scholarly journals Effect of spray air settings of speed-increasing contra-angle handpieces on intrapulpal temperatures, drilling times, and coolant spray pattern

2021 ◽  
Author(s):  
Edina Lempel ◽  
József Szalma
Keyword(s):  
Water Jet ◽  
Drilling Force ◽  
Cooling Mode ◽  
Preparation Time ◽  
Spray Pattern ◽  
Jet Cooling ◽  
Custom Made ◽  
Molar Teeth ◽  
Dental Practices ◽  
Mist Cooling

Abstract Objectives Decreasing aerosol leaks are of great interest, especially in the recent era of COVID-19. The aim was to investigate intrapulpal heat development, coolant spray patterns, and the preparation efficiency of speed-increasing contra-angle handpieces with the spray air on (mist) or off (water jet) settings during restorative cavity preparations. Methods Standard-sized cavities were prepared in 80 extracted intact human molar teeth using diamond cylindrical drills with a 1:5 speed-increasing contra-angle handpiece. A custom-made device maintained the standardized lateral drilling force (3 N) and predetermined depth. Temperatures were measured using intrapulpal thermocouple probes. The four experimental groups were as follows: mist cooling mode at 15 mL/min (AIR15), water jet cooling mode at 15 mL/min (JET15), mist cooling mode at 30 mL/min (AIR30), and water jet cooling mode at 30 mL/min (JET30). The coolant spray pattern was captured using macro-photo imaging. Results The JET15 group had the highest increase in temperature (ΔT = 6.02 °C), while JET30 (ΔT = 2.24 °C; p < 0.001), AIR15 (ΔT = 3.34 °C; p = 0.042), and AIR30 (ΔT = 2.95 °C; p = 0.003) had significantly lower increases in temperature. Fine mist aerosol was formed in the AIR15 and AIR30 preparations but not in the JET15 and JET30 preparations (p < 0.001). The irrigation mode had no influence on the preparation time (p = 0.672). Conclusions Water jet irrigation using coolant at 30 mL/min appeared to be the optimal mode. Considering the safe intrapulpal temperatures and the absence of fine mist aerosols, this mode can be recommended for restorative cavity preparations. Clinical significance To increase infection control in dental practices, the water jet irrigation mode of speed-increasing handpieces with coolant flow rates of 30 mL/min should be considered for restorative cavity preparations.

Performance characteristics of a downward spray water-jet cooling tower

2014 ◽  
Vol 69 (1-2) ◽  
pp. 165-176 ◽  
Author(s):  
Thirapong Muangnoi ◽  
Wanchai Asvapoositkul ◽  
Pibool Hungspreugs
Keyword(s):  
Cooling Tower ◽  
Water Jet ◽  
Performance Characteristics ◽  
Jet Cooling

Water-jet cooling in the thermal strengthening of asymmetric profiles

2015 ◽  
Vol 45 (3) ◽  
pp. 226-230 ◽  
Author(s):  
Yu. I. Lipunov ◽  
K. Yu. Eismondt ◽  
E. V. Nekrasova ◽  
M. V. Zakharchenko ◽  
Yu. G. Yaroshenko ◽  
...  
Keyword(s):  
Water Jet ◽  
Jet Cooling

scholarly journals Characteristics and Applications to the Iron and Steel Making Processes of Water Jet Cooling

1981 ◽  
Vol 67 (14) ◽  
pp. 2117-2124
Author(s):  
Yasushi UENO ◽  
Shunichi SUGIYAMA ◽  
Kazuo KUNIOKA
Keyword(s):  
Water Jet ◽  
Iron And Steel ◽  
Jet Cooling ◽  
Steel Making

scholarly journals Comparison of Canal Transportation, Separation Rate, and Preparation Time between One Shape and Neoniti (Neolix): An In Vitro CBCT Study

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Maryam Kuzekanani ◽  
Faranak Sadeghi ◽  
Nima Hatami ◽  
Maryam Rad ◽  
Mansoureh Darijani ◽  
...  
Keyword(s):  
File Systems ◽  
In Vitro Study ◽  
Acrylic Resin ◽  
Preparation Time ◽  
Technical Performance ◽  
Molar Teeth ◽  
Canal Transportation ◽  
Time Required ◽  
Instrument Separation

Purpose. This in vitro study compared root canal preparation in curved mesiobuccal canals of molar teeth using either the One Shape™ or the Neoniti (Neolix) rotary NiTi single-file systems, assessing canal transportation, instrument separation and time required for preparation. Methods. Extracted maxillary and mandibular human molar teeth with mesiobuccal canals having apical angles of curvature between 25 and 35o were selected and embedded in acrylic resin blocks, and an initial CBCT was taken. The teeth were divided into two equal groups (n = 20), and the canals were cleaned and shaped using either Neoniti™ or One Shape™ engine-driven NiTi rotary files. Each individual instrument was used to prepare 5 canals. The time required for the preparation of each canal was recorded. Postpreparation CBCT scans were taken and used to determine the extent of canal transportation at levels of 2, 4, 6, and 8 mm from the apex. The Kolmogorov–Smirnov test for normality was applied, and then, datasets were compared using independent t-tests, with a threshold of P < 0.05 . Results. Neoniti rotary files caused significantly less canal transportation of the curved canals ( P = 0.0001 ). On the other hand, the time required for canal preparation was significantly shorter for One Shape ( P = 0.0001 ). No instrument separation was recorded in both groups. Conclusion. Based on these results, the Neoniti™ rotary file system is preferred because it maintains the original shape of curved root canals better than One Shape™; even though this benefit comes at the cost of an increase in preparation time in clinical practice, the better technical performance may be more important than a difference in procedural time.

