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Biomedical subjects

M Hülsmann

Publications and source records attributed to M Hülsmann.

At least 19 recordsLinked to original sources
PubMed2001

Effects of endothelin a receptor blockade on endothelial function in patients with chronic heart failure.

BACKGROUND: Chronic heart failure (CHF) is associated with impaired endothelium-dependent vasodilation and increased basal vascular tone due, in part, to elevated endothelin-1 plasma levels. In the present study, we investigated whether a reduction of vascular tone using an endothelin A receptor blocker attenuates the impairment of endothelium-dependent, flow-mediated vasodilation (FMD). METHODS AND RESULTS: Twenty-one patients with CHF randomly received either the endothelin A receptor blocker LU 135252 (30 mg/d, n=7; 300 mg/d, n=7) or a placebo (n=7). Using high-resolution ultrasound, FMD and endothelium-independent, nitroglycerin-induced dilation of the brachial artery were assessed at baseline in the 21 patients with CHF and in 11 controls and after 3 weeks treatment in the 21 patients with CHF. FMD at baseline was impaired in all 21 patients with CHF (3.2+/-2%) when compared with the 11 controls (9.7+/-4.9%; P=0.0005). In comparison with baseline, FMD significantly improved after 3 weeks of treatment with LU 135252 in all 14 patients receiving it (from 3.0+/-2.0% to 4.9+/-2.9%; P=0.04), but FMD remained unchanged with placebo. Subgroup analysis, according to different dosages, revealed a significant increase of FMD compared with baseline (from 2.4+/-1.5% to 5.5+/-2.4%; P=0.03) in the patients treated with the low-dose (30 mg/d), whereas a high dose of 300 mg/d failed to increase FMD significantly. Improvement in the high-dose group, however, may have been masked by reduced vasodilator capacity due to a significant increase in vessel size (from 4.8+/-0.4 to 5.1+/-0.7 mm; P=0.03). CONCLUSIONS: These results suggest that endothelin A receptor blockade improves FMD in CHF patients.

Blood Flow Velocity↗
PubMed2000

Response of right ventricular function to prostaglandin E1 infusion predicts outcome for severe chronic heart failure patients awaiting urgent transplantation.

BACKGROUND: Selection of patients for urgent heart transplantation who have end-stage heart failure requires objective criteria to distinguish between subjects who may deteriorate clinically and those who can be stabilized. This population appears to differ in terms of right ventricular function, and right ventricular changes in loading may provide prognostic information. To investigate predictive parameters of patients admitted for urgent heart transplantation, we prospectively studied the mechanical performance of the right ventricle during acute afterload reduction. PATIENTS AND METHODS: We studied 68 heart failure patients hospitalized for bridge-to-transplant. The patients underwent right heart catherization at baseline and during prostaglandin E1 infusion. We stratified patients according to clinical outcome: Group A comprised patients who could be weaned from bridging therapy or who were electively transplanted after at least 90 days, and Group B comprised patients who died or who remained unstable and required transplant under urgent conditions. RESULTS: Right ventricular hemodynamics at baseline were comparable in both groups. However, during maximal vasodilatation, with prostaglandin E1 infusion, the right ventricular end-diastolic volume index (EDVI) was significantly reduced in Group A, (-23 ml/m(2) (p < 0.01) vs +12 ml/m(2) (p = n.s. DeltaEDVI in Group B. Reduction of EDVI by less than 10% during prostaglandin E1 infusion has a sensitivity of 89% and a specificity of 70% for clinical deterioration. CONCLUSIONS: The response of right ventricular volumes to prostaglandin E1 may predict the outcome of patients with severe congestive heart failure listed for urgent heart transplantation.

Aged↗
PubMed2000

Experience with beta-blocker therapy in patients with advanced heart failure evaluated for HTx.

