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[Hygienic processing of dental transmission instruments (handpieces and instruments, turbines) in dental practice].

The efficacy of a steam disinfection method for the processing of used instruments in dental practice was tested with 274 high-speed turbines and handpieces. The instruments treated with streaming steam were both taken out of the dental practice of treatment and artificially contaminated with five different test-microorganisms (E. coli, P. aeruginosa, S. aureus, E. faecium, C. albicans) and different concentrations of serum (1%, 10%, 20%). In spite of the narrow channels of these instruments a microbial reduction of more than 5 log10 steps could be achieved in all cases. Thus dental high-speed turbines and handpieces can reliably be disinfected with streaming steam.

Colony Count, Microbial↗

[History of surgical instruments: 7. The first electrosurgical instruments: galvanic cauterization and electric cutting snare].

In 1854 the surgeon Albrecht Theodor Middeldorpf (1824-1868) published the first monography on the application of electrical current in surgical operations ("galvanocautery"). By galvanocautery Middeldorpf defined a procedure in which specially constructed parts of surgical instruments (usually thin platinum wires) were transformed into glowing heat by means of galvanic current from a zinc-platinum-battery. In this manner it was possible to perform dissection and destruction of tissue as well as coagulation of vessels for hemostasis. His most important electrosurgical instruments comprised an electrosurgical knife ("galvanocautery") and the electrical cutting snare ("ligatura candens") for removal of polypoid tumors. These instruments are the direct ancestors of modern electrocautery or cautery snare. The glowing platinum wire was later also applied as a light source of cystoscopes. Thus, galvanocautery enabled development of endoscopy. Modern diathermy with high-frequent alternating current was introduced in medicine by the Dermatologist Franz Nagelschmidt from Berlin.

Electrocoagulation↗

Posterior instrumentation of the cervical spine using the neon occipito-cervical system. Part 2: cervical and cervicothoracic instrumentation.

OBJECTIVE: Posterior cervical and cervicothoracic stabilization, if necessary, in combination with posterior spondylodesis, after closed or open reduction as well as with or without neural decompression as clinically indicated. INDICATIONS: Instabilities and deformities of rheumatoid, traumatic, neoplastic, infectious, iatrogenic or congenital origin. Multilevel cervical spinal stenosis with degenerative instability or kyphosis of the affected spinal segment. Corrective spondylodesis for posttraumatic or postinfectious kyphosis. CONTRAINDICATIONS: Infection in the operative field. Inability to undergo anesthesia. SURGICAL TECHNIQUE: Prone position, rigid head fixation, e. g., with Mayfield tongs. If appropriate, closed reduction under lateral image intensification. Midline posterior surgical approach at the level of the segment to be instrumented. If necessary, open reduction. Insertion of the cervical/upper thoracic screws. If necessary, posterior decompression. Instrumentation with prebent longitudinal rods. If a fusion is to be obtained, decortication of the posterior bone elements with a burr and onlay of cancellous bone. RESULTS: 44 patients, 13 women and 31 men, with an average age of 57 years were operated on between August 2000 and August 2003. All patients underwent a follow-up examination 4-39 months (average 15.7 months) after the initial surgery. Fusion was achieved in all patients who had undergone a posterior spondylodesis: no implant failure, no implant removal or reoperation. The preoperatively planned instrumentation could be implemented intraoperatively in all patients.

Bone Screws↗

The instrument explosion--a study of aircraft cockpit instruments.

Aircraft cockpit instruments have been increasing in number since the Wright Brothers made their first powered flight. As aeroplane development progresses, new systems are continually being added to improve performance or capability and cockpits have now reached the stage where there is often little space left in which to install the monitoring instruments for these additional systems. Fortunately, the advent of electronic cockpit displays offers a solution to this problem. One electronic display can be used to present the information previously requiring several conventional electro-mechanical instruments, with a consequent saving in cockpit panel space. However, cockpit displays must be matched to the pilot's information requirements and processing abilities. If this is not done the advantages of electronic displays will not be realised and the pilot will be in an even worse position than he was before.

