High-speed Air Turbine Handpiece Research Articles

Machinability of high-speed enamel cutting with carbide bur

The cutting of tooth enamel using a high-speed air-turbine handpiece and carbide bur is a key procedure in oral surgeries, such as the minimally invasive extraction. However, presently little is known about the cutting mechanics and material removal mechanism related to tooth enamel machinability. In this study, the machinability of high-speed enamel cutting with carbide bur is studied by a computer-aided numerical control system. The dynamic cutting forces of enamel of the occlusal, buccal/lingual, and proximal surfaces were measured by the force measuring system. The force ratio, cutting torque, rotating speed, specific cutting energy, and bur wear were analyzed. The microstructure of enamel and carbide burs was observed by the scanning electron microscope, and the relationship between enamel microstructures and machinability was further analyzed. The results show that during the high-speed enamel cutting with carbide bur, the chip thickness is on the nano-scale, and the plastic deformation of the machined surface is obvious. With increased material removal rate, the cutting force, torque, specific cutting energy, and bur wear increases accordingly, whereas the rotating speed decelerates (p < 0.05). The different angles between the cutting direction and the axial direction of the enamel rods give rise to the large differences in the cutting mechanics and mechanism of the proximal, buccal/lingual, and occlusal surfaces of the teeth. When the cutting direction is parallel, vertical, and oblique 45° to the axial direction of the enamel rods, the force required for material fracture and crack propagation increases, and the cutting force increases as a consequence. Parallel and oblique 45° cutting are the main modes of tooth segmentation in the minimally invasive extraction. In comparison with the parallel cutting mode, the cutting force, torque, and cutting ratio of the oblique 45° cutting mode can be significantly increased, and the tool wear is obviously accelerated. This is the lowest priority in segmentation surgery, hence the problems of overload and temperature rise need to be considered. The cutting mechanics and cutting mechanism obtained in this study will provide scientific process guidance for dental cutting operations with the air-turbine handpiece driving bur.

Designing high-speed dental air-turbine handpiece by using a computational approach

The high-speed dental air-turbine handpieces are widely used in the dentistry as a tool for cutting and drilling a tooth. The impeller of the air-turbine handpiece rotates a cutting bur through the compressed-air. Two dental handpieces which have standard type head (Model 1) and torque type head (Model 2) were designed using computational analysis. The advanced existing high-speed dental air-turbine handpieces were investigated to compare with the designed dental handpieces. The computational domain of the air-turbine was investigated using ANSYS CFX software. The impeller blade type which has high torque value was selected to design the air-turbine impeller. The performance of the designed handpieces was verified through the measurements and the pre-clinical tests. The results showed that the newly designed handpieces had excellent performance which is compatible with existing advanced handpieces.

Can you identify faults in a high-speed handpiece?

Holliday R, Venugopal S, Howell A, Keys W (2015) Operator's ability at assessing a high-speed (air turbine) handpiece before use: an audit. Br Dent J 218: doi: 10.1038/sj.bdj.2015.40

A testing methodology for suck-back behavior of high-speed air-turbine dental handpiece

치과용 고속 에어터빈 핸드피스는 압축공기를 이용하여 핸드피스 헤드 내부의 임펠러를 구동시키는 치아절삭에 사용되는 치과용 의료기기이다. 압축공기의 유동특성에 따른 압력 변화로 인하여 고속 치과용 에어터빈 핸드피스는 사용 중 기체 흡입 현상이 발생하는데 이런 현상을 에어터빈 핸드피스의 suck-back 현상이라고 한다. Suck-back 현상 때문에 치료 시 환자 구강 내의 혈액, 박테리아 등 유해물질이 핸드피스의 내부로 흡입되는데 치과용 에어티빈 핸드피스는 일회용 의료기기가 아니므로 여러 환자들한테 사용될 때 설령 소독하더라도 교차감염(cross-infection)의 위험이 발생하게 된다. 하지만 suck-back 현상에 대해 평가하는 연구가 아직 많이 부족한 상태이다. 연구에서는 suck-back을 방지할 수 있는 기능으로 설계된 상용화 된 5개 제품의 핸드피스에 대해 특별히 제작된 측정 장치를 이용하여 suck-back 성능을 평가하였다. 실험은 측정하려는 5사 제품의 구동 시 최대 압력, 정지 순간의 최소 압력을 측정하고 suck-back 현상이 지속되는 시간을 측정하였다. 실험 결과 A사 제품은 최소 압력이 0 bar로써 suck-back 현상이 발생하지 않았다. 반면 기타 4사의 제품은 suck-back 현상이 발생하였는데 그 중 B사 제품은 평균값 -0.00bar(-0.01bar부터 0bar 사이의 값), E사 제품은 -0.01(0)bar, C사 제품은 -0.019(0.003)bar, D사 제품은 -0.04(0)bar의 결과를 보였다. 또한 suck-back 현상의 지속 시간은 B사 제품이 1.83초로 가장 오래 유지되었으며 그 다음으로 D사 제품이 1.82초, E사 제품은 1.56초, C사 제품은 1.30초, 그리고 A사 제품은 0초로 가장 짧았다. 실험 결과 본 연구에서 고안한 에어터빈 핸드피스의 suck-back 현상 시험 방법은 정량적으로 측정할 수 있을 것으로 사료되었다.

