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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Dental Materials and Techniques
- نوع مقاله: Journal Article
- کلمات کلیدی: torque wrench,Hand driver,one-piece abutment,removal torque,two-piece abutment
- چکیده:
- چکیده انگلیسی: Introduction: Some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. The aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. Methods: 40 ITI implants were placed in acrylic blocks and divided into 4 groups. In groups one and two, 10 ITI one-piece abutments (Solid®) and in groups three and four, 10 ITI two-piece abutments (Synocta®) were placed on the implants. In groups one and three abutments were tightened by 5 experienced males and 5 experienced females using a handheld driver. In groups two and four abutments were tightened using a torque wrench with torque values of 10, 20 and 35 N.cm. Insertion torque and removal torque values of the abutments were measured with a digital torque meter. Results: The insertion torque values (ITVs) of males in both abutments were significantly higher than those of females. ITVs in both Solid® and Synocta® abutments tightened with a handheld screwdriver were similar to the torque of 20 N.cm in the torque wrench. Removal torque values (RTVs) of solid® abutments were higher than those of synocta® abutments. Conclusion: The one- piece abutments (solid®) showed higher RTVs than the two-piece abutments (synocta®). Hand driver does not produce sufficient preload force for the final tightening of the abutment
- انتشار مقاله: 25-04-1392
- نویسندگان: Jalil Ghanbarzadeh,Mahboobeh Rajabzadeh,Mohammadreza Nakhaei,Hamidreza Rajatihaghi,Niloufar Tayarani Najjaran
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dental Materials and Techniques
- نوع مقاله: Journal Article
- کلمات کلیدی: Torque,Implant,torque wrench
- چکیده:
- چکیده انگلیسی: Introduction: The purpose of this study was to compare the accuracy of the torque wrenches used in different dental implant systems. Methods: We evaluated 42 torque wrenches used in different dental clinics in Mashhad, Iran, using a digital torque meter (Mark 10). High (25, 30 and 35 N·cm) and low (15 N·cm) levels of torque were examined. Ten tests were performed on each wrench, and the mean value was considered as the real torque of the instrument. Different characteristics (Model (spring or friction), System, Duration of use, Sterilization, Calibration) of each wrench were also recorded. The difference between the torque applied by the instrument and the target torque required was calculated numerically and as a percentage. A one-way ANOVA and Student’s t-test were used for statistical analysis. Results: There was a significant difference between the error at higher torques in the spring wrenches compared with the friction wrenches (P<0.05). At higher torques, an error greater than 10% was more common in the friction wrenches (29.4%) than in the spring wrenches (4.3%). No significant differences were observed regarding the duration instruments usage and the mean numerical error at high and low torque. In the wrenches that had been used for more than three years, 21.1% of samples showed an error of more than 10%, compared with 9.5% in wrenches that had been used for less than three years (P=0.39). At higher torques the Straumann system produced the least error and the Biohorizon system produced the greatest error which was significantly greater than the other systems (P<0.05). Conclusion: Our results indicate that spring wrenches produce more accurate results than friction wrenches; however, friction wrenches are more reliable at lower torques than higher torques. The length of time in use and sterilization of torque wrenches does not affect the function of the instruments significantly. The precision of the instrument system used is also important.
