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PubMed2004

Factors influencing the ability to detect motion reversals in rotation simulations.

Five experiments probed the conditions under which observers fail to report instantaneous reversals in the direction of motion of pixels that define the rotation of a transparent sphere or plane. Our results showed that the extent to which rotation reversals were not reported depended upon whether observers used strict or lax criteria to make their judgments, the degree of perspective present in the rotation simulations, and the percentage of pixels that actually reversed direction. Furthermore, we found failures to report rotation reversals both with stimuli whose pixels were confined to smooth surfaces and scattered within volumes. Reversal detection with planar stimuli, unlike sphere stimuli, depended upon the orientation of the stimulus at the moment of reversal. Treue et al. (1995) postulated a surface-interpolation process as the explanation for the apparent insensitivity of observers to such reversals. However, we suggest that other stages of processing (e.g. a structure-from-motion process) are required to account for these results.

Adult↗
PubMed2000

Partial reversibility of airflow limitation and increased exhaled NO and sputum eosinophilia in chronic obstructive pulmonary disease.

We investigated the relationship between the reversibility of airflow limitation, the concentration of nitric oxide (NO) in exhaled air, and the inflammatory cells in the sputum of patients with stable chronic obstructive pulmonary disease (COPD). We examined nine normal healthy control subjects and 20 nonatopic patients with COPD. Ten patients had no reversibility of airflow limitation (increase in FEV(1) of < 12% and < 200 ml after 200 microg of inhaled salbutamol), and 10 patients had partial reversibility of airflow limitation (increase in FEV(1) of < 12% but > 200 ml after 200 microg of inhaled salbutamol). Exhaled NO levels were higher in COPD patients with partial reversibility of airflow limitation than in those with no reversibility of airflow limitation (median 24 [interquartile range 15.3 to 32] ppb versus 8.9 [4.6 to 14.7] ppb; p < 0.01). Compared with healthy control subjects, only COPD patients with partial reversibility of airflow limitation had increased concentrations of sputum eosinophils. We conclude that, in patients with stable COPD, even a partial bronchodilator response to inhaled salbutamol is associated with increased exhaled NO and sputum eosinophilia, suggesting that these patients may have a different response to treatment than do those without reversible airflow limitation.

Administration, Inhalation↗
PubMed2006

The effects of alpha1-acid glycoprotein on the reversal of chloroquine resistance in Plasmodium falciparum.

An in-vitro model based on the semi-automated microdilution technique has been developed for selecting compounds that might be used clinically for the reversal of chloroquine resistance. This was used initially to test the susceptibility of Plasmodium falciparum clone W2 to chloroquine (CQ). The model was then employed to investigate the effects of each of four resistance-reversing agents (verapamil, desipramine, chlorpheniramine and promethazine, at 1 microM) on this parasite's susceptibility to CQ, with and without alpha(1)-acid glycoprotein (AGP), at a patho-physiological concentration (1.25 g/litre), in the culture medium. In the absence of AGP, each of the resistance-reversing agents reduced the median inhibitory concentrations of CQ by 82%-97%, from a baseline value of about 94 ng/ml. In the presence of AGP, however, most of the resistance-reversing agents had much less effect. There appears to be competitive interaction between CQ, the resistance-reversing agents and AGP. The binding kinetics between CQ, resistance-reversing agents, AGP and other plasma proteins will clearly need to elucidated if clinically effective resistance-reversing agents are to be selected in vitro.

Animals↗
PubMed2003

LPS resistance in monocytic cells caused by reverse signaling through transmembrane TNF (mTNF) is mediated by the MAPK/ERK pathway.

The transmembrane form of tumor necrosis factor (mTNF), expressed on activated monocytes (MO) and macrophages (MPhi), is able to induce apoptosis in human endothelial cells (EC). Apoptosis is mediated by two distinct mechanisms: direct cell contact and a yet-unidentified soluble protein, death factor X. In addition, mTNF acts as a receptor that transduces a "reverse signal" into MO/MPhi when bound to the TNF receptor on EC. Reverse signaling by mTNF confers resistance to bacterial lipopolysaccharide (LPS). Stimulation of reverse signaling by mTNF blocks the ability of MO/MPhi to produce death factor X and proinflammatory cytokines. We have investigated which signaling pathways are used by mTNF acting as receptor. Reverse signaling triggers two independent pathways that can be distinguished by protein kinase C (PKC) inhibitors. The suppression of LPS-induced death factor X is dependent on PKC, whereas the suppression of LPS-mediated cytokine release is not. LPS and reverse signaling stimulate the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. It is interesting that the activation of reverse signaling by mTNF renders MO/MPhi refractory to a subsequent activation of the MAPK/ERK pathway by LPS. Thus, reverse signaling achieves LPS resistance in monocytic cells through interference with key signal-transduction pathways.

