 channel. The control of salivary Mg level and the intervention of TRPM7 should not be ignored during the study of HNC. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the effect of an experimental adhesive silane blend system in achieving optimal orthodontic bonding to zirconia surfaces. Also, the effect of the sandblasting distance on the adhesion strength and surface roughness of the zirconia bonding surface was determined. A total of 180 zirconia specimens were used for 3 test groups (n=60), and then grit-blasted with various distance (5mm, 10mm and 15mm). The grit-blasted specimens were allocated to three silanizations (n=30): with 1.0 vol% 3 methacryloyloxypropyltrimethoxy-silane (EP1) or their blends with 0.5% (EP2), and 1.0 vol% (EP3) 1, 2-bis-(triethoxysilyl) ethane (all in ethanol/water). Premolar brackets were bonded to zirconia specimen surfaces using TransbondTM XT adhesive resin. Next, ten specimens from each subgroup were subjected to thermo-cycling of 5000 cycles. Adhesion strength tests were performed at baseline (dry), and after thermo-cycling. The grit-blasted specimens were studied by scanning electron microscopy (SEM) and their surface roughness was evaluated. Contact angles and wettability of the primers on the zirconia surface was determined. The highest surface roughness was 0.69 ± 0.0097 μm for specimens grit-blasted at a distance of 5 mm (group 1), and the lowest surface roughness was 0.29 ± 0.0078 μm for the control specimens. Significant differences in the mean surface roughness were observed between the study groups (P ˂ 0.05). ANOVA showed a significant influence of the grit-blasting distance, silane blend and artificial aging on the shear bond strength values (P ˂ 0.05). The highest adhesion strengths were obtained for baseline specimens irrespective of the grit-blasting distance or the silane primer blend system used. The water contact angle of the control zirconia specimen was 53.5° and the contact angle ranged between 3-7° after primer coating. Grit-blasting at 10mm and silane primer blend system of 1.0 vol% 3-methacryloyloxy-propyltrimethoxysilane + 0.5 vol% 1,2-bis- (triethoxysilyl) ethane demonstrated optimal orthodontic bonding with least surface damage to the zirconia surface.

Jihad Saade,1 Hasan Skienhe,1 Hani F Ounsi,2 Jukka P Matinlinna,3 Ziad Salameh4 1Department of Prosthodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon; 2Department of Restorative Dentistry and Endodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon; 3Department of Restorative Dentistry and Endodontics, Faculty of Dental Medicine, Siena University, Siena, Italy; 4Department of Dental Materials Science, Faculty of Dentistry, University of Hong Kong, Pokfulam, Hong KongCorrespondence: Jihad SaadeFaculty of Dental Medicine, Lebanese University, Beirut, LebanonTel +961 3 763 404Email jihadsaade00@gmail.comPurpose: The purpose of this study was to evaluate the effect of surface treatments on zirconia-resin bonding and the effect of aging on bond durability for one year.Method: Three hundred and twenty zirconia blocks were divided into 4 equal study groups. Group 1 (control): as-sintered, group 2: (GB): grit-blasted, group 3: (LAS): laser-etched, group 4: (SIE): selective infiltration etching. Composite cylinders were bonded to the zirconia with resin cement and ceramic primer. Aging was performed following 3 different aging protocols: thermocycling, storage in distilled water, or storage in an enzymatic esterase solution. Micro-shear bond strength test (μSBS) was recorded using a universal testing machine. μSBS values were analyzed using two-way Analysis of Variance followed by Tukey post-hoc tests. Level of significance was set at 0.05.Results: GB, LAS and SIE groups showed significantly higher values when compared to control. Groups GB, LAS and SIE reported a significant decrease up to 50% in μSBS after water storage and enzymatic degradation, while control group reported a 90% decrease. Failure analysis showed mainly adhesive failure for control group, while the percentage of cohesive failure in resin cement was higher in SIE group compared to GB and LAS groups.Conclusion: Water aging and esterase solutions played a significant role by increasing bond degradation. A minimum of one-year water and esterase storage medium should be used to evaluate the durability of the bond between resin cement and zirconia.Keywords: air abrasion, laser, MDP primer, resin cement, aging

