bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Attachment Systems on Load Transfer of an Implant‐Assisted Maxillary Overdenture
Authors: Fanuscu Mete I. , Caputo Angelo A. 
Published: September 2010

Purpose:
This photoelastic study compared the load transfer characteristics of 2 retention mechanisms in an implant‐assisted overdenture prosthesis.
Materials and Methods:
Four implants were incorporated into a photoelastic model of a moderately resorbed edentulous human maxilla. Two retention mechanisms were studied by changing components on the same model and the palateless overdenture. The retention mechanisms studied were bar splint with anterior clip and distal resilient attachments, and solitary ball/O‐ring attachments. Loads, ranging from 1.4 to 14.4 kg, were applied to the palatal incline of central incisors and buccal incline of premolars with and without balancing contacts. Stresses developed around all the implants under each loading condition were photographed in the field of a circular polariscope.
Results:
With both retention mechanisms, protrusive and laterotrusive loads without balancing contacts caused instability of the overdenture, producing minimal stress around the implants in the supporting structure. High intensity stresses indicating intrusion of the posterior implants were noted when the bar/distal resilient attachment overdenture had balancing contacts for protrusive and laterotrusive loads. The posterior implants of ball/O‐ring attachment overdenture exhibited high intensity stresses indicating not only intrusion, but also bending, when the occlusion was balanced.
Conclusions:
Balanced occlusion was required in both retention mechanisms for stability of the implant‐assisted overdenture when clinically acceptable loads were applied. The protrusive and laterotrusive loads were not distributed equitably in either mechanism, since highest stresses occurred at the posterior implants.
Retention Characteristics of Attachment Systems for Implant Overdentures
Authors: Chung Kwok‐Hung , Chung Cho‐Yao , Cagna David R. , Cronin Robert J. 
Published: September 2010

Purpose:
The aim of this study was to compare the retention characteristics of various overdenture attachment systems commonly used to retain overdentures to dental implants.
Materials and Methods:
An edentulous mandibular model was constructed incorporating 2 parallel 4.0 mm × 13 mm Branemark implants placed in the canine regions. Attachments were embedded in a metal‐reinforced experimental overdenture designed to be dislodged from the model by a universal testing machine. Tensile dislodging force was applied to the overdenture at a cross‐head speed of 50 mm/min. Five overdentures were constructed for each of the attachment systems. The attachments evaluated were the Hader bar & metal clip, Locator LR pink, Locator LR white, Spheroflex ball, Shiner magnet, Maxi magnet, Magnedisc magnet, ERA white, and ERA gray. Each apparatus was tested with 5 specimens per attachment system. Peak load‐to‐dislodgement was measured. Analysis of variance and Scheffé multiple comparison tests were applied to the data with α≤ 0.05 level of significance.
Results:
Peak load‐to‐dislodgement for all attachment systems ranged from 3.68 ± 1.32 N to 35.24 ± 1.99 N. Strain‐at‐dislodgement, calculated from stress‐strain curves, ranged from 0.78 ± 0.20% to 2.78 ± 0.5%. The ERA gray attachment demonstrated the greatest retention, with a peak load‐to‐dislodgement of 35.24 ± 1.99 N, and a relatively low strain‐at‐dislodgement of 1.64 ± 0.09%. Less retention was recorded for the Locator LR white, Spheroflex ball, Hader bar & metal clip, and ERA white systems. The Locator LR pink attachment demonstrated still less retention with a load‐to‐dislodgement of 12.33 ± 1.28 N. Significantly high strain‐at‐dislodgement was recorded for the Hader bar & metal clip and Locator nylon attachment systems. The lowest dislodging loads and strains were recorded for the Shiner magnet, Maxi magnet, and Magnedisc magnet attachments.
Conclusions:
Results suggest that the attachment systems evaluated may be grouped into high (ERA gray), medium (Locator LR white, Spheroflex ball, Hader bar & metal clip, ERA white), low (Locator LR pink), and very low (Shiner magnet, Maxi magnet, Magnedisc magnet) retention characteristics.
Anesthesia (1)
Authors: Maneksha Farrokh R. , Mirza Himayun , Poppers Paul J. 
Published: September 2010

