SEARCH · PubMed Health

Results for “Application”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources

PubMed2000

Ocular penetration of topical Delta9-tetrahydrocannabinol from rabbit corneal or cul-de-sac application site.

PURPOSE: To determine the relative effects of low-volume drop placement either on the corneal surface or in the lower cul-de-sac on Delta9-tetrahydrocannabinol (THC) penetration into ocular fluids and tissues. METHODS: Pigmented rabbits received 10 microl drops in one eye at either application site. Care was taken to ensure that the drop remained at the site of drug placement. At different intervals after drop administration containing ( 3)H-Delta9-tetrahydrocannabinol in combination with either alpha-cyclodextrin or hydroxypropylmethylcellulose as excipients in different vehicles, eye fluids and tissues were harvested, digested, sampled and counted. RESULTS: Greater quantities of THC were found in the corneal epithelium, stroma/endothelium and aqueous humor of treated eyes after corneal drug application relative to values obtained after cul-de-sac drug application. Cul-de-sac applications gave higher values for inferior bulbar conjunctiva compared with corneal application. These results occurred for each vehicle despite a quantitative difference in drug penetration between the two vehicles. No THC was found in untreated contralateral eyes. CONCLUSIONS: Application of a lipophilic drug to the rabbit corneal surface exposed in the interpalpebral space produced higher tissue and fluid drug concentrations in the anterior segment of the eye compared with drug application into the lower cul-de-sac. This observation has relevance to pre-clinical drug toxicity testing as well as drop placement in patients for the treatment of ocular diseases.

Administration, Topical↗

PubMed2000

U.S. dental school applicants and enrollees: a ten year perspective.

Applications to dental schools increased throughout the 1990s until 1997. In 1998 this pattern reversed, and the number of dental school applicants has dropped each year since that time and continues to decline through the application cycle for the 2001-2002 first-year class. Possible reasons for the decline in applications include an abundance of financially rewarding career opportunities fueled by the robust U.S. economy, a reluctance by college students to assume more educational debt, an unfavorable view of healthcare careers in the light of managed care and declining federal reimbursement, and assumptions about the difficulty of gaining admittance to dental school given the high academic achievement of those who have been admitted in recent years. A national decline in the applicant pool does not necessarily translate into a decline for any given dental school. The quality of applicants, judged by grade point averages and Dental Admissions Test scores, is high. Nevertheless, the recent drop in dental school applicants is a cause for concern. Because recruitment must be approached as a process that takes years to yield results, stakeholders in dental education need to sustain vigorous recruiting efforts even in the best of times.

Career Choice↗

PubMedDate not supplied

Second trimester pregnancy termination in primigravidas by double application of dinoprostone gel and intramuscular administration of carboprost tromethamine.

A randomized study of legal pregnancy termination in the second trimester has been performed in primigravidas by endocervical application of Prepidil gel (dinoprostone gel) in combination with intramuscular application of Prostin 15 M (carboprost tromethamine). The study comprised 97 patients. The control group (N = 35) included patients in whom pharmacologic preparation of the cervix was performed by a singleton endocervical application of 0.5 mg dinoprostone gel and intramuscular administration of Prostin 15 M (Carboprost Tromethamine) (1 ml/2 h) 10 h later and until abortion. The investigated group A (N = 31) underwent pharmacologic preparation of the cervix by endocervical application of 0.5 dinoprostone gel, 2 times during an interval of 4 hours. Intramuscular injection of Prostin 15 M (Carboprost Tromethamine) (1 ml/h) was administered 6 hours after the second application of gel and until abortion. The investigated group B (N = 31) underwent pharmacologic preparation of the cervix by a singleton double-dose endocervical application of 0.5 mg dinoprostone gel and intramuscular treatment by 1 ml/2 h of Prostin 15 M (Carboprost Tromethamine) applied 10 hours later and until abortion. On the basis of obtained results, a conclusion was made that the NEW combination of endocervical and intramuscular application of prostaglandins gives statistically significantly shortened abortion interval (the control group x = 9.97; SD = 5.22 versus investigation group: A-x = 6.80; SD = 4.31 and investigation group: B-x = 5.55; SD = 3.48). Better pharmacologic preparation of the uterine cervix resulted in shorter abortion interval and decreased amount of systemically applied prostaglandins. A shortened abortion interval significantly decreases the rate of immediate, early and late complications. A decreased amount of systemically applied prostaglandins results in significantly lower rate of unwanted side-effects caused by prostaglandins, making this method of pregnancy termination significantly cheaper.

