Triple antibiotic paste: momentous roles and applications in endodontics: a review

Parhizkar, Ardavan,Nojehdehian, Hanieh,Asgary, Saeed The Korean Academy of Conservative Dentistry 2018 Restorative Dentistry & Endodontics Vol.43 No.3

This study investigated the latest findings and notions regarding 'triple antibiotic paste' (TAP) and its applications in dentistry, particularly endodontics. TAP is a combination of 3 antibiotics, ciprofloxacin, metronidazole, and minocycline. Despite the problems and pitfalls research pertaining to this paste has unveiled, it has been vastly used in endodontic treatments. The paste's applications vary, from vital pulp therapy to the recently introduced regeneration and revascularisation protocol. Studies have shown that the paste can eliminate the root canal microorganisms and prepare an appropriate matrix for further treatments. This combination is able to remove diverse groups of obligate and facultative gram-positive and gram-negative bacteria, providing an environment for healing. In regeneration protocol cases, this allows the development, disinfection, and possible sterilization of the root canal system, so that new tissue can infiltrate and grow into the radicular area. Moreover, TAP is capable of creating a discipline in which other wanted and needed treatments can be successfully performed. In conclusion, TAP, as an antibacterial intracanal medication, has diverse uses. Nevertheless, despite its positive effects, the paste has shown drawbacks. Further research concerning the combined paste and other intracanal medications to control microbiota is a must.

Mechanical and thermal properties of Homo-PP/GF/CaCO₃ hybrid nanocomposites

Parhizkar, Mehran,Shelesh-Nezhad, Karim,Rezaei, Abbas Techno-Press 2016 Advances in materials research Vol.5 No.2

In an attempt to reach a balance of performances in homo-polypropylene based system, the effects of single and hybrid reinforcements inclusions comprising calcium carbonate nanoparticles (2, 4 and 6 phc) and glass fibers (10 wt.%) on the mechanical and thermal properties were investigated. Different samples were prepared by employing twin-screw extruder and injection molding machine. In morphological studies, the uniform distribution of glass fibers in PP matrix, relative adhesion between glass fibers and polymer, and existence of nanoparticles in polymer matrix were observed. $PP/CaCO_3$ (6 phc) as compared to pure PP and PP/GF had superior tensile and flexural strengths, impact resistance and deformation temperature under load (DTUL). $PP/GF/CaCO_3$ (6 phc) composite displayed comparable tensile and flexural strengths and impact resistance to neat PP, while its tensile and flexural moduli and deformation temperature under load (DTUL) were 436%, 99% and $26^{\circ}C$greater respectively. The maximum impact resistance was observed in $PP/CaCO_3$(6 phc). The highest DTUL was perceived in PP hybrid nanocomposite containing 10 wt.% glass fiber and 4 phc $CaCO_3$ nanoparticle.

Development and Evaluation of Midazolam In Situ Nasal Gel Properties in Presence of Solubility Enhancers at Cilia-Friendly pH

Elahehnaz Parhizkar,Leila Emadi,Shohreh Alipour 한국고분자학회 2017 Macromolecular Research Vol.25 No.3

Midazolam (MDZ) is a short acting benzodiazepine not only used in treatment of pediatric status epilepticus but also is the most common preoperative sedative-agent in many surgical processes especially in children. According to MDZ hydrophobic characteristics at physiological-pH, its commercial parenteral aqueous solution is formulated in acidic pH that may cause pain and inflammation at administration-site. Alternatively, it is administered orally especially in children, however its bitter taste results low patient-compliance. Nasal route shows better acceptance than oral route. Considering fast clearance and frequent administration of nasal solutions, the mucoadhesive gels are considerable. According to MDZ poor aqueous solubility at physiologic pH (≈6) and nasal dose volume limitation, MDZ solubility enhancement techniques evaluation seems to be necessary in mucoadhesive gel formulation. Solubilized MDZ gel at physiologic pH -as a replacement of commercial acidic parenteral formulations- not only can improve MDZ residence-time in nasal-cavity but also reduces nasal administered volume. In this study, thermosensitive Poloxamer407 used as in situ gel-forming agent in various concentrations in presence of different solubility enhancers such as propylene glycol (P.G), polyethylene glycol400 (PEG400) and β-cyclodextrin (β-CD) in various amounts. MDZ solubility and gelation properties of different gel formulations were evaluated. Results showed Poloxamer gel containing P.G, enhanced MDZ solubility at nasal physiologic-pH up to 15.1 fold. Optimized nasal gel formulation indicated acceptable gelation-temperature (34±0.5 oC), gelation-capacity (1.5±0.10 min) with shearthinning pattern, which released MDZ within 1hour. Rat nasal histopathological showed no damage within 3 hours after nasal administration of MDZ nasal-gel. Stability tests of MDZ nasal-gel were acceptable over 90 days.