Complex regional pain syndrome (CRPS) with resistance to local anesthetic block: a case report. (State University of New York at Stony Brook, Stony Brook, NY) J Clin Anesth 2000;12:67–71.A case of complex regional pain syndrome (CRPS) Type 1 in a 12‐year‐old girl is presented. The patient did not respond to the usual therapeutic modalities used to treat CRPS including physical therapy, lumbar sympathetic block, epidural local anesthetic block, intravenous lidocaine infusion, or other oral medications. Of note is the fact that during epidural block the patient demonstrated a resistance to local anesthetic neural blockade in the area of the body involved with the pain problem. The mechanism of this resistance could be related to the changes in the dorsal horn cells of the spinal cord, secondary to activation of N‐methyl‐D‐aspartate receptors, which may play a role in the pathophysiology of this pain syndrome.
Anesthesia (15)
Authors: Okunda Yasuhisa , Okuda Keiko , Shinohara Masayuki , Kitajima Toshimitsu 
Published: September 2010

Use of computed tomography for maxillary nerve block in the treatment of trigeminal neuralgia. (Dokkyo University School of Medicine, Mibu, Tochigi, Japan) Reg Anesth Pain Med 2000;25:417–419.A report of a 90‐year‐old woman who had a 30‐year history of episodic pain in her right maxillary region is presented. An attempt to block the nerve with classic technique was made, but eliciting paresthesia could not identify the nerve. In addition, bleeding was noted after repeated attempts. To minimize complications and confirm the correct position of the needle tip, the block was planned with a suprazygomatic approach using computed tomography (CT) guidance. The needle was inserted without paresthesia. The CT scan showed the needle tip was placed at the entrance of the pterygopalatine fossa and the distribution of contrast medium spread appropriately around the pterygopalatine fossa. After confirming the clinical effect and lack of complications of the block using the local anesthetic, 0.5 mL of 7% phenol was injected. The technique resulted in complete sensory loss in the area innervated by the maxillary nerve and did so without complications. Comment by Andrew D. Rosenberg, MD.This is an interesting article in which the authors describe their technique for treating trigeminal neuralgia. The authors were faced with a significant problem, which was to perform a maxillary nerve block in a patient with difficult anatomy. The approach and technique were clearly thought out with an excellent result. The axial cuts demonstrate needle position under CT scan and the appropriate spread of contrast material through the pterygopalatine fossa.
Anesthesia (16)
Authors: Calvillo Octavio , Skaribas Ioannis M. , Rockett Carl 
Published: September 2010

Computed tomography—guided pudendal nerve block. A new diagnostic approach to long‐term anoperineal pain: a report of two cases. (Baylor College of Medicine, Houston, TX) Reg Anesth Pain Med 2000;25:420–423.This report showed the value of computed tomography (CT) in selectively blocking the pudendal nerve in patients with long‐term anogenital pain of uncertain etiology. In 1 patient, a competitive cyclist, blocking the nerve under CT substantiated the diagnosis of pudendal neuralgia. The procedure relieved the pain for approximately 24 h. In the other patient, pudendal nerve block produced perineal analgesia, but no pain relief. Superior hypogastric plexus block relieved the pain significantly for about 4 weeks on 2 separate occasions, suggesting sympathetically maintained pain. Conclude that the use of CT to guide the procedure allowed precision in performing the procedure and in making a differential diagnosis.
Anesthesia (18)
Authors: Casati Andrea , Magistris Luca , Fanelli Guido 
Published: September 2010