Abortion, Induced↗

PubMed2000

Influence of incorrect application of a water-based adhesive system on the marginal adaptation of Class V restorations.

PURPOSE: To determine the influence of incorrectly performed steps during the application of the water-based adhesive system OptiBond FL on the marginal adaptation of Class V composite restorations. MATERIALS AND METHODS: In 96 extracted human teeth Class V cavities were prepared. Half of the margin length was situated in dentin. The teeth were randomly divided into 12 groups. The cavities were filled with Prodigy resin-based composite in combination with OptiBond FL according to the manufacturer's instructions (Group O) and including several incorrect application steps: Group A: prolonged etching (60 s); Group B: no etching of dentin; Group C: excessive drying after etching; Group D: short rewetting after excessive drying; Group E: air drying and rewetting; Group F: blot drying; Group G: saliva contamination; Group H: application of primer and immediate drying; group I: application of only primer; group J: application of only adhesive; Group K: no light curing of the adhesive before the application of composite. After thermocycling, replicas were taken and the margins were quantitatively analyzed in the SEM. Statistical analysis of the results was performed using non-parametric procedures. RESULTS: With exception of the "rewetting groups" (D and E) and the group with saliva contamination (G), all other application procedures showed a significantly higher amount of marginal openings in dentin compared to the control group (O). Margin quality in enamel was only affected when the primer was not applied.

Acid Etching, Dental↗

PubMed2002

Stimulatory effect of topical application of caffeine on UVB-induced apoptosis in mouse skin.

In an earlier study, we showed that oral administration of green tea or caffeine to SKH-1 mice for 2 weeks prior to a single application of UVB enhanced UVB-induced increases in the number of p53-positive cells, p21(WAF1/CIP1)-positive cells, and apoptotic sunburn cells in the epidermis. In the present study, we found that topical application of caffeine, a major chemopreventive agent in tea, to the dorsal skin of SKH-1 mice immediately after irradiation with UVB (30 mJ/cm2) enhanced UVB-induced apoptosis as measured by the number of morphologically distinct epidermal apoptotic sunburn cells and the number of caspase 3-positive cells. Time course studies indicated that UVB-induced increases in apoptotic sunburn cells were correlated with elevated levels of caspase 3, a key protease that becomes activated during an early stage of apoptosis. Topical application of caffeine immediately after UVB enhanced UVB-induced increases in caspase 3 (active form)-immunoreactive-positive cells and in caspase 3 enzyme activity in the epidermis. Topical application of caffeine had only a small stimulatory effect on UVB-induced increases in the level of wild-type p53 protein and these changes were not related temporally to caffeine-induced increases in apoptotic cells. There was little or no effect of topical applications of caffeine on epidermal cell proliferation as determined by bromodeoxyuridine (BrdU) incorporation into DNA. Topical application of (-)-epigallocatechin gallate (EGCG) to the dorsal skin of mice immediately after irradiation with UVB had a small inhibitory effect on UVB-induced increases in BrdU-positive cells in the basal layer of the epidermis, but this treatment had no effect on UVB-induced increases in apoptotic sunburn cells. The results of this study indicate a proapoptotic effect of topical application of caffeine on UVB-irradiated mouse skin.

Administration, Topical↗

PubMed2002

Effect of sequential applications of foliar nutrients, biofertilizers and sowing dates on the incidence of corn stem borers in Egypt.

