Tramadol and o-desmethyl tramadol clearance maturation and disposition in humans: a pooled pharmacokinetic study.

BACKGROUND AND OBJECTIVES: We aimed to study the impact of size, maturation and cytochrome P450 2D6 (CYP2D6) genotype activity score as predictors of intravenous tramadol disposition. METHODS: Tramadol and O-desmethyl tramadol (M1) observations in 295 human subjects (postmenstrual age 25 weeks to 84.8 years, weight 0.5-186 kg) were pooled. A population pharmacokinetic analysis was performed using a two-compartment model for tramadol and two additional M1 compartments. Covariate analysis included weight, age, sex, disease characteristics (healthy subject or patient) and CYP2D6 genotype activity. A sigmoid maturation model was used to describe age-related changes in tramadol clearance (CLPO), M1 formation clearance (CLPM) and M1 elimination clearance (CLMO). A phenotype-based mixture model was used to identify CLPM polymorphism. RESULTS: Differences in clearances were largely accounted for by maturation and size. The time to reach 50 % of adult clearance (TM50) values was used to describe maturation. CLPM (TM50 39.8 weeks) and CLPO (TM50 39.1 weeks) displayed fast maturation, while CLMO matured slower, similar to glomerular filtration rate (TM50 47 weeks). The phenotype-based mixture model identified a slow and a faster metabolizer group. Slow metabolizers comprised 9.8 % of subjects with 19.4 % of faster metabolizer CLPM. Low CYP2D6 genotype activity was associated with lower (25 %) than faster metabolizer CLPM, but only 32 % of those with low genotype activity were in the slow metabolizer group. CONCLUSIONS: Maturation and size are key predictors of variability. A two-group polymorphism was identified based on phenotypic M1 formation clearance. Maturation of tramadol elimination occurs early (50 % of adult value at term gestation).

Ultrasound-guided tranversus abdominis plane block for herniorrhaphy in children: what is the optimal dose of levobupivacaine?

BACKGROUND: Regional anaesthesic techniques are commonly used for the management of pain following lower abdominal surgery in children. The transversus abdominis plane (TAP) block has shown promise for perioperative analgesia, but data on the optimal dose regimen are limited. OBJECTIVE: To evaluate the optimal dose of levobupivacaine for successful ultrasound-guided TAP block in children. DESIGN: A dose finding prospective study using Dixon's up-and-down sequential method. SETTING: University Hospital Paediatric Anaesthesia Unit. PATIENTS: Twenty-seven consecutive children aged 1 to 5 years scheduled for day-case elective herniorrhaphy. INTERVENTION: After standardised induction of general anaesthesia, ultrasound-guided TAP block was performed with a fixed volume of 0.2  ml  kg(-1) of levobupivacaine solution. The dose of levobupivacaine was determined by Dixon's up-and-down method starting from 0.5  mg  kg(-1)with an interval of 0.1 mg   kg(-1). Block failure was defined as a 20% increase in heart rate or mean arterial pressure from baseline. Rescue analgesia consisted of intravenous remifentanil infusion during surgery and intravenous nalbuphine in the postanaesthetic care unit (PACU). Patients were assessed using the FLACC (face, legs, activity, cry and consolability) pain scale, the rescue analgesic consumption in the PACU and day-case unit and the postoperative pain measure for parents score at home. MAIN OUTCOME MEASURES: The mean effective dose of levobupivacaine resulting in an effective TAP block in 50% of cases (ED50) obtained by using Dixon's up-and-down sequential method. The ED50 and ED95 were further estimated by bootstrapping. RESULTS: The ED50 according to the up-and-down staircase method was 0.22  mg   kg(-1) [95% confidence interval (CI) 0.19 to 0.25]. Bootstrap replicates of the original dataset resulted in ED50 and ED95 estimates of 0.16  mg    kg(-1) (95% CI 0.11 to 0.24) and 0.43 mg  kg(-1)(95% CI 0.30 to 0.57), respectively. CONCLUSION: As part of a multimodal analgesia strategy, ultrasound-guided TAP block with 0.2  ml  kg(-1)of 0.2% levobupivacaine provides successful peroperative analgesia in 95% of children who underwent herniorrhaphy.