Effects of handpiece speed on the performance of undergraduate dental students in preclinical training

Abstract Objective Low-speed high-torque handpieces are popular for the pre-clinical training of dental students. However, in clinical practice, high-speed air turbine handpieces are commonly used. This dissimilarity creates a gap between pre-clinical and clinical training skills. The current study sought to evaluate the effects of the use of high-speed and low-speed handpieces by dental students during their pre-clinical training. Methods Twenty-one undergraduate dental students at the College of Dentistry of Taibah University participated in this study. Each student was asked to prepare class I cavities using high-speed air turbine and low-speed/high-torque handpieces. The time required for cavity preparation was recorded by the authors. The prepared cavities were evaluated for quality and skill using a six-point scale. The data were statistically analysed with paired t and Mann–Whitney tests. Results There was no significant difference in cavity preparation time between the low-speed and high-speed handpieces (538.29 and 483.76 s, respectively). The evaluations of the cavities revealed no difference in the quality of preparations between the low- and high-speed handpieces. Additionally, no significant difference in the surface roughness of the preparations was observed. Conclusions The type of handpiece did not influence the learning capabilities of the undergraduate dental students in the preparation of preparing class I cavities. This study did not observe any significant differences between the cavities that were prepared by our students using either high-speed or low-speed handpieces.

Subcutaneous Emphysema and Pneumomediastinum during Extraction of Maxillary Third Molar: A Case Report

Subcutaneous emphysema and pneumomediastinum is a relatively uncommon phenomenon. It may occur secondary to dental treatment using high-speed air turbine handpieces, especially after extraction of tooth. Subcutaneous emphysema is often limited only to the areas of head and neck, but also can involve deeper structures. Thorough examination and conservative treatment of these problems are essential in preventing life-threatening complications such as airway obstruction and mediastinitis. The subject of this report is a 57-year-old woman with subcutaneous emphysema and pneumomediastinum during the extraction of maxillary third molar using highspeed air turbine handpiece. If there isn’t any appropriate measure, severe complications may occur. Therefore it is important to be well-informed of proper diagnosis and treatment. This article shall present a case report with literature review.

Cervicofacial subcutaneous emphysema associated with dental laser treatment

Cervicofacial subcutaneous emphysema is a rare complication of dental procedures. Although most cases of emphysema occur incidentally with the use of a high-speed air turbine handpiece, there have been some reports over the past decade of cases caused by dental laser treatment. Emphysema as a complication caused by the air cooling spray of a dental laser is not well known, even though dental lasers utilize compressed air just as air turbines and syringes do. In this study, we comprehensively reviewed cases of emphysema attributed to dental laser treatment that appeared in the literature between January 2001 and September 2012, and we included three such cases referred to us. Among 13 cases identified in total, nine had cervicofacial subcutaneous and mediastinal emphysema. Compared with past reviews, the incidence of mediastinal emphysema caused by dental laser treatment was higher than emphysema caused by dental procedure without dental laser use. Eight patients underwent CO2 laser treatment and two underwent Er:YAG laser treatment. Nine patients had emphysema following laser irradiation for soft tissue incision. Dentists and oral surgeons should be cognizant of the potential risk for iatrogenic emphysema caused by the air cooling spray during dental laser treatment and ensure proper usage of lasers.