In this study either early sown (May 1st) or lately sown (June 2nd) corn plants were treated with Phosphorin & Rhizobactrin as biofertilizers and sprayed with six selected foliar nutrients, i.e. Polymex; Greenzit SP100, Greenzit NPK, Potasin-F, Copper sulphate and Ascorbic acid; in mono-, bi-, and/or tri-sequential applications. Such practices were conducted to show their beneficial effects compared with the chemical treatment in checking the incidence of the stem borers and hence increasing the corn yield. The obtained results could be summarized in the following chief points: (a) the lately sown biofertilized plants showed somewhat higher levels of infestation than the early planted ones., (b) in general, spraying the biofertilized corn plants in both sowing dates with the tested foliar nutrients, significantly decreased the rate of the stem borers infestation than the untreated plants of control., (c) the foliar sprays of Greenzit NPK alone, bi- or tri-sequential applications of Potasin-F, Polymex, Ascorbic acid and Copper sulphate achieved considerable success in reducing larval numbers of the borers species. For example, in case of using the bi-sequential nutrients (Polymex/Ascorbic acid) the numbers were 1.2, 1.5 and 1.2 larvae/5 plants, whereas the numbers were 1.3, 1.0 and 0.7 larvae/5 plants as a result, of the tri-sequential applications (Potasin-F/Ascorbic acid/Polymex) for the pink stem borer, Sesamia cretica, (Led.), the purple lined borer, Chilo agamemnon, (Bels.), and the European corn borer Ostrinia nubilalis (Hb.), in respect, vs. 4.8, 4.5 and 2.9 larvae/5 plants for the same stem borers, respectively, in case of the untreated corn plants. In addition, the other trisequential applications (Polymex/ascorbic acid/Copper sulphate), (Potasin-F/Copper sulphate/ascorbic acid) and (Potasin-F/Copper sulphate/Polymex) reduced the stem borers infestation; (d) from the view point of the interaction effects of sowing dates and the tested foliar nutrients, it was found that the tri-sequential sprayings (Potasin-F/Copper sulphate/Polymex) and/or (Potasin-F/Copper sulphate/Ascorbic acid) have lowered the rate of the stem borers infestation to 3.3 and 3.3 and 5.7 and 4.3 larvae/5 plants for the tri-applications in the 1st and 2nd sowing dates, respectively. Such reductions in the levels of infestation led to an increase in the grain yield up to 6.9 and 7.2 and 5.4 and 5.8 ton/fed, for the early and lately sown corn plants, in respect, and (e) All the foliar nutrients, with no exception, proved to be efficient in managing the stem borers infestation as compared with the insecticide treatment using Polytrin. Although the chemical application had lowered the level of infestation to 2.3 and 5.7 larvae/5 plants in the 1st and 2nd sowing dates as compared with 9.7 and 14.7 larvae/5 untreated plants for the same sowing dates, lesser grain yield of 5.6 and 4.4 ton/fed. was obtained in the first and second dates of planting, successively, in comparison to the grain yield resulted from the tri-applications of Potasin-F/Copper sulphate with either Polymex or Ascorbic acid. The abovementioned results assured the profitable effects of using foliar nutrients as well as the biofertilizers for attaining healthy corn plants, which would be capable of tolerating the injury inflicted by the studied stem borers and compensating for the harmful effects of insects infestation, so high grain yields could be obtained than those of the untreated and/or the insecticide treated plants.

Agrochemicals↗

PubMedDate not supplied

Drug registration application in China.

PURPOSE: This article is used to give a brief overview for people who would like to submit a drug registration application in China, or for those who would like to get a broader international drug registration perspective. METHODS: This paper concretely describes the new items in the current drug registration application through introducing following contents: qualification of the applicant, registration classification or type, the procedures for drug registration application review, the intellectual property rights concerning the pharmaceutical (drug substance and product), the process for submitting a drug registration application and the materials required in application for registration. RESULTS: From the paper, we have a comprehensive knowledge of drug registration application in China. CONCLUSIONS: The current Provision for Drug Registration is more reasonable and suitable for China's entry into WTO and further guarantee that safe and effective drugs are available to Chinese people.

China↗

PubMedDate not supplied

Antitumour effectiveness of hyperthermia is potentiated by local application of electric pulses to LPB tumours in mice.

BACKGROUND: The aim of our study was to determine whether local application of electric pulses to tumours, which induce transient reduction of tumour perfusion, could potentiate the antitumour effectiveness of hyperthermia. MATERIALS AND METHODS: The antitumour effectiveness of local application of electric pulses (1300 V/cm, 100 micros, 1 Hz) and 910 MHz local hyperthermia at 43.5 degrees C, alone or in combination, was determined on LPB tumours in C57Bl/6 mice by measurement of tumour growth delay, changes in tumour perfusion using the Patent blue technique and extent of tumour necrosis. RESULTS: When hyperthermia was performed immediately after application of electric pulses, at a time of maximally reduced tumour perfusion, greater than additive antitumour effectiveness was observed, resulting in 14.5 +/- 3.1 days growth delay of tumours that regrew and 43% complete responses. Single treatment, application of electric pulses or hyperthermia had minor or no effect on tumour growth. When hyperthermia was performed 24 hours after application of electric pulses, at a point when tumour perfusion was restored, the effect of both treatments was additive, resulting in 4.1 +/- 1.1 days growth delay and no cures. CONCLUSION: The probable mechanisms for the observed, more than additive, interaction when hyperthermia was performed immediately after application of electric pulses are the potentiation of thermic cytotoxicity, due to the reduced tumour perfusion induced by application of electric pulses and prolonged tumour perfusion reduction after combined treatment leading to additional cell kill, due to the protracted ischemia.