Journal Article↗

Comparing apical preparations of root canals shaped by nickel-titanium rotary instruments and nickel-titanium hand instruments.

This study measured displacement of canal centers in extracted human teeth after preparation by Lightspeed and nickel-titanium K-files. The specimens were divided into two groups (n = 11), after radiographing the roots from the buccolingual and mesiodistal planes with pathfinding files in situ. More strongly and less strongly curved canals were, respectively, assigned to the Lightspeed and nickel-titanium K-file groups. Using a reassembly technique, cross-sections at 1.25 mm, 3.25 mm, and 5.25 mm from the apices were made of the experimental roots embedded in clear plastic. Stereomicroscopic 35-mm slides were taken of the uninstrumented sectioned canals. The sections were reassembled and then prepared to size 50 Master Apical Rotary and size 40 Master Apical Files, for the Lightspeed and K-file groups, respectively. Similar 35-mm slides of the instrumented canals were taken and electronically superimposed over their uninstrumented counterparts. Displacements of root canal centers after preparation and increases in cross-sectional areas of the prepared root canals were evaluated at specific levels. No significant differences in displacement of canal centers or between the mean cross-sectional areas of the instrumented root canals were recorded between the Lightspeed and K-file groups. Both types of instruments produced similar displacement of canal centers after preparation.

Anatomy, Cross-Sectional↗

[Ultrasonic instrumentation versus hand instrumentation in periodontics. A review of the literature].

The working mechanism and the correct use of ultrasonic devices is discussed. Comparative efficiency of ultrasonic and hand instrumentation is evaluated for the removal of subgingival plaque and calculus, for the effect on root surfaces and for the ability in removing endotoxins. Possible side effects of the ultrasonic vibrations on the tooth structures and periodontal tissues, the incidence of bacteremias and the spreading of oral infections via aerosols are stated. Particular attention is given to the clinical results of both instrumentation technics and the necessity of root planing. One can conclude, that ultrasonics present an alternative and/or a supply for hand instruments, provided that a selective and careful use is taken into account.

Dental Calculus↗

Instrument development tools and activities for measure validation using Rasch models: part I - instrument development tools.

Instrument development is an arduous task that, if undertaken with care and consideration, can lay the foundation for the development of validity arguments relating to the inferences and decisions that are based on test measures. This article, Part I of a two-part series, provides an overview of validity concepts and describes how instrument development efforts can be conducted to facilitate the development of validity arguments. Our discussion focuses on documentation of the purpose of measurement, creation of test specifications, item development, expert review, and planning of pilot studies. Through these instrument development activities and tools, essential information is documented that will feed into the analysis, summary, and reporting of data relevant to validity arguments discussed in Part II of this series.

Culture↗

["In vitro" analysis of root dentin permeability during endodontic instrument use, as a function of change of instruments and number of times used].

The increase of dentinal permeability is a very important issue related to root canal disinfection. Beside the auxiliary substance used for the chemical/mechanical preparation, time and type of instruments were also considered. Based on these facts, we have studied the percentage of dentinal penetration of a stain (Patent blue V), in recently extracted teeth. By this way, areas of tooth hemisection and dentinal stain penetration could be assessed. Two different brands of type Kerr files (kerr and Maillefer) and a type K-Flex file were used for root canal preparation. They were used with the Endo PTC as an auxiliary chemical substance. The number of time used by each file was also considered. Results have shown no significant statistical differences of percentage of dentin stained, when different instruments were used. Less stain penetration could be observed when an increase of instrument action was placed, mainly observed in the apical area and tooth hemisection.

Dentin Permeability↗

Control of instrumental performance by Pavlovian and instrumental stimuli.

Two experiments used rats to examine the transfer of control of a stimulus to a new instrumental response. That transfer was successful to the degree that the stimulus and the response shared a common outcome. The transfer was more substantial, however, when the stimulus signaled the availability of that outcome for another instrumental response compared with signaling its occurrence in a Pavlovian manner. That result suggests that the stimulus-outcome associations formed during instrumental training are not reducible to a Pavlovian association.