Intraoperative tranexamic acid reduces blood transfusion in children undergoing craniosynostosis surgery: a randomized double-blind study.

BACKGROUND: Surgical correction of craniosynostosis in children is associated with substantial intraoperative bleeding. Tranexamic acid (TXA) decreases intraoperative blood loss during cardiac or orthopedic surgery in children. We hypothesized that intraoperative TXA would reduce blood transfusion relative to placebo in patients pretreated with erythropoietin. METHODS: Forty consecutive children, American Society of Anesthesiologists status 1 or 2, scheduled to undergo surgical correction of craniosynostosis were randomly assigned to receive either intravenous TXA or saline, 0.9%, intraoperatively. All children received preoperative erythropoietin (600 U/kg once a week for 3 weeks before surgery). Perioperative blood loss, number and volume of transfusions, percentage of children who underwent transfusion, and side effects were noted after surgery and at the end of the study. Surgeon satisfaction and cost of treatment were also recorded. RESULTS: There was no significant difference between groups in demographic or surgical data. In the TXA group, the volume of packed erythrocytes transfused was significantly reduced by 85% (from 11 to 1.6 ml/kg) intraoperatively and by 57% (from 16.6 to 7.2 ml/kg) throughout the study period (P < 0.05). Compared with the placebo group, the percentage of children requiring blood transfusion was lower in the TXA group during surgery (9 [45%] of 20 vs. 2 [11%] of 19 children; P < 0.05) and during the whole study period (14 [70%] of 20 vs. 7 [37%] of 19; P < 0.05). Preoperative and postoperative hematologic parameters were comparable in both groups. There were no adverse events. CONCLUSION: In children undergoing surgical correction of craniosynostosis and pretreated with erythropoietin, intraoperative TXA reduces the transfusion requirement.

Developmental pharmacology of tramadol during infancy: ontogeny, pharmacogenetics and elimination clearance.

AIMS AND OBJECTIVES: To illustrate the complex interaction between ontogeny, i.e., age-dependent maturation, genetic polymorphisms and renal elimination clearance during infancy, based on developmental disposition of intravenous tramadol during infancy. BACKGROUND: Tramadol (M) is metabolized by O-demethylation (cytochrome P450 [CYP] 2D6) to the pharmacodynamic active metabolite O-demethyl tramadol (M1). This metabolite is subsequently eliminated by renal route while M1 formation will in part depend on ontogeny, i.e., age-dependent activity and CYP2D6 polymorphisms. However, these pathways do not mature simultaneously. METHODS: A pooled pharmacokinetic analysis of earlier reported time-concentration profiles in neonates and infants was performed with subsequent simulation of the impact of ontogeny, polymorphisms and renal elimination clearance during infancy. RESULTS: Tramadol plasma time-concentration profile changes with postmenstrual age. The highest metabolite concentrations occur in the 52-week infant, where M1 formation clearance (hepatic, CYP2D6) is already mature but metabolite elimination clearance (through glomerular filtration rate) is immature. DISCUSSION: The phenotypic observations might in part explain unanticipated (side-)effects of tramadol. In addition to the compound-specific clinical implications, it is important to stress that the maturational trends in the elimination processes described can be considered for other compounds (e.g., codeine) that undergo similar elimination routes.

A new approach for peri-operative analgesia of cleft palate repair in infants: the bilateral suprazygomatic maxillary nerve block.