Cell Line↗
PubMed1996

The dominant white spotting oncogene allele Kit(W-42J) exacerbates XY(DOM) sex reversal.

The Y chromosome from certain populations of M. m. domesticus is incapable of normal testis determination in the B6 inbred strain resulting in XY hermaphrodites or XY females (XY(DOM) sex reversal). B6 consomic strains have been developed with either transient (B6-Y(AKR)) or severe (B6-Y(TIR)) XY(DOM) sex reversal. We report that a point mutation, the dominant white spotting oncogene allele, Kit(W-42J), exacerbates XY(DOM) sex reversal. In B6-Y(AKR), penetrance of the trait is low; however, in B6-Y(TIR), Kit(W-42J) exacerbated sex reversal to such an extent that almost all XY progeny developed into females. The exacerbation of sex reversal was not linked to retardation of early fetal growth or reduction of testis size. Furthermore, semiquantitative RT-PCR for the testis-determining gene, Sry, suggests that exacerbation of sex reversal in B6-Y(TIR) is not due to blockade of Sry expression, a substantial delay in initiation of Sry expression, or exceptionally low levels of Sry mRNAs. We propose that Kit(W-42J) enhances sex reversal by adversely affecting a critical step in testis differentiation that is downstream of Sry.

Alleles↗
PubMed2003

Photolysis of caged calcium in cilia induces ciliary reversal in Paramecium caudatum.

Intracellular Ca(2+) concentration controls both the pattern and frequency of ciliary and flagellar beating in eukaryotes. In Paramecium, it is widely accepted that the reversal of the direction of ciliary beating (ciliary reversal) is induced by an increase in intra-ciliary Ca(2+) levels. Despite this, the Ca(2+)-sensitive region of the cilium that initiates ciliary reversal has not been clearly identified. We injected caged calcium into living P. caudatum cells and applied ultraviolet (UV) light to portions of the injected cells to raise artificially the intracellular Ca(2+) level ([Ca(2+)](i)). UV application to the upper ciliary region above the basal body induced ciliary reversal in injected cells. Furthermore, UV application to the tips of cilia induced weak ciliary reversal. Larger areas of photolysis in the cilium gave rise to greater angles of ciliary reversal. These results strongly suggest that the Ca(2+)-sensitive region for ciliary reversal is distributed all over the cilium, above the basal body.

Animals↗
PubMed2004

Characteristics of airway inflammation and bronchodilator reversibility in COPD: a potential guide to treatment.

STUDY OBJECTIVES: The management of stable patients with COPD depends on the severity of symptoms and airflow limitation. Regarding inflammation, corticosteroids are the only medications that are recommended for use, and only under restricted circumstances. Corticosteroids tend to undertreat or overtreat patients with COPD when only clinical manifestations and the findings of simple spirometry are considered. Accordingly, our aim was to survey the characteristics of airway inflammation in stable COPD patients, and to assess the interrelations among inflammatory cells, inflammatory mediators, bronchodilator reversibility, and pulmonary function. Factors related to airway inflammation and bronchodilator reversibility may be important in the management of stable COPD patients. METHODS: A total of 88 stable patients with smoking-related COPD were recruited into the study. All patients were steroid-free, and had been treated with theophylline, oral beta(2)-agonist agents, anticholinergic agents, and possibly mucolytic agents. Bronchodilator tests and sputum induction were performed to evaluate bronchodilator reversibility, and numbers of inflammatory cells and mediators (eg, interleukin [IL]-8, eotaxin, and regulated on activation, normal T cells expressed and secreted [RANTES]). RESULTS: Thirty-one of 48 patients (64.6%) who had bronchodilator reversibility, and 19 of 40 patients (47.5%) without bronchodilator reversibility had sputum eosinophilia (median, 8.0% and 7.0%, respectively). FEV(1) showed a significant inverse correlation with the number of sputum neutrophils. The correlation coefficient for postbronchodilator FEV(1) vs the percentage of neutrophils in patients with nonreversible COPD was higher than that in those with reversible COPD. The levels of IL-8 were closely associated with the percentage of neutrophils. The sputum concentrations of IL-8 and albumin were significantly higher in patients with nonreversible COPD than in those with reversible COPD. A significant inverse correlation was found between bronchodilator response (ie, DeltaFEV(1) and DeltaFVC) and prebronchodilator FEV(1). CONCLUSIONS: Eosinophilic inflammation may play a substantial role in COPD, while neutrophils and IL-8 may have a great influence on nonreversible obstructive airways. The assessment of airway inflammation and bronchodilator responses can help the selection of specific therapies and the prediction of clinical outcomes for COPD patients.

