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PubMedDate not supplied

Clinical evaluation of the efficacy and safety of an ultrasonic toothbrush system in an elderly patient population.

Twelve dentulous patients, age 65 or older, with no medical or pharmacologic predisposition to gingival hyperplasia were enrolled in a controlled clinical trial to evaluate the effect of the unaided use of an ultrasonic toothbrush on supragingival plaque and gingival bleeding. Subjects used the ultrasonic toothbrush in lieu of their conventional toothbrushes for a 30-day period. Clinical measurements of the plaque index and bleeding index were made at baseline and at 15 and 30 days. At the end of the 30-day test period, the use of the ultrasonic toothbrush resulted in significant reductions in plaque score, proportion of high plaque surfaces, and bleeding index. The reduction of the bleeding index indicates significant improvement in oral health. In this study, the use of an ultrasonic toothbrush effectively improved oral hygiene and health in a population that often exhibits decreased manual dexterity. Strategies for oral health care assessment and education for guidance of effective interventions are included in checklist form; level of care classification, cost in both time involved and equipment, and purchase instructions also are discussed. Further study is warranted to evaluate this instrument for cognitively impaired elders, who often rely on caregivers for oral hygiene procedures.

Aged↗

PubMed2000

Experimental designs in the optimisation of ultrasonic bath-acid-leaching procedures for the determination of trace elements in human hair samples by atomic absorption spectrometry.

Experimental designs were used for the optimisation of acid-leaching procedures assisted by ultrasonic energy for the extraction of Ca, Cu, Fe, Mg, Mn and Zn from human hair samples. A Plackett-Burman 2(7) x 3/32 design for seven factors ([HNO3], [HCl], [H2O2], acid/oxidant solution volume, exposure time to ultrasounds, temperature of the ultrasonic bath and hair particle size) was used in order to choose the variables affecting the acid-leaching process. The variables [HNO3], [HCl] and temperature of the ultrasonic bath were found to be the most important parameters for the acid-leaching procedure, and these variables were optimised by a response surface design (central composite design 2(3) + star) which involved 16 experiments. Optimum values in the 3.7-4.2 M range were found for [HNO3], while optimum values between 3.0 and 3.5 M were found for [HCl]. The optimum temperature of the ultrasonic bath was between 80 and 90 degrees C. An acid digestion induced by microwave energy (details given) was used to obtain the total metal concentration and also for comparative purposes. Ca, Cu, Fe, Mg and Zn were measured by flame atomic absorption spectrometry (FAAS) using a conventional air/acetylene flame, while Mn was determined by electrothermal atomic absorption spectrometry (ETAAS) under optimised conditions. Two different reference materials, IAEA-085 International Atomic Energy Agency, Monaco) and NIES No. 13 (National Institute for Environmental Studies, Japan), with certified metal contents for some of the elements investigated, were used in order to verify the accuracy of the methods.

Calcium↗

PubMed1993

Effect of an ultrasonic device on temperatures generated in bone and on bone-cement structure.

Cement removal during revision arthroplasty can be a tedious, time-consuming process. The usual methods of removing cement include high-speed drills, chisels, saws and reamers, which are often associated with fracture and/or perforation of the femoral shaft. Ultrasound has been used in dentistry to remove plaque and in ophthalmology to remove cataracts and is now applied to cement removal in orthopaedic surgery. There is little data available on the effect of ultrasound on temperatures generated in bone and on its effects on the structure of bone-cement. A cement mantle was constructed in the intramedullary canal in each of six 10 cm lengths of human cadaver femora. A temperature probe was then inserted into predrilled holes and temperatures generated by the ultrasonic device were recorded under a variety of conditions. In addition, a cement cylinder was microscopically evaluated after an ultrasonic tool had been inserted. Temperatures generated by the ultrasonic tool in cadaver bone were no higher than previously reported temperatures of 140 degrees C generated by high-speed drills. Furthermore, temperatures at the bone-cement interface never exceeded 60 degrees C when saline irrigation was used in conjunction with the ultrasonic tools, and were below 40 degrees C 1 minute after deactivation of the device. Microscopic examination shows that ultrasound produced local changes in the structure of bone-cement converting it from a microscopically spherical interlocked material to one that appears homogeneous and granular.