BACKGROUND: Congenital cleft palate (CP) is a common and painful surgical procedure in infants. CP repair is associated with the risk of postoperative airway obstruction, which may be increased with administration of opioids, often needed for analgesia. No described regional anesthesia technique can provide adequate pain control following CP repair in infants. The primary aim of this prospective and descriptive study was to observe the effectiveness of bilateral maxillary nerve blocks (BMB) using a suprazygomatic approach on pain relief and consumption of rescue analgesics following CP repair in infants. Analgesic consumption was compared to retrospective data. Complications related to this new technique in infants were also reviewed. METHODS: The landmarks and measurements recently defined in a three-dimensional study using computed tomography in infants were used. After general anesthesia, a BMB was performed bilaterally with 0.15 ml x kg(-1) 0.2% ropivacaine in infants scheduled for CP repair. Postoperative analgesia, administration of rescue analgesics, adverse effects, and time to feed were recorded in the 48-h period following surgery and compared to retrospective data. RESULTS: Thirty-three children, mean age 5 +/- 1.8 months and weight 8.3 +/- 1.2 kg, were studied. Eighteen patients out of 33 (55%) did not require additional opioids intra-operatively, vs two out of 20 (10%) without block. None needed morphine postoperatively, and intravenous nalbuphine was required in only six children (18%), vs 16 (80%) without block. Median time to feed was 8 h (range 2-24 h), vs 13 h (4-25) without block. No technical failure or complication related to the BMB was reported. CONCLUSION: BMB using a suprazygomatic approach seems to improve pain relief, to decrease peri-operative consumption of opioids, and to favor early feeding resumption after CP repair in infants.

Continuous peripheral nerve blocks for postoperative analgesia in children: feasibility and side effects in a cohort study of 339 catheters.

INTRODUCTION: Perioperative continuous peripheral nerve blocks (CPNB) are increasingly being used in children. Only one previous study has reported adverse events of CPNB in a high number of pediatric cases. We evaluated the indications, block efficacy, and adverse events related to CPNB in children. METHODS: All CPNBs that were performed in children for postoperative analgesia over a 5-year period at the Montpellier University Hospital in France were included in this study. The first bolus dose and the continuous doses of local anesthetic were not standardized. In the postoperative period, demographic data, quality of analgesia, amount of rescue analgesic medication, child/parent satisfaction, and adverse events were recorded in our Departmental Regional Anesthesia registry. RESULTS: A total of 339 catheters were evaluated in 292 children ASA physical status I to III. The median age was 8 yr (0.6-17 yr) and the median weight was 28 kg (7-116 kg). The main surgical indications were hip, femoral, or tibial osteotomies (44.5%) and club foot repair (27.4%). The local anesthetics used were either bupivacaine or ropivacaine. The mean volume of the local anesthetic bolus dose was 0.49 +/- 0.16 mL . kg(-1), and the mean regimen of local anesthetic continuous infusion was 0.11 +/- 0.04 mL . kg(-1) . hr(-1). The median duration of CPNB was 61.6 hr (range 0-264 hr). Pain relief, which was evaluated with the children at rest, was considered optimal in the majority of patients throughout the study period. The Children and Infants Postoperative Pain Scale (CHIPPS) was used in children age 0-6 yr and the Visual Analog Pain Scale (VAS) was used in children 7 yr and older. There were no major adverse events. There were 211 minor adverse events recorded in 153 CPNBs (45.1%). The most frequently reported complication (20.1%) involved mechanical problems with the catheter, followed by nausea and vomiting (14.7%). CONCLUSION: CPNBs are indicated after orthopedic surgery in children. Our results demonstrate that CPNBs are feasible in the pediatric setting, and in skilled hands, they promote prolonged analgesia in the majority of patients without major adverse events. The most common minor adverse events are catheter-related mechanical problems and postoperative nausea and vomiting.

Continuous infusion of ropivacaïne: an optimal postoperative analgesia regimen for iliac crest bone graft in children.