Aged↗
PubMed1996

[Changes in intestinal motility after massive small bowel resection with a reversed jejunal segment].

To evaluate the functioning and effectiveness of a 20-cm reversed jejunal segment after 75-80% massive small bowel resection (MSBR), and whether migrating polarity changes or not, we continuously measured the postoperative bowel motility (using bipolar electrodes and/or contractile strain gage force transducers) in interdigestive and postprandial conscious dogs in short- (2-5 weeks) and long-term (6-10 months) after surgery. The fasting migrating myoelectric (or motor) complex (MMC) arising from the duodenum was often interrupted at the jejunum above the proximal anastomosis and did not migrate smoothly to the reversed segment or terminal ileum. In addition, brief small discordant contractions were frequent in the jejunum above the proximal anastomosis and the proximal part of the reversed segment. The duodenal MMCs predominantly propagated to the ileum through the inherent anatomic continuity of the bowel. These findings of the MMC propagation pattern are very similar in short- and in long-term after surgery. The duration of the postprandial period without duodenal MMC activity was markedly longer in short-term, but shorter in long-term (both were significantly longer than in controls). Marked dilatation of the jejunum and reversed jejunal segment was noted across the proximal anastomosis. These results suggest that the transit time and passage of intestinal contents can be delayed and stagnated for at least 10 months after MSBR with a 20-cm reversed jejunal segment. Although, reports on the polarity of peristalsis in the reversed segment in long-term followup have been contradictory in both experimental and clinical studies, this results support the conclusion that the reversed jejunal segment maintains its inherent propagative polarity and pattern over a long postoperative period.

Anastomosis, Surgical↗
PubMed2003

Mutations in the SRY, DAX1, SF1 and WNT4 genes in Brazilian sex-reversed patients.

In most mammals, male development is triggered by the transient expression of the SRY gene, which initiates a cascade of gene interactions ultimately leading to the formation of a testis from the indifferent fetal gonad. Mutation studies have identified several genes essential for early gonadal development. We report here a molecular study of the SRY, DAX1, SF1 and WNT4 genes, mainly involved in sexual determination, in Brazilian 46,XX and 46,XY sex-reversed patients. The group of 46,XX sex-reversed patients consisted of thirteen 46,XX true hermaphrodites and four 46,XX males, and was examined for the presence of the SRY gene and for the loss of function (inactivating mutations and deletions) of DAX1 and WNT4 genes. In the second group consisting of thirty-three 46,XY sex-reversed patients we investigated the presence of inactivating mutations in the SRY and SF1 genes as well as the overexpression (duplication) of the DAX1 and WNT4 genes. The SRY gene was present in two 46,XX male patients and in none of the true hermaphrodites. Only one mutation, located outside homeobox domain of the 5' region of the HMG box of SRY (S18N), was identified in a patient with 46,XY sex reversal. A novel 8-bp microdeletion of the SF1 gene was identified in a 46,XY sex-reversed patient without adrenal insufficiency. The dosage of DAX1 and WNT4 was normal in the sex-reversed patients studied. We conclude that these genes are rarely involved in the etiology of male gonadal development in sex-reversed patients, a fact suggesting the presence of other genes in the sex determination cascade.

DAX-1 Orphan Nuclear Receptor↗
PubMed2005

Reversed halo sign in pulmonary paracoccidioidomycosis.