Animals↗

PubMed2004

[A new applicator with regulatable air bag designed for intracavitary brachytherapy of nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Nasopharynx applicator used in intracavitary brachytherapy plays an important role in the radiotherapy of nasopharyngeal carcinoma (NPC), its quality affects the efficiency of treatment. This study was to design a new applicator for clinical use. METHODS: An inexpensive, reusable, and flexible latex nasopharynx applicator was designed. An air bag was placed at 15 mm from the foreside of the applicator, clung to the tube. The edge of air bag is tangent to the axis of tube. When the bag was full of air, the tube would hunch reversely,close to nasopharyngeal vault. After introduced into nasopharynx through middle nasal meatus, the applicator could be fixed in suitable position by its rotation, and air bag regulation, and confirmed its position by simulation. RESULTS: A total of 221 patients with NPC were treated with external beam radiation therapy in our hospital, and boosted HDR brachytherapy using this new applicator. The response rate was 92.6% in the primary tumor group (200/216), and 100% in the recurrent tumor group (5/5). Mucosal necrosis in the posterior or anterior wall of nasopharynx occurred in 5 patients, 8 patients experienced nasal congestion and nasal synechia. CONCLUSIONS: This new nasopharynx applicator is easy to operate, painless, and well dosage-distributed. Mucosal necrosis is likely due to higher fractional dose.

Adolescent↗

PubMed2005

Effects of one versus two-layer applications of a self-etching adhesive to dentin of primary teeth: a SEM study.

Resin composite is increasingly the material of choice for the restoration of primary teeth, and new materials with simplified procedures are increasingly being offered. Self-etching primers have been developed to simplify the bonding procedures. Some manufacturers recommend the application of these materials in two layers. However little is known about the application times. Therefore, this study evaluated the quality of the interfacial seal and the micromorphology of the hybrid layer in composite restorations bonded with one or two layer applications of a self-etching adhesive to the dentin of the primary teeth. The superfacial dentin (within 1-2 mm of dentinoenamel junction (DEJ)) on the occlusal surfaces of fourteen primary molars was exposed by a flat cut perpendicular to the long axis of the tooth. The occlusal surfaces were divided into two halves by a 1 mm deep groove in the labial-lingual orientation. The teeth were randomly divided into two groups: Group 1: Single Bond (control group) was applied according to the manufacturer's instructions on one half of the surface. On the other half of the same tooth, one layer of Prompt-L-Pop (experimental group) was applied according to the manufacturer's instructions. Group 2: the teeth received the same bonding regimes as group 1, but the experimental group had two layer application of Prompt-L-Pop. All samples were analyzed in SEM. Student's t-test was used to compare the width of the gap and hybrid layer thickness generated by experimental groups and control. There was a statistically significant difference between control (Single Bond) and the experimental groups (one or two layer application of Prompt-L-Pop) (p<0.05). Single Bond showed the best results. Two layer application of Prompt-L-Pop showed better sealing ability than one layer application of it (p<0.05). Only Single Bond presented a visible hybrid layer that had an average thickness of 3.7microm.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2006

A high-intensity functional weight-bearing exercise program for older people dependent in activities of daily living and living in residential care facilities: evaluation of the applicability with focus on cognitive function.

