Nano Hydroxyapatite Research Articles

Green Synthesis and Characterization of Nano Silver Doped Nano Hydroxyapatite (nAg-nHAP) using OcimumTenuiflorum Leaf Extract and Sea Shell - A New Approach

Green Synthesis and Characterization of Nano Silver Doped Nano Hydroxyapatite (nAg-nHAP) using OcimumTenuiflorum Leaf Extract and Sea Shell - A New Approach

Optimized osteogenesis of porcine bone-derived xenograft through surface coating of magnesium-doped nanohydroxyapatite

As one of the key factors influencing the outcome of guided bone regeneration, the currently used xenografts possess insufficient capability in osteogenesis. With the aim of improving the osteogenic performance of xenografts, porcine bone-derived hydroxyapatite (PHA) was prepared and subsequently coated by magnesium-doped nano hydroxyapatite (nMgHA, 10%, 20%, and 30% of Mg/Ca + Mg) through a straightforward and cost-efficient approach. The physiochemical and biological properties of nMgHA/PHAs were examined in vitro and in vivo. The inherent three-dimensional (3D) porous framework with the average pore size of 300 μm was well preserved in nMgHA/PHAs. Meanwhile, excess magnesium released from the so-called ‘surface pool’ of PHA was verified. In contrast, slower release of magnesium at lower concentrations was detected for nMgHA/PHAs. Significantly more newly-formed bone and microvessels were observed in 20%nMgHA/PHA than the other specimens. With the limitations of the present study, it could be concluded that PHA coated by 20%nMgHA may have the optimized osteogenic performance due to the elimination of the excess magnesium from the ‘surface pool’, the preservation of the inherent 3D porous framework with the favorable pore size, and the release of magnesium at an appropriate concentration that possessed osteoimmunomodulatory effects on macrophages.

Mechanical Properties and Liquid Absorption of Calcium Phosphate Composite Cements.

Calcium phosphate cements present increased biocompatibility due to their chemical composition being similar to that of the hydroxyapatite in the hard tissues of the living body. It has certain limitations due to its poor mechanical properties, such as low tensile strength and increased brittleness. Thus, the optimal way to improve properties is through the design of novel composite cements. The purpose was fulfilled using a 25% hydroxyethyl methacrylate (HEMA) mixed with 3% urethane dimethacrzlate (UDMA) base matrix with various ratios of polyethylene glycol (PEG 400) and polycaprolactone (PCL). Mineral filler is based on tricalcium phosphate (TCP) with different chitosan ratio used as bio-response enhancer additive. Four mixtures were prepared: S0-unfilled polymer matrix; S1 with 50% TCP filler; S2 with 50% chitosan + TCP filler; and S3 with 17.5% chitosan + TCP mixed with 17.5% nano hydroxyapatite (HA). The mechanical properties testing revealed that the best compressive strength was obtained by S2, followed by S3, and the worst value was obtained for the unfilled matrix. The same tendency was observed for tensile and flexural strength. These results show that the novel filler system increases the mechanical resistance of the TCP composite cements. Liquid exposure investigation reveals a relative constant solubility of the used filler systems during 21 days of exposure: the most soluble fillers being S3 and S2 revealing that the additivated TCP is more soluble than without additives ones. Thus, the filler embedding mode into the polymer matrix plays a key role in the liquid absorption. It was observed that additive filler enhances the hydrophobicity of UDMA monomer, with the matrix resulting in the lowest liquid absorption values, while the non-additivated samples are more absorbent due to the prevalence of hydrolytic aliphatic groups within PEG 400. The higher liquid absorption was obtained on the first day of immersion, and it progressively decreased with exposure time due to the relative swelling of the surface microstructural features. The obtained results are confirmed by the microstructural changes monitored by SEM microscopy. S3 and S2 present a very uniform and compact filler distribution, while S1 presents local clustering of the TCP powder at the contact with the polymer matrix. The liquid exposure revealed significant pore formation in S0 and S1 samples, while S3 and S2 proved to be more resistant against superficial erosion, proving the best resistance against liquid penetration.