Animals↗

A comparison of Wisconsin instrumentation and Cotrel-Dubousset instrumentation.

Twenty-six patients who underwent Wisconsin instrumentation and 36 patients who underwent Cotrel-Dubousset instrumentation (CDI) for idiopathic scoliosis were studied. Inclusion in the study required at least 24-month follow-up. Variables compared included operating time, blood loss, frontal plane correction, axial and sagittal plane changes, effects on compensation, and complications. In general, operating time, blood loss, and instrumentation problems were greater with CDI. Thoracic curve correction in King II curves was better with CDI. There was no advantage to either system with respect to sagittal plane alignment or rotation. When all factors were considered, a significant advantage to use of CDI could not be demonstrated.

Adolescent↗

The development of an instrumented tamp-filling capsule machine I. Instrumentation Of a Bosch GKF 400S machine and feasibility study.

The instrumentation of capsule filling machines operating by the tamp-filling principle has been described only once, using strain gauges. In the present paper the instrumentation of a Bosch GKF 400S tamp-filling machine has been described using a prototype of a pneumatic tamping head equipped with a piezoelectric force transducer. The pneumatic system replaces the conventional springs situated between tamping pins and upper part of the tamping head. Via a feedback switch valve, the air pressure inside the pneumatic chamber can be regulated. This provides a potential mechanism for feedback control of capsule fill weight during continuous capsule filling. It was found that the use of the pneumatic tamping head is limited to the control of fill weight during tamping. Major adjustments of fill weight at the set-up stage of the machine should be made by alteration of the tamping pin and powder bed height settings. The principles of capsule fill weight control by continuous monitoring of tamping forces have been established, but the transfer of the system to full industrial use requires further development of the prototype by the machine manufacturer.

Capsules↗

The tabletting machine as an analytical instrument: qualification of the tabletting machine and the instrumentation with respect to the determination of punch separation and validation of the calibration procedures.

The quality of the determination of punch separation in an eccentric tabletting machine equipped with two inductive displacement transducers was carefully investigated, since this tabletting machine is used as an 'analytical instrument' for the evaluation of the compression behaviour of pharmaceutical materials. For a quasistatic calibration procedure using gauge blocks, the repeatability under standard conditions and the robustness against variations in machine settings, installation conditions, equipment and methods were examined. The readings during calibration can be easily influenced by machine parameters as a result of deficiencies in the construction of the machine and in the mode of instrumentation. The poor plane-parallelism of the punch faces has a further negative effect on the accuracy of punch separation. In addition, the response at loading to lower and higher forces as during calibration was investigated. While at loading up to 100 N, the response of the system to the gauge blocks is systematically influenced by punch separation, for slow manually applied punch-to-punch loading up to 16.5 kN at a broad range of penetration depths, no significant effects were observed in the region of interest for tabletting. To get an indication of the transferability of the calibration and the determination of punch deformation to normal operating conditions, the lateral tilting of the punches during dynamic idle runs, punch-to-punch loading, and compression of microcrystalline cellulose was analyzed. A transfer of the response derived from punch-to-punch compression to tabletting conditions seems to be possible, although this must be questioned on grounds of theoretical considerations. From all the experiments performed, a total error of about +/- 30 microns must be assessed for the determination of punch separation.

Calibration↗

ADCS Prevention Instrument Project: assessment of instrumental activities of daily living for community-dwelling elderly individuals in dementia prevention clinical trials.

