The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform

Robert Sader - One of the best experts on this subject based on the ideXlab platform.

  • comparison of er yag laser piezoelectric and Drill osteotomy for Dental implant site preparation a biomechanical and histological analysis in sheep
    Lasers in Surgery and Medicine, 2010
    Co-Authors: Stefan Stubinger, Robert Sader, Kristina Biermeier, Beatus Bachi, Stephen J Ferguson, Brigitte Von Rechenberg
    Abstract:

    Background and Objectives The aim of this study was to examine the influence of implant bed preparation, using either Er:YAG laser ablation, piezoelectric surgery or Drill osteotomy, on osseointegration of titanium Dental implants after 4, 6, and 8 weeks. Material and Methods A total of 108 implants (Camlog) were placed in the pelvis of 6 sheep (18 implants/sheep). Implant sites were prepared by an Er:YAG laser, a Dental Drill or a piezoelectric device. For each time period, six implants were used for biomechanical removal torque testing and six implants for a semi-quantitative histological assessment of the bone-to-implant contact (BIC). Results An initially missing implant adjusted site preparation led to slightly higher BIC and torque values in the piezoelectric and laser groups due to a press-fit effect after 4 weeks. Statistical analysis of the average mean BIC after 4, 6, and 8 weeks revealed no significant differences (P > 0.05) between the different osteotomy techniques. Comparison of individual removal torque values showed the highest value for laser osteotomy after 8 weeks (1,698.50 ± 67.52 Nmm), which was significantly higher than the corresponding value for Drill osteotomy (P = 0.006). Conclusion Although BIC and removal torque values decreased in the laser and piezoelectric groups at 6 weeks during an active remodeling process, favorable and superior BIC as well as torque values could be demonstrated at 8 weeks. Thus laser and piezoelectric osteotomy seem to be at least comparable to Drill osteotomy, concerning early osseointegration and implant stability. Lasers Surg. Med. 42:652–661, 2010. © 2010 Wiley-Liss, Inc.

  • ultrasonic bone cutting in oral surgery a review of 60 cases
    Ultraschall in Der Medizin, 2008
    Co-Authors: Stefan Stubinger, Constantin A Landes, O Seitz, Hansflorian Zeilhofer, Robert Sader
    Abstract:

    Surgical reconstruction of bony defects in the oral cavity can often be challenging since thin and fragile bony structures are especially prone to fracture cased by bulky cutting tips or the application of significant pressure by conventional mechanical instruments. The risk of acciDental damage to adjacent soft tissue structures, such as nerves, by a Dental Drill or saw is also extremely high. The use of modulated ultrasound (piezosurgery) makes it possible to overcome such complications as a result of the precise and minimally invasive surgery technique which is limited to mineralized hard tissue.

Mikako Hayashi - One of the best experts on this subject based on the ideXlab platform.

  • Statistical Analysis for Subjective and Objective Evaluations of Dental Drill Sounds
    PloS one, 2016
    Co-Authors: Tomomi Yamada, Sonoko Kuwano, Shigeyuki Ebisu, Mikako Hayashi
    Abstract:

    The sound produced by a Dental air turbine handpiece (Dental Drill) can markedly influence the sound environment in a Dental clinic. Indeed, many patients report that the sound of a Dental Drill elicits an unpleasant feeling. Although several manufacturers have attempted to reduce the sound pressure levels produced by Dental Drills during idling based on ISO 14457, the sound emitted by such Drills under active Drilling conditions may negatively influence the Dental clinic sound environment. The physical metrics related to the unpleasant impressions associated with Dental Drill sounds have not been determined. In the present study, psychological measurements of Dental Drill sounds were conducted with the aim of facilitating improvement of the sound environment at Dental clinics. Specifically, we examined the impressions elicited by the sounds of 12 types of Dental Drills in idling and Drilling conditions using a semantic differential. The analysis revealed that the impressions of Dental Drill sounds varied considerably between idling and Drilling conditions and among the examined Drills. This finding suggests that measuring the sound of a Dental Drill in idling conditions alone may be insufficient for evaluating the effects of the sound. We related the results of the psychological evaluations to those of measurements of the physical metrics of equivalent continuous A-weighted sound pressure levels (LAeq) and sharpness. Factor analysis indicated that impressions of the Dental Drill sounds consisted of two factors: "metallic and unpleasant" and "powerful". LAeq had a strong relationship with "powerful impression", calculated sharpness was positively related to "metallic impression", and "unpleasant impression" was predicted by the combination of both LAeq and calculated sharpness. The present analyses indicate that, in addition to a reduction in sound pressure level, refining the frequency components of Dental Drill sounds is important for creating a comfortable sound environment in Dental clinics.