Establishment Differences Odontoblast Like Cell On Reversible Pulpitis With MTA And Nano Hydroxyapatite Sell Duck Eggs (In Vivo Study)

Reversible pulpitis is a pathological condition of the pulp which can return to normal when the etiology of the condition is removed. Reversible pulpitis can be treated with pulp capping treatments to stimulate formation odontoblast like cell. Alternative materials are mineral trioxide aggregate (MTA), Biodentine and Nano hydroxyapatite (nHA) from duck shells. Purpose: to find out whether there is a difference in the number of formations odontoblast like cell in reversible pulpitis with MTA and nano hydroxyapatite duck egg shell. in vivo laboratory experiment test only control design with the independent variables, namely MTA and Nano Hydroxyapatite duck eggs and the dependent variable, namely the difference in the number of formation Odontoblast like-cell. The sample used was the RA right molar tooth of a male Sprague Dawley rat. Results: The results obtained were (p value 0.001), there was a significant difference between the average number of formations odontoblast like cell in each treatment group and control group. Administration of Nano hydroxyapatite medicament from duck egg shells and MTA medicament in the treatment of pulp caps can increase the formation of odontoblast like cell in reversible pulpitis.

Effect Of Application Of Mineral Trioide Aggregate (Mta) And Nanohydroxyapatite In Duck Egg Shell On Macrophages In Reversible Pulpitis

Pulp disease is caused by bacteria that cause tooth decay in the form of caries. These bacteria can penetrate the pulp through the gaps in the dentine, and develop in the dentinal tubules so that the permeability of the dentinal tubules decreases. Reversible pulpitis is a type of pulp disease, which if left untreated will develop into irreversible pulpitis. Pulp capping treatment as a treatment for non medicament aims to maintain the pulp to remain vital by reducing the inflammatory process. Macrophages as a marker that can be used as a sign when inflammation occurs. Pulp capping treatment usually use calcium hydroxide and Mineral Trioxide Aggregate (MTA) as material agent. Duck egg shells contain calcium carbonate and Mineral Trioxide Aggregate has an effectiveness over calcium hydroxide. the purpose of this study is to determine the difference in the number of macrophages in reversible pulpitis using duck egg nanohydroxyapatite (NHA) and MTA. this research is an in vivo laboratory experimental post test only control design with 27 research samples which one control group and two experiment group. The independent variables are duck egg nanohydroxyapatite and MTA, and the dependent variable is differences in the number of macrophages. there were significant differences in the three groups, where the average value of macrophage formation was lowest in the group of rats that were applied to MTA and followed by the NHA group. Meanwhile, the control group, the reversible pulpitis rat group without medicament application, had the highest average score. The application of MTA as a pulp capping medicament can reduce macrophages in reversible pulpitis using rats Sprague Dawley.

Injectable systems of chitosan in situ forming composite gel incorporating linezolid-loaded biodegradable nanoparticles for long-term treatment of bone infections

The objective of the current study was to create an efficient, minimally invasive combined system comprising in situ forming hydrogel loaded with both spray-dried polymeric nanoparticles encapsulating linezolid and nanohydroxyapatite for local injection to bones or their close vicinity. The developed system was designed for a dual function namely releasing the drug in a sustained manner for long-term treatment of bone infections and supporting bone proliferation and new tissues generation. To achieve these objectives, two release sustainment systems for linezolid were optimized namely a composite in situ forming chitosan hydrogel and spray-dried PLGA/PLA solid nanoparticles. The composite, in situ forming hydrogel of chitosan was prepared using two different gelling agents namely glycerophosphate (GP) and sodium bicarbonate (NaHCO3) at 3 different concentrations each. The spray-dried linezolid-loaded PLGA/PLA nanoparticles were developed using a water-soluble carrier (PVP K30) and a lipid soluble one (cetyl alcohol) along with 3 types of dl-lactide and/or dl-lactide-co-glycolide copolymer using nano-spray-drying technique. Finally, the optimized spray-dried linezolid nanoparticles were incorporated into the optimized composite hydrogel containing nanohydroxy apatite (nHA). The combined hydrogel/nanoparticle systems displayed reasonable injectability with excellent gelation time at 37 °C. The optimum formulae sustained the release of linezolid for 7–10 days, which reveals its ability to reduce the frequency of injection during the course of treatment of bones infections and increase the patients’ compliance. They succeeded to alleviate the bone infections and the associated clinical, biochemical, radiological, and histopathological changes within 2–4 weeks of injection. As to the state of art in this study and to the best of our knowledge, no such complete and systematic study on this type of combined in situ forming hydrogel loaded with spray-dried nanoparticles of linezolid is available yet in literatures.Graphical