Changes in the cutting efficiency of different types of dental diamond rotary instrument with repeated cuts and disinfection

Cutting efficiency is one of the most important factors to consider when a specific dental diamond rotary instrument is selected. However, the selection of a dental diamond rotary instrument is based on clinical experience rather than any scientific evidence. The purpose of this study was to identify how the cutting efficiency of different types of dental diamond rotary instrument changed with repeated cuts and disinfection. Four types of diamond rotary instrument from 2 dental manufacturers (Shofu, Jin Dental) were investigated with a high-speed air-turbine handpiece. The groups were as follows: S cham group (n=10): chamfer design from Shofu; J cham group (n=10): chamfer design from Jin Dental; S thin group (n=10): thin tapered design from Shofu; J thin group (n=10): thin tapered design from Jin Dental. Changes in the cutting efficiency of diamond rotary instruments on glass ceramic blocks were measured after repeated cuts. Changes in cutting efficiency also were measured for 30 diamond rotary instruments, the same type as those used in group J cham after disinfection with ethylene oxide gas, immersion in solution, or autoclaving. One-way ANOVA, 2-way ANOVA, and repeated-measures ANOVA were used to identify differences in cutting efficiency, in total cutting efficiency, and change trend in cutting efficiency (α=.05). The Tukey honestly significant difference method was used for the post hoc tests. The principal metal components of the diamond rotary instruments were detected with x-ray spectrometry. The mean (standard deviation [SD]) total cutting efficiency after 10 cuts in the 4 groups was in the following order: J cham group (0.210 ± 0.064 g/min) > S cham group (0.170 ± 0.064 g/min) > J thin group (0.130 ± 0.042 g/min) > S thin group (0.010 ± 0.040 g/min) (P<.05).The decrease in the cutting efficiency was greatest after the first cut. The cutting efficiency was not influenced by repeated disinfection. The cutting efficiencies of diamond rotary instruments with different designs and particle sizes showed a decreasing trend after repeated cuts but did not show any change after various disinfecting procedures.

How the development of the high-speed turbine handpiece changed the practice of dentistry

The development of the high-speed air turbine handpiece changed the practice of dentistry dramatically for both dentists and patients and created a practice transformation that perhaps was more rapid than any the profession has seen. The decade of the 1950s was the period in which a few investigators worked on developing handpieces that could drive tooth cutting instruments at higher and higher speeds. The early 1960s is when the high-speed air turbine handpiece changed dentistry.

How the development of the high-speed turbine handpiece changed the practice of dentistry

The development of the high-speed air turbine handpiece changed the practice of dentistry dramatically for both dentists and patients and created a practice transformation that perhaps was more rapid than any the profession has seen. The decade of the 1950s was the period in which a few investigators worked on developing handpieces that could drive tooth cutting instruments at higher and higher speeds. The early 1960s is when the high-speed air turbine handpiece changed dentistry.

In vitro study of anti-suck-back ability by themselves on new high-speed air turbine handpieces

The anti-suck-back ability of five new high-speed air turbine handpiece models was evaluated in this study. First, suck-back pressure with water displacement within a glass tube was measured. Next, under three different conditions, how many on-off times it takes before fluorescent stains became visible on a piece of gauze at the exhaust vent was counted and the presence of fluorescent stains on the exhaust vents itself was examined. As a result, the water height for each part of one handpiece, the TWINPOWER TURBINE PAR-4HX-O, was below 0 mm. Except for under full emersion, this model, the TWINPOWER TURBINE PAR-4HX-O, did not have any visible fluorescence penetration to the exhaust vent even after 500 on-off switches under fume/mist conditions. Conversely, the other handpieces (Ti-Max X700L, T1 CONTROL, SYNEA TA-98CLED, GENTLE silence LUX 8000B) showed suck-back. In conclusion, the first mentioned new turbine handpiece, the TWINPOWER TURBINE PAR-4HX-O, had a possibility of no suck-back by itself. However, full immersion of the whole head of the handpiece which is not completely sealed must be avoided to prevent liquid intake.

Efficacy of pre-procedural rinsing in reducing aerosol contamination during dental procedures

Our objective was to determine the efficacy of pre-procedural rinsing with chlorhexidine in reducing bacterial aerosol contamination during use of ultrasonic scaler and high speed air turbine handpiece. Twenty patients, ten each for the two groups who were found to satisfy the inclusion criteria were selected for the study. Four predesignated locations of the dental clinic were chosen to be evaluated for each patient using blood agar plates. Aerosols were collected during treatment procedures for control and experimental quadrants. Results showed that a regimen of 30-seconds pre-procedural rinsing with 0.12% chlorhexidine gluconate before dental procedures consistently reduced colony-forming units than without rinsing due to the ability of antiseptic mouthwash to inhibit microbial growth. There was more aerosol contamination during scaling procedures than during the use of a high speed air turbine handpiece. The conclusion is that chlorhexidine is an effective primary measure in reducing aerosol cross-contamination when using dental devices in a dental set up.

