0000000000218453
AUTHOR
Negin Ghasemi
showing 8 related works from this author
Effect of different mixing and placement methods on the quality of MTA apical plug in simulated apexification model
2017
Background It is necessary apical plug material to exhibit proper adaptation with the root canal walls. Presence of voids at the interface between the root canal wall and this material result in micro leakage, which might have a relationship with post treatment disease. The aim of the present study was to evaluate the effect of different mixing (manual and ultrasonic) and placement (manual and manual in association with indirect ultrasonic) method of Mineral Trioxide Aggregate (MTA) on the void count and dimension in the apical plug in natural teeth with simulated open apices. Material and methods Eighty human maxillary central incisors were selected. After simulation of the open apex model…
Evaluation of Antibacterial Efficacy of Photodynamic Therapy vs. 2.5% NaOCl against E. faecalis-infected Root Canals Using Real-time PCR Technique
2017
Background Bacteria like E. faecalis can produce intra- and extra-radicular biofilms. Theoretically, the adjustable penetration ability of lasers enables better access to root canal system. Therefore the aim of the present study was to compare the ability of photoactivated laser and 2.5% NaOCl irrigation solution to eliminate E. faecalis from the root canals by real-time PCR technique. Material and methods Sixty extracted human upper central incisors were selected and sterilized in an autoclave. The root canals were infected with E. faecalis (PTCC 1237, Persian Type Culture Collection, Iran) and then incubated for 24 hours. The samples were randomly divided into 3 groups. No intervention wa…
Zeolite-silver-zinc nanoparticles : biocompatibility and their effect on the compressive strength of mineral trioxide aggregate
2016
Background This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Ze-Ag-Zn) nanoparticles and their effect on the compressive strength of Mineral Trioxide Aggregate (MTA). Material and Methods Biocompatibility was evaluated by an MTT assay on the pulmonary adenocarcinoma cells with 0.05, 0.1, 0.25, 0.5, 1 and 5 mg/mL concentrations of Ze-Ag-Zn. For compressive strength test, four groups containing 15 stainless-steel cylinders with an internal diameter of 4 and a height of 6 mm were prepared and MTA (groups 1 and 2) or MTA + 2% Ze-Ag-Zn (groups 3 and 4) were placed in the cylinders. The compressive strength was evaluated using a universal testing machine 4 days a…
The effect of photodynamic therapy and polymer solution containing nano-particles of Ag /ZnO on push-out bond strength of the sealers AH-Plus and MTA…
2017
BACKGROUND The aim of this in vitrostudy was to examine and compare the effect of photodynamic therapy and solution containing nano particles Ag/ZnO on adhesion of endodontic sealers to dentinal walls of human root canal. MATERIAL AND METHODS Ninty single-rooted human teeth were selected and their clinical crown was cut from the cemento-enamel junction zone. Canals were prepared by RaCe rotary system and the smear layer was removed using 17% EDTA and 5.25% NaOCl. Samples were randomly divided into two groups of AH Plus and MTA Fillapex based on the sealer type and each group based on antimicrobial method was divided into two sub-groups of photodynamic therapy and polymer containing nano par…
Biocompatibility of Mineral Trioxide Aggregate with TiO2 Nanoparticles on Human Gingival Fibroblasts
2016
Background The New compositions of white mineral trioxide aggregate (WMTA) or use of various additives like nanoparticles might affect MTA’s ideal characteristics This study was performed to evaluate the cytotoxicity of WMTA and WMTA with Titanium dioxide (TiO2) nanoparticles (1% weight ratio) at different storage times after mixing on human gingival fibroblasts (HGFs). Material and Methods HGFs were obtained from the attached gingiva of human premolars. HGFs were cultured in Dulbecco’s Modified Eagle medium, supplemented with 10% fetal calf serum, penicillin and streptomycin. The cells were exposed to WMTA (groups 1 and 2) and WMTA+TiO2 (groups 3 and 4). The fifth and sixth groups served a…
Effects of different intra canal medicaments on the push out bond strength of endodontic sealers
2016
BACKGROUND One of the essential properties of the root canal sealers is the adhesion to root canal dentin and their higher bond strength decreases the microleakage. The aim of the present study was to compare the effect of Different Intracanal medicaments on the push out bond strength of AH26 and MTA Fillapex sealers. MATERIAL AND METHODS A total of 104 one-rooted extracted human teeth were divided into 4 (n=26) experimental groups. After the cleaning and shaping, the root canals were filled with Ca(OH)2, triantibiotic paste (TAP), Metapex or 2% chlorhexidine gel for two weeks. Then, intracanal medicaments were rinsed away and the samples in the sub-groups were obturated with gutta-percha a…
Effects of different powder to liquid ratios on the push out bond strength of CEM cement on simulated perforations in the furcal area
2017
Background Proper bond strength to dentin is one of the properties of biomaterials used for therapeutic purposes such as repair of furcal perforations. The aim of the present study to evaluate the effects of different powder to liquid ratios of Calcium-enriched mixture (CEM) on the push-out bond strengths in simulated perforations in the furcal area and compare it with Mineral trioxide aggregate (MTA). Material and Methods Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were prepared in 120 mandibular first molars. Then the samples were randomly assigned to two groups (n=60). MTA and CEM cement were used for the repair of perforations in groups 1 and 2, respectively. E…
Effect of the TiO2 nanoparticles on the selected physical properties of mineral trioxide aggregate
2017
Background Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) include incorporation of some nanoparticles such as Titanium dioxide (TiO2). The aim of this study was to evaluate the effect of TiO2 nanoparticles on the setting time, working time, push-out bond strength and compressive strength of MTA. Material and methods The physical properties to be evaluated were determined using the ISO 6786:2001 and 9917 specifications. Fifteen samples of each material (MTA or MTA with 1% weight ratio of TiO2 Nanoparticles) were prepared for any evaluated physical property. Data were analyzed using descriptive statistics and T-test. Statistical significance was set at P Res…