Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DENTAL APPARATUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed1979

Treatment with a position feedback-controlled head stabilizer.

A position feedback-controlled head stabilizer has been developed to provide cerebral palsied individuals with resistive exercise to strengthen the neck musculature. This apparatus detects "involuntary" head motion and stabilizes the head by applying opposing forces; it also can be used to facilitate muscular contraction by resisting the subject's voluntary movements. The purpose of the present study was to determine whether voluntary head control in cerebral palsied individuals can be improved through systematic exercise using the stabilizer to strengthen the muscles of the neck and improve their balance of action. The findings support the author's contention that this is possible. The apparatus consists of a helmet and shoulder pads, interconnected so that the head is supported in the helmet by a manipulator arm. At its lower end, the manipulator arm is attached to the shoulder pad mounting frame via a gimbal assembly which allows head movement in two planes of tilt (pitch, or forward-and back, and roll, or side-to-side). Feedback control circuitry is so arranged that any deviation of the head from the desired position leads to actuation of pneumatic cylinders, which apply torques to the manipulator gimbal axes so as to oppose or conteract the incipient head movement. It is particularly significant that none of these patients participating in these experiments were at all apprehensive about or resisted being placed in the apparatus. (Even the youngest subject to use the apparatus--five year old-- did not mind being restrained by the shoulder pads or having his head gripped by helment.) While JG utilized the safety release valve quite often during the first few head control training sessions, he soon became confident enough in the action of the stabilizer that he did not even bother to grip the handle of the release valve. While DA had the action of safety valve explained and demonstrated for her, she never bothered to use it even from the outset of her experience with the stabilizer. Thus, it seems that the football shoulder pads use to stabilize the shoulders and the hockey helmet used to grip and manipulate the head actually make the apparatus attractive to younger patients, while the padding thereby provided makes it comfortable enough to be tolerated well by older individuals. And, the subject's knowing that he has an override control by means of which he can assert command over the entire system appears to be of psychological benefit in establishing confidence in both the apparatus and the investigator.

Adolescent↗
PubMedDate not supplied

[Prevention and early treatment of gingivitis and periodontitis].

The presence of dental plaque leading to gingivitis is regarded as the most important cause of periodontitis which develops from gingivitis. The destruction of the periodontal tissues may be accelerated by functional disorders of the masticatory apparatus. Chemical prevention and therapy is still in its initial stages with their future being uncertain. On the other hand, prevention and therapy of periodontitis are possible by hygienic measures. The mechanical removal of dental plaque and calculus is the best way of prevention and early treatment. This is shown with the aid of a clinical study.

Dental Calculus↗
PubMed1989

[Quality of marginal sealing of Evicrol fillings when using dental adhesives in vitro].

The quality of the marginal sealing of fillings made from Evicrol in vitro was investigated by means of a couloured indicator. The close adherence of the composite filing to the surface of the tooth was ensured by the by micro retention treatment of the marginal enamel and different dentin adhesives. The thermal strain of filling materials and their combination with the tooth, corresponding roughly to conditions in the oral cavity, was modelled by cyclic temperature changes using a special apparatus designed by the authors.

Adhesives↗
PubMed1998

The effectiveness of the "Clean-Area-System" for infection control in the dental clinic.

The use of effective infection control procedures and universal precautions in dental clinics, prevents cross contamination that could extend to dental health care workers and patients. The present study was initiated to investigate airborne environmental contamination in the dental clinic by viable cell count of oral streptococci grown on Mitis-Salivarius and blood agar plates. The reduction of the contamination by the "Clean-Area-System" was evaluated. "Andersen-Microbe-Sampler-Apparatus" and "Laser-Particle-Counter-System" were used for sampling and counting the bacterial cells and airborne dust, respectively. Numbers of viable cells counted as total colony forming units (CFUs) in the dental clinic were found to be significantly higher than those in the waiting room and the research laboratory. We found that the "Clean-Area-System" significantly reduced the CFUs grown on blood agar plates (p < 0.05), and that using the "Clean-Area-System" combined with the "Extra-Oral-Vacuum-Aspirator" is desirable in dental procedures such as cavity preparation. The "Extra-Oral-Vacuum-Aspirator" reduced airborne environmental contamination during tooth cutting and ultrasonic scaling procedures. In non-grinding procedures, this system proved to be very useful for infection control in the operative area. The authors concluded that the combined use of "Clean-Area-System" (dust collection ablation) and "Extra-Oral-Vacuum-Aspirator" (absorb dust ablation) was effective to reduce airborne environmental contamination in the dental clinic. We also fully confirmed that oral streptococci were an adequate indicator in the assessment for infection control in dental institutions.

Air Conditioning↗
PubMed1979

Extrusion of rheometry of fluid materials.

A capillary extrusion rheometer was developed and tested using Newtonian oils of known viscosity and seven endodontic sealers. The described apparatus and technique appear appropriate for comparative assessment of the rheological characteristics of a variety of fluid dental materials.

Oils↗
PubMedDate not supplied

A comparative study of intravenous anaesthesia with thiopental versus althesin in outpatient dental practice.

Clinical effects of two intravenous anaesthetics--thiopental and althesin--were compared in a group of 160 outpatients. Each anaesthetic was used in 80 cases. The administration of these anaesthetics was preceded by an intravenous injection of fentanyl and atropine sulphate. Anaesthesia was carried out with the patient sitting in dental chair. The observations confirmed that this method of anaesthesia provides good conditions for carrying out minor dental operations and is safe for the patient, as evidenced by a negligible number of minor complications. A comparison of the results of clinical observations and gasometric determinations indicates that althesin is superior in outpatient practice to thiopental. This simple and easy technique of anaesthesia without the necessity of using expensive apparatus should be widely introduced in outpatient practice.