Small‐dose clonidine prolongs postoperative analgesia after sciatic‐femoral nerve block with 0.75% ropivacaine for foot surgery. (University of Milan, Milan, Italy) Anesth Analg 2000;91:388–392.This study evaluated the effects of adding small‐dose clonidine to 0.75% ropivacaine during peripheral nerve blocks, 30 ASA physical status I and II patients undergoing hallux valgus repair under combined sciatic‐femoral nerve block were randomly allocated in a double‐blinded fashion to receive block placement with 30 mL of either 0.75% ropivacaine alone (Group Ropivacaine, n = 15) or 0.75% ropivacaine plus μg/kg clonidine (Group Ropivacaine‐Clonidine, n = 15). Hemodynamic variables, oxygen saturation, and levels of sedation, as well as the time required to achieve surgical block and time to first analgesic request, were recorded by a blinded observer. Time to surgical blockade required 10 min in both groups. Patients in the Ropivacaine‐Clonidine Group were more sedated than patients in the Ropivacaine Group only 10 min after block placement. No differences in oxygen saturation and hemodynamic variables, degree of pain measurement at first analgesic request, and consumption of postoperative analgesics were observed between the two groups. The mean time from block placement to first request for pain medication was shorter in Group Ropivacaine (13.7 h; 25th–75th percentiles: 11.8–14.5 h) than in Group Ropivacaine‐Clonidine (16.8; 25th–75th percentiles: 13.5–17.8 h) (P = 0.038). Conclude that adding 1 μg/kg clonidine to 0.75% ropivacaine provided a 3‐h delay in first request for pain medication after hallus valgus repair, with no clinically relevant side effects.
Anesthesia (19)
Authors: Steinbrook Richard A. , Concepcion Mercedes A. 
Published: September 2010

Respiratory gas exchange and hemodynamics during lumbar epidural anesthesia: effects of lidocaine with and without epinephrine. (New England Medical Center, Tufts University School of Medicine, Boston, MA) Reg Anesth Pain Med 2000;25:380–384.In this study, 12 healthy patients (age, 22 to 46 years) undergoing surgery on the knee were randomly assigned to receive either 2% lidocaine (Group L) or 2% lidocaine with epinephrine 5 μg · mL−1 (Group E), approximately 20 mL, over 10 min via lumbar epidural catheter. Total‐body oxygen consumption (VO2) and carbon dioxide production (VCO2) were determined by indirect calorimetry; hemodynamic measurements were obtained by noninvasive thoracic electrical bioimpedance. Values of VO2, VCO2, heart rate (HR), cardiac index (CI), and mean arterial blood pressure (MAP) were determined every minute and averaged every 5 min for 30 min. Comparisons were made with analysis of variance (ANOVA) (within groups) and t‐tests (between groups). Differences were considered significantly different if P < 0.05. VO2 did not change in either group, while VCO2 increased significantly by 22% at 20 min in Group E. Increases in HR were apparent in both groups, with significantly greater increases in Group E. CI did not change in Group L, but increased by 41% in Group E. MAP decreased significantly by 11% in Group E, but did not change in Group L. Conclude that the addition of epinephrine, 5 μg · mL−1, to the epidural injection of 2% lidocaine is associated with changes not only in hemodynamics, but also in respiratory gas exchange.
Anesthesia (2)
Authors: Buchheit Thomas , Crews James C. 
Published: September 2010

Lateral cervical epidural catheter placement for continuous unilateral upper extremity analgesia and sympathetic block. (Wake Forest University School of Medicine, Winston‐Salem, NC) Reg Anesth Pain Med 2000;25:313–317.This article discussed the use of a laterally directed cervical epidural catheter for the treatment of acute and chronic pain. The technique was used in a series of 30 patients to produce unilateral upper extremity analgesia and sympathetic block. A case report of a patient treated with this technique and a description of the technique as well as the results from the series are presented. The method included placement of an epidural catheter at the C6‐7 vertebral interspace; the needle bevel and catheter were directed to the affected side in a woman with a history of complex regional pain syndrome of the right upper extremity. A unilateral block was shown with the technique by anatomic parameters (unilateral contrast dye spread), physiologic parameters (unilateral Horner's syndrome), and symptomatic parameters (unilateral, subjective neural block). One patient treated with the technique had bilateral effects; however, no patient had a predominant block on the contralateral side and no complications developed. The case report showed results that were typical of the series of 30 patients. Conclude that the laterally directed cervical epidural catheter was an effective technique to produce continuous unilateral analgesia and sympathetic block.
Anesthesia (20)
Authors: Schuepfer Guido , Konrad Christoph , Schmeck Joachim , Poortmans Gert , Staffelbach Bruno , Jöhr Martin 
Published: September 2010

