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Papers by farshad-bajoghli bajoghli

مجله دانشکده دندانپزشکی اصفهان, Mar 15, 2012

Introduction: Toxicity of dental alloys depends on their composition and element release, which m... more Introduction: Toxicity of dental alloys depends on their composition and element release, which may, in turn, be affected by re-casting of the alloy. The aim of this study was to evaluate the effect of re-casting on the release of elements from Verabond base metal alloy . Materials and Methods: In this laboratory study Verabond base metal alloy was evaluated. At first cubic wax patterns measuring 11×13×1.4 mm were prepared. Then alloy disks were cast as follows: 100% new alloy; 50% new with 50% re-cast alloy; and 100% re-cast alloy. Each alloy specimen was finished and polished under simulated clinical conditions and sterilized in an autoclave. Each specimen was conditioned in artificial saliva at 37°C for 72 hours. The specimens were retrieved from artificial saliva and release of elements from the alloys was investigated by Atomic Absorption Spectrophotometry. Data was analyzed by one-way ANOVA and a post hoc Tukey test (α = 0.05). Results: ANOVA revealed significant differences between the cast and re-cast Verabond groups; release of titanium, nickel, aluminum and chloride were respectively higher in recast alloys compared to cast alloys (p value < 0.05). The amounts of Be, Mo, Co were not quantified by spectrophotometry due to their low concentrations. Conclusion: Based on the results of the present study, re-casting of alloys significantly increases the release of elements. Therefore, re-casting of alloys should be avoided . Key words : Artificial saliva, Atomic Emission spectrophotometry, Dental casting alloy .

The Journal of Indian Prosthodontic Society, 2022

PubMed, Jul 1, 2015

Background: Marginal adaptation is very important in cast restorations. Maladaptation leads to pl... more Background: Marginal adaptation is very important in cast restorations. Maladaptation leads to plaque retention, reduction of mechanical and esthetic properties. The aim of this study was to evaluate the precision of three different impression materials (including: Additional silicone [AS] and condensational silicone [CS] and polyether [PE]) for duplicating master dies. Materials and methods: Three master dies from an acrylic tooth model-with supragingival and shoulder finishing line was made by using PE: Impergum, CS: Speedex, and AS: Panasil separately. The Ni-Cr copings were prepared from master dies separately. They were placed on the acrylic model and the mean marginal difference was recorded by using a stereomicroscope. Then 30 duplicate test dies were made by using the same impression materials and the marginal gaps were recorded. The comparison was done by one-way ANOVA and SPSS software (Version 13) at a significant level of 0.05. Results: The mean marginal difference of four walls from Impergum (38.56 um) was the lowest than Speedex (38.92 um) and Panasil (38.24 um). The Impergum had the highest capability in making duplicate dies (P > 0.05). Conclusion: The Impergum impression material manifested the highest capability in making a better marginal adaptation of duplicate dies but further studies are needed to make a precise decision.

PubMed, Aug 1, 2015

Background: Dental instruments, like endodontic files, are hardly disinfected. The aim of this st... more Background: Dental instruments, like endodontic files, are hardly disinfected. The aim of this study was to evaluate the efficacy of mechanical, chemical, and ultrasonic (in combinations or separately) techniques for removing debris from files, prior to sterilization. Materials and methods: Totally, 90 new endodontic files with size of 15, 25, and 40 (30 files of each one) were sterilized and one files of each one kept as negative control (NC) group. The rest of files (29 files of each size) were divided into five groups after endodontic therapies and prior to autoclaving: (Positive control [PC]: Without interventions, A: Cleaned with scouring sponge soaked in chlorhexidine 0.2%, B: Stored in Micro 10 enzyme, C: Subjected to Micro 10 enzyme in both conventional and ultrasonic way for 15 min, D: Decontaminated by Micro 10 enzyme with ultrasonic). Finally, the samples were observed under a metallographic microscope, and the data were analyzed by Tuckey, paired t-test, two-way ANOVA tests using SPSS software version 15 at a significant level of 0.05. Results: Significant differences were observed in heads of the files among groups C and PC (P = 0.02), and high amount of debris were seen in the shafts of groups A and D (P < 0.001). The amount of remaining debris were significant in the shafts of sizes 15 (P < 0.001) and 25 (P = 0.01). Conclusion: Using Micro 10 in both ultrasonic and conventional methods were acceptable for removing debris from the files. Furthermore, higher amounts of debris were found in the shafts and heads of files with lower sizes (15 and 25).