Potential of nano hydroxyapatite synthesized from blood clam shells as a remineralizing agent after in-office bleaching

Introduction: The effect of bleaching on tooth structure is the loss of interprismatic substance which causes prism irregularities and changes in enamel morphology such as increased porosity and demineralization. This can be stopped by encouraging remineralization if the pH is neutralized and there are enough calcium and phosphate ions in the oral cavity. One agent that can be used to help the remineralization process is nano hydroxyapatite (nHA) which is a bioactive and biocompatible material for the natural mineral enamel. This study aims to determine change in the percentage of porosity, calcium, phosphate and hydroxyapatite synthesized from blood clam shells (Anadara granosa) and CPP-ACP as a positive control. Material and methods: The research design was a pre-post test control group design. Six maxillary first premolars were cut to the CEJ with a size of 5x5x2 mm then 40% hydrogen peroxide was applied. The first group was applied nHA synthesized from blood clam shells and the second group was applied CPP-ACP. Determination the percentage of porosity, calcium, phosphate and hydroxyapatite was carried out before and after bleaching and after aplication of remineralizing agent. Results: The study showed an decrease the porosity, calcium, phospate and increase hydroxyapatite precentage after sampel was applied to the remineralizating material nHA synthesized from blood clam shells and CPP-ACP. Conlusion: nHA results of blood clam shell synthesis has the potential to be used as an enamel remineralization agent after in-office bleaching.
 Key words: Blood clam shell, Casein Phosphopeptide-Amorphous Calcium Phosphate, In-office bleaching, Nano Hydroxyapatite

Influence of nano-hydroxyapatite particles on the mechanical and antibacterial properties of polycarbonate films

In the present research, eco-friendly composite films of polycarbonate (PC)/nano-hydroxyapatite (nHAP) have been successfully prepared using the solution casting method with a concentration of (3, 5, 10 and 15% PS/PC with 1.6 nHAP). These films were characterized to investigate the influence of nano material upon the Ultraviolet (UV)-wethering of the mechanical properties employing tensile test, thermal properties utilizing Lee disk, and antibacterial properties utilizing culture method. From the tests, it was observed that the nano hydroxyapatite led to a reduction in the degradation and an increase in the thermal conductivity. The antibacterial studies manifested that the toxicity was severely decreased via the incorporation of nano hydroxyapatite and became highly antibacterial. Optical constants have been analyzed using UV–vis spectroscopy.Results reveal the decrease in band gap and enhancement in optical constants. FESEM images of 10% PS/PC and 10% PS/PC+1.6 nano particles exhibit a high degree of particle dispersion homogeneity within the 10% PS/PC matrix. The contact angle tests elucidated that the prepared films were highly hydrophobic with a hydrophobocity of 99%, which aids in the antibacterial capabilities and hence they can be used as packaging materials.

Nano hydroxyapatite pre-treatment effectively reduces Cd accumulation in rice (Oryza sativa L.) and its impact on paddy microbial communities