Bone Cements↗

PubMedDate not supplied

Detection of remote myocardial infarction with quantitative real-time ultrasonic characterization.

We have previously shown that the intrinsic properties of myocardium can be characterized quantitatively by the assessment of ultrasonic integrated backscatter. In this study we utilized a novel, real-time, two-dimensional system capable of quantitative integrated backscatter imaging to determine whether zones of remote myocardial infarction in dogs could be delineated definitively by ultrasonic tissue characterization. Detection of such zones in patients is needed as a basis for management decisions related to thrombolysis, angioplasty, and coronary surgery. Integrated backscatter was measured through the closed chest from 25 myocardial sites. Zones of infarction exhibited time-averaged integrated backscatter values approximately 10 dB (9.5 +/- 0.5 dB, standard error of the mean) greater than those in normal regions (p less than 0.001). In addition, the physiologic cardiac cycle--dependent variation of integrated backscatter was blunted significantly in zones of infarction [0.8 dB +/- 0.3 vs. 3.8 +/- 0.6 (p less than 0.01) for normal regions]. Ultrasonic results matched the histopathologic features assessed directly. Thus quantitative ultrasonic tissue characterization can differentiate infarcted tissue from normal myocardium and offers promise for quantitative detection of histopathology in vivo.

Animals↗

PubMed1996

Aortic valve debridement by ultrasonic surgical aspirator in degenerative, aortic valve stenosis: follow-up with Doppler echocardiography.

OBJECTIVE: Recently there has been an emphasis on reconstructing diseases native valves as an alternative to prosthetic valve replacement. Whereas; the surgical repair of aortic valve stenosis has been always problematic. This study was performed to estimate the clinical results after aortic valve debridement using ultrasonic energy. METHODS: Between 1990-1994 26 patients underwent ultrasonic aortic valve decalcification. There were 15 females and 11 males, the age was in average 74 years. As a concomitant diagnosis 88% patients (23) had mostly mild, aortic valve insufficiency, 16 (61%) had coronary artery disease and 11 (42%) had mild mitral valve incompetence. All of the patients were operated with cardiopulmonary bypass using moderate hypothermia, cardioplegical arrest and topical cooling for myocardial protection. The calcifications were removed tangentially using Cavitron Ultrasonic Surgical Aspirator. (CUSA), CAVITRON, USA. Leaflet perforation and/or unsatisfactory valve closure have been indications for aortic valve replacement. RESULTS: Two operative death (8%) have occurred and six patients have died in the further course (follow-up mean 17 months ranging from 4 to 61 months). Postoperative Doppler-Echocardiography results taken directly after surgery and then again 17 months later (n = 18) showed a decrease of peak and mean gradients across the aortic valve three and two times respectively (p < 0.001). 17 months after debridement we observed a mild rise in both gradients (by peak gradient p < 0.05). Directly postoperative, the aortic valve area increased doubly and decreased 17 months later slight, but it was still statistically significant in comparison with our preoperative data (p < 0.001). Follow-up echocardiography demonstrated late onset of moderate aortic valve insufficiency in 6 patients. The classification of New York Heart Association was improved in 13 (72%) survivors after 17 months. CONCLUSIONS: Ultrasonic debridement of aortic valve stenosis allows precise and energy-controlled removal of calcium, increased doubly the valve area and decreased of peak and mean gradients statistically significant. The advantages of preserving the native aortic valve in elderly patients are relative good arguments; although a longer follow-up is necessary to establish this procedure.

Aged↗

PubMed1995

Effects of ultrasonic root-end cavity preparation on the root apex.