Jihad Saade,1 Hasan Skienhe,2 Hani Ounsi,3 Jukka P Matinlinna,4 Ziad Salameh51Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon; 2Department of Prosthodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon; 3Department of Restorative Dentistry and Endodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon; 4Dental Materials Science, Faculty of Dentistry, University of Hong Kong, Sai Ying Pun, Hong Kong; 5Research Center, Faculty of Dental Medicine, Lebanese University, Beirut, LebanonPurpose: The purpose of this laboratory study was to evaluate the effect of different surface treatment combinations on resin zirconia bonding.Materials and methods: One hundred and five pre-sintered zirconia quadrangles were prepared out of zirconia blocks, polished, then sintered and divided into five groups (n=21). Group I (control): samples were untreated, group II: grit-blasting with 50 μm alumina particles, group III: grit-blasting with 100 μm alumina particles, group IV: Er,Cr:YSGG laser, and group V: selective infiltration etching technique. Microstructural analysis was performed using scanning electron microscopy, atomic force microscopy, a diffractometer, and a profilometer. Cylinders of composite resin were luted with Panavia resin composite cementand Clearfil ceramic primer. Shear bond strength (SBS) was determined using a universal testing machine.Results: SBS results were analyzed using one-way ANOVA followed by Tukey post hoc tests for multiple comparisons. The level of significance was set to 0.05. SBS values of the studied groups II, III, IV, and V were 16.2±1.8 MPa, 15.7±3.7 MPa, 14.8±3.4 MPa, and 16.8±3.0 MPa, respectively. All values were significantly higher than the control group (10.48±1.80 MPa), but without a significant difference between them. Group III exhibited the roughest surface, and Group I had a more significantly reduced surface roughness value than any other group. Group III presented the highest significant increase of tetragonal to monoclinic phase transformation (13%).Conclusion: The use of grit-blasting with greater particles size enhanced SBS with resin composite cement, but induced a higher amount of monoclinic phase transformation. The use of primer based on adhesive monomer with the resin cement is required to enhance the bonding efficiency. The use of laser enhanced the surface roughness and the bonding ability to zirconia.Keywords: air abrasion, laser, MDP primer, resin cement

In dentistry, adhesion promotion with 3- methacryloyloxypropyltrimethoxysilane is usually sufficient, but its hydrolytic stability is a continuous concern. The hydrolytic stability of an alternative, 3-isocyanatopropyltriethoxysilane, was compared with that of conventional 3- methacryloyloxypropyltrimethoxysilane. Two silanes, both in 0.1 and 1.0 vol-% in ethanolwater, were evaluated in the attachment of an experimental bis-phenol-A-diglycidyldimethacrylate (Bis-GMA) resin to grit-blasted (with two different systems) titanium. Silane hydrolysis was monitored by FTIR spectrometry. Bis-GMA resin was applied and photo-polymerized on titanium. The specimens were thermocycled (6000 cycles, 5-55°C). Surface analysis was carried out with scanning electron microscopy. Statistical analysis (ANOVA) showed that the highest shear bond was achieved with 0.1% 3-isocyanatopropyltriethoxysilane (12.5 MPa) with silica-coating, and the lowest with 1.0% 3-methacryloyloxypropyltrimethoxysilane (3.4 MPa) with aluminacoating. The silane, its concentration, and the gritblasting method significantly affected the shear bond strength (p < 0.05). SEM images indicated cohesive failure of bonding, and, in conclusion, 3- isocyanatopropyltriethoxysilane is a potential coupling agent. [ABSTRACT FROM AUTHOR]

Background: Treated or coated sutures promise to prevent contamination of wounds., Purpose: The purpose of the study was to coat surgical sutures with a new quaternary ammonium silane (QAS) antimicrobial compound at two different application temperatures and then to evaluate the resulting structural, physical, mechanical, and biological properties., Study Design, Setting, Sample: In vitro and in vivo studies were conducted using male albino Wistar rats approved by the Joint Ethical Committee of IMU and Postgraduate Medical Institute, Lahore. Only suture samples, coated uniformly with verified presence of the compound and of adequate length were used. Samples which were not coated uniformly and with inadequate length or damaged were excluded., Predictor Variable: Predictor variables were sutures with and without QAS coatings and different temperatures. Sutures were coated with QAS at 0.5 and 1.0% wt/vol using the dip coating technique and sutures with and without QAS coating were tested at 25 and 40 °C temperatures., Main Outcome Variable(s): Outcome variables of structural and physico-mechanical properties of QAS-coated and non-coated sutures were measured using Fourier transform infrared spectroscopy (for structural changes), confocal laser and scanning electron (for diameter changes), and tensile strength/modulus (for mechanical testing). Biologic outcome variables were tested (bacterial viability); macrophage cultures from Wistar rats were tested (M1/M2 polarization detecting IL-6 and IL-10). Macrophage cells were analyzed with CD80+ (M1) and CD163+ (M2). Chemotaxis index was calculated as a ratio of quantitative fluorescence of cells., Covariates: Not applicable., Analyses: Ordinal data among groups were compared using the Wilcoxon Mann-Whitney U test along with the comparison of histological analysis using the Wilcoxon Sign-rank test (P < .05)., Results: Fourier transform infrared spectroscopy peak at 1490 cm -1 confirmed the presence of QAS on suture's surfaces with a significant increase (P < .05) in diameter (0.99 ± 0.5-mm) and weight (0.77 ± 0.02-mg) observed for 1% QAS groups treated at 40 °C. Non-coated samples heated at 25 °C had significantly (P < .05) less diameters (0.22 ± 