Cadmium (Cd) contamination in paddy soil has become a worldwide concern and severely endangered human health. Nano hydroxyapatite (n-HAP) is a practical material to manage paddy Cd pollution, but its dosage should not be excessive. Based on previous studies, we validated the effect of n-HAP pre-treatment on rice Cd uptake in pot and field experiments. The results indicated that n-HAP pre-treatment effectively restricted Cd translocation in the soil-rice system. In pot experiment, when soil n-HAP concentration was 5000 mg/kg, the Cd content in the grains of n-HAP pre-treated rice was 0.171 mg/kg, decreased by 29.3% compared with normal rice (0.242 mg/kg). In field experiment, when soil n-HAP concentration was 20,000 mg/kg, the Cd content in the grains of n-HAP pre-treated rice was 0.156 mg/kg, decreased by 35.3% compared with normal rice (0.241 mg/kg). The primary mechanism was that n-HAP pre-treatment altered the formation and composition of iron plaque and therefore enhanced the Cd binding ability of iron plaque. The available N and P content and urease activity in paddy field were increased. We further investigated the impact of n-HAP on the diversity and structure of paddy microbial communities. The Chao1 and Shannon diversity indices showed no significant difference. The relative abundance of Actinobacteria and Proteobacteria was significantly decreased by n-HAP, indicating that Cd pollution might be alleviated. Desulfobacterota, Gemmatimonadota, and Geobacteraceae were significantly enriched by n-HAP. The declining relative abundance of Basidiomycota and the increasing relative abundance of other fungal taxa also suggested that n-HAP could alleviate Cd toxicity in soil.

Nano-hydroxyapatite/carbon nanotube: An excellent anode modifying material for improving the power output and diclofenac sodium removal of microbial fuel cells

Anode material and surface properties have a crucial impact on the performance of MFCs. Designing and fabricating various modified carbon-based anodes with functional materials is an effective strategy to improve anode performance in MFCs. Anode materials with excellent bioaffinity can promote bacterial attachment, growth, and extracellular electron transfer. In this study, positively charged nano hydroxyapatite (nHA) with remarkable biocompatibility combined with carbon nanotubes (CNTs) with unique structure and high conductivity were used as anode modifying material. The nHA/CNTs modified carbon brush (CB) exhibited improved bacteria adsorption capacity, electrochemical activity and reticular porous structure, thus providing abundant sites and biocompatible microenvironment for the attachment and growth of functional microbial and accelerating extracellular electron transfer. Consequently, the nHA/CNTs/CB-MFCs achieved the maximum power density of 4.50 ± 0.23 mW m−2, which was 1.93 times higher than that of the CB-MFCs. Furthermore, diclofenac sodium (DS), which is a widely used anti-inflammatory drug and is also a persistent toxic organic pollutant constituting a serious threat to public health, was used as the model organic pollutant. After 322 days of long-term operation, enhanced diclofenac sodium removal efficiency and simultaneous bioelectricity generation were realized in nHA/CNTs/CB-MFCs, benefiting from the mature biofilm and the diverse functional microorganisms revealed by microbial community analysis. The nHA/CNTs/CB anode with outstanding bioaffinity, electrochemical activity and porous structure presents great potential for the fabrication of high-performance anodes in MFCs.

Static adsorption and photocatalytic degradation of amoxicillin using titanium dioxide/hydroxyapatite nanoparticles based on sea scallop shells.

The objective of this study is to investigate the efficiency of two processes for the amoxicillin removal through static (batch) adsorption and photocatalytic degradation onto the prepared samples. Three solid materials as photocatalyst and/or adsorbent were synthesized viz. nanotitanium dioxide (NT) prepared by the sol-gel method, scallop shells-based nanohydroxyapatite (NP), and nanotitanium dioxide/nanohydroxyapatite composite (NTP). The physicochemical and morphological properties of the prepared samples were tested by TGA, XRD, DRS, ATR-FTIR, nitrogen adsorption/desorption isotherm, zeta potential, SEM, and TEM. The major operational conditions were optimized for catalyst or adsorbent mass, pH, shaking time, initial amoxicillin (AMX) concentration, power of UV lamp, and temperature. The results illuminated that NTP achieved the highest adsorption capacity (88.46mg/g) at 20 ℃ and AMX adsorption onto all the solid materials was well applied by Langmuir, Temkin, pseudo-second order, and Elovich models. The maximum desorption percent (98%) was attained by acetone. The degradation percent of AMX reached 85.3 and 99.5% for NT and NTP, respectively, using 0.9g/L of catalyst dosage through 90min. AMX photodegradation onto the catalysts' surface was well fitted by Langmuir-Hinshelwood, Arrhenius, and Eyring-Polanyi models with endothermic, physical, and nonspontaneous nature of photocatalysis process. NTP acts as a promising adsorbent and photocatalyst for the antibiotics' removal in wastewater.

