scholarly journals Piezosurgery – A novel tool in modern dentistry

2021 ◽  
Vol 7 ◽  
pp. 31-35
Author(s):  
B. Aishwarya ◽  
S. Lakshmi Sree ◽  
R. Balasubramanian

Dentistry has undergone significant improvement with a lot of changing concepts involving novel surgical tools over the past two decades. Piezoelectric surgery, also popularly called as piezosurgery (PS), is a rapidly evolving technique of bone surgery which is gaining importance because of its ability to place osteotomy cuts with absolute precision and confidence, especially near the vital structures. Piezosurgical device functions with an ultrasonic frequency (25–29 KHz) resulting in microvibrations in the range of 60–200 µm/s enabling bone cutting that is secured and accurate preserving the underlying neurovascular elements along with improved visibility through bloodless surgical site and thorough debridement using internal irrigation system. Till date, PS has seen wide applications in various disciplines of medicine. In the field of dentistry, PS has emerged as a promising technical modality in bone graft harvesting, alveolar ridge expansion, sinus lift procedures, osteogenic distraction, and endodontic and periodontal surgeries. The present review addresses the efficiency of PS comparing it with the traditional dental surgical equipment. The advantages, limitations, and biological effects of PS as well its various applications in dentistry have also been discussed.

1996 ◽  
Vol 35 (4I) ◽  
pp. 399-417 ◽  
Author(s):  
John W. Mellor

The right to the flow of income from water is vigorously pursued, protected, and fought over in any arid part of the world. Pakistan is of course no exception. Reform of irrigation institutions necessarily changes the rights to water, whether it be those of farmers, government, or government functionaries. Those perceived rights may be explicit and broadly accepted, or simply takings that are not even considered legitimate. Nevertheless they will be fought over. Pakistan has a long history of proposals for irrigation reform, little or none being implemented, except as isolated pilot projects. Thus, to propose major changes in irrigation institutions must be clearly shown to have major benefits to justify the hard battles that must be fought and the goodwill of those who might win those battles for reform. Proponents of irrigation institution reform have always argued the necessity of the reforms and the large gains to be achieved. Perhaps, however, those arguments have not been convincing. This paper will briefly outline the failed attempts at irrigation reform to provide an element of reality to the discussion. It will then proceed to make the case of the urgency of reform in a somewhat different manner to the past. Finally, current major reform proposals will be presented. This paper approaches justification of irrigation reform by focusing on the agricultural growth rate. It does so because that is the critical variable influencing poverty rates and is a significant determinant of over-all economic growth rates. The paper decomposes growth rates and suggests a residual effect of deterioration of the irrigation system that is large and calls for policy and institutional reform. The data are notional, suggesting the usefulness of the approach and paves the way for more detailed empirical analysis and enquiry for the future.


2019 ◽  
Vol 26 (9) ◽  
pp. 664-675
Author(s):  
Sulochana Priya

Bioactive peptides are short chain of amino acids (usually 2-20) that are linked by amide bond in a specific sequence which have some biological effects in animals or humans. These can be of diverse origin like plant, animal, fish, microbe, marine organism or even synthetic. They are successfully used in the management of many diseases. In recent years increased attention has been raised for its effects and mechanism of action in various disease conditions like cancer, immunity, cardiovascular disease, hypertension, inflammation, diabetes, microbial infections etc. Bioactive peptides are more bioavailable and less allergenic when compared to total proteins. Food derived bioactive peptides have health benefits and its demand has increased tremendously over the past decade. This review gives a view on last two years research on potential bioactive peptides derived from food which have significant therapeutic effects.


2019 ◽  
Vol 14 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Hidayat Hussain ◽  
Ivan R. Green ◽  
Muhammad Saleem ◽  
Khanzadi F. Khattak ◽  
Muhammad Irshad ◽  
...  

Background: Cucurbitacins belong to a group of tetracyclic triterpenoids that display a wide range of biological effects. In the past, numerous cucurbitacins have been isolated from natural sources and many active compounds have been synthesized using the privileged scaffold in order to enhance its cytotoxic effects. Objective: his review covers patents on the therapeutic effects of natural cucurbitacins and their synthetic analogs published during the past decade. By far, the majority of patents published are related to cancer and Structure-Activity Relationships (SAR) of these compounds are included to lend gravitas to this important class of natural products. Methods: The date about the published patents was downloaded via online open access patent databases. Results: Cucurbitacins display significant cytotoxic properties, in particular cucurbitacins B and D which possess very potent effects towards a number of cancer cells. Numerous cucurbitacins isolated from natural sources have been derivatized through chemical modification at the C(2)-OH and C(25)- OH groups. Most importantly, an acyl ester of the C(25)-OH and, iso-propyl, n-propyl and ethyl ether groups of the C(2)-OH demonstrated the most increased cytotoxic activity. Conclusion: The significant cytotoxic effects of natural and semi-synthetic cucurbitacins make them attractive as new drug candidates. Moreover, cucurbitacins have the capability to form conjugates with other anticancer drugs which will synergistically enhance their anticancer effects. The authors believe that in order to get lead compounds, there should be a greater focus on the synthesis of homodimers, heterodimers, and halo derivatives of cucurbitacins. In the opinion of the authors the analysis of the published patents on the cucurbitacins indicates that these compounds can be developed into a regimen to treat a wide spectrum of cancers.