Triple antibiotic paste: momentous roles and applications in endodontics: a review

Ardavan Parhizkar,Hanieh Nojehdehian,Saeed Asgary 대한치과보존학회 2018 Restorative Dentistry & Endodontics Vol.43 No.3

This study investigated the latest findings and notions regarding ‘triple antibiotic paste' (TAP) and its applications in dentistry, particularly endodontics. TAP is a combination of 3 antibiotics, ciprofloxacin, metronidazole, and minocycline. Despite the problems and pitfalls research pertaining to this paste has unveiled, it has been vastly used in endodontic treatments. The paste's applications vary, from vital pulp therapy to the recently introduced regeneration and revascularisation protocol. Studies have shown that the paste can eliminate the root canal microorganisms and prepare an appropriate matrix for further treatments. This combination is able to remove diverse groups of obligate and facultative gram-positive and gram-negative bacteria, providing an environment for healing. In regeneration protocol cases, this allows the development, disinfection, and possible sterilization of the root canal system, so that new tissue can infiltrate and grow into the radicular area. Moreover, TAP is capable of creating a discipline in which other wanted and needed treatments can be successfully performed. In conclusion, TAP, as an antibacterial intracanal medication, has diverse uses. Nevertheless, despite its positive effects, the paste has shown drawbacks. Further research concerning the combined paste and other intracanal medications to control microbiota is a must. This study investigated the latest findings and notions regarding ‘triple antibiotic paste’ (TAP) and its applications in dentistry, particularly endodontics. TAP is a combination of 3 antibiotics, ciprofloxacin, metronidazole, and minocycline. Despite the problems and pitfalls research pertaining to this paste has unveiled, it has been vastly used in endodontic treatments. The paste's applications vary, from vital pulp therapy to the recently introduced regeneration and revascularisation protocol. Studies have shown that the paste can eliminate the root canal microorganisms and prepare an appropriate matrix for further treatments. This combination is able to remove diverse groups of obligate and facultative gram-positive and gram-negative bacteria, providing an environment for healing. In regeneration protocol cases, this allows the development, disinfection, and possible sterilization of the root canal system, so that new tissue can infiltrate and grow into the radicular area. Moreover, TAP is capable of creating a discipline in which other wanted and needed treatments can be successfully performed. In conclusion, TAP, as an antibacterial intracanal medication, has diverse uses. Nevertheless, despite its positive effects, the paste has shown drawbacks. Further research concerning the combined paste and other intracanal medications to control microbiota is a must.

The epoxy coating interfacial adhesion and corrosion protection properties enhancement through deposition of cerium oxide nanofilm modified by graphene oxide

Nafise Parhizkar,Bahram Ramezanzadeh,Taghi Shahrabi 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-

This paper aims at improving the cathodic disbonding, corrosion protection and adhesion properties of epoxy coating through steel substrate treatment by cerium nanofilm. For this purpose, the cerium film was modified by graphene oxide nanosheets, which are covalently functionalized with silane coupling agent. The performance of this coating was studied by electrochemical impedance spectroscopy, Pull-off adhesion and cathodic delamination tests and the morphology of the modified cerium film was investigated by field-emission scanning electron microscopy. Results revealed that modifying the cerium nanofilm led to the better adhesion strength, corrosion protection performance and lower cathodic delamination rate of epoxy coating.