This study determined the effect of bur and ultrasonic preparation on the root apex. After cleaning, shaping, and obturation of root canals of 47 single-rooted teeth and resection of their apexes were done, 24 root-end cavities were prepared with a bur, and the rest were prepared with ultrasonic tips attached to two different ultrasonic units. After photographs of the prepared root ends were taken, their resin replicas were prepared and examined with a scanning electron microscope. Photographs and scanning electron microscope photomicrographs were examined for the presence or absence of cracks. The results showed a significantly higher incidence of crack formation in the walls of root-end cavities prepared by ultrasonic tips compared with those made by the bur.

Analysis of Variance↗

PubMed1998

Ultrasonic root end cavity preparation assessed by an in situ impression technique.

PROBLEM: In vitro studies have demonstrated microfractures in resected roots after root end cavity preparation with ultrasonic tips. Such microfractures are of concern; however, they may be artifacts. OBJECTIVES: To assess the incidence of microfractures after ultrasonic root end cavity preparation in situ. STUDY DESIGN: Fifty-two roots in two cadavers were endodontically treated, the soft tissues excised, and the root ends exposed and resected. The resected root surfaces were replicated with polyvinylsiloxane impressions. Root end cavities were prepared with ultrasonic tips, then impressed a second time. The roots were retrieved; 25 were processed for direct SEM examination as were both the impressions of each root. The specimens were examined by stereomicroscope and scanning electron microscope. RESULTS: In the impressions, the resected and prepared surfaces appeared irregular, but none demonstrated microfractures. In contrast, 15 retrieved roots showed microfractures. CONCLUSIONS: Ultrasonic root end cavity preparation in situ did not cause root microfractures, and the impression technique could be clinically usable with minor modifications.

Artifacts↗

PubMed2001

Simple quantification of ultrasonic intensity using aqueous solution of phenolphthalein.

Aqueous phenolphthalein solution under sonication was investigated for use as a chemical dosimeter. The fading time of aqueous phenolphthalein solution under sonication depended on the concentration of phenolphthalein and the pH values of solutions. The fading time was correlated to the ultrasonic intensity in a reaction vessel that is estimated on the basis of decomposition of porphyrin. The relation between the fading time and the ultrasonic intensity for different frequencies is expressed by a single curve. From these results, it is indicated that aqueous solutions of phenolphthalein is useful for simple quantification of ultrasonic intensity for practical use, and one can regard it as one of the ultrasonic intensity indicators.

Phenolphthalein↗

PubMed2001

Ultrasonic irradiation effect in the impregnation-reduction process of preparing Pt/Nafion NH(4)(+) sensor.

A systematic study on the ultrasonic irradiation effect in the impregnation-reduction (I-R) process for preparing a Pt/Nafion electrode was carried out in a flow-injection system of ammonium ion detection. Both the impregnation and the reduction stages were affected by ultrasonic irradiation which increased the sensing currents of electrodes. Moreover, the effect of ultrasonic irradiation was found more significant in the reduction process than in the impregnation process. The relationship between sensing current and power of ultrasonic irradiation was also obtained. The specific active surface area of the Pt/Nafion electrodes were evaluated by the cyclic voltametric technique. Meanwhile, the surfaces of the electrodes were characterized by XRD and SEM.

Electrodes↗

PubMed2002

Kinetics and mechanisms of ultrasonic degradation of volatile chlorinated aromatics in aqueous solutions.