BACKGROUND: Postoperative analgesia of iliac crest (IC) donor site can be performed by on site infiltrations of local anesthetics (LA) or morphine. Single injections or continuous infusions of LA proved their efficacy in adults, but was not reported in children. We prospectively evaluated the interest of a continuous infusion of 0.2% ropivacaïne at the IC donor site in terms of postoperative pain relief and rescue analgesics consumption. METHODS: Sixteen consecutive patients, aged from 4 to 16 years scheduled for maxillar alveolar graft with IC bone, were included. After IC bone graft surgery under general anesthesia, they received a 0.2-0.4 ml x kg(-1) bolus of 0.2% ropivacaïne through the IC catheter; then a continuous infusion of 0.2% ropivacaïne at 0.125 ml x kg(-1) x h(-1) was administrated for 48 h with disposable elastomeric pumps. Children systematically received paracetamol (15 mg x kg(-1) four times a day) and niflumic acid (40 mg x kg(-1) twice a day). Postoperative pain was evaluated using a Visual Analog Scale (>7 years old) or Children and Infants Postoperative Pain Score (between 4 and 7 years old) every 4 h until H48. Doses of rescue analgesics and adverse events (LA toxicity, catheter's removal, nausea-vomiting) were also noted. Three months after surgery a blinded clinical research assistant reviewed all children and assessed functional recovery, neuropathic chronic pain symptoms or local complications. RESULTS: The median value of IC graft pain scores was 0 during whole studied period. Of the patients, 31.2% did not require any rescue analgesics and 43.8% needed only once. No adverse events related to LA and no removal of catheter were noted. One child had nausea in the 48-h postoperative period, and one child had neuropathic pain symptoms at 3 months at the donor site. CONCLUSION: Continuous infusion of 0.2% ropivacaïne through an IC catheter is an optimal and safe technique of regional postoperative analgesia after bone graft harvest in children.

A prospective comparison of post-surgical behavioral pain scales in preschoolers highlighting the risk of false evaluations.

Four behavioral rating scales (BRS) (CHEOPS, CHIPPS, FLACC and OPS) assessing postoperative pain in children aged 1-7 years were studied to compare their psychometric properties, sensitivity and specificity. One hundred and fifty children included in this prospective longitudinal study were videotaped to analyze retrospectively peri-operative behaviors. Pain and anxiety were evaluated by children or by their parents prospectively. At the end of the study, four observers rated the peri-operative videos using the four BRS. Because self-reporting cannot be used for all the children, facial expression of pain was analyzed from the videos to create a Facial Action Summary Score (FASS) which was considered as a reference for the study of validity of the four BRS. Internal validities were excellent but external validities were mixed. The FLACC seems to be better adapted to assess post-surgical pain in children between 1 and 7 years old. Nevertheless, it was significantly correlated with anxiety measures. Moreover, the analysis of sensitivity and specificity using both self-reporting of pain and FASS showed that some children were still under-evaluated. The multivariate analysis underlines silence as a high risk factor of misevaluating postoperative pain. In conclusion, this study highlights the difficulty of discriminating pain intensity from anxiety when using the four BRS and that postoperatively, nearly one child in 10 was misevaluated.

Changing trends in paediatric regional anaesthetic practice in recent years.

PURPOSE OF REVIEW: Regional anaesthesia has come to a substantial position in paediatric anaesthesia. Time has now come to assess what has reached significant acceptance in daily practice and try to clear possible ways up for the next steps to come. RECENT FINDINGS: Epidemiologic data produced in the last 2 years provide useful information about the place taken by regional anaesthesia as a whole and by the most popular blocks nowadays. Significant series seem to open a track in the field of postoperative pain management at home. Ultrasound guidance takes a great part in recent publications. The most relevant, according to the location of blocks and in the scope of security, are presented. Change in anatomical background that ultrasonography demands is questioned. Finally, most recently described approaches and their potential advantages have been looked at. SUMMARY: Lessons can be drawn from epidemiologic data now available and possible ways for changes in a near future can be anticipated. Ultrasonology brings clear advantages in abdominal wall blocks. Its use in place of nerve stimulation is claimed forcefully but not yet widely used for the blocks of the limbs in children. This switch requires profound changes in the practice of regional anaesthesia which will probably not take place immediately. Blocks of the face appear innovating and promising, according to recent literature.