0.03-mm) and weights (0.26 ± 0.06-mg). Highest tensile strength/modulus was observed for 0.5% QAS-coated samples which also had significantly higher antibacterial characteristics than other sutures (P < .05). QAS-coated sutures significantly increased M1 and M2 markers., Conclusion and Relevance: QAS coating conferred antibacterial action properties without compromising the physical and mechanical properties of the suture., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This pilot study evaluated the immediate effect of different herbal solutions in oral use on the tensile strength of the sutures used in oral surgical procedures. Three frequently used suture materials, polyglactin 910 (PGA), poliglecaprone (PGCL), and polypropylene (PP), were chosen in a 4-0-gauge size. The sutures' tensile stress was evaluated before being immersed (baseline) and after immersion at 24 h, 1 week, and 2 weeks in four different media: artificial saliva, chlorhexidine, Commiphora myrrh, and frankincense. The tensile strength was assessed by applying a 50 N load at a standardized speed of 2 mm/min. The data were analyzed using one-way and three-way analysis of variance (ANOVA) and the Tukey post hoc test with a significance level of p ≤ 0.05 significance level. The mean values of the maximum load showed a significant statistical difference across the three types of sutures (PGA, PGCL, and PP). The mean tensile strength of the PP suture was statistically lower than that of the other sutures. There was a statistically significant difference in the mean tensile strength of the PGA suture when stored in chlorohexidine media and the PGCL suture for frankincense media. The tensile strength for all sutures was the lowest value when immersed in Commiphora myrrh media. Home-prepared herbal solutions can affect the tensile strength and maximum load of suture materials. Careful and controlled use of herbal solutions after any dental surgical procedures is advisable., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Objectives: Evaluate the ability of strontium fluoride on bond strength and enamel integrity after incorporation within orthodontic adhesive system as a delivery vehicle., Methods: Experimental orthodontic adhesive system Transbond™ XT were modified with 1% Sr 2+ , 0.5% SrF 2 , 1% strontium, 0.5% Sr 2+ , 1% F - , 0.5% F - , and no additions were control. Mixing of formulation was monitored using Fourier transform infrared spectroscopy. Small-molecule drug-discovery suite was used to gain insights into Sr 2+ , F - , and SrF 2 binding. Shear bond testing was performed after 6-months of ageing. Enamel blocks were cut, and STEM pictures were recorded. Specimens were indented to evaluate elastic modulus. Raman microscope was used to collect Raman spectra and inspected using a scanning electron microscope. Crystal structural analysis was performed using X-ray diffraction. Effect of material on cellular proliferation was determined. Confocal was performed to evaluate the effect of formulation on biofilms., Results: FTIR of modified adhesives depicted peak changes within range due to various functional groups existing within samples. TEM represented structurally optimized hexagonal unit-cell of hydroxyapatite. Mean shear bond strength is recorded highest for Transbond XT with 1% SrF 2 . Dead bacterial percentage appeared higher in 0.5% SrF 2 and 1% F - specimens. Crystal lengths showed an increase in 0.5% and 1% SrF 2 specimens. Phase contrast within TEM images showed a union of 0.5% SrF 2 crystal with enamel crystal with higher elastic modulus and highly mineralized crystalline hydroxyapatite. Intensity of ν1 PO 4 3- and ν1 CO 3 2- along with carbonate - / ν1PO 4 3- ratio displayed good association with strontium fluoride. The formulation showed acceptable cell biocompatibility (p < 0.353). All specimens displayed characteristic diffraction maxima of different apatite angles within XRD., Significance: Experimental results suggested good biocompatibility, adequate mechanical strength, and far-ranging crystallization ability. This would provide a new strategy to overcome the two major challenges of fixed orthodontics, biofilm growth, and demineralization of enamel., Competing Interests: Declaration of Competing Interest The authors whose names are listed in the manuscript have no affiliation or involvement in an organization or entity with a financial or non-financial interest in the subject matter or materials discussed in this manuscript., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The ability of cancer cells to be invasive and metastasize depend on several factors, of which the action of protease activity takes center stage in disease progression., Purpose/objective: To analyze function of new K21 molecule in the invasive process of oral squamous cell carcinoma (OSCC) cell line., Materials & Methods: The Fusobacterium (ATCC 23726) streaks were made, and pellets were resuspended in Cal27 (ATCC CRL-2095) OSCC cell line spheroid cell microplate. Cells were seeded and Lysotracker staining performed for CathepsinK red channel. Cell and morphology were evaluated using Transmission Electron microscopy. Thiobarbituric acid assay was performed. OSCC