Comparative histopathological analysis of human pulps after class I cavity preparation with a high-speed air-turbine handpiece or Er:YAG laser

The purpose of this study was to comparatively evaluate the response of human pulps after cavity preparation with different devices. Deep class I cavities were prepared in sound mandibular premolars using either a high-speed air-turbine handpiece (Group 1) or an Er:YAG laser (Group 2). Following total acid etching and the application of an adhesive system, all cavities were restored with composite resin. Fifteen days after the clinical procedure, the teeth were extracted and processed for analysis under optical microscopy. In Group 1 in which the average for the remaining dentin thickness (RDT) between the cavity floor and the coronal pulp was 909.5 μm, a discrete inflammatory response occurred in only one specimen with an RDT of 214 μm. However, tissue disorganization occurred in most specimens. In Group 2 (average RDT = 935.2 μm), the discrete inflammatory pulp response was observed in only one specimen (average RDT = 413 μm). It may be concluded that the high-speed air-turbine handpiece caused greater structural alterations in the pulp, although without inducing inflammatory processes.

Discharge of lubricant from air turbine handpieces

To demonstrate and quantify the discharge of lubricating oil from high-speed air turbine handpieces whilst running. Dye-marked oil (Kavospray, KaVo) was used to lubricate four handpieces (Quiet-Air, Midwest) and the air discharged from around the lower bearing was directed at the moving chart paper on a recorder whilst running for 40 minutes. Secondly, seven new handpieces (Quiet-Air, 300SE, Midwest; Topair 796, Topair 795, W+H; VIP-Sigma, Pana-air, NSK; Lares, Lares Research) were cleaned, weighed and then lubricated with unmarked oil (Kavospray, KaVo). Oil discharge was determined gravimetrically over runs of 240 minutes. Data were fitted to the logistic dose response function. The dye-marked oil tests showed that oil was discharged for at least 40 minutes in the direction of the bur. The gravimetric tests showed that oil continued to be discharged up to at least 240 minutes, and that the usual practice of removing excess lubricant by running for 1-2 minutes was ineffective in preventing cut-surface contamination. Bonding procedures in dentistry may be jeopardised by oil contamination from handpiece lubricants. Decontamination with a detergent is suggested as a means of ensuring effective adhesive dentistry.

Contamination by air turbine handpieces

Objective To demonstrate and quantify the discharge of lubricating oil from high-speed air turbine handpieces whilst running. Materials and methods Dye-marked oil (Kavospray, KaVo) was used to lubricate four handpieces (Quiet-Air, Midwest) and the air discharged from around the lower bearing was directed at the moving chart paper on a recorder whilst running for 40 minutes. Secondly, seven new handpieces (Quiet-Air, 300SE, Midwest; Topair 796, Topair 795, WH VIP-Σ, Pana-air, NSK; Lares, Lares Research) were cleaned, weighed and then lubricated with unmarked oil (Kavospray, KaVo). Oil discharge was determined gravimetrically over runs of 240 minutes. Data were fitted to the logistic dose response function. Result The dye-marked oil tests showed that oil was discharged for at least 40 minutes in the direction of the bur. The gravimetric tests showed that oil continued to be discharged up to at least 240 minutes, and that the usual practice of removing excess lubricant by running for 1-2 minutes was ineffective in preventing cut-surface contamination. Significance Bonding procedures in dentistry may be jeopardised by oil contamination from handpiece lubricants. Decontamination with a detergent is suggested as a means of ensuring effective adhesive dentistry.

The development of the dental high-speed air turbine handpiece. Part 2.

Australian Dental JournalVolume 38, Issue 2 p. 131-143 The development of the dental high-speed air turbine handpiece. Part 2* J. E. Dyson, Corresponding Author J. E. Dyson Lecturer, Department of Prosthetic Dentistry, University of Hong Kong.Department of Prosthetic Dentistry, University of Hong Kong, Prince Philip Dental Hospital. 34 Hospital Road, Hong Kong.Search for more papers by this authorB. W. Darvell, Corresponding Author B. W. Darvell Head, Dental Materials Science Unit, University of Hong Kong.Department of Prosthetic Dentistry, University of Hong Kong, Prince Philip Dental Hospital. 34 Hospital Road, Hong Kong.Search for more papers by this author J. E. Dyson, Corresponding Author J. E. Dyson Lecturer, Department of Prosthetic Dentistry, University of Hong Kong.Department of Prosthetic Dentistry, University of Hong Kong, Prince Philip Dental Hospital. 34 Hospital Road, Hong Kong.Search for more papers by this authorB. W. Darvell, Corresponding Author B. W. Darvell Head, Dental Materials Science Unit, University of Hong Kong.Department of Prosthetic Dentistry, University of Hong Kong, Prince Philip Dental Hospital. 34 Hospital Road, Hong Kong.Search for more papers by this author First published: April 1993 https://doi.org/10.1111/j.1834-7819.1993.tb05475.xCitations: 17 * Based on work undertaken by JED for the degree of PhD, University of London. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume38, Issue2April 1993Pages 131-143 RelatedInformation

The development of the dental high-speed air turbine handpiece. Part 1.