- انتشار مقاله: 05-01-1392
- نویسندگان: Hamidreza Rajatihaghi,Jalil Ghanbarzadeh,Neda Daneshsani,Rasul Sahebalam,Mohammadreza Nakhaee
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dental Materials and Techniques
- نوع مقاله: Journal Article
- کلمات کلیدی: torque wrench,Hand driver,one-piece abutment,removal torque,two-piece abutment
- چکیده:
- چکیده انگلیسی: Introduction: Some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. The aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. Methods: 40 ITI implants were placed in acrylic blocks and divided into 4 groups. In groups one and two, 10 ITI one-piece abutments (Solid®) and in groups three and four, 10 ITI two-piece abutments (Synocta®) were placed on the implants. In groups one and three abutments were tightened by 5 experienced males and 5 experienced females using a handheld driver. In groups two and four abutments were tightened using a torque wrench with torque values of 10, 20 and 35 N.cm. Insertion torque and removal torque values of the abutments were measured with a digital torque meter. Results: The insertion torque values (ITVs) of males in both abutments were significantly higher than those of females. ITVs in both Solid® and Synocta® abutments tightened with a handheld screwdriver were similar to the torque of 20 N.cm in the torque wrench. Removal torque values (RTVs) of solid® abutments were higher than those of synocta® abutments. Conclusion: The one- piece abutments (solid®) showed higher RTVs than the two-piece abutments (synocta®). Hand driver does not produce sufficient preload force for the final tightening of the abutment
- انتشار مقاله: 25-04-1392
- نویسندگان: Jalil Ghanbarzadeh,Mahboobeh Rajabzadeh,Mohammadreza Nakhaei,Hamidreza Rajatihaghi,Niloufar Tayarani Najjaran
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dental Materials and Techniques
- نوع مقاله: Journal Article
- کلمات کلیدی: Torque,Implant,torque wrench
- چکیده:
- چکیده انگلیسی: Introduction: The purpose of this study was to compare the accuracy of the torque wrenches used in different dental implant systems. Methods: We evaluated 42 torque wrenches used in different dental clinics in Mashhad, Iran, using a digital torque meter (Mark 10). High (25, 30 and 35 N·cm) and low (15 N·cm) levels of torque were examined. Ten tests were performed on each wrench, and the mean value was considered as the real torque of the instrument. Different characteristics (Model (spring or friction), System, Duration of use, Sterilization, Calibration) of each wrench were also recorded. The difference between the torque applied by the instrument and the target torque required was calculated numerically and as a percentage. A one-way ANOVA and Student’s t-test were used for statistical analysis. Results: There was a significant difference between the error at higher torques in the spring wrenches compared with the friction wrenches (P<0.05). At higher torques, an error greater than 10% was more common in the friction wrenches (29.4%) than in the spring wrenches (4.3%). No significant differences were observed regarding the duration instruments usage and the mean numerical error at high and low torque. In the wrenches that had been used for more than three years, 21.1% of samples showed an error of more than 10%, compared with 9.5% in wrenches that had been used for less than three years (P=0.39). At higher torques the Straumann system produced the least error and the Biohorizon system produced the greatest error which was significantly greater than the other systems (P<0.05). Conclusion: Our results indicate that spring wrenches produce more accurate results than friction wrenches; however, friction wrenches are more reliable at lower torques than higher torques. The length of time in use and sterilization of torque wrenches does not affect the function of the instruments significantly. The precision of the instrument system used is also important.
- انتشار مقاله: 05-01-1392
- نویسندگان: Hamidreza Rajatihaghi,Jalil Ghanbarzadeh,Neda Daneshsani,Rasul Sahebalam,Mohammadreza Nakhaee
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: modeling,Biodistribution,Compartmental Analysis,Samarium- 153,Maltolate
- چکیده:
- چکیده انگلیسی: Introduction
Compartmental analysis allows the mathematical separation of tissues and organs to determine activity concentration in each point of interest. Biodistribution studies on humans are costly and complicated, whereas such assessments can be easily performed on rodents.
In this study, we aimed to develop a pharmacokinetic model of 153Sm-maltolate complex as a novel therapeutic agent and free 153Sm cation in normal rats using compartmental analysis to evaluate the behavior of this complex.
Materials and Methods
We developed a physiologically-based pharmacokinetic model for scaling up the activity concentration in each organ with respect to time. In the mathematical model, physiological parameters including organ volume, blood flow rate, and vascular permeability were used. The compartments (organs) were connected anatomically, which allowed the use of scale-up techniques to predict new complex distribution in each body organ.
Results
The concentration of 153Sm-maltolate complex and free 153Sm cation in various organs was measured at different time intervals. The time-dependent behavior of the biodistribution of these two radiotracers was modeled, using compartmental analysis; the detected behaviors were drawn as a function of time.
Conclusion
The variation in radiopharmaceutical concentration in organs of interest could be described by summing seven to nine exponential terms, which approximated the experimental data with a precision of > 1% in comparison with the original data from animal studies.- انتشار مقاله: 22-04-1394
- نویسندگان: Amir Hakimi,Amir Reza Jalilian,Ali Ghanbarzadeh,Hamed Rezaee Jam
- مشاهده