OBJECTIVE: The purpose of this study was to evaluate the prevalence of the reversed halo sign in pulmonary paracoccidioidomycosis. MATERIALS AND METHODS: The high-resolution CT scans (1- or 2-mm collimation scans) of 148 consecutive patients with proven pulmonary paracoccidioidomycosis were reviewed to determine the prevalence of the reversed halo sign in these patients. The reversed halo sign was defined as central ground-glass opacity surrounded by a crescent or ring of consolidation. The images were reviewed by two radiologists who reached a decision by consensus. RESULTS: A reversed halo sign was found in 15 patients (10%), including 13 men and two women ranging in age from 20 to 58 years (mean, 48 years). Three patients had only one reversed halo sign, one had two lesions, and the remaining had multiple lesions. The size of the sign ranged from 10 to 50 mm (average, 20 mm). In two cases the reversed halo sign was the only finding on CT. The most common associated findings seen in the remaining 13 patients included bilateral patchy areas of ground-glass attenuation (n = 10), parenchymal bands (n = 8), and small centrilobular nodules (n = 8). Three patients underwent surgical lung biopsy. Histologically the central area of the lesions consisted of an inflammatory infiltrate in the alveolar septa, composed of macrophages, lymphocytes, plasma cells, and some giant cells, with relative preservation of the alveolar spaces. The periphery of the lesion consisted of dense and homogeneous intraalveolar cellular infiltrate. There was no evidence of organizing pneumonia. CONCLUSION: The reversed halo sign is seen in approximately 10% of patients with paracoccidioidomycosis. In these patients, this sign reflects the presence of a central area of predominantly interstitial inflammation surrounded by predominantly air-space infiltration.

Female↗
PubMed1981

Satiation effects with reversible figures.

Three experiments were performed to examine the rate at which reversible perspective figures (Necker cubes) undergo apparent reversal, as a function of selected stimulus variables. 100 subjects were instructed not to inhibit or to promote reversals of perspective, but to remain neutral. The data indicated: (1) an incomplete cube reverses less frequently than does a corresponding complete figure, (2) two adjacent cubes reverse in synchrony when of equal luminance but often out of phase when differing in luminance, (3) a shift of the cube's retinal position causes its reversal rate to drop to baseline level. These results suggest that the reversal effect increases over time due to a localized rather than general process, and are thus compatible with a sensory satiation model of perceptual alternation.

Discrimination Learning↗
PubMed1986

Relationship of left-right reversals to academic achievement.

The study was designed to investigate the relationship of reversal of letters and numbers to academic achievement to decide if the tendency to reversal might be used to predict achievement. Two groups of 45 predominantly white third-grade students whose chronological ages were 9.0 yr. or above were administered the California Achievement Tests and the Jordan Left-Right Reversal Test. A statistical comparison was made using scaled scores on the California Achievement Tests and raw errors on the Jordan Left-Right Reversal Test. Reversal was significantly correlated with academic achievement. Children who exhibit reversals at 9 yr. of age or older may be expected to perform less well academically than children who do not reverse letters.

Achievement↗
PubMed2003

Lack of association between negative priming and Necker Cube reversals.

50 undergraduates were tested on two tasks presented in a counterbalanced fashion: their ability to inhibit irrelevant information measured on a negative priming task involving letter case information and on the number of Necker Cube reversals produced in a specific time period. Since number of reversals presumably reflects a person's ability to see various interpretations of the Necker Cube, this assumes that multiple interpretations are available to a subject and no one interpretation dominates over another. If true, then more reversals could indicate an ability to inhibit irrelevant information. That is, observing one reversal at the expense of another reversal indicates a subject can adequately inhibit these various interpretations successfully, with more reversals indicating a higher ability to inhibit information successfully. Although it was predicted that negative priming performance would be related to the number of Necker Cube reversals, this was not the case (r = -.07).

Adult↗
PubMed2005

Reversible anaesthesia of free-ranging lions (Panthera leo) in Zimbabwe.