A review of pediatric regional anesthesia practice during a 17-year period in a single institution.

BACKGROUND: There is anecdotal evidence of changes in pediatric regional anesthesia (RA) practice. We performed a retrospective review of prospective data on pediatric RA over 17 years in our institution. METHODS: Data were collected from an electronic database for every anesthetic performed between 1989 and 2005. Type of RA, if any, and age of the patient were noted. Patients were divided into two groups:

Transpulmonary thermodilution hemodynamic monitoring for pheochromocytoma surgery in a child with complex congenital heart disease.

Hemodynamic alterations related to pheochromocytoma surgery may lead to decompensation with an associated cardiac malformation. Moreover, they are incompletely described in children because of potential hazards of invasive monitoring. We report transpulmonary thermodilution hemodynamic monitoring during pheochromocytoma surgery in a child with a complex congenital heart malformation. Comprehensive analysis of hemodynamic events was obtained that guided therapeutic decisions. Cardiac function was preserved and no complication occurred.

Continuous epidural block versus continuous popliteal nerve block for postoperative pain relief after major podiatric surgery in children: a prospective, comparative randomized study.

Foot and ankle surgery in children is very painful postoperatively. Adverse effects from opioids and continuous epidural block (CEB) limit their use in children. Continuous popliteal nerve blocks (CPNB) have not been studied for this indication in children. In this prospective, randomized study we evaluated the effectiveness and adverse events of CPNB or CEB in children after podiatric surgery. Fifty-two children scheduled for foot surgery were separated into four groups by age and analgesia technique. After general anesthesia, 0.5 to 1 mL/kg of an equal-volume mixture of 0.25% bupivacaine and 1% lidocaine with 1:200000 epinephrine was injected via epidural or popliteal catheters. In the postoperative period, 0.1 mL x kg(-1) x h(-1) (group CPNB) or 0.2 mL x kg(-1) x h(-1) (group CEB) of 0.2% ropivacaine was administered for 48 h. Niflumic acid was routinely used. Adverse events were noted in each treatment group. Postoperative pain during motion was evaluated at 1, 6, 12, 18, 24, 36, and 48 h. Requirement for rescue analgesia (first-line propacetamol 30 mg/kg 4 times daily or second-line 0.2 mg/kg IV nalbuphine), and motor blockade were recorded. Parental satisfaction was noted at 48 h. Twenty-seven patients were included in the CEB groups and 25 in CPNB groups. There were 32 children 1 to 6 yr of age (CPNB = 15; CEB = 17) and 20 children 7 to 12 yr of age (CPNB = 10; CEB = 10). The demographic data were comparable among groups. Postoperative analgesia was excellent for the two continuous block techniques and in the two age groups. Motor block intensity was equal between techniques. Adverse events (postoperative nausea or vomiting, urinary retention, and premature discontinuation of local anesthetic infusion in the 1- to 6-yr-old group) were significantly more frequent in the CEB group (P < 0.05). Eighty-six percent of the parents in the CEB groups and 100% in the CPNB groups were satisfied. We conclude that although both CEB and CPNB resulted in excellent postoperative analgesia in this study, CPNB was associated with less urinary retention and nausea and vomiting. Therefore, we recommend CPNB as the ideal form of postoperative analgesia after major podiatric surgery in 1- to 12-yr-old children.

Clonidine added to bupivacaine in neonatal spinal anesthesia: a prospective comparison in 124 preterm and term infants.