BACKGROUND: The aim of this study was to review our experience with beta-blocker therapy on top of high-dose angiotensin-converting enzyme inhibitors (ACE-I) in patients with advanced heart failure evaluated for heart transplantation, and to question the value of intended heart transplantation for patients receiving this therapy. METHODS: Three hundred eighteen patients (New York Heart Association (NYHA) function class III 34%, class IV 66%, average left ventricular ejection fraction (LVEF) 16%, and average cardiac index 2.2 l/min per m(2) at time of referral) were treated with digitalis, loop diuretics, maximally uptitrated ACE-I, beta-blockers (if tolerated), and intravenous support (if needed). After 3 months, patients were retrospectively stratified into those receiving beta-blockers plus ACE-I (Group A, n = 126), ACE-I (Group B, n = 135), and ACE-I plus intravenous support (Group C, n = 57). Endpoint 1 of the study was combined urgent heart transplantation, mechanical assist device implantation, and pretransplant death during a follow-up of 12 to 48 (mean 19 +/- 11) months. Endpoint 2 was posttransplant mortality up to 48 (mean 14 +/- 8) months. RESULTS: In the pretransplantation period the survival rate was 58% and the mortality rate was 20%. Between Groups A and B there was a significant difference in mortality (9% vs 27%, p = 0.001) due to a lower sudden-death rate in Group A (6% vs 17%, p < 0.01). While between Groups A and C all event rates of Endpoint 1 differed significantly, between Group C and Group B total mortality (30% vs 27%) was similar. However, in Group C urgent heart transplantation (HTx) was more often performed than in Group B (54% vs 11%, p < 0.0001). Seventy of 318 patients (22%) underwent heart transplantation (16% urgent, 6% elective). Posttransplant actuarial survival of the entire transplanted cohort (n = 70, 12 deaths) was significantly lower (log rank p < 0.01) than event-free survival in Group A (n = 126, 18 events), significantly higher (log rank p < 0. 0001) than event-free survival in Group C (n = 57, 34 events), and similar to that in Group B (n = 135, 52 events). CONCLUSION: This experience suggests that it may be particularly useful to add a beta-blocker to ACE-I therapy in patients referred for heart transplantation. In patients who tolerate this treatment, heart transplantation does not seem to provide additional survival benefit in the short term (2 years).

Actuarial Analysis↗
PubMed1999

An evaluation of root canal preparation with the automated Excalibur endodontic handpiece.

The aim of this study was to evaluate several parameters for automated root canal preparation with the Excalibur handpiece compared with hand instrumentation. The parameters investigated were straightening of curved canals, cleaning ability, working safety (loss of working length, instrument separation, perforation), cross sectional diameter before and after enlargement, and working time. Sixty curved root canals were prepared using the Excalibur handpiece and 30 curved canals with conventional hand instruments to ISO-size 35. The Excalibur left significantly less debris and smear layer on the root canal walls, but hand preparation resulted in fewer unprepared regions. Root canal curvature was well maintained by either technique; the degree of straightening depended on original root canal curvature rather than on the preparation technique. The Excalibur removed significantly more dentin. In the coronal part of the root canal, hand instruments produced significantly more round and oval cross sections; in the middle and apical part no differences could be detected. Working time was shorter for hand preparation, but the difference was not significant. Manual instrumentation proved to be safe; no instrument fracture, perforation or loss of working length could be observed, whereas automated preparation resulted in one perforation and two cases of loss of working length.

Analysis of Variance↗
PubMed1999

An improved technique for the evaluation of root canal preparation.

A device and a method are described for the simultaneous in vitro evaluation of several important parameters of root canal preparation, including root canal cleanliness, straightening, changes in root canal diameter, working safety (loss of working length, apical blockage, instrument fracture, and apical perforation), measurement of apically extruded debris, working time, and practicability. Using a modification of the muffle system described by Bramante et al. (J. Endodon, 13:243-5, 1987), all of these parameters can be investigated simultaneously during preparation of two mesial root canals in extracted mandibular molars.

Evaluation Studies as Topic↗
PubMed1999

Bridging to heart transplantation: prostaglandin E1 versus prostacyclin versus dobutamine.