Evaluation of the Remineralisation of the Demineralized Enamel Surrounding Orthodontic Brackets using the Nano Hydroxyapatite: An Original Study.

The orthodontic appliances have been known to accelerate enamel loss due to various reasons. Since there are few studies supporting the role of the nano-HAP in the mineralization of the demineralized tooth surfaces, the current study compared nano-HAP's capacity to remineralize the demineralized enamel layer surrounding braces at various concentration levels. This investigation involved 60 healthy permanent premolars that had just been excised. All specimens had 3M-Unitek brackets glued to their buccal surfaces. The samples were artificially demineralized and divided into three groups. The control group, Toothpaste ApaCare, and ApaCareTM varnish. Before and after remineralization, selected samples from each group were analyzed using a "Scanning Electron Microscope (SEM)" and evaluated using "Energy Dispersive X-Ray Analysis (EDAX)." Spectrometer and profilometer were used for the study of surface and the color. Statistics were used to analyze the outcomes. The threshold for significance was fixed at 0.05. After remineralization by nano-HAP, there was a significant rise (P < 0.001) in both calcium and phosphorus levels. This was picked up by EDAX, and SEM verified it. When compared to the control group, the nano-HAP application greatly improved the color measurements in the study groups (P < 0.001), and it also resulted in a significant decrease in surface roughness (P < 0.001). Our study's results showed that nano-HAP could be successful in restoring demineralized enamel around brackets, reducing the surface roughness and color of the enamel surface.

The effect addition of epigallocatechin-3-gallate (EGCG) in nano hydroxyapatite on surface porosity as a candidate pulp capping materia

Background: Deep caries, cavity preparation and use of burs or other dental instruments often result in pulpal perforation. In the case of an exposed pulp, regenerative pulp tissue treatment aims to regenerate normal tissue and maintain pulp vitality by inducing pulp regeneration using the right material, so that a good percentage and size of material porosity is needed to help cell regeneration by supporting cell proliferation and attachment, stimulating remineralization and differentiation of odontoblast-like cells. Nano-HA has the ability to produce dentine bridges continuously, has porous properties that allow cell growth, improves mechanical properties, but is not anti-inflammatory so that EGCG is added which has the advantage of being an antioxidant, anti-inflammatory which can optimize pulp tissue regeneration and also acts as an antimicrobial by reduce the growth of bacteria in the oral cavity and can trigger the proliferation and differentiation of human dental pulp cells. Purpose: This study aims to prove the difference in surface porosity of nano hydroxyapatite added with EGCG compared to nano hydroxyapatite and aquadest. Methods: This study used a laboratory experimental study with a posttest-only control group design. The research sample consisted of 32 samples which were divided into 2 groups, the treatment group (nano HA - EGCG) and the control group (nano HA - aquadest). Each research group was subjected to freeze drying and SEM tests. Results: There was a significant difference in the percentage of surface porosity between the nano hydroxyapatite added with EGCG compared to nano hydroxyapatite and aquadest.on the results of the Independent T-test (p&lt;0.05). Conclusion: The addition of EGCG to nano hydroxyapatite has a higher porosity percentage compared to nano hydroxyapatite with aquadest.