BACKGROUND: In primary prevention trials for Alzheimer disease, the inception cohort typically has normal or minimally impaired complex activities of daily living (ADL). ADL change during a trial could trigger detailed evaluation or serve as an outcome measure. A brief, easily administered, and reliable ADL rating scale would assist prevention studies. OBJECTIVES: To develop an ADL scale for prevention trials that allows self-rating or completion by informants. METHODS: The Activities of Daily Living-Prevention Instrument (ADL-PI) was developed, comprising 15 ADL and 5 physical function questions. Six hundred forty-four elderly subjects participating in the Prevention Instrument Project completed a self-rated version of the ADL-PI, and informants for 632 subjects completed an informant version. Informants also completed a Mild Cognitive Impairment (MCI) ADL questionnaire to allow comparisons. RESULTS: Subjects performed well on all ADL scales at baseline. Completion of the ADL-PI questionnaires at home or in-clinic yielded comparable information. Scores from baseline to 3 months had good reliability. The ADL-PI, obtained from either self-report or informants, discriminated between subjects rated as CDR 0 and CDR 0.5. Subjects with worse baseline cognitive performance also had slightly worse ADL-PI scores. Preliminary analysis indicates that subjects who triggered cognitive evaluations had slightly lower baseline ADL-PI scores by both self and informant reports. CONCLUSIONS: The ADL-PI can be completed at home or in clinic, and has adequate reliability. The utility of self-administered and informant versions and predictive value of reported deficits requires further follow-up.

Activities of Daily Living↗

Linguistic aspects of magnitude-estimation scaling of instrumental music, instrumental music with vocal accompaniment, and spoken lyrics.

An analysis of variance of magnitude estimates of loudness of three different types of complex auditory stimuli, instrumental music, instrumental music with vocal accompaniment, and spoken lyrics showed, for 100 young adults, no differences for the types of stimuli. The linguistic aspects of these complex auditory stimuli do not differentially influence loudness judgments.

Adolescent↗

Early mobilization of adolescent scoliosis patients following Wisconsin interspinous segmental instrumentation as an adjunct to Harrington distraction instrumentation. Preliminary report.

This is a preliminary report of the authors' first 40 patients treated by posterior spinal fusion with Wisconsin interspinous segmental instrumentation (WISSI) with a minimum 18-month follow-up period. No major complications because of the instrumentation were encountered. The patients were allowed to sit in a chair on the second or third postoperative day. Early elimination of postoperative casts resulted in an increased rate of problems with fixation and led to reintroduction of a postoperative orthosis, but not the body cast. Some fixation problems may have been related to technical errors and use of the earlier one-button technique. In two patients who had hook dislodgement, the WISSI maintained spinal correction thereby demonstrating its stabilizing effect.

Adolescent↗

A comparison of instrument-centering ability within the root canal for three contemporary instrumentation techniques.

AIM: To study and compare Great Taper (GT) hand files using a reversed balanced force technique, nickel-titanium (NiTi)flex files with a balanced force technique and stainless steel (SS) K-type files using a step-back technique. METHODOLOGY: Forty-eight extracted mandibular premolar teeth with single root canals having curvatures between 15 and 45 degrees were prepared using a modified Bramante model and randomly divided into three groups. The teeth were cross-sectioned at 2, 6 and 10 mm from the working length. Preoperative images of canals at three levels were captured at 20x magnification using a stereomicroscope. Canals in each group were, respectively, prepared to an apical size.10 GT file with 0.2 mm tip diameter, size 30 NiTiflex file and size 30 SS K-file. The GT file was used in a reversed balanced force technique, the NiTiflex file was used in a balanced force technique, and the SS K-file was used in a step-back technique. Postoperative canals were imaged under the conditions same as those for the preoperative canals. The postoperative images were superimposed over the preoperative images using software photoshop 6.0. The ability to maintain the instrument in the central axis of the canal and the deviation from the central canal axis were determined and compared by statistical analysis, along with the assessment of the amount of dentine removed. RESULTS: At apical level, the centering ratio, the distance of transportation and the dentine removed in GT and NiTiflex groups were significantly less than those in SS group (P < 0.01), but no statistical differences were found between the two NiTi groups. At other levels, there were no substantial differences amongst the groups. CONCLUSIONS: Compared with SS K-files, GT hand files and NiTiflex files remain better centered and produce significantly less transportation in curved canals.

Bicuspid↗