BACKGROUND: Prostaglandin E1 (PGE1) and prostacyclin have potent pulmonary and systemic vasodilating properties. This prospective, randomized trial compared PGE1 vs prostacyclin vs. low-dose dobutamine in patients with low-output heart failure awaiting heart transplantation (HTx) who were refractory to oral treatment. METHODS: Patients in advanced heart failure in New York Heart Association (NYHA) Class IV, with a cardiac index < or = 2.5 L/minute/m2 and a pulmonary capillary wedge pressure > or = 20 mmHg, who were listed for HTx were studied. In an inpatient study phase of 12 hours duration, therapy was aimed to increase cardiac output by 20% or more, when compared to baseline values, and to achieve a reduction of pulmonary vascular resistance below 550 dyn.s/cm-5m-2. During a long-term outpatient phase, the drugs were continuously infused to bridge these patients to HTx using three combined negative endpoints (worsening heart failure, serious adverse events, death) for analysis. RESULTS: Sixty-eight patients were enrolled, 30 patients on PGE1, 8 patients on prostacyclin, and 30 patients on dobutamine. During the inpatient study phase, maximum doses were 22 +/- 1.8 ng/kg/minute for PGE1, 7 +/- 1 ng/kg/minute for prostacyclin and 5 +/- 0.4 micrograms/kg/minute for dobutamine. During the inpatient study phase 21 patients failed, 4/30 (13%) patients on PGE1, 4/8 patients on prostacyclin (50%), and 13/30 (43%) on dobutamine (p < 0.05). Long-term continuous intravenous drug infusion in outpatients was begun in 26 patients on PGE1, in 4 patients on prostacyclin, and in 17 patients on dobutamine. Infusion therapy lasted for 88 +/- 14 days in the PGE1 group with 31 +/- 22 days in the prostacyclin group, and 30 +/- 8 days in the dobutamine group (NS). During the outpatient phase 23 patients reached a negative endpoint with 16 patients developing worsening heart failure, 5 severe adverse events and 2 deaths. Seven out of 26 (27%) failed on PGE1, 4/4 (100%) failed on prostacyclin, and 12/17 (71%) failed on dobutamine (p < 0.05, log rank test). Because prostacyclin treatment was ineffective in the first 8 patients, this trial arm was stopped prematurely. CONCLUSIONS: The findings from this prospective open pilot trial suggest that continuous PGE1 infusions at individualized dosages can be useful in certain patients as a pharmacologic bridging procedure with reduced risk to develop worsening heart failure before HTx compared to prostacyclin and dobutamine. Further comparative studies are warranted to investigate the effects of PGE1 among other bridging agents.

Alprostadil↗
PubMed1999

Impact of different therapeutic alternatives in treatment of severe limb ischemia: experiences on 190 consecutive patients at a department of medical angiology.

BACKGROUND: Different therapies in consecutive patients (1987-1992) with chronic critical limb ischemia at a department of medical angiology, their short- and long-term outcome were investigated. PATIENTS AND METHODS: 190 patients (112 males, 78 females; age: 67 +/- 12 years); 78 in grade II, 112 in grade III according to Rutherford's classification. Therapeutic regimen: 1. vascular recanalisation by percutaneous transluminal angioplasty [PTA], local or systemic lysis; 2. surgical vascular reconstruction in case of impossibility or failure of catheter procedures; 3. prostanoids and/or antibiotics; 4. local wound treatment including amputations. RESULTS: Vascular recanalisation was attempted in 156/190 (82.1%): PTA in 116/190, surgical vascular reconstruction in 50/190, local in 24/190 and systemic lysis in 8/190 patients. Prostanoids were applied in 89/190 and antibiotics in 73/190 patients. At the time of dismissal 164/190 (86.3%) patients were clinically improved; 11/190 (5.8%) unchanged, 13/190 (6.8%) had undergone major amputations and 2/190 (1.1%) had died. After 2.6 +/- 2.2 years 77 of the 141 patients, who were still alive, were reexamined. Among these 77 patients 84.4% were in grade 0 or 1, 15.6% in chronic critical limb ischemia. Furthermore 13.0% had been amputated since dismissal. Forty-nine of 190 (25.8%) patients had died 3.2 +/- 1.9 years after dismissal from hospital. CONCLUSION: Catheter techniques, mostly PTA, is possible in the majority of patients with chronic critical limb ischemia. Cooperation with vascular surgeons in case of technical impossibility or failure of catheter recanalisation is mandatory. Such a regimen yields satisfactory short- and long-term results and a low rate of complications.