The high-speed air turbine handpiece is currently used for most dental cutting procedures and has been in widespread use for more than thirty years. Although reports of its historical background have been previously published these have not dealt with all relevant developments and some inconsistencies exist. The history of the development of turbines and their application in dental cutting systems from the late 19th century to the present day is now reviewed. An historical account of the recognition of benefits that may accrue from rotary cutting at increased speeds is given and the various attempts that have been made to design equipment capable of high speeds are discussed. Consideration is given to the development of non-rotary cutting devices, as is the failure of these adequately to replace the air turbine handpiece for routine work. It is concluded that the air turbine handpiece will continue to hold a leading position in the field for some years to come but that future improvements would be facilitated by the development of an understanding of the theoretical aspects of its behaviour.

Hearing-damage Risk and Communication Interference in Dental Practice

The use of high-speed air-turbine handpieces, operated at 300,000 to 400,000 revolutions per minute, has led to concern over the possibility of noise-induced hearing loss. Sound levels were measured in clinical settings and in a pre-clinical laboratory for estimation of hearing-damage risk among dentists, and the extent of communication interference. Octave-band sound pressure levels were obtained with use of a Fast-Fourier-Transform analyzer and associated instrumentation. The results of this study indicate that the sound energy contribution of a typical dental practice is about 8% to 12% of the dentist's average 24-hour noise exposure. However, noise levels during dental procedures result in an articulation index of 0.21 to 0.37, corresponding to understanding of about 18% to 48% of nonsense syllables and 52% to 90% of sentences. It appears that hearing-damage risk is slight among dentists using modern equipment. However, further noise control in handpieces is necessary so that error-free communication during dental procedures can be ensured.

Benign osteoblastoma of the mandible : Sidhu S. S., Parkash H. and Dhanani N. J. Dent. 8 (1980) 254–256

Low-speed high-torque handpieces are popular for the pre-clinical training of dental students. However, in clinical practice, high-speed air turbine handpieces are commonly used. This dissimilarity creates a gap between pre-clinical and clinical training skills. The current study sought to evaluate the effects of the use of high-speed and low-speed handpieces by dental students during their pre-clinical training.Twenty-one undergraduate dental students at the College of Dentistry of Taibah University participated in this study. Each student was asked to prepare class I cavities using high-speed air turbine and low-speed/high-torque handpieces. The time required for cavity preparation was recorded by the authors. The prepared cavities were evaluated for quality and skill using a six-point scale. The data were statistically analysed with paired t and Mann–Whitney tests.There was no significant difference in cavity preparation time between the low-speed and high-speed handpieces (538.29 and 483.76 s, respectively). The evaluations of the cavities revealed no difference in the quality of preparations between the low- and high-speed handpieces. Additionally, no significant difference in the surface roughness of the preparations was observed.The type of handpiece did not influence the learning capabilities of the undergraduate dental students in the preparation of preparing class I cavities. This study did not observe any significant differences between the cavities that were prepared by our students using either high-speed or low-speed handpieces.

Bilateral 180° rotation of maxillary second premolars: a case report : Lui J. L. J. Dent. 8 (1980) 257–259

Low-speed high-torque handpieces are popular for the pre-clinical training of dental students. However, in clinical practice, high-speed air turbine handpieces are commonly used. This dissimilarity creates a gap between pre-clinical and clinical training skills. The current study sought to evaluate the effects of the use of high-speed and low-speed handpieces by dental students during their pre-clinical training.Twenty-one undergraduate dental students at the College of Dentistry of Taibah University participated in this study. Each student was asked to prepare class I cavities using high-speed air turbine and low-speed/high-torque handpieces. The time required for cavity preparation was recorded by the authors. The prepared cavities were evaluated for quality and skill using a six-point scale. The data were statistically analysed with paired t and Mann–Whitney tests.There was no significant difference in cavity preparation time between the low-speed and high-speed handpieces (538.29 and 483.76 s, respectively). The evaluations of the cavities revealed no difference in the quality of preparations between the low- and high-speed handpieces. Additionally, no significant difference in the surface roughness of the preparations was observed.The type of handpiece did not influence the learning capabilities of the undergraduate dental students in the preparation of preparing class I cavities. This study did not observe any significant differences between the cavities that were prepared by our students using either high-speed or low-speed handpieces.