Effect of Al Content, Substrate Temperature and Nitrogen Flow on the Reactive Magnetron Co-sputtered Nanostructure in TiAlN Thin Films Intended for Use as Barrier Material in DRAMs

Reza Jalali,Mojtaba Parhizkar,Hasan Bidadi,Hamid Naghshara,Seyd Reza Hosseini,Majid Jafari 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.6

TiAlN thin films were deposited by using the reactive magnetron co-sputtering method whitindividual Ti and Al targets, where the Ti and the Al targets were simultaneously powered by usingDC and RF sources, respectively. the electrical resistivity and the structural and microstructuralproperties of the deposited TiAlN thin films and the effects of Al content, substrate temperatureand nitrogen gas flow rate on those properties were investigated. At a low flow rate of nitrogen gas(0.51 sccm), the electrical resistivity of the films was found to increase with increasing AC power,but at a high flow rate of nitrogen gas, it was found to decrease. The structural and microstructuralanalyses performed by using X-ray diffraction and scanning electron microscopy (SEM) showed thatwith increasing substrate temperature from room temperature to 400◦C, the films prepared at 400◦C have a crystalline structure while those prepared at room temperature had an amorphous nature. Also, the SEM analysis revealed that with decreasing AC power and increasing nitrogen flow rate,the size of the grains in the prepared films become larger.

Effect of Galanin Infusion into the Third Ventricle on Plasma Concentrations of Metabolic Parameters in Goats Fed Diets of Different Energy Content

Khazali, H.,Towhidi, A.,Moravej, H.,Parhizkar, A. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.6

The goal of this study was to determine whether galanin affects the mean plasma concentrations of metabolic parameters such as thyroxine (T4), triiodothyronine (T3), growth hormone (GH), insulin, glucagon, glucose, fatty acid and urea in goats fed diets differing in energy content. Sixteen goats were randomly divided into 4 groups. Animals in groups 1 and 2 were fed 100% and animals in groups 3 and 4 were fed 50% energy content in the diet for 20 days. After 20 days, animals in groups 1 and 3 received a daily infusion of $1{\mu}g$ galanin and groups 2 and 4 received a daily infusion of $2{\mu}g$ galanin into their third ventricle for 5 days. Blood samples were collected daily from the jugular vein before infusion on day 4 until 4 days after the last infusion of galanin. Samples were assayed for plasma T3, T4, GH, insulin and glucagon concentrations by double-antibody RIA. Glucose, fatty acid and urea concentrations were also measured. Lower dietary energy intake and infusions of 1 and $2{\mu}g$ galanin significantly (p<0.01) decreased the mean plasma concentrations of T3, T4, insulin and glucose and significantly (p<0.01) increased the mean plasma concentrations of GH, glucagon, fatty acid and urea of the animals in groups 3 and 4. Different dosages of the galanin infusions did not change the plasma concentrations of the metabolic parameters in the animals fed a normal dietary energy content. The results of this experiment indicated that galanin may negatively affect T3, T4, insulin and glucose and increase GH, glucagon, fatty acid and urea in goats with negative energy balance, but not in those with positive energy balance.

Temperature dependent electrophysical characteristics of GaAs-polymer composite varistors

H. Bidadi,Mohammadi Aref,M. Ghafouri,M. Parhizkar,A. Olad 한국물리학회 2013 Current Applied Physics Vol.13 No.2

A composition of GaAs-polymer tiny particles was pressed at a temperature of 130 C and a pressure of 60 MPa and its currentevoltage characteristic was studied. The result shows that the prepared disk has varistor behavior and can therefore be used to protect circuits from low overvoltage transients higher than 62 V. Temperature dependence of current-voltage characteristic and the electrical conductivity of the sample were investigated in the temperature range of 25e100 C. It has been found that increase in temperature results in lower breakdown voltage and nonlinearity coefficient. At high temperatures, nonlinearity in the IeV characteristic of sample disappears and the conductivity becomes Ohmic in nature. The sample has hysteresis which decreases through increase in temperature. Annealing effect on leakage current and breakdown voltage was both investigated and analyzed using SEM micrographs. Finally, the electrical bandgap of the sample was measured.