Generating a learning curve for pediatric caudal epidural blocks: an empirical evaluation of technical skills in novice and experienced anesthetists. (Institute of Anesthesiology, Lucerne, Switzerland) Reg Anesth Pain Med 2000;25:385–388.The aim of this study was to assess the number of caudal blocks needed to guarantee a high success rate in performing caudal epidural analgesia in children. The technical skills of 7 residents in anesthesiology who performed caudal blocks were evaluated during 4 months using a standardized self‐evaluation questionnaire. At the start of the study period, the residents had no prior experience in pediatric anesthesia or in performing caudal epidural blocks. All residents entered the pediatric rotation after a minimum of 1 year of training in adult general and regional anesthesia. The blocks were rated using a binary score. For comparison, the success rates of 8 experienced staff anesthesiologists were collected during the same period using the same self‐evaluation questionnaire. Statistical analyses were performed by generating individual and institutional learning curves using the pooled data. The learning curves were calculated with the aid of a least‐square fit model and 95% confidence intervals were estimated by a Monte‐Carlo procedure with a bootstrap technique. The success rate of residents was 80% after 32 procedures (95% confidence interval of 0.59 to 1.00). The pooled success rate of the staff anesthesiologists was 0.73 (mean) with a standard deviation of 0.45, which was not statistically different from the success rate of the residents. Conclude that high success rates in performing caudal anesthesia in pediatric patients can be acquired after a limited number of cases. Success rates of residents learning this procedure are comparable to the results of the staff anesthesiologists.
Basic Science (23)
Authors: Kissin Igor , Bright Cheryl A. , Bradley Edwin L. 
Published: September 2010

Acute tolerance to continuously infused alfentanil: the role of cholecystokinin and N‐methyl‐D‐aspartate‐nitric oxide systems. (Brigham and Women's Hospital, Boston, MA) Anesth Analg 2000;91:110–119.To test the role of cholecystokinin (CCK) and N‐methyl‐D‐aspartate‐nitric oxide (NMDA‐NO) systems in the development of acute tolerance to analgesia during alfentanil IV infusion, experiments were conducted in rats with the use of an infusion algorithm designed to maintain a constant plasma level of the opioid for 4 h. The degree of acute tolerance was determined on the basis of decline in the level of analgesia measured with a tail compression test. CCKB receptor antagonists (proglumide, CI‐988, and L‐365,260) and NMDA‐NO cascade inhibitors (dizocilpine and NO synthase inhibitor) were administered before the start of alfentanil infusion. Use of 30 mg/kg proglumide, 10 mg/kg CI‐988, and 1 mg/kg L‐365,260 attenuated acute tolerance at 1 h of alfentanil infusion by approximately 60%, 55%, and 70%, respectively, and by the end of the 4‐h infusion by 50%, 50%, and 25%, respectively. Use of 0.1 mg/kg dizocilpine and 10 mg/kg NG‐nitro‐L‐arginine methyl ester attenuated acute tolerance at 1 h of alfentanil infusion by approximately 65% and 65% and by the end of the 4‐h infusion by 30% and 0%, respectively. Comparison of the results with CCKB receptor antagonists and inhibitors of NMDA‐NO cascade demonstrates that both groups provide more or less similar degrees of attenuation of acute tolerance to the antinociceptive effect of alfentanil, and none of these drugs completely prevents tolerance development.
Basic Science (24)
Authors: Li Xinhui , Zhao Zhihong , Pan Hui‐Lin , Eisenach James C. , Paqueron Xavier 
Published: September 2010

Norepinephrine release from spinal synaptosomes. (Wake Forest University School of Medicine, Winston‐Salem, NC) Anesthesiology 2000;93:164–172.The purpose of this study was to determine if clonidine could inhibit release of NE in a preparation of spinal cord tissue lacking synaptic circuits. Crude synaptosomes were prepared from male Sprague‐Dawley rat spinal cord, loaded with [3H]NE, and stimulated by potassium chloride to release [3H]NE. Samples were incubated with clonidine in the absence or presence of various inhibitors. To study the effect of α2A‐adrenergic receptor subtypes, some animals were pretreated with an oligodeoxynucleotide (ODN) composed of a sense or antisense sequence to a portion of this receptor. Potassium chloride produced a concentration‐dependent increase in [3H]NE release, and this release was inhibited by clonidine with a concentration producing 50% maximal inhibition (IC50) of 1.3 μm. The effect of clonidine was inhibited by the α2A‐adrenergic antagonists, yohimbine, and idazoxan, but not by α1A‐adrenergic, muscarinic, or opioid antagonists. Intrathecal pretreatment with antisense ODN to α2A‐adrenergic receptors reduced α2A‐adrenergic receptor protein expression compared with sense ODN control and also reduced clonidine‐induced inhibition of [3H]NE release. Conclude that these data demonstrate the existence of classic autoinhibitory α2A‐adrenergic receptors in the spinal cord, probably of the α2A subtype. They further suggest that clonidine‐induced stimulation of spinal NE release must occur from indirect actions, presumably due to activation of a spinal circuit.
Basic Science (26)
Authors: Khodorova Alla B. , Strichartz Gary R. 
Published: September 2010

