Percussive ultrasonic drills participate in asteroid exploration missions. Since space environments are complex and working loads vary dramatically, it is necessary to design a drive that better matches the percussive ultrasonic drill to make it achieve high-speed drilling with low power consumption. Impedance characteristics under different load conditions and the load varying in one drilling cycle are investigated based on analyzing the working principle of the percussive ultrasonic drill. An ultrasonic drill driver with automatic scanning resonant frequency and digital phase-locked loop frequency tracking control is designed according to the load characteristics. Series capacitance impedance matching ultrasonic drills is experimentally studied. Vibration amplitude and impedance characteristics of the ultrasonic drill driven by the designed driver are measured to evaluate the frequency tracking ability and the impedance matching. Finally, ultrasonic drilling experiments are conducted in room, low, and high temperature environments to investigate the driving performance. Under room temperature and 5 N drilling pressure, the speed of ultrasonic drilling into soft sandstone is 52 mm/min, and the power consumption is less than 70 W. The experimental results indicate that the designed driver can drive the percussive ultrasonic drill to achieve stable and high-speed drilling with low power consumption and low drilling pressure.
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http://dx.doi.org/10.1016/j.ultras.2022.106835 | DOI Listing |
J Pharm Bioallied Sci
July 2024
Department of Dentistry, NMC Speciality Hospital, Al Ain, UAE.
Internal root resorption (IRR) commonly occurs as a single oval-shaped defect radiographically; however, variation like bilocular IRR defect is rarely reported in the literature. This case report presents a 28-year-old male patient who reported with pain of dull nature, in his front upper tooth for the past 1 week. He reported with a history of trauma 8 years back.
View Article and Find Full Text PDFIran Endod J
January 2024
Dental School, Universidade de Pernambuco (FOP/UPE), Professor Luis Freire Avenue, 700, Cidade Universitária, Recife/PE, Brazil.
Photodiagnosis Photodyn Ther
February 2024
Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gundulićeva 5, Zagreb 10 000, Croatia. Electronic address:
Background: The aim of this randomized clinical trial was to evaluate the effects of photodynamic therapy (PDT) after traditional activated final irrigation protocol (ultrasonically activated irrigation, UAI) on periapical lesion healing after single-visit root canal retreatment.
Methods: We included 36 patients with asymptomatic chronic apical periodontitis with periapical lesions larger than 5 mm and teeth sensitive to percussion and palpation, who had previous root canal treatment. All patients who signed informed consent underwent cone-beam computed tomography (CBCT) to determine and calculate the preoperative volume of the periapical lesion.
PLoS One
May 2023
Clinic for Conservative Dentistry and Periodontology, Christian-Albrechts-University of Kiel, Kiel, Germany.
Objectives: Sonic/ultrasonic devices are essential tools in today's endodontics. This prospective trial evaluated for the first time the impact of practitioners' proficiency levels and patient-related factors on complications associated with a high frequency polyamide sonic irrigant activation device.
Methods: In total 334 patients (females:158, males:176; age:18-95 years) received in the course of their endodontic therapy an intracanal irrigation, using a high frequency polyamide sonic irrigant activation device, by practitioners of different proficiency levels (undergraduate students, general practitioners or endodontists).
J Conserv Dent
December 2022
Department of Conservative Dentistry and Endodontics, Vishnu Dental College and Hospital, Bhimavaram, Andhra Pradesh, India.
Dental trauma results in various complications and poses an enigma to the practitioner. Calcific metamorphosis is one of the sequelae of trauma. A female patient of 35 years visited the specialty clinic of endodontics for the management of a discolored tooth.
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