BACKGROUND: Spinal anesthesia (SA) remains the 'gold standard' in neonatal anesthesia for inguinal herniorrhaphy but its short duration impedes its usefulness. We previously demonstrated that clonidine prolongs neonatal SA without immediate side effects. METHODS: We conducted a prospective observational study of 124 infants undergoing herniorrhaphy under SA with bupivacaine and clonidine. Two cohorts, term (n = 57) and former preterm (n = 67) infants, were evaluated and compared with regard to episodes of apnea, desaturation, and bradycardia within 24 h of SA. RESULTS: In both groups, postoperative desaturation episodes were unchanged after SA, compared with the 12 preoperative hours, despite significantly increased apnea (P < 0.003 and <0.011 respectively). Transient bradycardias occurred in former preterm infants (P < 0.014): they spontaneously resolved in all cases. Mean arterial pressure did not vary during the study. Upper sensory level of SA, sedation on entering the postanesthesia care unit (PACU) and duration of stay in the PACU were similar in both groups. CONCLUSIONS: The clinical significance of short apneas, recovering spontaneously without desaturation, remains debatable. It is concluded that addition of clonidine to neonatal SA results in acceptable side effects. Side effects must be compared with the potential advantages before future recommendations.

The effects of spread of block and adrenaline on cardiac output after epidural anesthesia in young children: a randomized, double-blind, prospective study.

UNLABELLED: Epidural anesthesia is considered to be without significant hemodynamic consequence in young children. However, conversely to adults, few studies have investigated cardiac output. Using transesophageal Doppler monitoring of cardiac output, we prospectively investigated hemodynamic alterations in 48 children (median age, 22.5 mo) receiving sevoflurane general anesthesia combined with caudal or thoracolumbar epidural anesthesia. They were randomly assigned to receive 0.8 mL/kg of plain local anesthetic mixture (lidocaine 1% + bupivacaine 0.25% (50/50) + 1 microg/mL of fentanyl) or 1 mL/kg of the same mixture with 5 microg/mL of adrenaline. No significant hemodynamic alteration was elicited in caudal and thoracolumbar groups receiving the plain mixture except a moderate decrease in heart rate. Conversely, a mixture with adrenaline added provoked a significant decrease in mean arterial blood pressure by 14% and 17%, in systemic vascular resistance by 24% and 40%, and an increase in cardiac output by 20% and 34% in caudal and thoracolumbar groups, respectively. The adrenaline effect was greater by the thoracolumbar than the caudal approach. In young children, epidural anesthesia induces an increase in cardiac output only when adrenaline is added to local anesthetics, probably through its systemic absorption from the epidural space. IMPLICATIONS: Epidural anesthesia may induce significant hemodynamic changes, well documented in adults. Using noninvasive hemodynamic monitoring in children, we reported an increase in cardiac output and a decrease in arterial blood pressure only when epinephrine was added to epidurally-injected local anesthetics.

Clonidine prolongs spinal anesthesia in newborns: a prospective dose-ranging study.

UNLABELLED: Spinal anesthesia may reduce the incidence of morbidity that follows general anesthesia in neonates and in former preterm infants. However, bupivacaine alone provides a block too short for complete surgery in up to 40% of the patients. Clonidine lengthens spinal anesthesia in adults and caudal block in children without significant side effects. We conducted a controlled, prospective, dose-ranging study of clonidine in spinal anesthesia in 75 neonates, including 50% of former preterm infants, undergoing elective inguinal herniorrhaphy. Patients were given a spinal anesthetic with either 0.5% plain isobaric bupivacaine (1 mg/kg), or bupivacaine plus 0.25, 0.5, 1, or 2 micro g/kg clonidine. Mean arterial blood pressure, heart rate, SpO(2), sensory block extension and duration were the main data recorded. Mean arterial blood pressure, heart rate, SpO(2), and block extension were similar in the five groups. Duration of spinal block increased from 67 (58-82) min in the control group up to 111 (93-125) min in the group receiving 1 micro g/kg clonidine (P < 0.003). Transient hypotension occurred more often (P < 0.05), and caffeine was given more often, when 2 micro g/kg clonidine was given. We conclude that 1 micro g/kg clonidine provides a significant improvement in spinal anesthesia duration in newborns without significant side effects. IMPLICATIONS: Spinal anesthesia is suitable but often too short for complete surgery in newborns. This controlled, randomized, prospective, dose-ranging study was conducted in 75 neonates to test the hypothesis that clonidine could significantly lengthen bupivacaine spinal block. Clonidine 1 micro g/kg, added to spinal isobaric bupivacaine, doubles the duration of the block without significant deleterious hemodynamic or respiratory side effects.