was analyzed for Mic60. Raman spectra were collected from the cancer cell line. L929 dermal fibroblast cells were used for Scratch Assay. ELISA muti arrays were used for cytokines and matrix molecules. Internalization ability of fibroblast cells were also analyzed. Structure of K21 as a surfactant molecule with best docked poses were presented., Results: Decrease in lysosomal staining was observed after 15 and 30 min of 0.1% treatment. Tumor clusters were associated with cell membrane destruction in K21 primed cells. There was functional silencing of Mic60 via K21, especially with 1% concentration with reduced cell migration and invasiveness. Raman intensity differences were seen at 700 cm -1 , 1200 cm -1 and 1600 cm -1 regions. EVs were detected within presence of fibroblast cells amongst K21 groups. Wound area and wound closure showed the progress of wound healing., Conclusion: Over expression of CatK can be reduced by a newly developed targeted K21 based drug delivery system leading to reduced migration and adhesion of oral squamous cell carcinoma cells. The K21 drug formulation can have great potential for cancer therapies due to targeting and cytotoxicity effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

The aim of the study is to investigate a new formulation, based on dioctadecyldimethyl ammonium-bromide (QA) and riboflavin (RF), combining antimicrobial activities and protease inhibitory properties with collagen crosslinking without interference to bonding capabilities in a rabbit model. Quaternary ammonium riboflavin (QARF) experimental adhesives modified with dioctadecyldimethyl ammonium-bromide and riboflavin were bonded (0.5/1.0/2.0%) to rabbit dentin to investigate for pulpal-histology, interfacial-morphology, transmission electron microscopy, mechanical properties, collagen crosslinking, micro-Raman analysis, antimicrobial, and anti-protease activities. Collagen type-I molecules were generated using molecular-docking. Odontoblasts appeared with normal histology, were seen in controls with no inflammatory cells detected in 0.5% specimens at day 7 and mild inflammatory response at day 30. In QARF 2.0%, inflammatory cells were not detected at day 7 and 30 (p < .05). Dentinal tubules are seen with intact collagen surface in 1% specimens. Resin penetrated inside 1% adhesive specimens with few irregularly funnel-shaped tags. Transmission electron microscopy showed thinner collagen in all specimens except 1% QARF specimens. Biofilms were influenced by QARF adhesives. Elastic moduli were significantly higher in 1.0% and 2.0% QARF adhesive specimens with a significant increase in total crosslinks. Stable amide groups with anti-protease activity was observed in QARF groups. Charged residues were seen in the triple helix hCOL3A1, Gly489-Gly510 after stabilisation with formulation. The 1% QARF modified adhesives improved biochemical and biomechanical properties of rabbit dentin., (© 2021 Wiley Periodicals LLC.)

Objectives: Evaluate a new modified quaternary ammonium silane irrigant solution for its antimicrobial, cytotoxic and mechanical properties of dentine substrate., Methods: Root canal preparation was performed using stainless steel K-files™ and F4 size protaper with irrigation protocols of 6% NaOCl + 2% CHX; 3.5% QIS; 2% QIS and sterile saline. Biofilms were prepared using E. faecalis adjusted and allowed to grow for 3 days, treated with irrigants, and allowed to grow for 7 days. AFM was performed and surface free energy calculated. MC3T3 cells were infected with endo irrigant treated E. faecalis biofilms. Raman spectroscopy of biofilms were performed after bacterial re-growth on root dentine and exposed to different irrigation protocols and collagen fibers analysed collagen fibers using TEM. Antimicrobial potency against E. faecalis biofilms and cytoxicity against 3T3 NIH cells were also. Resin penetration and MitoTracker green were also evaluated for sealer penetration and mitochondrial viability. Data were analysed using One-way ANOVA, principal component analysis and post-hoc Fisher's least-significant difference., Results: Elastic moduli were maintained amongst control (5.5 ± 0.9) and 3.5% QIS (4.4 ± 1.1) specimens with surface free energy higher in QIS specimens. MC3T3 cells showed reduced viability in 6%NaOCl+2%CHX specimens compared to QIS specimens. DNA/purine were expressed in increased intensities in control and 6% NaOCl + 2% CHX specimens with bands around 480-490 cm -1 reduced in QIS specimens. 3.5% QIS specimens showed intact collagen fibrillar network and predominantly dead bacterial cells in confocal microscopy. 