The addition of dilute epinephrine produces equieffectivenes of bupivacaine enantiomers for cutaneous analgesia in the rat. (Brigham and Women's Hospital, Boston, MA) Anesth Analg 2000;91:410–416.This study investigated the effectiveness for cutaneous analgesia of bupivacaine (Bup) stereoisomers in male rats. As a model of infiltration anesthesia, inhibition of a nocifensive reflex by subcutaneous injection of 0.6mL of different concentrations of R‐, S‐, and racemic‐Bup was evaluated quantitatively by the fraction of times a pinprick failed to evoke a nocifensive motor response. R‐Bup was more potent in the extent of the block; however, S‐Bup had a longer‐lasting action at smaller doses. This significant difference was apparent when R‐Bup and S‐Bup were administered in equipotent doses of 0.06% and 0.075%, respectively. Co‐injection of epinephrine (Epi) with these equipotent doses enhanced and prolonged the blocking effects of both Bup stereoisomers, although the dilutions of 1:100,000 to 1:1,000,000 Epi itself induced partial, transient analgesia. At 1:2,000,000 dilution, Epi alone had no analgesic effect; however, when co‐injected with the shorter‐acting R‐Bup (0.06%), Epi prolonged its blocking effect to equal the duration of the block evoked by equipotent S‐Bup (0.075%). Conclude that R‐Bup is more potent for cutaneous analgesia and that the longer duration of the block by S‐Bup probably originates from vasoconstrictor activity.
Basic Science (28)
Authors: Kawamata Tomoyuki , Omote Keiichi , Sonoda Hajime , Kawamata Mikito , Namiki Akiyoshi 
Published: September 2010

Analgesic mechanisms of ketamine in the presence and absence of peripheral. (Sapporo Medical University School of Medicine, Sapporo, Japan) Anesthesiology 2000;93:520–528.In this study, the authors investigated the contribution of the supraspinal monoaminergic descending inhibitory system to ketamine analgesia for acute nociception and inflammation‐induced hyperalgesia. Male Sprague‐Dawley rats were used. The paw withdrawal latencies to radiant heat stimuli were measured to assess the thermal nociceptive threshold. The analgesic effects of intrathecal or intraperitoneal ketamine were examined in the rats that received unilateral intraplantar carrageenan and in those that were untreated. In addition, it was examined whether pretreatment with intrathecal yohimbine or methysergide inhibited the analgesic effects of ketamine. Using an intrathecal microdialysis method, noradrenaline and 5‐hydroxytryptamine concentrations in lumbar cerebrospinal fluid were measured after intraperitoneal ketamine in both saline‐ and carrageenan‐treated rats. In the untreated rats, intraperitoneal but not intrathecal ketamine produced antinociceptive effects in a dose‐dependent manner. Pretreatment with intrathecal yohimbine or methysergide inhibited these antinociceptive effects. Intraplantar carrageenan significantly reduced paw withdrawal latencies on the injected paw, but not on the contralateral paw. Both intraperitoneal and intrathecal ketamine reversed the shortened paw withdrawal latencies on the injected side in a dose‐dependent manner without any effects on the contralateral side. Neither yohimbine nor methysergide inhibited these antihyperalgesic effects. In analyses of monoamines, the magnitiute of increase in monoamines after intraperitoneal ketamine was significantly smaller in the carrageenan‐treated rats than in the saline‐treated rats. Conclude that these results demonstrated that ketamine produced antinociceptive effects through an activation of the monoaminergic descending inhibitory system, whereas, in a unilateral peripheral inflammation‐induced hyperalgesic state, the monoaminergic system did not contribute to the antihyperalgesic effects of ketamine. The mechanisms of the antinociceptive and antihyperalgesic properties of ketamine are different.