In Vitro Study of Composite Cements on Mesenchymal Stem Cells of Palatal Origin

Uniform filler distribution in composites is an important requirement. Therefore, BaO glass, nano hydroxyapatite and quartz filler distribution was realized through PCL microcapsules which progressively release filler during matrix polymerization. Two composites were realized based on a complex matrix containing BisGMA, UDMA, HEMA and PEG400 mixed with a previously described mineral filler: 33% for C1 and 31% for C2. The spreading efficiency was observed via SEM, revealing a complete disintegration of the microcapsules during C1 polymerization, while C2 preserved some microcapsule parts that were well embedded into the matrix beside BaO filler particles; this was confirmed by means of the EDS spectra. Mesenchymal stem cells of palatal origin were cultured on the composites for 1, 3, 5 and 7 days. The alkaline phosphatase (ALP) level was measured at each time interval and the cytotoxicity was tested after 3, 5 and 7 days of co-culture on the composite samples. The SEM investigation showed that both composites allowed for robust proliferation of the cells. The MSC cell pluripotency stage was observed from 1 to 3 days with an average level of ALP of 209.2 u/L for C1 and 193.0 u/L for C2 as well as a spindle cell morphology. Cell differentiation occurred after 5 and 7 days of culture, implied by morphological changes such as flattened, star and rounded shapes, observed via SEM, which were correlated with an increased ALP level (279.4 u/L for C1 and 284.3 u/L for C2). The EDX spectra after 7 days of co-culture revealed increasing amounts of P and Ca close to the hydroxyapatite stoichiometry, indicating the stimulation of the osteoinductive behavior of MSCs by C1 and C2. The MTT assay test showed a cell viability of 98.08% for C1 and 97.33% for C2 after 3 days, proving the increased biocompatibility of the composite samples. The cell viability slightly decreased at 5 and 7 days but the results were still excellent: 89.5% for C1 and 87.3% for C2. Thus, both C1 and C2 are suitable for further in vivo testing.

Preparing of Nano-Hydroxyapatite from Seashell and Mixed with Gold to Repair Bony Defect of Mandibular Bone in Rabbits

The objectives of the present study were undertaken to prepared hydroxyapatite powder from seashell and convert this to nano size and then added to gold nanoparticles. Materials and Methods: The seashells was cleaned and the phosphoric acid was added. The product was inserted in oven then calcined in the muffled furnace, to evaporate CO2 and getting the white crystalline powder which indicated presence of hydroxyapatite. This powder was converted to nanoparticle. Gold 1% mixed with prepared seashell nano hydroxyapatite. The characteristics of the prepared nano hydroxyapatite from seashell, were studied by the FTIR infrared spectrophotometer. The most biocompatible nano hydroxyapatite estimation by chemical test and examine prepared nano hydroxyapatite from seashell alone or when mixed with gold 1% in vivo to detect the effectiveness on reparing bone defect in mandibulare rabbits. Results: The results of an infrared measurement (FTIR Spectroscopy) for prepared nano hydroxyapatite showed that the chemical structure and band have the same FTIR spectrum of standard nano hydroxyapatite and have the same nano traits as the chemical test showed a yellow precipitation consisting in the nHA seashells. As an indication of biocompatibility and increase Bone Mineral Density by repairing bone defect in rabbits. And when added gold to nano hydroxyapatite, increased the efficacy of bone remodeling and repair bone. Conclusions: The possibility of preparing nanoparticles for hydroxyapatite from seashell are simple and inexpensive feedstock's and can be successfully produced by chemical precipitation technology from seashells with a phosphoric acid solution.

Bio-waste derived hydroxyapatite nano rods for U(VI) uptake from aqueous medium

Bio-waste derived hydroxyapatite nano rods for U(VI) uptake from aqueous medium

Green synthesis of nanohydroxy apatite using Calotropis procera and Wrightia tinctoria plant latex serum extract for biomedical application

Green synthesis of nanohydroxy apatite using Calotropis procera and Wrightia tinctoria plant latex serum extract for biomedical application

Effects of Fe3O4 nanoparticles and nano hydroxyapatite on Pb and Cd stressed rice (Oryza sativa L.) seedling

Nowadays, Lead (Pb) and Cadmium (Cd) contamination in rice is an important worldwide environmental concern. Fe3O4 nanoparticles (Fe3O4 NPs) and Nano hydroxyapatite (n-HAP) are promising materials to manage Pb and Cd contamination. This study systematically investigated the effect of Fe3O4 NPs and n-HAP on Pb and Cd stressed rice seedlings’ growth, oxidative stress, Pb and Cd uptake and subcellular distribution in roots. Furthermore, we clarified the immobilization mechanism of Pb and Cd in the hydroponic system. Fe3O4 NPs and n-HAP could reduce Pb and Cd uptake of rice mainly through decreasing Pb and Cd concentrations in culture solution and combining with Pb and Cd in root tissues. Pb and Cd were immobilized by Fe3O4 NPs through complex sorption processes and by n-HAP through dissolution-precipitation and cation exchange, respectively. On the 7th day, 1000 mg/L Fe3O4 NPs reduced the contents of Pb and Cd in shoots by 90.4% and 95.8%, in roots by 23.6% and 12.6%, 2000 mg/L n-HAP reduced the contents of Pb and Cd in shoots by 94.7% and 97.3%, in roots by 93.7% and 77.6%, respectively. Both NPs enhanced the growth of rice seedlings by alleviating oxidative stress and upregulating glutathione secretion and antioxidant enzymes activity. However, Cd uptake of rice was promoted at certain concentrations of NPs. The subcellular distribution of Pb and Cd in roots indicated that both NPs decreased the percentage of Pb and Cd in the cell wall, which was unfavorable for Pb and Cd immobilization in roots. Cautious choice was needed when using these NPs to manage rice Pb and Cd contamination.