Perioperative continuous peripheral nerve blocks with disposable infusion pumps in children: a prospective descriptive study.

Continuous peripheral nerve blocks (CPNB) after pediatric major orthopedic surgery are not widely used. We conducted a prospective descriptive study to evaluate the effectiveness of disposable elastomeric pumps for CPNB in children. After inducing general anesthesia, 25 consecutive children scheduled for major orthopedic surgery received a 0.5-mL/kg bolus of a mixture of 1% lidocaine with epinephrine and 0.25% bupivacaine in axillary, femoral, or popliteal catheters. After surgery, disposable pumps with 0.2% ropivacaine were connected. Pump flows were adjusted to the patient's weight. Postoperative pain was evaluated using a visual analog scale or Children and Infants Postoperative Pain Scale scores at H1, H6, H12, H24, and H48, as well as amounts of rescue analgesia, adverse events, and motor and sensory block. An ambulation score for the children was also evaluated. Eleven popliteal, nine femoral, and five axillary continuous blocks were performed. All the blocks were effective for surgery. The mean total dose consumption of 0.2% ropivacaine was 10.1 mg/kg. Disposable pump flow varied from -9.61% to +8.6% compared with the theoretical one. Postoperative analgesia was excellent. The median of pain score was zero at each period studied. Sensory and motor block were noted at H1 and decreased from the sixth hour. No adverse events were noted. We concluded that the use of elastomeric disposable pumps for CPNB in children was an effective technique.

Retenedores de adhesión directa: puente de Maryland y otras alternativas

Prefacio. Introducción al retenedor de adhesión directa. Técnica básica de adhesión. Los materiales. Fundamentos de la adhesión de aleaciones. Consideraciones clínicas sobre el retenedor de adhesión directa. Grabado de aleaciones dentales para colado. Diseño del esqueleto posterior. Diseños de esqueletos anteriores. Técnica de laboratorio de encerado y colado. Técnica del grabado electrolítico. Procedimientos clínicos de adhesión. El retenedor perforado. la técnica de los abalorios. Técnica de la malla colada. Diseños del esqueleto más avanzados y resolución de problemas. Fijadores de precisión usados con retenedores de adhesión directa en tratamientos con dentaduras parciales removibles. Carillas de porcelana de adhesión directa. Retenedores de adhesión directa no colados

Retenedores de adhesión directa: puente de Maryland y otras alternativas

Prefacio. Introducción al retenedor de adhesión directa. Técnica básica de adhesión. Los materiales. Fundamentos de la adhesión de aleaciones. Consideraciones clínicas sobre el retenedor de adhesión directa. Grabado de aleaciones dentales para colado. Diseño del esqueleto posterior. Diseños de esqueletos anteriores. Técnica de laboratorio de encerado y colado. Técnica del grabado electrolítico. Procedimientos clínicos de adhesión. El retenedor perforado. la técnica de los abalorios. Técnica de la malla colada. Diseños del esqueleto más avanzados y resolución de problemas. Fijadores de precisión usados con retenedores de adhesión directa en tratamientos con dentaduras parciales removibles. Carillas de porcelana de adhesión directa. Retenedores de adhesión directa no colados