Aged↗
PubMed1999

Influence of several factors on the success or failure of removal of fractured instruments from the root canal.

The influence of several factors on the success rate of removal procedures of fractured endodontic instruments was evaluated postoperatively. In 105 teeth with 113 fragments removal attempts were undertaken using a wide range of techniques and instruments. All cases were analyzed with special regard to the following factors: type of tooth and root canal, site of fragment in relation to root canal curvature, length of fragment, and type of fractured instrument. Success of treatment was defined as removal or complete bypassing of the fragment. Of 82 instruments in molars (maxillary: 32, mandibular: 50), 56 were removed or bypassed (max.: 26, mand.: 30). Of 16 fragments in premolars (max.: 12, mand.: 4), 8 could be removed or bypassed (max.: 6, mand.: 2). Of 14 fragments in canines and incisors (max.: 7, mand.: 7), 13 could be removed completely (max.: 6, mand.: 7). When the fragment was localized before the curvature 2 of 18 cases failed, when localized inside the curvature 13 of 31 cases failed and when localized beyond the curvature 15 of 33 cases failed. Anatomical factors favorable for removal were: straight canals, incisors and canines, localization before the curvature, length of fragment more than 5 mm, localization in the coronal or mesial third of the root canal, reamer or lentulo spirales. In molars removal procedures were most successful in the palatal canals of maxillary molars.

Dental Instruments↗
PubMed1999

Sonography and scintigraphy are necessary in diagnostics of cystic thyroid lesions.

Thyroid sonography in an otherwise asymptomatic 50-year-old woman revealed a mainly cystic lesion within the right thyroid lobe. Thyroid (99)Tc scan showed an enhanced uptake over the right thyroid lobe with suppressed activity over the remaining thyroid tissue. Following aspiration of 6 ml of cyst fluid, a solid lesion became apparent in the location of the original cyst corresponding to the scintigraphically detected autonomous adenoma. This case report emphasizes that ultrasonography and scintigraphy are complementary methods and should be used as such in the primary evaluation of thyroid nodules.

Adenoma↗
PubMed1998

Value of cardiopulmonary exercise testing and big endothelin plasma levels to predict short-term prognosis of patients with chronic heart failure.

OBJECTIVES: We tested the hypothesis that, in patients with stable heart failure, measuring big endothelin-1 (ET-1) plasma level at rest predicts short-term prognosis better than peak oxygen consumption (VO2max) at exercise. BACKGROUND: Cardiopulmonary exercise testing and evaluation of neurohumoral plasma factors are established tools to estimate survival in patients with heart failure. No data, however, exist comparing the prognostic value of both marker categories simultaneously. METHODS: Two hundred twenty-six heart failure patients were studied in regard to a combined end point of death and prioritization for urgent cardiac transplantation within 1 year follow-up. RESULTS: During the study period 149 patients were without cardiac events (group A), 69 patients died or were urgently transplanted (group B) and 8 patients were alive after a nonurgent heart transplant operation. Norepinephrine (p < 0.0001), atrial natriuretic peptide (p < 0.001), big endothelin plasma levels (p < 0.0001 as well as workload, VO2max and achieved percentage of predicted peak oxygen consumption (pVO2max) (all p < 0.0001) differed significantly between groups A and B. In multivariate stepwise regression analysis, however, only big ET-1 plasma concentration (chi2=74.4, p < 0.0001), New York Heart Association function class (chi2=33.9, p < 0.0001), maximal workload (chi2=7.2, p < 0.01, and plasma atrial natriuretic peptide (ANP) concentration (chi2=4.6, p < 0.05) were independently related to outcome. Peak oxygen consumption or pVO2max did not reach statistical significance in this model. Event-free survival rates were significantly lower in patients with a big ET-1 level of 4.3 fmol/ml or more than with lower big ET-1 levels (p < 0.0001). CONCLUSION: We conclude that in patients with chronic heart failure who are stable on oral therapy measuring big ET-1 and ANP plasma levels may be a valuable noninvasive adjunct to improve the prognostic accuracy of detecting high risk patients compared with exercise testing alone.