2010 ◽  
Vol 23 (1) ◽  
pp. 47-64 ◽  
Author(s):  
Fátima Martel ◽  
Rosário Monteiro ◽  
Conceição Calhau

Polyphenols are a group of widely distributed phytochemicals present in most foods of vegetable origin. A growing number of biological effects have been attributed to these molecules in the past few years and only recently has their interference with the transport capacity of epithelial barriers received attention. This review will present data obtained concerning the effect of polyphenols upon the transport of some compounds (organic cations, glucose and the vitamins thiamin and folic acid) at the intestinal and placental barriers. Important conclusions can be drawn: (i) different classes of polyphenols affect transport of these bioactive compounds at the intestinal epithelia and the placenta; (ii) different compounds belonging to the same phenolic family often possess opposite effects upon transport of a given molecule; (iii) the acute and chronic/short-term and long-term exposures to polyphenols do not produce parallel results and, therefore, care should be taken when extrapolating results; (iv) the effect of polyphenolics in combination may be very different from the expected ones taking into account the effect of each of these compounds alone, and so care should be taken when speculating on the effect of a drink based on the effect of one component only; (v) care should be taken in drawing conclusions for alcoholic beverages from results obtained with ethanol alone. Although most of the data reviewed in the present paper refer to in vitro experiments with cell-culture systems, these studies raise a concern about possible changes in the bioavailability of substrates upon concomitant ingestion of polyphenols.


2010 ◽  
Vol 6 (2) ◽  
pp. 261-280 ◽  
Author(s):  
BRADLEY PLUNKETT ◽  
FABIO R. CHADDAD ◽  
MICHAEL L. COOK

Abstract:In the past decade, Australia has begun to privatize its irrigation system. Two general models have emerged: a single and a dual ownership structure. This paper examines the trade-offs, costs and benefits, and the attendant efficiencies regarding costs of ownership. In particular, we examine member capital investment incentives and resultant risk-bearing costs related to capital formation. The paper concludes that the dual ownership structure system has significant economic advantages relative to its single-structured counterpart.


Neurosurgery ◽  
2003 ◽  
Vol 52 (4) ◽  
pp. 867-871 ◽  
Author(s):  
Hiromu Hadeishi ◽  
Akifumi Suzuki ◽  
Nobuyuki Yasui ◽  
Yuichirou Satou

Abstract OBJECTIVE During cranial base surgery, use of a high-speed drill for osteotomy has become common. We performed anterior clinoidectomy and opening of the internal auditory canal using an ultrasonic bone curette, and we report the advantages and clinical applications of this method. DESCRIPTION OF INSTRUMENTATION The ultrasonic surgical equipment comprises a power supply unit, footswitch, and handpiece (weight, 110 g; diameter, 20 mm; length, 140 mm from tip to angled section). The handpiece tip is 2 mm wide, and the amplitude of longitudinal vibration can be varied from 120 to 365 μm at an ultrasonic frequency of 25 kHz. Cool-controlled irrigation fluid emerges near the tip, through the sheath. EXPERIENCE AND RESULTS We performed anterior clinoidectomy in eight cases of paraclinoid aneurysm and opening of the internal auditory canal in six cases of acoustic neuroma without damage to the dura mater or nearby structures such as brain tissue, blood vessels, and cranial nerves. In addition, no damage to the facial nerve or labyrinthine organ resulted from heat or vibration caused by the ultrasonic bone curette. CONCLUSION Ultrasonic bone curettage represents safe instrumentation for performance of anterior clinoidectomy and opening of the internal auditory canal without damage to surrounding structures. This technique allows surgeons to perform procedures on deep areas without incurring psychomotor stress.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shao-Yi Hsia ◽  
Yu-Tuan Chou

Massive utilization of petroleum and natural gas caused fossil fuel shortages. Consequently, a large amount of carbon dioxide and other pollutants are produced and induced environmental impact. Hydrogen is considered a clean and alternative energy source. It contains relatively high amount of energy compared with other fuels and by-product is water. In this study, the combination of ultrasonic mechanical and biological effects is utilized to increase biohydrogen production from dark fermentation bacteria. The hydrogen production is affected by many process conditions. For obtaining the optimal result, experimental design is planned using the Taguchi Method. Four controlling factors, the ultrasonic frequency, energy, exposure time, and starch concentration, are considered to calculate the highest hydrogen production by the Taguchi Method. Under the best operating conditions, the biohydrogen production efficiency of dark fermentation increases by 19.11%. Results have shown that the combination of ultrasound and biological reactors for dark fermentation hydrogen production outperforms the traditional biohydrogen production method. The ultrasonic mechanical effects in this research always own different significances on biohydrogen production.