  • Effect of processing of Dental Drill noise on subjective impression
    Applied Acoustics, 1
    Co-Authors: Tomomi Yamada, Sonoko Kuwano, Shigeyuki Ebisu, Mikako Hayashi
    Abstract:

    Abstract The sound produced by a Dental air turbine handpiece (Dental Drill) can markedly influence the sound environment in a Dental clinic, and many patients have reported that the sound of a Dental Drill elicits unpleasant feelings. A comfortable sound environment for patients is desirable in medical care. To identify approaches for improving the sound quality of Dental Drills, we need to determine systematically the effects of the physical properties of the sounds of Dental Drills on their impressions. We, therefore, prepared 40 sound stimuli by processing different sound levels or frequency components comprising the sounds emitted by four kinds of Dental Drills. This study is designed to use psychoacoustic experiments to determine the effects of Dental Drill sounds on subjective impressions. The analysis resulted in the following findings: the overall attenuation of each original sound stimulus by 5 dB or 10 dB had statistically significant effects and improved the unpleasant impression. Attenuation of the frequency components above 9 kHz by 10 dB also improved the impressions, relative to those for the original sound stimuli. When the prominent frequency components at approximately 6 kHz were attenuated by 10 dB, no statistically significant differences were observed between the impressions corresponding to the original and processed stimuli. The Comfort Index (CI), which consists of the equivalent continuous A-weighted sound pressure level (LAeq) and calculated sharpness, showed a good correlation with unpleasant impressions. The present findings suggest that the consideration of acoustical characteristics based on the CI is useful in reducing the sound pressure level and refining the frequency characteristics of sounds emitted by Dental Drills, and this can aid in the development of new Dental devices to create a comfortable sound environment in Dental clinics.

Brian Millar - One of the best experts on this subject based on the ideXlab platform.

  • Noise Reduction of Dental Drill Noise
    Mechatronics, 2008
    Co-Authors: Krgr Rotter, E Kaymak, Mark Atherton, Brian Millar
    Abstract:

    Dental Drills produce a characteristic noise that is uncomfortable for patients and is also known to be harmful to dentists under prolonged exposure. It is therefore desirable to protect the patient and dentist whilst allowing two-way communication, which will require a headphone - type system. Re-establishing good communication between the dentist and patient will be achieved through a combination of three noise cancellation technologies, namely, Passive Noise Control (PNC), Adaptive Filtering (AF) and Active Noise Control (ANC). This paper describes how far a test-rig has been developed to achieve sufficient noise reduction that the uncomfortable noise can no longer be heard.

  • Dental Drill noise reduction using a combination of active noise control, passive noise control and adaptive filtering
    2007
    Co-Authors: E Kaymak, Krg Rotter, Ma Atherton, Brian Millar
    Abstract:

    Dental Drills produce a characteristic high frequency, narrow band noise that is uncomfortable for patients and is also known to be harmful to dentists under prolonged exposure. It is therefore desirable to protect the patient and dentist whilst allowing twoway communication. A solution is to use a combination of the three main noise control methods, namely, Passive Noise Control (PNC), Adaptive Filtering (AF) and Active Noise Control (ANC). This paper discusses the application of the three methods to reduce Dental Drill noise while allowing two-way communication. Experimental setup for measuring the noise reduction by PNC is explained and results from different headphones and headphone types are presented. The implementation and results of an AF system using the Least Mean Square (LMS) algorithm are shown. ANC requires a modification of the LMS algorithm due to the introduction of the electro-acoustical cancellation path transfer function to compensate for the delays introduced by the control system. Therefore a cancellation path transfer function modeling method based on the filtered reference LMS (FXLMS) algorithm is presented along with preliminary results of the implementation.