Ultrasonic decompositions of chlorobenzene (ClBz), 1,4-dichlorobenzene and 1-chloronaphthalene were investigated at 500 kHz in order to gain insight into the kinetics and mechanisms of the decomposition process. The disappearance of ClBz on sonication is almost simultaneously accompanied by the release of chloride ions as a result of the rapid cleavage of carbon-chlorine bonds with a concomitant release of CO, C2H2, CH4 and CO2. The intermediates resulting from attack of HO. radicals were detected but in a quite low yield (less than 2 microM). The generation of H2O2 on sonolysis is not significantly affected by the presence of aqueous ClBz while the generation of NO2- and NO3- is inhibited initially due to the presence of ClBz which diffuses into the gas-bubble interfaces and inhibits the interactions between free radicals and nitrogen. Moreover, brown carbonaceous particles are present throughout the ultrasonic irradiation process, which are consistent with soot formation under pyrolytic conditions. These important features suggest that, at the relatively high initial substrate concentrations used in this study, ultrasonic degradation of ClBz takes place predominantly both within the bubbles and within the liquid-gas interfaces of bubbles where it undergoes high-temperature combustion. Under these conditions, the oxidation of ClBz by free radical HO. outside of bubbles is a minor factor (though results of recent studies suggest that attack by HO. is more important at lower initial substrate concentrations). The sonochemical decomposition of volatiles follows pseudo-first-order reaction kinetics but the degradation rates are affected by operating conditions, particularly initial substrate concentration and ultrasonic intensity.

Calibration↗

PubMed1999

Effect of ultrasonic treatment on the molecular weight of carboxymethylated chitin-glucan complex from Aspergillus niger.

Different factors affecting the efficiency of the ultrasonic depolymerization of the high-molecular-weight carboxymethylated chitin-glucan prepared from the fungal mycelium of Aspergillus niger have been investigated. The influence of the following parameters was examined: concentration of the chitin-glucan complex, duration of ultrasonic irradiation, reaction temperature and volume of the ultrasonicated solution. The optimized conditions for the efficient ultrasonic depolymerization include: polysaccharide concentration--0.2 mg ml-1; volume of the sonicated solution--25 ml; duration of the sonication--10 min; and constant cooling of the sonicated sample in an ice-water bath.

Aspergillus niger↗

PubMed1998

Ultrasonication: the way to achieve antimutagenic effect of carboxymethyl-chitin-glucan by oral administration.

Carboxymethyl-chitin-glucan (CMCG) isolated from Aspergillus niger was ultrasonicated to decrease its molecular weight. Ultrasonicated CMCG with molecular weight 0.19 x 10(-5) was administered either intraperitoneally or orally prior to cyclophosphamide (CP) injection and its effect on the frequency of micronuclei in polychromatic erythrocytes of mouse bone marrow was evaluated. Both ways of CMCG administration significantly decreased the clastogenic effect of CP. The protective effect of CMCG was concentration dependent, with a higher decrease achieved by 200 mg/kg than by 100 mg/kg b.wt. Ultrasonic depolymerization of high molecular CMCG resulted in its anticlastogenic effect against CP not only on intraperitoneal, but also on oral administration, achieved by decreasing its molecular weight. Ultrasonication proved to be an efficient way to obtain molecules of CMCG able to pass through the cell walls of the gastrointestinal tract.

Administration, Oral↗

PubMed2000

Low-megahertz ultrasonic properties of bovine cancellous bone.