Indian Journal of Dental Research, 2013

Resistance form of full metal-ceramic crown is an important feature that determines longevity of ... more Resistance form of full metal-ceramic crown is an important feature that determines longevity of these restorations. This study evaluated the resistance form of full metal-ceramic prepared with four different design features. An acrylic tooth was prepared with 20° total occlusal convergence (TOC) angle, 2.5 mm of occlusocervical dimension and a shoulder finishing line. This design lacked resistance form. The crown preparation was subsequently modified by preparing Mesial Occlusal Distal isthmus, placing occlusal inclined plane, and reducing TOC. Four metal dies from these designs were constructed by lathe machine and then 10 metal copings were fabricated for each preparation. Metal coping were cemented on metal dies with temp-bond cement. Force was applied at 45° from lingual to buccal direction with universal testing machine. The data were evaluated by Kruskal-Wallis and non-parametric Mann-Whitney test. All features increased resistance form when compare to control group. However, reduce TOC group showed greatest value of resistance. Within the limitation of this study, reducing the tapering of occlusocervival dimension is the most effective way in increasing resistance form, although, other features were also effective.

Journal of Oral Implantology, Aug 1, 2009

One of the main goals of prosthetic dentistry is to reconstruct the masticatory system. Replacing... more One of the main goals of prosthetic dentistry is to reconstruct the masticatory system. Replacing missing teeth by complete or partial denture is associated with decreased bite force and patient satisfaction. The aim of the present study was to measure the maximum bite force (MBF) and to evaluate patients' satisfaction from their conventional complete dentures and their mandibular implant-supported overdentures opposed by complete denture. In this cross sectional analytical descriptive study, seventy-five 45-to 65-year-old patients were divided into 3 groups wearing: (1) conventional complete dentures for up to 6 months; (2) conventional complete dentures for 10 years or more; and (3) complete maxillary dentures opposing mandibular implant-supported overdentures. Bite force was measured by means of electronic bite force measuring device with strain gauges. Three measurements were made on each side on the first molar region and the mean values were recorded. Patient satisfaction was also recorded using questionnaires. Results were analyzed by analysis of variance (ANOVA), t test, chi-square, and Pearson correlation test. The mean MBF for the first, the second, and the third group was, respectively, 5.65 6 1.46 kgf, 7.01 6 2.1 kgf, and 12.22 6 27 kgf. The difference between MBF in patients with overdentures and in patients with conventional complete dentures was statistically significant (P 5 .001). Patient satisfaction with mandibular implant-supported overdentures was recorded as ''great.'' Results indicated MBF in the patients with mandibular implant-supported overdentures was significantly higher than that of patients with conventional complete dentures. This difference may indicate the important role of dental implants in the improvement of bite force and chewing efficiency and therefore patients' satisfaction.

... 3rd ed. St Louis: Mosby Co; 2001, 805-829. 3. El-Mowafy O, Rubo MH. Resin-bonded fixed partia... more ... 3rd ed. St Louis: Mosby Co; 2001, 805-829. 3. El-Mowafy O, Rubo MH. Resin-bonded fixed partial dentures--a literature review with presentation of a novel ... 17. El-Sherif MH, el-Messery A, Halhoul MN. The effects of alloy surface treatments and resins on the retention of ...