  • Active noise control on high frequency narrow band Dental Drill noise: Preliminary results
    2007
    Co-Authors: E Kaymak, Krg Rotter, Ma Atherton, Brian Millar
    Abstract:

    Dental Drills produce a characteristic noise that is uncomfortable for patients and is also known to be harmful to dentists under prolonged exposure. It is therefore desirable to protect the patient and dentist whilst allowing two-way communication. A solution is to use a combination of the three main noise cancellation methods, namely, Passive Noise Control, Adaptive Filtering and Active Noise Control. Dental Drill noise occurs at very high frequency ranges in relation to conventional ANC, typically 2kHz to 6kHz and it has a narrow band characteristic due to the direct relation of the noise to the rotational speed of the bearing. This paper presents a design of an experimental rig where first applications of ANC on Dental Drill noise are executed using the standard filtered reference Least Mean Square (FXLMS) algorithm. The secondary path is kept as simple as possible, due to the high frequency range of interest, and hence is chosen as the space between headphone loudspeaker and error microphone placed in the ear (input of the headphone loudspeaker and the output of the error microphone). A standard headphone loudspeaker is used for the control source and the microphone inside of an “Ear and Cheek Simulator Type 43AG” is used as the error microphone. The secondary path transfer function is obtained and preliminary results of the application of ANC are discussed.

  • Real-time adaptive filtering of Dental Drill noise using a digital signal processor
    2006
    Co-Authors: E Kaymak, Mark Atherton, Krg Rotter, Brian Millar
    Abstract:

    The application of noise reduction methods requires the integration of acoustics engineering and digital signal processing, which is well served by a mechatronic approach as described in this paper. The Normalised Least Mean Square (NLMS) algorithm is implemented on the Texas Instruments TMS320C6713 DSK Digital Signal Processor (DSP) as an adaptive digital filter for Dental Drill noise. Blocks within the Matlab/Simulink Signal Processing Blockset and the Embedded Target for TI C6000 DSP family are used. A working model of the algorithm is then transferred to the Code Composer Studio (CCS), where the desired code can be linked and transferred to the target DSP. The experimental rig comprises a noise reference microphone, a microphone for the desired signal, the DSK and loudspeakers. Different load situations of the Dental Drill are considered as the noise characteristics change when the Drill load changes. The result is that annoying Drill noise peaks, which occur in a frequency range from 1.5 kHz to 10 kHz, are filtered out adaptively by the DSP. Additionally a schematic design for its implementation in a dentist’s surgery will also be presented.

Peter Schaps - One of the best experts on this subject based on the ideXlab platform.

  • Percutaneous burrhole trephination of the skull: a study of 519 cases
    Neurosurgical Review, 1994
    Co-Authors: Gilfe Reiß, Gert Andersch, Wolfgang Handrick, Christian Kellner, Jan Koy, Thomas Pinzer, Peter Schaps
    Abstract:

    We want to report on our experiences with the percutaneous trephination using a 2.35 mm round Dental Drill with serrated saws around it, a “Rosenbohrer”. It is a methodically similar activity as described by J. Zentner [11]. From 1981 to 1992 519 patients were treated and 546 trephinations were performed. At the beginning this treatment was only used in connection with intracerebral bleedings and biopsies. In a considerable short time the indication could be extended to the subdural hematoma, tumor cyst, obstructive hydrocephalus as well as to the abscess and the subdural epyema. The rate of infection was 1.28% and the risk of bleeding 0.36%. In our opinion the advantages of this small electrical trephination are the easy handling, the universal use and mobility and the avoidable risk of anesthesia as well as the sterilisation at the same time and the stopping of blood, caused by the contact surface friction.

Michael W. Berns - One of the best experts on this subject based on the ideXlab platform.

  • Effects of cavity preparation using a nanosecond-pulsed Nd-YAG laser on tooth-restoration interface
    Lasers in Medical Science, 1997
    Co-Authors: Petra Wilder-smith, Steve Lin, A Nguyen, Michael W. Berns
    Abstract:

    This study evaluated the tooth-restoration interface between composite resin or glass ionomer cement and the tooth surface in teeth where caries removal and cavity preparation were performed either with the Dental Drill, the Dental Drill and laser irradiation, or laser irradiation alone. A nanosecond-pulsed Nd-YAG laser was used at energy densities of 2–8 J cm^-2. After tooth restoration, microleakage tests were performed using methylene blue. Using general linear model procedures, no significant differences in microleakage were determined between ‘Drill’ and ‘Drill and laser’-prepared groups (p< 0.01) in resinand in glass-ionomer-restored teeth. These specimens showed significantly less dye penetration than the ‘laser only’ group (p< 0.0001). No correlation was found between fluence and microleakage using either restorative material ( p = 0.8). Dye penetration was significantly greater in the composite-filled than in the glass-ionomer group (p< 0.05). Mechanisms influencing laser effects on bonding require further investigation before clinical application of lasers as an alternative to the Dental Drill can become viable.