BACKGROUND AND PURPOSE: Knowledge concerning the applicability and the effect of high-intensity exercise programs is very limited for older people with severe cognitive and physical impairments. The primary aim of this study was to evaluate the applicability of a high-intensity functional weight-bearing exercise program among older people who are dependent in activities of daily living and living in residential care facilities. A second aim was to analyze whether cognitive function was associated with the applicability of the program. SUBJECTS: The subjects were 91 older people (mean age=85.3 years, SD=6.1, range=68-100) who were dependent in personal activities of daily living and randomly assigned to participate in an exercise intervention. Their mean score for the Mini-Mental State Examination (MMSE) was 17.5 (SD=5.0, range=10-29). METHODS: A high-intensity functional weight-bearing exercise program was performed in groups of 3 to 7 participants who were supervised by physical therapists. There were 29 exercise sessions over 13 weeks. Attendance, intensity of lower-limb strength and balance exercises, and occurrence and seriousness of adverse events were the outcome variables in evaluating the applicability of the program. RESULTS: The median attendance rate was 76%. Lower-limb strength exercises with high intensity were performed in a median of 53% of the attended exercise sessions, and balance exercises with high intensity were performed in a median of 73% of the attended exercise sessions. The median rate of sessions with adverse events was 5%. All except 2 adverse events were assessed as minor and temporary, and none led to manifest injury or disease. No significant differences were observed in applicability when comparing participants with dementia and participants without dementia. In addition, there was no significant correlation between applicability and the MMSE score. DISCUSSION AND CONCLUSION: The results suggest that a high-intensity functional weight-bearing exercise program is applicable for use, regardless of cognitive function, among older people who are dependent in activities of daily living, living in residential care facilities, and have an MMSE score of 10 or higher.

Activities of Daily Living↗

PubMedDate not supplied

Summary statements of the NIH Nursing Research Grant Applications.

Summary statements from the Nursing Research Study Section, Division of Research Grants, NIH, between October, 1986 and June, 1988 were used to identify reasons for recommending approval or disapproval of grant applications with RO1 and R29 activity codes. The 917 comments (25 +/- 4 per critique), sorted into one of nine categories (Aims, Significance, Investigator, Budget, Resources, Design, Sample, Techniques, Data Analysis) for analysis, were classified as Strengths (positive comments) or Weaknesses (negative comments). The weaknesses of approved applications were confined mostly to the categories of Design and Techniques. Disapproved applications had few strengths and many weaknesses in Design, Sample, Techniques, and Data Analysis. Critiques of First Award (R29) and traditional research project grant applications (RO1) were similar. The approved applications addressed meaningful problems, had well-synthesized literature reviews, and were solvable by available techniques. The research plans were consonant with stated aims, and the methods sections reflected understanding of the principles underlying the techniques to be used. A supportive environment and adequate research resources, including access to the study population were common to these applications. Disapproved applications provided poor synthesis of the literature, methods inconsistent with the aims, and often reflected inadequate understanding of techniques to be used.

Humans↗

PubMed1991

Thermal modalities: heat and cold. A review of physiologic effects with clinical applications.

Thermal modalities are safe, simple, inexpensive, and easily taught for self-application. Their efficacy has been demonstrated in anecdotal, clinical, and basic physiological research reports. Topical thermal modality application has potential therapeutic effects on three areas of physiologic functions in soft tissue disorders: 1) Local circulation/metabolism; 2) Local neuromuscular and musculotendinous function; and 3) Nociception, including local and central neural activity. Knowledge of the physiology of the modalities and the pathophysiology of these disorders enables the occupational health nurse to use them appropriately. Topical heat application is often more easily accepted, while cold application is less favorably accepted. Physiological findings, however, indicate that, for topical application, cold application has much greater potential for restorative, therapeutic effect, while topical heat is almost exclusively limited to palliative effects. By educating and encouraging employees in the self-application of these modalities the occupational health nurse promotes self-efficacy in health care, providing an alternative to reliance on prescription or OTC medications.

Cold Temperature↗

PubMed1989

Assessing applicants to the NASA flight program for their renal stone-forming potential.

Spaceflight could provoke formation of kidney stones, in part by causing hypercalciuria and hyperphosphaturia. Applicants for spaceflight who have metabolic or environmental derangements to begin with might be particularly susceptible to stone formation in space. We, therefore, analyzed 24-h urine samples for stone-forming risk factors in 104 male applicants before their selection into the astronaut-mission specialist corps. The urinary environment was abnormally supersaturated with calcium oxalate in 25.0% of applicants, brushite in 36.5%, and monosodium urate in 66.3%, predisposing these applicants to crystallization of stone-forming calcium salts. This high level of supersaturation was caused by both "metabolic" and environmental disturbances. Thus, hypercalciuria was found in 11.5% of applicants, hyperoxaluria in 2.9%, hyperuricosuria in 18.3% and hypocitraturia in 5.8%. Environmental derangements were generally more prominent, as indicated by low urine volume of less than 2 L.d-1 in 84.6%, high urinary phosphate in 24.4%, and high urinary sodium in 10.6% of applicants. The results suggest that most of the abnormal stone risk factors disclosed among applicants for spaceflight programs were environmental in origin.