Ultrasound offers a noninvasive means to detect changes that occur to the density of cancellous bone as a result of degenerative diseases such as osteoporosis. Techniques based on the velocity and frequency dependence of attenuation of ultrasonic pulses propagated through cancellous bone have proven sensitive to bone density. Most previous studies have investigated these two parameters in the frequency range of 0.1-1.0 MHz. The present study had two goals. The first was to measure three ultrasonic parameters: longitudinal mode velocity; broadband ultrasonic attenuation (BUA); and apparent integrated backscatter (AIB), at higher frequencies using a broadband 2.25 MHz measurement system. The second goal was to assess the dependence of these parameters on bone density. Twenty-one specimens of cancellous bone acquired from the proximal end of four bovine tibiae were investigated in this study. The apparent density of the specimens (determined with the bone marrow removed and the specimens thoroughly dry) ranged between 0.3 and 0.9 g/cm(3). Ultrasonic measurements were performed along three mutually perpendicular directions corresponding to the anteroposterior (AP), mediolateral (ML), and superoinferior (SI) axes of the tibia. A linear regression was used to analyze the results of these measurements as a function of apparent density. Velocity demonstrated a highly significant linear increase with density for all three directions (AP: p < 0.001; ML: p < 0.001; SI: p < 0.01). AIB decreased with density in all three directions; however, only the ML and SI directions demonstrated a significant linear correlation (AP: p = n.s.; ML: p < 0.05; SI: p < 0.05). In the frequency range 0.5-1.0 MHz, BUA exhibited a significant linear increase in the AP and ML directions, but not the SI direction (AP: p < 0.05; ML: p < 0.01; SI: p = n.s.). In contrast, in the frequency range 1.0-2.0 MHz, BUA exhibited a highly significant increase with density in the SI direction, but no significant change in the AP and ML directions (AP: p = n.s., ML: p = n.s., SI: p < 0.001).

Animals↗

PubMed1979

Stabilizing effect of cholesterol on phosphatidylcholine vesicles observed by ultrasonic velocity measurement.

The temperature dependence of the ultrasonic velocity was measured in sonicated vesicles of dipalmitoylphosphatidylcholine by varying the content of cholesterol. When cholesterol is incorporated, an anomalous dip of the ultrasonic velocity gradually smeared out. At the same time, the ultrasonic velocity of the membrane increased remarkably above 30 degrees C due to the increase of the bulk modulus by about 15%. On the other hand, the ultrasonic velocity and the bulk modulus decreased below 30 degrees C. Comparing the cholesterol-incorporated membrane with vesicles of bovine brain sphingomyelin and human erythrocyte membrane, we discuss the role of cholesterol in biological membranes in terms of the stability of the membrane as a barrier.

Chemical Phenomena↗

PubMedDate not supplied

Feasibility study of repeated harvesting of menthol from biologically viable Mentha x piperata using ultrasonic extraction.

To potentially replace the conventional destructive extraction process, we have shown the feasibility of devising a novel technique that uses ultrasound to nonlethally and repeatedly extract menthol from biologically viable peppermint plants (Mentha x piperita). Our results show that plants ultrasonicated for 1 h at 22 degrees C in a standard 40 kHz ultrasonic bath could release approximately 17.8 microg of menthol per gram of leaf tissue (2% of total product). The amount of menthol release increases with the time of treatment and is greatly affected by the temperature of the ultrasonic bath water. An increase from 2% to 12% of total product was observed when the temperature was increased from 22 degrees C to 39 degrees C. When the temperature effects were isolated, the mechanism of the product release was found to be that of cavitation. The treated plants remained viable and were ready for the subsequent ultrasound extraction after approximately 4 days of recuperation. However, the amount of product released is reduced in subsequent extractions. Scanning electron micrographs indicate that there are two mechanisms involved in extraction: (1) the diffusion of product through the cuticle of peppermint glandular trichomes and (2) the exudation of the product from broken and damaged trichomes. This study has shown the possibility of using an on-line ultrasonic, nondestructive extraction method to continuously release intracellular plant metabolites from the plants while maintaining the plant's viability.

Equipment Design↗

PubMed2006

Ultrasonically induced degradation of microcystin-LR and -RR: identification of products, effect of pH, formation and destruction of peroxides.