Adult↗
PubMed1998

[Improved kidney function with intravenous prostaglandin E1 in patients with terminal heart failure].

In end stage congestive heart failure activation of a series of compensatory mechanisms increase renal vascular resistance and impair renal function. Prostaglandin E1 is increasingly used in the treatment of severe heart failure for its vasodilating actions. In various experimental settings prostaglandin E analogues are known to improve renal function by modulating renal filtration pressure and redistribution of renal blood flow. However, prostaglandin E1 decreases systemic blood pressure and thus, also renal perfusion pressure, a fact by which renal function might be further compromized in heart failure patients. The aim of the study was to evaluate the effects of prostaglandin E1 on excretory renal function in patients with end stage heart failure and to prove the hypothesis, that the well known local actions of prostaglandins on renal microcirculation might outweigh the negative impact of an expected decrease in perfusion pressure. 25 patients with terminal congestive heart failure were investigated. 13 patients received prostaglandin E1 at a dose of 13.5 +/- 1.9 ng/kg/min in combination with constant rates of dopamine and dobutamine (group A), 12 patients received prostaglandin E1 at a dose of 10.3 +/- 1.7 ng/kg/min without catecholamines (group B). There was no significant difference in prostaglandin dosages between groups. Kidney function was assessed by measuring plasma creatinine and urea nitrogen, urinary output, creatinine clearance, osmotic and free water clearance at baseline and after 72 h of infusion therapy. Hemodynamic parameters were measured by using a balloon tipped pulmonary arterial catheter. Hemodynamic measurements during infusion showed a significant improvement in all patients. At the same time as expected mean arterial pressure decreased in both groups (p < 0.001). Nevertheless, in both groups a significant increase of creatinine clearance during infusion was observed (in group A from 45 ml/min to 78 ml/min., p < 0.05, in group B from 59 ml/min to 105 ml/min., p < 0.001). Creatinine clearance in group B (without catecholamines) reached higher levels than group A (p < 0.05). Urinary volumes did not change during infusion therapy, whereas free water clearance significantly decreased, as an indication of an improvement of renal concentrations ability. We conclude, that in patients with end stage heart failure continuous infusion of prostaglandin E1 improves excretory kidney function. These findings suggest that the local effects of prostaglandin E1 on renal microcirculation can counterregulate the negative impact of prostaglandins on renal perfusion pressure.

Alprostadil↗
PubMed1998

Relationship between kidney function, hemodynamic variables and circulating big endothelin levels in patients with severe refractory heart failure.

UNLABELLED: Fluid retention is a major characteristic of symptomatic, progressive heart failure when a main factor implicated in the pathogenesis of renal dysfunction is renal hypoperfusion. This may be a consequence of forward cardiac failure, resulting in a low cardiac output integrating poor left ventricular function secondary to myocardial impairment and increased resistance in the regional renal vasculature secondary to locally released vasoconstrictors, e.g. endothelin. So far, the role of the pulmonary circulation in perpetuating renal dysfunction in heart failure is unclear. METHODS: We investigated the relationship of hemodynamic variables obtained during right heart catheterization and plasma big endothelin levels to renal function variables in 18 male patients aged 52 +/- 3 years, with heart failure in the NYHA function class III-IV, based on idiopathic causes in 8 and ischemic causes in 10 patients. Renal plasma flow (RPF) was established by paraaminohippurate (PAH) clearance and the glomerular filtration rate (GFR) was measured by iothalamate clearance. RESULTS: Plasma big endothelin (ET) levels were increased above the upper normal range (1.8 fmol/ml) in 16 out of 18 patients, averaging 5.0 +/- 0.8 fmol/ml (1.7-11.9 fmol/ml). Positive correlations to big ET plasma levels were detected with mean pulmonary pressure (r = 0.73, p < 0.001) pulmonary capillary wedge pressure (r = 0.56, p < 0.05) and pulmonary vascular resistance index (r = 0.69, p < 0.01). Glomerular filtration rate (70 +/- 7 ml/min) and renal plasma flow (358 +/- 36 ml/min) were considerably reduced and exhibited a tendency to correlate inversely with big ET levels (r = -0.46, p = 0.056 and r = -0.44, p = 0.069, respectively). Contrary to expectations, RPF did not correlate significantly with cardiac index, systemic vascular resistance index or arterial blood pressure. In contrast, significant correlations were detected of RPF with pulmonary capillary wedge pressure (r = -0.69, p < 0.01), mean pulmonary artery pressure (r = -0.65, p < 0.01), right atrial pressure (r = -0.47, p < 0.05) and right ventricular ejection fraction (r = 0.49, p < 0.05). CONCLUSION: The findings suggest a role for endothelin in renal vasoconstriction and accord well with the concept that in severe heart failure renal hypoperfusion--by volume retention--as well as increased endothelin synthesis--by pulmonary vasoconstriction--play a part in the increased pulmonary filling pressures.