... J Prosthet Dent 2002; 87(4): 162-6. 8. Nakhaee M. Evaluation of recasting base metal alloy on... more ... J Prosthet Dent 2002; 87(4): 162-6. 8. Nakhaee M. Evaluation of recasting base metal alloy on marginal accuracy of cast crown. [Thesis]. Mashhad: Mashhad University of Medical Sciences; 2005. ... Farshad Bajoghli, Saeed Nosouhian * , Amir Saberian, Leila Ghadesi ...

... 11. El – Sherif MH, El – Messery A, Halhoul MN. The effects of alloy surface treatments and r... more ... 11. El – Sherif MH, El – Messery A, Halhoul MN. The effects of alloy surface treatments and resins on the retention of resin – bonded retainers. ... 13. EL Mowafy, MHM Rubo. Resin – bonded fixed partial denture – A literature review with presentation of novel approach. ...

European Journal of Dentistry, Aug 12, 2021

Objectives Polymethyl methacrylate as the most common material used in denture bases has some pro... more Objectives Polymethyl methacrylate as the most common material used in denture bases has some problems. The aim of this study was to introduce a new nanocomposite of PMMA to improve flexural strength and antifungal properties. Materials and Methods In this experimental study, AgSiO 2 nanoparticles were prepared, and their characteristics were confirmed by scanning electron microscope and energy dispersive spectroscopy techniques. Then the nanoparticles in the weight ratio of 0.1, 0.3, 0.5, and 0.7% were incorporated to heat-cured PMMA and the control group included no nanoparticles. To measure the flexural strength before and after thermocycling three-point bending test was used. Eight samples per group with dimensions of 65 × 10 × 2.5 mm were used. Antifungal activity against Candida albicans (PTCC 5027) was investigated through colony count method. Statistical analysis was done by SPSS at significance level of p-value ≤0.05. Results The mean flexural strength in groups 0.1, 0.3, and 0.7% was significantly higher than the control. After thermocycling flexural strength of the control group was significantly lower than 0.3 and 0.5% groups. As the concentration of nanoparticles increased the antifungal activity improved (p < 0.05). Conclusion Addition of nanoparticles AgSiO 2 improved flexural strength and antifungal characteristics of PMMA.

The journal of contemporary dental practice, 2013

Introduction: Base metals have a wide use in casting methods. Sometimes they are reused in labora... more Introduction: Base metals have a wide use in casting methods. Sometimes they are reused in laboratories which may have an adverse effect on the restoration marginal integrity. This study aimed to investigate the effect of recasting of alloys on marginal integrity of restorations. Materials and methods: Models with two types of finishing lines shoulder bevel 45° and shoulder 135° were produced and 15 wax copings were formed on each one of them. Each group containing 15 copings was divided into three subgroups A, B and C. Group A was casted with 100% new alloy, group B with 50% new and 50% recasted alloy and group C with 100% recasted alloy. Obtained metal copings were placed on dies and marginal gap size between restoration margin and the dies finishing line was measured using metric microscope and Moticam camera in four points, buccal, lingual, mesial and distal. Results: A significant difference in mean marginal gap size exists among three types of alloys used (p-value = 0.036). A significant difference is observed between mean marginal gap size of two types of finishing lines for different alloys (p-value = 0.001). Conclusion: Using 100% recasted alloy is not recommended for any of the two types of finishing lines.

Anesthesia: Essays and Researches, 2016

Dental anxiety and fear of needle injection is one of the most common problems encountered by den... more Dental anxiety and fear of needle injection is one of the most common problems encountered by dental practitioners, especially in the pediatric patient. In consequences, it might affect the patient&amp;amp;amp;amp;amp;#39;s quality of life. Several methods are suggested to lower the discomfort of local anesthesia injection during dental procedures. Desensitization of injection site is one of the recommended strategies. Among chemical anesthetic topical agents that are effective but might have allergic side effects, using some nonpharmacological and safe techniques might be useful. This study aimed to overview the efficacy of using cooling techniques, mostly by ice or popsicles, warming or pH buffering of drug, and using modern devices to diminish the discomfort of local anesthesia injection during dental procedures.