Microcystins (MCs) are a family of toxic peptides produced by a number of cyanobacteria commonly found in lakes, water reservoirs, and recreational facilities. The increased eutrophication of freshwater supplies has led to an increase in the incidence of cyanobacterial harmful algal blooms and concerns over the public health implications of these toxins in the water supply. Conventional water treatment methods are ineffective at removing low concentrations of cyanotoxins, hence specialized treatment is usually recommended for treatment of contaminated water. In this study, the products of ultrasonically induced degradation of microcystin-LR (MC-LR) and microcystin-RR (MC-RR) were analyzed by LC-MS to elucidate the probable pathways of degradation of these toxins. Results indicate preliminary products of sonolysis of MCs are due to the hydroxyl radical attack on the benzene ring and diene of the Adda peptide residue and cleavage of the Mdha-Ala peptide bond. The effect of pH on the toxin degradation was evaluated since the pH of the solution changes upon ultrasonic irradiation and varies with the water quality of treatable waters. The initial rate of MC-LR degradation is greater at acidic pH and coincides with the change in hydrophobic character of MC-LR as a function of pH. Hydrogen and organic peroxides are formed during ultrasonic irradiation, but can be eliminated by adding Fe(II). The addition of Fe(II) also accelerates the degradation of MC-LR, presumably by promoting the formation of hydroxyl radicals via conversion of ultrasonically produced H2O2. These findings suggest that sonolysis can effectively degrade MCs in drinking water.

Hydrogen-Ion Concentration↗

PubMed2004

Heat-induced changes in the ultrasonic properties of whey proteins.

The physical aggregation of commercial whey protein isolate (WPI) and purified beta-lactoglobulin was studied by ultrasound spectroscopy. Protein samples were dialyzed to achieve constant ionic strength backgrounds of 0.01 and 0.1 NaCl, and gelation was induced in situ at constant temperatures (from 50 to 75 degrees C) or with a temperature ramp from 20 to 85 degrees C. Changes in the ultrasonic properties were shown in the early stages of heating, at temperatures below those reported for protein denaturation. During heating, the relative ultrasound velocity (defined as the difference between sample velocity and reference velocity) decreased continuously with temperature, indicating a rearrangement of the hydration layer of the protein and an increase in compressibility of the protein shell. At temperatures <50 degrees C the ultrasonic attenuation decreased, and <65 degrees C both velocity and attenuation differentials showed increasing values. A sharp decrease in the relative velocity and an increase in the attenuation at 70 degrees C were indications of "classical" protein denaturation and the formation of a gel network. Values of attenuation were significantly different between samples prepared with 0.01 and 0.1 M NaCl, although no difference was shown in the overall ultrasonic behavior. WPI and beta-lactoglobulin showed similar ultrasonic properties during heating, but some differences were noted in the values of attenuation of WPI solutions, which may relate to a less homogeneous distribution of aggregates caused by the presence of alpha-lactalbumin and other minor proteins in WPI.

Chemical Phenomena↗

PubMed2005

Ultrasonic spectroscopy and differential scanning calorimetry of liposomal-encapsulated nisin.

The thermal stability of phosphatidylcholine (PC) liposomes (colloidal dispersions of bilayer-forming polar lipids in aqueous solvents) in the presence and absence of the antimicrobial polypeptide nisin was evaluated using differential scanning calorimetry (DSC) and low-intensity ultrasonic spectroscopy (US). PC liposome mixtures with varying acyl chain lengths (C16:0 and C18:0) were formed in buffer with or without entrapped nisin. Gel-to-liquid crystalline phase transition temperatures (T(M)) of liposomes determined from DSC thermograms were in excellent agreement with those determined by ultrasonic velocity and attenuation coefficient measurements recorded at 5 MHz. The dipalmitoylphosphatidylcholine (DPPC) T(M) measured by DSC was approximately 41.3 and approximately 40.7 degrees C when measured by ultrasonic spectroscopy. The T(M) of distearoylphosphatidylcholine (DSPC) and DPPC/DSPC 1:1 liposomes was 54.3 and 54.9 degrees C and approximately 44.8 and approximately 47.3 degrees C when measured by DSC and US, respectively. The thermotropic stability generally increased upon addition of nisin. Analysis of the stepwise decrease in ultrasonic velocity with temperature indicated an increased compressibility corresponding to a loss of structure upon heating.

Anti-Bacterial Agents↗