The combination of medetomidine-zolazepam-tiletamine with subsequent antagonism by atipamezole was evaluated for reversible anaesthesia of free-ranging lions (Panthera leo). Twenty-one anaesthetic events of 17 free-ranging lions (5 males and 12 females, body weight 105-211 kg) were studied in Zimbabwe. Medetomidine at 0.027-0.055 mg/kg (total dose 4-11 mg) and zolazepam-tiletamine at 0.38-1.32 mg/kg (total dose 50-275 mg) were administered i.m. by dart injection. The doses were gradually decreased to improve recovery. Respiratory and heart rates, rectal temperature and relative haemoglobin oxygen saturation (SpO2) were recorded every 15 min. Arterial blood samples were collected from 5 lions for analysis of blood gases and acid-base status. For anaesthetic reversal, atipamezole was administered i.m. at 2.5 or 5 times the medetomidine dose. Induction was smooth and all lions were anaesthetised with good muscle relaxation within 3.4-9.5 min after darting. The predictable working time was a minimum of 1 h and no additional drug doses were needed. Respiratory and heart rates and SpO2 were stable throughout anaesthesia, whereas rectal temperature changed significantly over time. Atipamezole at 2.5 times the medetomidine dose was sufficient for reversal and recoveries were smooth and calm in all lions independent of the atipamezole dose. First sign of recovery was observed 3-27 min after reversal. The animals were up walking 8-26 min after reversal when zolazepam-tiletamine doses < 1 mg/kg were used. In practice, a total dose of 6 mg medetomidine and 80 mg zolazepam-tiletamine and reversal with 15 mg atipamezole can be used for either sex of an adult or subadult lion. The drugs and doses used in this study provided a reliable, safe and reversible anaesthesia protocol for free-ranging lions.

Adrenergic alpha-Antagonists↗
PubMed2005

A prospective study of reversible dementias: frequency, causes, clinical profile and results of treatment.

BACKGROUND: Dementia due to potentially reversible etiologies is an important group of dementias to be identified not only because of the number of such Patients encountered but also due to the potential for substantial improvement with treatment. AIMS: To prospectively investigate the frequency and causes of dementias with potentially reversible etiologies; to examine the clinical features of this subgroup with a view to identifying a signature profile and to determine if this potential reversibility translates into actual reversibility with appropriate treatment. SETTING AND DESIGN: A prospective longitudinal study of patients with dementia presenting to the outpatient services of a tertiary referral hospital. METHODS: All Patients above 40 years referred for evaluation of cognitive complaints were serially enrolled and underwent clinical examination, various laboratory tests and neuroimaging. Patients were followed-up for one year. STATISTICAL ANALYSIS: One way analysis of variance for continuous variables followed by post hoc comparisons using Scheffe's procedure. RESULTS: A total of 129 patients met Diagnostic and Statistical Manual of Mental Disorders edition 4 (DSM IV) criteria for dementia and qualified for inclusion into the study. Twenty-four patients (18%), all with moderately severe cognitive [mean mini mental state examination (MMSE) score +/- SD = 17.9 +/- 4.8] and neuropsychiatric [mean neuropsychiatric inventory (NPI) score +/- SD = 30.7 +/- 8.7] dysfunction were diagnosed to have reversible causes - neuroinfections in 11 patients, normal pressure hydrocephalus in 8 patients and vitamin B12 deficiency in 5 patients. The majority of these patients had gait and urinary dysfunction reminiscent of subcortical dementias. These reversible causes were clinically suspected in only 58% of patients. In 20/24 patients in whom follow up was possible mean MMSE score had improved to 22.2 and mean NPI score had improved to 8.0, following 6 months of treatment. CONCLUSIONS: Reversible causes, especially neuroinfections and vitamin B12 deficiency accounted for 18% all dementias in this study. The majority of these conditions was not clinically suspected though resulting in moderate to severe cognitive and psychiatric dysfunction. Most of these patients had a subcortical pattern of dementia and showed substantial improvement with treatment.

Adult↗
PubMed1991

Reversible renal insufficiency due to angiotensin converting enzyme inhibitors in hypertensive nephrosclerosis.