Endothelin-1↗
PubMed1997

Effects of atenolol as add-on therapy to fosinopril in heart failure.

Several trials have demonstrated functional benefit with beta-blockers in patients with chronic heart failure. The aim of this observational study was to investigate if additional beneficial effects can be obtained from beta-blockade in a heart failure population that is already receiving high-dose ACE-inhibitor therapy. Atenolol is a long-acting cardioselective beta-blocking agent and is devoid of additional vasodilatory properties. Twenty-five male patients with class II or III heart failure and background therapy of digitalis, furosemide and 20 mg fosinopril per day were treated with 40 mg fosinopril per day and additional 75 mg atenolol per day (beta-blocker group) or with 40 mg fosinopril per day alone (control group). At the end of one year, changes in left ventricular function, exercise parameters and plasma neurohumoral variables reflecting vasoconstriction (noradrenaline, big endothelin) were measured and compared in the two treatment groups. Nineteen patients completed the study. Drop-outs were due to death (4 patients) and non-compliance (2 patients) with no significant difference between the groups. There was a beta-blocker related improvement in left ventricular ejection fraction (p < 0.05 between groups) and an increase in peak oxygen consumption in the control group only (p < 0.05 between groups). Thus, in a heart failure population receiving high-dose ACE inhibitor background therapy beta-blockade with atenolol produced additional benefit by reversing left ventricular dysfunction.

Adrenergic beta-Antagonists↗
PubMed1997

Effect of prostaglandin E1 infusion in severe chronic heart failure.

Prostaglandin E1 (PGE1, alprostadil) is a potent vasodilating agent that is frequently used to resolve cardiogenic pulmonary hypertension. To investigate the effect of PGE1 in refractory chronic heart failure in a double-blind trial, twenty patients (17 men, 3 women, 58 +/- 2 years, cardiac index < or = 2.5 l/min/m2, pulmonary capillary wedge pressure > or = 20 mmHg), who were in NYHA functional class IV on optimized treatment with ACE inhibitors and furosemide were infused with 30 ng/kg/min PGE1 or placebo through 48 hours. All patients received a concomitant therapy with standardized catecholamine infusions which were given 24 hours in advance and were continued throughout the study. There was no difference in baseline values between the randomized groups before PGE1 or placebo was added. PGE1 resulted in decrements in pulmonary artery pressure (from 37 +/- 4 to 30 +/- 4 mmHg; p < 0.01), pulmonary capillary wedge pressure (from 26 +/- 4 to 19 +/- 3 mmHg p < 0.001) systemic vascular resistance index (from 2048 +/- 213 to 1506 +/- 13 dyn.sec/cm5.m2, p < 0.05) and in increments in cardiac index and stroke volume index (from 2.2 +/- 0.1 to 2.8 +/- 0.2 l/min.m2; p < 0.05 and from 23 +/- 2 to 28 +/- 2 l/m2; p < 0.05, respectively). Moreover, creatinine clearance increased (p < 0.05). Placebo infusions did not result in any hemodynamic or renal effect. Between groups percentage hemodynamic changes differed with respect to pulmonary artery pressure (p < 0.01), cardiac index (p < 0.05), stroke volume index (p < 0.05) and pulmonary vascular resistance index (p < 0.05). It is concluded that intravenous infusions with PGE1 may add further substantial benefit to the hemodynamic state in refractory heart failure patients who are already stabilized on i.v. inotropic support with catecholamines.