Effect of different root canal irrigants on push-out bond strength of two novel root-end filling materials

BackgroundThe aim of this in vitro study was to evaluate push-out bond strength of different root-end filling materials using various irrigant solutions.MethodsA push-out bond strength test was performed to evaluate the bond strength of two experimental root-end filling materials: namely, nano-hybrid mineral trioxide aggregate (MTA) and polymethyl methacrylate (PMMA) cement filled with 20% weight nano hydroxyapatite (nHA) fillers compared to conventional MTA. The irrigant solutions employed were sodium hypochlorite (NaOCl) in concentrations 1%, 2.5% and 5.25% and 2% chlorhexidine gluconate (CHX) followed by application of 17% ethylene diamine tetra-acetic acid (EDTA). A freshly extracted sixty single-rooted human maxillary central incisors were used. The crowns were removed, the canal apex was widened to simulate immature teeth. Each type of irrigation protocols was performed. After application and setting of the root-end filling materials, a slice of one mm thickness was cut transversely from the apical end of each root. Specimens were stored for 1 month in artificial saliva and were subjected to a push-out test to evaluate the shear bond strength. Data were analyzed using two-way ANOVA and Tukey test.ResultsThe experimental nano-hybrid MTA showed the highest significant push-out bond strength values when irrigated by NaOCl at several concentrations (1%, 2.5% and 5.25%) (P< 0.05). Meanwhile, irrigation with 2% CHX resulted in highest bond strength values in nano-hybrid white MTA (18 MPa) and PMMA filled with 20% weight nHA (17.4 MPa) with nonsignificant difference between them (p = 0.25). In each root-end filling material, irrigation with 2% CHX led to the highest significant bond strength, followed by NaOCl 1%, while the least significant bond strength was produced after irrigation with NaOCl 2.5% and 5.25% (P< 0.05).ConclusionConsidering the limitations of this study, it may be concluded that the application of 2% CXH and 17% EDTA provides superior push-out bond strength to root canal dentin compared with irrigation with NaOCl irrigants and 17% EDTA, experimental nano-hybrid MTA root-end filling material provides enhanced shear bond strength than conventional micron-sized MTA root-end filling material.

Evaluation of efficacy of various remineralizing agents on artificially demineralized human enamel – An in-vitro study

Currently much research revolves around remineralization as incidence of white spot lesions in patient undergoing orthodontic treatment is 2-96%. The objective of this study was to find out the efficacy of Casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP), Functionalized tricalcium phosphate (f-TCP), Calcium sodium phosphosilicate (CSPS), Calcium sucrose phosphate (CSP), Nano hydroxyapatite (nHAP) and Fluoride (F) in remineralizing artificially demineralized enamel and DIAGNOdent and scanning electron microscope were used to record the changes. The study included 140 extracted premolars which were divided into 7 groups in which 6 were experimental groups: I (CPP-ACPF), II (f-TCP), III (CSPS), IV (CSP), V (nHAP), VI (F) and 1 control group: VII (C). All the samples were evaluated using DIAGNOdent at the baseline, post demineralization and post remineralization. One sample was randomly selected from each group for evaluation using SEM. Statistical analysis has shown that all the groups had higher amount of remineralization except control group. CSPS showed maximum remineralization. All the artificially demineralized samples treated with remineralizing agents for 3 weeks reduced the severity of lesions by forming calcific deposits. However CSPS showed marginally more amount of remineralization than others.