OBJECTIVE: To review the incidence of reversible renal insufficiency in patients with hypertensive nephrosclerosis undergoing antihypertensive therapy. DESIGN: Retrospective analysis of 73 patients in a long-term blood pressure control study that compared the effects of an angiotensin converting enzyme (ACE) inhibitor plus conventional antihypertensive agents compared with placebo plus antihypertensive agents. SETTING: Hospital-based outpatient treatment center. INTERVENTIONS: Patients were divided into group 1, which received enalapril plus conventional antihypertensives, and group 2, which received placebo plus conventional antihypertensives. MEASUREMENTS: Blood pressure and serum creatinine levels were measured, and imaging studies of the main renal arteries were done. MAIN RESULTS: In group 1, eight of 42 patients (19%, 95% CI, 9% to 34%) developed reversible renal insufficiency, defined as an unexpected increase in serum creatinine of 88 mumol/L or higher. Six episodes of reversible renal insufficiency occurred during July and August when temperatures were 32.2 degrees C to 37.8 degrees C (90 degrees F to 100 degrees F). Renal artery stenosis was excluded by renal arteriogram or ultrasonic duplex scanning. All eight group-1 patients had a significant decrease in mean arterial pressure below their baseline level during reversible renal insufficiency (mean change, -28 +/- 10 mm Hg, P less than 0.001). The increase in the serum creatinine level was inversely correlated with the decrease in the mean arterial pressure (r = -0.68, P less than 0.01). Reversible renal insufficiency was successfully managed by withdrawing or reducing enalapril as well as other antihypertensive agents. Subsequently, enalapril was tolerated by seven of the eight patients without recurrence of renal insufficiency. In contrast, none of 31 (CI, 0% to 11%) patients in group 2 developed reversible renal insufficiency despite the fact that both the incidence of decreases in mean arterial pressure in 6 of 31 patients (19%) and the magnitude of the decreases in mean arterial pressure (mean change, -33 +/- 16 mm Hg) were similar to those observed in group 1. CONCLUSIONS: Reversible renal insufficiency in hypertensive nephrosclerosis associated with ACE inhibitor therapy correlates with relative hypotension, is not dependent on renal artery stenosis, and can usually be managed by dose reduction.

Aged↗
PubMed2000

Should vasectomy reversal be performed in men with older female partners?

PURPOSE: An assumption exists that men with older female partners who seek treatment of post-vasectomy infertility should undergo in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) rather than vasectomy reversal. Although several studies have reviewed ICSI success rates with advancing maternal age, to our knowledge none has compared them to outcomes for vasectomy reversal in men with older partners. MATERIALS AND METHODS: The records of all patients with ovulating partners older than 37 years who underwent vasectomy reversal from 1994 through 1998 were reviewed. Patients were contacted to establish pregnancy and birth rates. Costs of vasectomy reversal, testicular sperm extraction, IVF and ICSI were obtained from the financial office of our institution. RESULTS: A total of 29 patients underwent vasectomy reversal with a followup of 3 to 59 months (median 25). Median male age was 46 years (range 37 to 67) and median female age was 40 years (range 38 to 48). A total of 5 pregnancies and 4 live births were achieved. In the 23 patients followed for more than 1 year the pregnancy rate was 22% and live birth rate was 17%. Using this 17% birth rate at our $4,850 cost for vasectomy reversal the cost per newborn was $28,530. In comparison, using the 8% birth rate per cycle of ICSI for women older than 36 years at a cost of $8,315 for testicular sperm extraction and 1 cycle of IVF with ICSI, the cost per newborn was estimated at $103,940. CONCLUSIONS: Vasectomy reversal appears to be cost-effective to achieve fertility in men with ovulating partners older than 37 years.

Adult↗
PubMed2004

[Initial clinic research on curved canal preparation by reverse flaring technique].

OBJECTIVE: Curved canal preparation is much difficult in root canal therapy(RCT). Step back technique and routine technique are still regular methods in curved canal preparation. The purpose of this study was to introduce a new method reverse flaring technique, and to investigate its preparation efficiency in intermediate-curvature canals. METHODS: 48 cases of lower first molars RCT were collected, which were first treated because of pulpitis or apical periodontitis in West China College of Stomatology, Sichuan University from Nov. 2001 to Aug. 2003, mesial canal curvature was intermediate (30 degrees-60 degrees), determined by Schineider method. Cases were divided into two groups, in reverse flaring technique group, canal preparation in 27 cases were finished by reverse flaring technique, 21 cases by step back technique as control. In working length determination and fitting master cone stages, cases in two groups which fit full working length were recorded, determined by radiograph, and analyzed by chi 2 test. RESULTS: In working length determination stage, cases which fit full working length in reverse flaring technique group were significantly more than that of step back technique group (P < 0.05), in fitting master cone stage, cases which fit full working length in reverse flaring technique group were also significantly more than that of step back technique group(P < 0.05). CONCLUSION: In working length determination stage, cases which fit full working length in reverse flaring technique group were significantly more than that of step back technique group (P < 0.05), in fitting master cone stage, cases which fit full working length in reverse flaring technique group were also significantly more than that of step back technique group(P < 0.05).

Adult↗