Bioactivity of endodontic biomaterials on dental pulp stem cells through dentin

Bahar Javid,Narges Panahandeh,Hassan Torabzadeh,Hamid Nazarian,Ardavan Parhizkar,Saeed Asgary 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.1

Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA), as 2 calcium silicate-based hydraulic cements, on human dental pulp stem cells (hDPSCs) through different dentin thicknesses. Materials and Methods: Two-chamber setups were designed to simulate indirect pulp capping (IPC). Human molars were sectioned to obtain 0.1-, 0.3-, and 0.5-mm-thick dentin discs, which were placed between the 2 chambers to simulate an IPC procedure. Then, MTA and CEM were applied on one side of the discs, while hDPSCs were cultured on the other side. After 2 weeks of incubation, the cells were removed, and cell proliferation, morphology, and attachment to the discs were evaluated under scanning electron microscopy (SEM). Energy-dispersive X-ray (EDXA) spectroscopy was performed for elemental analysis. Alkaline phosphatase (ALP) activity was assessed quantitatively. The data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. Results: SEM micrographs revealed elongated cells, collagen fibers, and calcified nucleations in all samples. EDXA verified that the calcified nucleations consisted of calcium phosphate. The largest calcifications were seen in the 0.1-mm-thick dentin subgroups. There was no significant difference in ALP activity across the CEM subgroups; however, ALP activity was significantly lower in the 0.1-mm-thick dentin subgroup than in the other MTA subgroups (p < 0.05). Conclusions: The employed capping biomaterials exerted biological activity on hDPSCs, as shown by cell proliferation, morphology, and attachment and calcific precipitations, through 0.1- to 0.5-mm-thick layers of dentin. In IPC, the bioactivity of these endodontic biomaterials is probably beneficial.

Bioactivity of endodontic biomaterials on dental pulp stem cells through dentin

Javid, Bahar,Panahandeh, Narges,Torabzadeh, Hassan,Nazarian, Hamid,Parhizkar, Ardavan,Asgary, Saeed The Korean Academy of Conservative Dentistry 2020 Restorative Dentistry & Endodontics Vol.45 No.1

Objectives: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA), as 2 calcium silicate-based hydraulic cements, on human dental pulp stem cells (hDPSCs) through different dentin thicknesses. Materials and Methods: Two-chamber setups were designed to simulate indirect pulp capping (IPC). Human molars were sectioned to obtain 0.1-, 0.3-, and 0.5-mm-thick dentin discs, which were placed between the 2 chambers to simulate an IPC procedure. Then, MTA and CEM were applied on one side of the discs, while hDPSCs were cultured on the other side. After 2 weeks of incubation, the cells were removed, and cell proliferation, morphology, and attachment to the discs were evaluated under scanning electron microscopy (SEM). Energy-dispersive X-ray (EDXA) spectroscopy was performed for elemental analysis. Alkaline phosphatase (ALP) activity was assessed quantitatively. The data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. Results: SEM micrographs revealed elongated cells, collagen fibers, and calcified nucleations in all samples. EDXA verified that the calcified nucleations consisted of calcium phosphate. The largest calcifications were seen in the 0.1-mm-thick dentin subgroups. There was no significant difference in ALP activity across the CEM subgroups; however, ALP activity was significantly lower in the 0.1-mm-thick dentin subgroup than in the other MTA subgroups (p < 0.05). Conclusions: The employed capping biomaterials exerted biological activity on hDPSCs, as shown by cell proliferation, morphology, and attachment and calcific precipitations, through 0.1- to 0.5-mm-thick layers of dentin. In IPC, the bioactivity of these endodontic biomaterials is probably beneficial.