Adult↗

PubMed1985

Positive pressure respirations and pneumatic antishock garment application--hemodynamic response.

Pneumatic antishock garment (PASG) application has been recommended for treatment of hypovolemic hypotension and intraperitoneal or retroperitoneal hemorrhage. Often these patients require positive pressure respiration (PPR). This study measured the hemodynamic response of low pressure PASG application, with and without PPR, in normovolemic man and the effects of PASG application on serum lactate. Ten patients after coronary artery bypass surgery were studied with PPR and PASG application (3 to 20 hours post-surgery), and PASG alone (24 to 30 hours post-surgery). PASG pressures of 0,5,10,20, and 0 mm Hg were applied for 10 minutes each after which LAP, PCWP, CVP, mean arterial pressure, heart rate, cardiac index, and serum lactate level were measured. PASG application produced significant elevations in right and left ventricular filling pressures. The left ventricular filling pressure response was significantly less with positive pressure respiration. The CVP and LAP increase did not result in a greater cardiac index. Serum lactate levels rose slightly during PASG application. Low-pressure PASG application results in an 'autotransfusion' effect which is greater without PPR.

Blood Pressure↗

PubMed1970

Canadian and landed immigrant applicants to Canadian medical schools for 1968-69.

There were 2337 Canadian and Landed Immigrant applicants for the fall 1968 entering classes at Canadian medical schools. These applicants filed a total of 4579 applications.The results of this study show that there are regional differences in the quantity and quality of the applicant pool for Canadian medical schools. The study also shows that despite the fact that Canadian and landed immigrant applicants are filing more applications than they have in the past two years, there has been no appreciable change in the ratio of applicants to available places. A further point to be noted is that the participation of women both as applicants to and as medical students in the entering class of 1968-69 at Canadian medical schools was higher than in previous years.

Canada↗

PubMed1983

Glucocorticoid receptor levels in mouse skin after repetitive applications of 12-O-tetradecanoylphorbol-13-acetate and mezerein.

Female Sencar mice were given twice weekly topical applications of 0.2 ml of acetone, 4 micrograms of 12-O-tetradecanoylphorbol-13-acetate (TPA), 2 micrograms of mezerein, or 4 micrograms of TPA followed by 2 micrograms of mezerein. Whole skin cytoplasmic glucocorticoid receptor content and dissociation constants were determined at various times after the last application of the agents. After four to 12 applications of acetone, the mean glucocorticoid receptor level was 0.49 +/- 0.02 pmol/mg cytosol protein, and the dissociation constant was 6.0 +/- 0.17 nM. The glucocorticoid receptor level was markedly reduced and remained low for at least 72 hr after repetitive applications of TPA. The mean receptor level was 0.113 +/- 0.011 (S.E.) pmol/mg cytosol protein, and the Kd was 2 to 4 times the control value. In contrast, the glucocorticoid receptor level was not significantly reduced after repetitive applications of mezerein. If four applications of mezerein were preceded by four applications of TPA, then the glucocorticoid receptor level was similar to that after TPA alone. It was also demonstrated that the glucocorticoid receptor level in papillomas was extremely low (0.022 pmol/mg cytosol protein) but was much higher in newborn skin (0.52 pmol/mg cytosol protein).

Administration, Topical↗

PubMedDate not supplied

Microabrasion: effect of time, number of applications, and pressure on enamel loss.

Enamel microabrasion using hydrochloric acid and pumice is an effective method to remove superficial enamel discoloration. This procedure is used in many dental offices but little is known about how different treatment combinations of hand applicator pressure on the tooth, number of applications, and duration of application affect the amount of enamel loss. This investigation studied variables of time, number of applications, and pressure individually and in combination. Twenty-seven extracted premolars were hand rubbed with an 18% HCL-pumice mixture at time intervals of 5, 10, and 20 sec and 5, 10, and 15 applications under pressures of 10, 20, and 30 g. Fifty-four longitudinal sections were cut from the treated sections and measured for enamel loss (P < 0.05). Enamel loss significantly increased as each variable separately increased. When two variables increased at the same time, a greater amount of enamel loss occurred than when one increased. The combination of 10 ten-sec applications or 15 five-sec applications with 20 g pressure resulted in enamel loss of slightly less than 250 microns.

Acid Etching, Dental↗