Adolescent↗
PubMed1989

[Application of electroforming for coronal restorations. Metal frame for porcelain fused to metal crowns].

Today, it has been quite important to realize that the esthetic factor the coronal restration is more emphasized in dental practice. It is popular to use porcelain as a dental material for the Coronal restoration and the technique is pretty much stabilized. Because of the color itself and its great affinity to the human body. Mostly used technique is the porcelain fused-to metal crown. However, there are various disadvantages relating to this technique. On the other hand. The electroforming technique has some great characteristics that is producing the complex shape with less difficulty, and the improvement of it's final surface. It also has the ability for reduplication. Overall, metal frame can be constracted on the same working model without a duplication of it. Therefore, it is possible to make the procedure extremely simple. Here, the author has done some experiments with the newly developed electroforming apparatus for constructing the Coronal restoration. The purpose of the experiments are to apply all these great advantages of the system to dental prosthodontics field. One characteristic of the equipment is the diffusion of current distribution by the cathode rotary system. The other one is the circulation of electrolyte for reducing the diffusion layer. Firstly, the author operated the electroposition with Ni on the three different standard models of abutment teeth, in order to determine the possibility of making a metal frame and the relationship between the shape of the abutment teeth and the current. Next experiment was to investigate if it's possible to apply the metal frame, constructed by the apparatus, to porcelain fused-to metal crown by again determining the relationship between the electropositioned metal and the porcelain. The results were obtained as follows. 1. It was possible to construct a metal frame for the porcelain fused-to metal crown by the method. 2. The minimum electroposition time was approximately 35-40 min. with a high current density. 3. The thickness of the metal frame did not effect the current, however it barely effected the shape of the abutment teeth. 4. The tensile strength by shear was approximately 150 kg/cm2. 5. There was no evident that the current has any effects on tensile strength.

Crowns↗
PubMed1976

[Studies on the strength and the cutting performance of dental canal reamer. (II). Torsional strength and tip diameter of dental canal reamers (author's transl)].

Strength of pulp canal reamers are important problems for cutting treatments of the root of tooth at the dental regions. Reamers have been used as cutting tools by the twisting movements, and then, fracture of reamers are especially caused by the shearing stress at the bite tips. So, this paper treated the shear strength of dental canal reamers, which are torsional strength and twisting rigidity of these cutting instruments. And we made the torsional apparatus for cutting and twisting tests, and tested the torsional strength of raw materials and pulp canal reamers. Type of reamer's configuration are treated by Japanese industrial standard (JIS) and these properties are readjusted with dimensions of diameter of reamers. Shear strength of reamers are 120 approximately 140 kg/mm2 and strength of straight bar with taper are about two times of that of reamers which are about 40 kg/mm2 (except reamer's number 1, 2). Scattering of value of strength and torsional angle of these reamers are examined and showed the range of scattering of these properties. Effectiveness of torsional angle on the fracture properties are considered on the clinical treatments and treated the safety of fracture of these reamers.

Dental Instruments↗
PubMed2005

Design of a stability-detecting device for dental implants.

Resonance frequency (RF) analysis technology was used to design a dental implant stability detector. The device uses a miniature-sized electromagnetic triggering rod to elicit vibration in a dental implant. Vibrational signals were recorded via an acoustic receiver. To assess the in vivo performance of the test apparatus, animal models were used. Implants were placed in the left tibia of 12 rabbits using a conventional surgical procedure. Standard 3.2 mm x 8 mm implants were placed in each test tibia with pre-tapping cavities of 3.2 mm and 3.7 mm diameters to simulate either a 'well-fitting' or a 'loosely fitting' situation. The RF values of the test implants were detected by the newly developed device which was directly mounted on the healing abutments of the implants. The results showed that the RF values of the implants under well-fitting conditions significantly increased (p < 0.01) 3 weeks after surgery and reached a plateau at around 6-7 weeks. Meanwhile implants with higher initial RF values had shorter healing times and higher final RF values at the plateau. Based on these findings, it was concluded that the idea of using the current designed device for detecting the degree of bone healing during the osseointegration process seems feasible.

Animals↗
PubMed1993

Enameloid formation in two tetraodontiform fish species with high and low fluoride contents in enameloid.

Forming teeth of parrotfish and pufferfish were viewed by transmission electron microscopy to correlate cytological features of the enameloid organ with the species' fluoride (F) content in mature enameloid. Secretory-stage inner dental epithelial cells (IDE) of parrotfish (high F) and pufferfish (low F) secreted procollagen granules into the enameloid collagen matrix. The odontoblasts of both species, less numerous than IDE cells, also contained procollagen granules at the enameloid matrix formation stage. After the full thickness of enameloid matrix collagen had been deposited, enameloid crystallites formed parallel to the long axis of the enameloid collagen fibres. Concurrently, the plasma membranes of the outer dental epithelial cells (ODE) became invaginated in both species, but to a much greater extent in parrotfish. Highly undulating parrotfish ODE cells surrounded numerous fenestrated capillaries. In contrast, pufferfish ODE cells remained straight with few adjacent capillaries. Extensive tight junctions formed between ODE and IDE cells of both species, sealing the extracellular space. With increased mineralization, enameloid collagen fibres were no longer discernible. A thin layer of amorphous material, which subsequently mineralized, was secreted on to the enameloid surface by IDE cells in both species. Pufferfish odontoblasts secreted a mineralizing amorphous layer on the pulpal aspect of the enameloid. The results suggest that at the mineralization stage, a triad of cytostructural features, highly invaginated ODE cells, highly vascularized ODE cells, and extensive tight junctions are strongly correlated with high fluoride content of mature enameloid mineral. Species without any one of these features have lower fluoride in the enameloid.

Animals↗