3.5% QIS irrigant formed a thin crust-type surface layer with cytoplasmic extensions of 3T3NIH spread over root dentine. Experiments confirmed MitoTracker accumulation in 3.5% treated cells., Significance: Novel QIS root canal irrigant achieved optimum antimicrobial protection inside the root canals facilitating a toxic effect against the Enterococcus faecalis biofilm. Root dentine substrates exhibited optimum mechanical properties and there was viability of fibroblastic mitochondria., (Copyright © 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Enterococcus faecalis is a biofilm-forming, nosocomial pathogen that is frequently isolated from failed root canal treatments. Contemporary root canal disinfectants are ineffective in eliminating these biofilms and preventing reinfection. As a result, there is a pressing need to identify novel and safe antibiofilm molecules. The effect of short-term (5 and 15 min) and long-term (24 h) treatments of trans-cinnamaldehyde (TC) on the viability of E. faecalis biofilms was compared with currently used root canal disinfectants. Treatment for 15 min with TC reduced biofilm metabolic activity as effective as 1% sodium hypochlorite and 2% chlorhexidine. Treatment with TC for 24 h was significantly more effective than 2% chlorhexidine in reducing the viable cell counts of biofilms. This serendipitous effect of TC was sustained for 10 days under growth-favoring conditions. For the first time, our study highlights the strong antibacterial activity of TC against E. faecalis biofilms, and notably, its ability to prevent biofilm recovery after treatment., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objective: To investigate the effect of blue light photoactivated riboflavin modified universal adhesives on dentin collagen biodegradation resistance, dentin apparent elastic modulus, and resin-dentin bond strength with interfacial morphology., 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 CH 2 peaks followed the trend of being lowest for control UA Scotch bond adhesive specimens and increasing in Amides, proline, and CH 2 intensities in 0.1%RF modified adhesive specimens. All 0.1%RF application groups showed statistically significant (p < 0.05) less levels of HYP released compared to controls. Dentin E appr of riboflavin application was significantly (p < 0.05) more as compared to control groups., Conclusion: Blue light photoactivated 0.1% riboflavin modified adhesives improved the biochemical and biomechanical properties of demineralized dentin as well as the long-term resin-dentin interfacial integrity and bond strength of universal adhesive to dentin., (Copyright © 2020. Published by Elsevier Ltd.)

Objective: To analyze effect of NaOCl+2% quaternary ammonium silane (QAS)-containing novel irrigant against bacteria impregnated inside the root canal system, and to evaluate its antimicrobial and mechanical potential of dentine substrate., Methods: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days., Results: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm -1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm -1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm -1 and 1609cm -1 Raman signal ratios were seen in the resin-depth region of 17μm>, 14.1μm> and 13.2μm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS., Significance: Favorable antimicrobial and endodontic profile of the NaOCl+2% QAS solution might suggest clinical use for it for more predictable reduction of intracanal bacteria., (Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to investigate EDC-assisted collagen crosslinking effect with different concentrations of tiopronin-protected gold (TPAu) nanoparticles on demineralized dentine., Methods: TPAu nanoparticles were fabricated from 0.31-g tetrachloroauric acid and 0.38-g of N-(2-mercaptopropionyl) glycine (2.4-mmol). Then co-dissolved using 35-mL of 6:1 methanol/acetic acid and mixed using NaBH 4 . EDC (0.3-M) was conjugated to TPAu nanoparticles at TPAU/EDC-0.25:1, and TPAU/EDC-0.5:1 treatment formulations ratios. Dentin specimens treated with 0.3-M EDC solution alone or left untreated were used as control. Nanoparticles formulations were characterized in term of particles morphology and size, Zeta potential, thermogravimetric analysis and small-angle X-ray scattering. Dentin substrates were characterized in term of TEM investigation, dentin proteases characterization, hydroxyproline liberation, elastic modulus measurement, Raman analysis and confocal microscopy viewing., Results: TEM evaluation of tiopronin protected gold nanoparticles dispersion revealed nano-clusters formations in both groups. However, based on our TEM measurements, the particle-size was ranging from ˜20 to 50 nm with spherical core-shape which were almost similar for both TPAu/EDC ratios (0.5:1 and 0.25:1). Zeta potential measurements indicate negative nanoparticles surface charge. SAXS profiles for both formulations, suggest a typical profile for uni-lamellar nanoparticles. Superior dentin collagen cross-linking effect was found with the TPAu/EDC nanoparticles formulations compared to the control and EDC treated groups., Significance: Cross-linking of dentin collagen using TPAu coupled with EDC through TPAu/EDC nanoparticles formulations is of potential significance in improving the biodegradation resistance, proteases inhibition, mechanical and structural stability of demineralized dentin substrates. In addition, the cross-linking effect is dependent on TPAu/EDC ratio, whereas higher cross-linking effect was found at TPAu/EDC ratio of 0.5:1., (Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objective: Effect of d-alpha-tocopheryl poly(ethyleneglycol)-1000-succinate (VE-TPGS) with riboflavin-5'-phosphate solution on crosslinking of dentine collagen was investigated to analyze collagen's structural integrity., Methods: VE-TPGS was added to RF-solution, at RF/VE-TPGS (w/w) ratios of 0.125/0.250 and 0.125/0.500. Demineralized dentine beams were used (10wt.