Aged↗
PubMed1997

Root canal cleanliness after preparation with different endodontic handpieces and hand instruments: a comparative SEM investigation.

The root canals of 150 extracted mandibular incisors were prepared to ISO 30 using eight different automated devices and hand instruments. The automated devices investigated were: Endoplaner, Excalibur, Ultrasonics (Piezon Master 400) with H2O2 (5%), or NaOCl (1%) as irrigants, Giromatic, Intra-Endo 3-LDSY, Canal Finder System, Canal Leader 2000, and Endolift. Hand instrumentation was performed using reamers and Hedstroem files. Fifteen teeth were instrumented with each device, cracked longitudinally, and investigated under the scanning electron microscope using five category scoring systems based on reference photographs for debris and smear layer. No preparation system or technique resulted in complete removal of smear layer and debris. The ultrasonic unit performed best followed by the Canal Leader 2000 and hand instrumentation, whereas the use of the Giromatic, the Endolift, the Canal Finder System, and the Intra-Endo-3-LDSY-handpiece resulted in insufficiently cleaned root canal walls.

Dental High-Speed Equipment↗
PubMed1997

Efficacy, cleaning ability and safety of different devices for gutta-percha removal in root canal retreatment.

The purpose of this study was to evaluate the efficacy, cleaning ability and safety of five different devices and techniques to remove gutta-percha root canal fillings. One hundred and twenty extracted single-rooted anterior and premolar teeth were enlarged to ISO size 35 and obturated with laterally condensed gutta-percha using AH 26 as the sealer. Removal of gutta-percha was performed with the following devices and techniques: (a) Gates-Glidden and Hedstrom files, (b) only Hedstrom files, (c) Hedstrom files and chloroform, (d) the Endotec and Hedstrom files, and (e) the XGP drill and Hedstrom files. The following data were recorded: time taken to reach the desired working length, time required for the removal of the gutta-percha, and the amount of material extruded apically. The teeth were split longitudinally and photographed. Cleanliness of the root canal walls was scored using the projected slides with a total magnification of approximately 70x. The fastest technique to reach the working length was using the XGP drill (e), followed by the Gates-Glidden drills (a), Hedstrom files and chloroform (c), and the Endotec device (d). The use of Hedstrom files (b) without any additional support proved to be most time-consuming. Differences were statistically significant (U-test, P > 0.05) between the rotary devices and the manual techniques. Time for complete removal of gutta-percha was again shortest with the XGP drills (e), followed by the Gates-Glidden burs (a), the Endotec device (d), Hedstrom files with chloroform (c), and Hedstrom files alone (b). The XGP burs and the Gates-Glidden drills worked significantly faster than the other techniques. The amount of debris and filling material extruded apically in most cases did not exceed 0.1 mg. No significant differences could be detected between the groups (U-test, P > 0.05). Root canal cleanliness proved best following the use of Hedstrom files without additional support (b) and the Gates-Glidden drills (a), followed by Hedstrom files in combination with chloroform (c), the XGP-gutta-percha remover (e), and the Endotec device (d). When using the XGP two instrument fractures occurred in the apical parts of the root canals preventing further instrumentation to the apical foramen. When using the Gates-Glidden burs four instrument fractures occurred, but all fragments could be removed with forceps immediately. The results suggest that the XGP gutta-percha remover and the Gates-Glidden drills are efficient and time saving devices to remove gutta-percha but include a certain risk of instrument breakage and may leave some filling material inside the root canal. The best root canal cleanliness was achieved with Hedstrom files alone which, on the other hand, were shown to be the most time-consuming.

Evaluation Studies as Topic↗