DOAJ (DOAJ: Directory of Open Access Journals), 2010

Children are more sensitive to radiation than adults. Computerized tomography (CT) consists of 25... more Children are more sensitive to radiation than adults. Computerized tomography (CT) consists of 25 % of all medical imaging. It was estimated that more than 2% of all carcinomas in the USA are due to CT scans. There is an ongoing focus on the reduction of CT scan radiation dose. Awareness about risk-benefits of CT has increased. Reduction of radiological exam is an important issue because the accumulation effects of radiation can be hazardous. In addition, proper protocol should be followed for diagnostic procedures of ionization radiation and computerized tomography. Effective radiation dose should range from 0.8 to 10.5 millisievert. The same protocol should be followed in different hospitals as well. Basic principles of radiation protection should be monitored. As much as possible, both technician and radiologist must be present during computerized tomography for children, and MRI and ultrasound should be replaced if possible.

Dental research journal, 2023

Introduction: Full coverage of teeth chosen correctly, could be the best treatment, but because o... more Introduction: Full coverage of teeth chosen correctly, could be the best treatment, but because of different steps involved in crown fabrication, dentists must try to make crowns with noticeable duration. The purpose of this study was to evaluate the effect of auxillary preparation elements and occlusal surface modifications on the resistance form of a complete lower molar crown. Methods and materials: This study was of experimental-laboratory type. Ivorine tooth was prepared with 20 degree TOC (Total Occlusal Convergence), 3 mm occlusocervical dimension and shoulder finishing line (First group=control group). Ten standard metal dies were replicated from this model. Standard metal crowns were made for all samples. After the cementation of metal crowns to metal dies with resin cement, the resistance of each samples against lateral forces were determined by instron machine. Next groups consisted of interproximal boxes+ buccolingual grooves (2nd group), occlusal isthmus (3rd group) and...

A microgap between implant and abutment connection can act as a bacterial source and cause inflam... more A microgap between implant and abutment connection can act as a bacterial source and cause inflammation, even endanger Osseointegration and subsequently change clinical and histological parameters. The goal of this study was to evaluate the microgap and microbial leakage of implant-abutment connection in three different implant systems. In this experimental study, 28 implants in 3 groups (10 Zimmer with conical connection of 8 degrees, 10 Dentium with conical connection of 11 degrees, 8 Test implants with conical connection of 16 degrees) were used. Microleakage of Escherichia coli was assessed at intervals of 5, 24, 48 hours and 2 weeks. Microgap was measured at 4 random points by scanning electron microscope. Data were analysed by Spss version 22 and kruskal-Wallis, Mann-Whitney, Chisquare, Kaplan-Meier tests. (alpha=0.5) Mean microgap was 4.8 mu m (+/- 2.2) in Zimmer group, 3.1 mu m (+/- 1.4) in Implantium group and 16.9 mu m (+/- 8.7) in test group. After 2 weeks from start of t...

Journal of Periodontology & Implant Dentistry, 2012

Background and aims. Different clinical studies have reported high survival rates in immediate im... more Background and aims. Different clinical studies have reported high survival rates in immediate implant placement in extraction sockets with periapical lesions. The aim of this study was to investigate the effect of Er:YAG laser irradiation on success rate of immediate implant placement in tooth extraction sockets with chronic periapical lesions. Materials and methods. Thirty patients requiring a single-root tooth extraction with chronic periapical lesions were included in this prospective, randomized, clinical trial and divided into control (n=15) and test (n=15) groups. After tooth extraction, the implant were placed with guided bone regeneration in the control group after periapical curettage and socket irrigation and in the test group, irrigation of the periapical region was accompanied with Er:YAG laser for 1 min at 100 mJ, 10 Hz, 12.73 J/cm 2 . Radiographic (using standard long-cone parallel) and clinical parameters (plaque index [PI], modified bleeding index [mBI], probing dep...