% phosphoric acid), rinsed using deionized-water and analysed using ELISA (Human MMP2 ELISA; Human CTSK/Cathepsin-K for MMP2 and Cathepsin K analysis). AFM of dentine collagen-fibrils structure was done before and after dentine specimens' placement in mineralization solution and tested after 14days in artificial saliva/collagenase (AS/Co) solution. The specimens were tested after 24h in mineralization solution for surface/bulk elastic modulus. Nano-indentation was carried out for each specimen on intertubular-dentine with lateral spacing of 400nm. Reduced elastic-modulus and nano-hardness were calculated and collagen content was determined using hydroxyproline-assay. Micro-Raman were performed. TEM was carried out to study structural variations of dentine-collagen in artificial-saliva (collagenase). Data were presented as mean±standard deviation and analyzed by SPSS v.15, by analysis of variance., Results: Synergetic effect of VE-TPGS was observed with RF through higher structural integrity of dentine collagen-fibrils shown by TEM/AFM. Superior surface/bulk mechanical stability was shown by nano-indentation/mechanical testing. Improvement in collagenase degradation resistance for hydroxyproline release was observed and lower endogenous-protease release of MMP-2/Cathepsin-K. Raman-analysis analysed chemical interactions between RF and collagen confirming structural-integrity of collagen fibrils after crosslinking. After 24h mineralization, AFM showed mineral depositions in close association with dentine-collagen fibrils with RF/VE-TPGS formulations., Significance: Potential synergetic effect of RF/VE-TPGS was observed by reflection of higher structural integrity and conformational-stability of dentine-collagen fibrils., (Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objective: Collagen fibrils aid in anchoring resin composite restorations to the dentine substrate. The aim of the study was to investigate effect of non-enzymatic glycation on bond strength and durability of demineralized dentine specimens in a modified two-step etch-and-rinse dentine adhesive., Methods: Dentine surfaces were etched with 37% phosphoric acid, bonded with respective in vitro ethanol and acetone adhesives modified with (m/m, 0, 1%, 2% and 3% ribose), restored with restorative composite-resin, and sectioned into resin-dentine slabs and beams to be stored for 24h or 12 months in artificial saliva. Bond-strength testing was performed with bond failure analysis. Pentosidine assay was performed on demineralized ribose modified dentine specimens with HPLC sensitive fluorescent detection. The structural variations of ribose-modified dentine were analysed using TEM and human dental pulpal cells were used for cell viability. Three-point bending test of ribose-modified dentine beams were performed and depth of penetration of adhesives evaluated with micro-Raman spectroscopy. The MMP-2 and cathepsin K activities in ribose-treated dentine powder were also quantified using ELISA. Bond strength data was expressed using two-way ANOVA followed by Tukey's test. Paired T tests were used to analyse the specimens for pentosidine crosslinks. The modulus of elasticity and dentinal MMP-2 and cathepsin K concentrations was separately analyzed using one-way ANOVA., Results: The incorporation of RB in the experimental two-step etch-and-rinse adhesive at 1% improved the adhesive bond strength without adversely affecting the degree of polymerisation. The newly developed adhesive increases the resistance of dentine collagen to degradation by inhibiting endogenous matrix metalloproteinases and cysteine cathepsins. The application of RB to acid-etched dentine helps maintain the mechanical properties., Significance: The incorporation of 1%RB can be considered as a potential candidate stabilizing resin dentine bond., (Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of the present study was to evaluate the effect of novel silane system coatings on zirconia and titanium implant surfaces and the attachment of the fungal pathogen Candida albicans., Materials and Methods: Titanium and zirconia specimens were silica-coated and silanized either with a commercial silane primer (RelyX Ceramic Primer™, 3M ESPE) or a novel silane system primer. The novel silane system primer was a blend of 1.0 vol% 3-acryloxypropyltrimethoxysilane and 0.3 vol% bis-1,2-(triethoxysilyl)ethane diluted in acidified ethanol-water solvent. The surface roughness (Ra ), the surface free energy and the chemical composition of substrate surfaces after treatments were evaluated. C. albcans biofilms were developed on silica-coated + silanized surfaces during 48 h of incubation time. Colony forming units (CFU) and real-time PCR (RT-PCR) quantified the cells on the material surfaces. Statistical analyses were carried out by 1-way ANOVA, Tukey post hoc and Games Howell post hoc test at 5% significance level (p)., Results: On zirconia and titanium surfaces, the Ra and the chemical composition of the specimens were equal (P < 0.05). The surface free energy was decreased on titanium specimens and increased on zirconia specimen after silanization. CFU of C. albicans was significantly lower on zirconia coated with RelyX Ceramic Primer™, (P < 0.001) and on titanium coated with both silanes (P = 0.002). RT-PCR revealed no differences between the mean quantities of C. albicans (P ≥ 0.067)., Conclusion: Silica-coating and silanization had modified the titanium and zirconia surfaces significantly. Both the control and experimental silane primers might inhibit the biofilm formation of C. albicans., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The purpose of coatings on implants is to achieve some or all of the improvements in biocompatibility, bioactivity, and increased protection from the release of harmful or unnecessary metal ions. During the last decade, there has been substantially increased interest in nanomaterials in biomedical science and dentistry. Nanocomposites can be described as a combination of two or more nanomaterials. By this approach, it is possible to manipulate mechanical properties, such as strength and modulus of the composites, to become closer to those of natural bone. This is feasible with the help of secondary substitution phases. Currently, the most common composite materials used for clinical applications are those selected from a handful of available and well-characterized biocompatible ceramics and natural and synthetic polymers. This approach is currently being explored in the development of a new generation of nanocomposite coatings with a wider range of oral and dental applications to promote osseointegration. The aim of this review is to give a brief introduction into the new advances in calcium phosphate nanocoatings and their composites, with a range of materials such as bioglass, carbon nanotubes, silica, ceramic oxide, and other nanoparticles being investigated or used in dentistry.

Objective of this study was to evaluate the effects of long term water storage and ageing on the bond strength of resin composite cement to yttria-stabilized zirconium dioxide (zirconia) and dialuminium trioxide (alumina). Substrate specimens of alumina and zirconia were air particle abraded with dialuminium trioxide before priming and application of composite resin. Priming was made with gamma metharyloxy-trimethoxysilane or acryloxypropyl-trimethoxysilane monomer after which the intermediate dimethacrylate resin was applied and photopolymerized. This was followed by curing particulate composite resin cement (Relyx ARC) to the substrate as a resin stub. The ageing methods of the specimens (n=6) were: (1) they stored four years in 37±1ºC distilled water, (2) thermocycled 8000 times between 55±1ºC and 5±1ºC, (3) stored first in water for four years and then thermocycled. Specimens which were stored dry, were used as controls. Bonding of composite resin was measured by shear-bond strength test set-up. Both thermocycling and long-term water storage decreased significantly shear bond strength values compared to the control group (from the level of 20 MPa to 5 MPa) regardless of the used primer or the type of the substrate. Combination of four years water storage and thermocyling reduced the bond strength even more, to the level of two to three megapascals. In can be concluded that water storage and thermocycling itselves, and especially combination of water storage and thermocycling can cause considerable reduction in the bond strength of composite resin cement to alumina and zirconia.

Objective: Silver compounds have been used for their medical properties for centuries and in dentistry for more than a century. The aim of this review is to examine the evidence supporting the therapeutic use of silver in dentistry and the outcomes from the clinical trials, as well as mode of action and biocompatibility., Data Sources: Literature was searched using the PubMed database between the year 1966 and 2011, with principle key terms such as "Silver Nitrate", "Silver Fluoride", "Silver Diammine Fluoride", "Silver compounds" and "Dental caries". Hand searching was performed for relevant papers cited in the indices back to the year 1905., Results: In vitro, in vivo and clinical evidence have demonstrated that silver compounds are viable agents for preventing and arresting caries both in the primary and permanent dentition; however they are associated with adverse tooth discolouration and some reports that pulp irritation may occur. Further research has investigated its effectiveness as a dentine desensitiser, root canal disinfectant and even in silver impregnated restorative materials. The mode of action of silver compounds on carious tooth tissues is thought to include inhibition of the demineralization process, as well as an anti-bacterial effect by interference of bacterial cell membranes, cytoplasmic enzymes and inhibition of bacterial DNA replication., Conclusion: Silver compounds have been shown to be an effective anti-caries agent; however, there is an incomplete understanding of how silver compounds prevent caries. Further research is required to help identify its most efficacious use and limitations., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: Four experimental blends of an organo-functional silane monomer with a non-functional cross-linking silane monomer (a novel silane system) were evaluated as adhesion promoters in an experiment in which a resin-composite cement was bonded to silica-coated titanium., Material and Methods: 3-Acryloyloxypropyltrimethoxysilane (as constant 1.0 vol%) was blended with 1,2-bis-(triethoxysilyl)ethane, where its concentration was 0.1, 0.2, 0.3, or 0.5 vol%. Titanium slides (n=20) were grit-blasted, silica-coated, and silanized with four experimental silane solutions, with a pre-activated silane Cimaratrade mark (VOCO, Germany) as control. After silanization, resin-composite cement stubs (Bifixtrade mark QM; VOCO, Germany) were photo-polymerized. The shear bond strength was measured after dry storage (24 h) or after thermo-cycling (6000 cycles between 5 degrees C and 55 degrees C). The resin stub failure mode was determined., Results: Statistical analysis (ANOVA) showed that type of storage (p <0.05) and concentration of cross-linker silane (p<0.005) both significantly affected the shear bond strength. The highest shear bond strength was obtained with a blend of 1.0 vol% 3-acryloyloxypropyltrimethoxysilane+0.3 vol% 1,2-bis-(triethoxysilyl)ethane, 15.9 MPa (standard deviation SD 3.4 MPa) for both the thermo-cycled group and after dry storage (24 h), 14.3 MPa (SD 4.1 MPa) (n=8/group). The lowest values were obtained with Cimaratrade mark silane 7.3 MPa (SD 2.2 MPa) in dry storage and 7.9 MPa (SD 2.0 MPa) obtained with 1.0 vol% 3-acryloyloxypropyltrimethoxysilane+0.1 vol% 1,2-bis-(triethoxysilyl)ethane. The failure type was mainly cohesive., Conclusion: A novel silane system with an optimal concentration of the cross-linking silane may produce significantly higher shear bond strength between silica-coated titanium and resin-composite cement compared to a pre-activated silane product.

Deciduous wood, birch, pretreated by a technique combining heat and water vapor was applied for the reconstruction of bone defects in the knee joint of rabbits. It was observed that wood showed characteristic properties to be incorporated by the host bone during observation time of 4, 8, and 20 weeks. The natural channel structure of wood served as a porous scaffold, allowing host bone growth as small islets into the wood implants. The other properties of heat-treated wood, such as bioactivity, good handling properties, and sufficient biomechanical properties, might be additional favorable factors for the application of wood as a natural composite material for bone and cartilage repair. At the interface of the surfaces of wood and living bone, bonding occurred. The Chemical Interface Model for bonding bone to wood consists of the reactive ions, such as hydroxyl groups --OH, and covalent bonding as well as hydrogen bonding, which originate from both wood and bone. The bone tissue trauma, with its reactive Ca(2+) and PO(4) (3-) ions, proteins, and collagen, available for interaction at ionic and nanolevel, are associated with the complicated chemistry in the cellular response of the early bone healing process. It was concluded that heat-treated wood acted like a porous biomaterial scaffold, allowing ongrowth and ingrowth of bone and cartilage differentiation on its surface, and demonstrating osteoconductive contact, bonding at the interface.

Objectives: Three activated organofunctional silane coupling agents alone and blended with a non-functional cross-linker silane were evaluated as adhesion promoters in an experiment where a bis-GMA (bis-phenol-A-diglycidyldimethacrylate) resin was bonded to silicatized titanium. The adhesive performances of the silanes were assessed as shear bond strength values., Materials and Methods: 3-Methacryloyloxypropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine and [3-(triethoxysilyl)propyl]urea were prepared as 1.0vol.% solutions in 95 vol.% ethanol. They were each also blended with 1.0 vol.% 1,2-bis-(triethoxysilyl)ethane solutions that were activated for 1 or 24 h. Titanium slides were cleaned, silicatized, distributed randomly to study groups and silanized with nine silane solutions. After silanization experimental bis-GMA resin stubs were photo-polymerized and post-polymerized in a light-curing unit. The shear bond strength was measured as 'dry samples' and after thermo-cycling (6000 cycles at 5-55 degrees C)., Results: The type of silane affected significantly the shear bond strength (p<0.001) and the use of cross-linker silane (p<0.005) according to the statistical analysis (ANOVA). It showed that the highest shear bond strength for thermo-cycled resin stub samples (n=8/group) was obtained with a blend of 1.0vol.% 3-methacryloyloxypropyltrimethoxysilane+1.0 vol.% 1,2-bis-(triethoxysilyl)ethane blend (10.4+/-3.5 MPa). The lowest results were obtained with 1.0 vol.% [3-(triethoxysilyl)propyl]urea (4.5+/-1.0 MPa), and with 1.0 vol.% N-[3-(trimethoxysilyl)propyl]ethylenediamine (4.5+/-1.4 MPa)., Conclusions: Silanization with a blend of a functional silane and a cross-linker silane (a novel silane system) might improve the hydrolytic stability of a siloxane film between silicatized titanium and a bis-GMA resin.