33 research outputs found
Wideband Inductorless Low-Noise Amplifier Using Three Feedback Paths
This paper presents the design of a wideband inductorless low noise amplifier (LNA) in 0.18 m CMOS technology for multiband wireless communication standards. The LNA is a fully differential common-gate structure. It uses three feedback paths, for choosing arbitrary value of LNA transconductance which leads to a LNA with higher gain and lower noise figure (NF) over the previously reported amplifiers. Post-layout simulation results show a gain of 20.4 dB with a 3-dB bandwidth of 2.84GHZ, with a 2.62dB NF while dissipating 2.97mW. The IIP3 is -1.67dB
Effect of autoclave sterilisation and heat activated sodium hypochlorite irrigation on the performance of nickel-titanium rotary files against cyclic fatigue
The present study aims to assess the impact of heat-activated sodium hypochlorite (NaOCl) and/or autoclave sterilisation on the cyclic fatigue resistance (CFR) of heat-treated nickel-titanium rotary files used in root canal treatment. The CFR of One Curve (OC) files was evaluated under the following conditions: as received (Group 1; control), immersion in NaOCl at 23 ± 1ÂșC (Group 2), immersion in NaOCl at 60 ± 1ÂșC (Group 3), autoclave sterilisation at 135 1ÂșC (Group 4), combined treatment of autoclave sterilisation and immersion in NaOCl at 23 ± 1ÂșC (Group 5), and combined treatment of autoclave sterilisation and immersion in NaOCl at 60 ± 1ÂșC (Group 6). A simulated root canal in a zirconia block was utilised to test the performance of the files. All the types of treatments resulted in significant reductions in fracture resistance of the OC files. Immersion of the files in NaOCl at 23ÂșC revealed the smallest reduction, while combined treatment of autoclaving and immersion in NaOCl at 60ÂșC caused the greatest reduction. Autoclave sterilisation or exposure of OC files to 2.5% NaOCl adversely affect the cyclic fatigue life and increasing solution temperature or combined treatment caused additionally significant reduction in CFR
Prevalence and distribution of radix paramolaris in the mandibular first and second molars of an Iranian Population
Prevalence and distribution of radix paramolaris in the mandibular first and second molars of an Iranian Population
Root canal anatomy and morphology of permanent maxillary canine teeth in an Iranian population
Root and Canal Morphology of Mandibular Third Molars in an Iranian Population
Background and aims. A through knowledge of the root canal morphology is required for successful endodontic therapy.
The aim of this study was to investigate the root and canal morphology of mandibular third molars in Kerman, a province
in southeast of Iran.
Materials and methods. One-hundred-fifty extracted mandibular third molars were collected randomly from different
dental clinics in Kerman. The root canal anatomy and morphology of each tooth was carefully studied using a clearing technique.
Root number and morphology, number of canals per root, root canal configuration according to Vertucci classification,
and incidence of dilacerated roots and C-shaped canals in mandibular third molars were evaluated under stereomicroscope
with Ă2 to Ă3 magnifications.
Results. From the total of 150 mandibular third molars studied, 21% had one root. The majority of teeth (73%) had two
roots. 5.5% of the teeth had three roots. The incidence of C-shaped canal was 3.5% in this study and 8% of the teeth had at
least one dilacerated root.
Conclusion. Although root canal anatomy and morphology of mandibular third molars is very variable having two roots
seems to be the normal anatomy for these teeth