Metal Machining With High-Pressure Water-Jet Cooling Assistance—A New Possibility

1989 ◽  
Vol 111 (1) ◽  
pp. 7-12 ◽  
Author(s):  
M. Mazurkiewicz ◽  
Z. Kubala ◽  
J. Chow
Keyword(s):  
High Pressure ◽  
Removal Rate ◽  
Water Jet ◽  
Jet Injection ◽  
Jet Cooling ◽  
Metal Machining ◽  
The Coefficient Of Friction ◽  
Pressure Water ◽  
Frictional Forces ◽  
High Pressure Water Jet

Metal machining is one of the fundamental manufacturing processes. The principal cost of shaping metal parts is generated both in the work involved in shearing metal from the original stock, at the area where the chips are formed, and also in the work required to overcome the high frictional forces that exist between the chip and rake face. Current techniques for the lubrication and cooling of this area are not very effective, resulting in a machining cost which is much higher than need be. A more efficient lubricooling effect can be achieved by the use of a high-pressure water jet directed into the tool/chip interface. The study of this idea was prompted by results achieved in the 1950’s, but now extended to much higher jet injection pressures (up to 280 MPa). The emphasis of this article is on the comparison of the coefficient of friction at the tool/rake interface for conventional and high-pressure jet cooling and also on reporting some practical results. Evaluation of these results indicates both a significant gain in the material removal rate as well as an improvement in the chip shape. The results are for a UNS 1020 steel—a representative of the poorly machinable materials.

scholarly journals Glide path enlargement of curved molar canals using HyFlex EDM glide path file versus PathFile: a comparative study of preparation time and postoperative pain

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yi Han ◽  
Xiao-Mei Hou
Keyword(s):  
Postoperative Pain ◽  
Mixed Models ◽  
Preparation Time ◽  
Cavity Preparation ◽  
Electric Discharge Machine ◽  
Pain Scores ◽  
Glide Path ◽  
Molar Teeth ◽  
Discharge Machine ◽  
To Receive

Abstract Background This randomized clinical trial aimed to compare the preparation time and severity of postoperative pain between HyFlex Electric Discharge Machine (EDM) glide path file (GPF) and PathFile. Methods Eighty patients whose molar teeth had at least one severely curved canal were treated by the same specialist. After access cavity preparation, the patients were randomly assigned to receive glide path enlargement with either HyFlex EDM GPF or PathFile. ProTaper Next X1 and X2 files were used to prepare the canals. The time of preparation was assessed and the severity of postoperative pain over the next 7 days was recorded. The preparation time and the postoperative pain scores were compared using the Linear Mixed Models (P ≤ 0.05). Results Glide path enlargement time was significantly shorter with HyFlex EDM GPF (27.828 ± 2.345 s) than with PathFile (48.942 ± 2.864 s) (P < 0.001). The highest postoperative pain score was recorded on the first day and the pain decreased over time in both groups. HyFlex EDM GPF group patients reported significantly less postoperative pain than PathFile group patients overall (P < 0.001). Conclusions Postoperative pain and glide path preparation time could be reduced by using HyFlex EDM GPF system. Trial registration PKUSSNCT, PKUSSNCT-17B12, Registered 24 October 2017.

Prediction of Surface Temperature and Heat Flux of a Microelectronic Chip With Jet Impingement Cooling

1990 ◽  
Vol 112 (1) ◽  
pp. 57-62 ◽  
Author(s):  
X. S. Wang ◽  
Z. Dagan ◽  
L. M. Jiji
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Temperature ◽  
Transfer Problem ◽  
Jet Impingement ◽  
Lower Surface ◽  
Water Jet ◽  
Uniform Heat Flux ◽  
Impingement Cooling ◽  
Jet Cooling

In this paper, a previously developed analytic solution is applied to the conjugate heat transfer problem of jet impingement cooling of a microelectronic chip. The analysis is used to predict the surface temperature and heat flux distributions of a chip cooled by a laminar impinging FC-77 liquid or water jet with uniform heat flux dissipation at the heated bottom of the chip. Results are presented for two jet diameters of 0.5 and 1 mm. It is shown that, for a constant Reynolds number, the surface temperature is lower when the jet diameter is smaller. On the other hand, when the jet diameter is increased, the surface temperature and heat flux distributions are more uniform. Water jet impingement cooling shows much lower surface temperature and much higher heat transfer coefficient than FC-77 jet cooling. The thermal resistance for FC-77 liquid jet is 6 times larger than that for a water jet.

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