2018 ◽  
Vol 11 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Konstantin A Konovalov ◽  
Dmitriy V Davydov ◽  
Vitaliy Yu Roshchin

Currently a wide range of instruments for surgical procedures on the bony structures of the orbits is offered. Each of them has its advantages and disadvantages. Cutter causes less injury, in comparison with a chisel or an ultrasonic saw [15]. In using a drill during surgery there was an increase in temperature of bone edge of the opening above acceptable values [17]. The use of low frequency ultrasonic tools allows you to create holes in the bones of any desired size and shape with smooth edges [5, 11, 16, 20]. The disadvantages of this method include the heating of tool’s tip up to 140° during prolonged continuous action [6]. Thus, techniques using tools for formation of the bone window require further study and improvement. Aim: to compare surgical equipment for bone window formation in modeling an orbital decompression. Materials and methods. In an experimental study in vivo, 12 surgical interventions on the scapula on both sides were performed in 6 Chinchilla breed rabbits. On the right side, the formation of a bone window was carried out by the ultrasonic bone scalpel MISONIX, on the left side - by a drill. Results. It was found that during first 7-21 days there was more pronounced inflammation of soft tissues on the left side. At the same time, delayed proliferation and maturation of fibrous connective tissue was observed in comparison to the opposite side. Bone tissue inflammation and subsequent regeneration took place without significant differences on both sides. The experiment showed that the use of ultrasonic scalpel in flat bones creates less inflammation of surrounding tissues and the bone itself as compared to a diode laser. A.V. Kravchenko (2006) reports that, after exposure to a diode laser in an acute experiment there was a scalloped edge with an area of photocarbonization (charring) on the 7th and the 21st day; while the use of an ultrasonic scalpel did not create any signs of infiltrative inflammation, later on a nonspecific inflammation developed. Conclusion. Ultrasonic scalpel has a number of advantages when performing osteoperforation, such as time-saving during surgical procedure, control of the osteotomy process, less trauma to surrounding tissues during action and less pronounced inflammatory response of the wound during early postoperative period. (For citation: Konovalov KA, Davydov DV, Roshchin VY. A comparative analysis of the application of piezoelectric surgery and mechanical osteoperforation techniques in modeling an orbital decompression. Ophthalmology Journal. 2018;11(1):10-18. doi: 10.17816/OV11110-18).


EDIS ◽  
2020 ◽  
Vol 2020 (5) ◽  
Author(s):  
Jonathan Henry Crane ◽  
Haimanote Bayabil ◽  
Edward A. Evans ◽  
Fredy Ballen

Florida's tropical and subtropical fruit crop industries use various irrigation systems, including high-volume systems designed for irrigation and freeze protection, drip systems for herbaceous fruit crops (papaya, banana), and microsprinkler types, mainly for irrigation and fertigation. There continues to be a steady stream of potential tropical and subtropical fruit producers in Florida, many with little to no knowledge of the various types or purposes of various irrigation system that have been used successfully for the past 60 years. This new 9-page publication of the UF/IFAS Horticultural Sciences Department includes potential producers, Extension faculty and agents, and irrigation companies. Written by Jonathan Crane, Haimanote Bayabil, Edward A. Evans, and Fredy Ballen.https://edis.ifas.ufl.edu/hs1375


1991 ◽  
Vol 69 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Thomas M. S. Wolever

Recent dietary guidelines advocate increased starch intake, but it is not clear as to how the increased intake of starch should be achieved. Recent data suggest that the quality of starch as well as its quantity is important in determining the biological effects of high carbohydrate diets. The quality of starchy foods can be assessed by their rates of digestion, which in turn are related to their glycaemic responses. Many factors affect the rate of digestion of foods and these are probably related to alterations in the chemical structure or nature of the starch. The incorporation of slowly digested, low glycaemic index foods into the diets of healthy subjects and individuals with diabetes and hyperlipidaemia is associated with the predicted reductions in postprandial glycaemic responses and with reductions in insulin secretion and blood lipids. In the past, the aim of starch processing has been to increase digestibility and improve absorption. However, it is now suggested that the use of more slowly digested starchy foods may have positive health benefits.Key words: carbohydrate, blood glucose responses, diet, small intestine, colonic fermentation.


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