Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM.

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

Differential distribution of Ca2+-activated K+ channel splice variants among hair cells along the tonotopic axis of the chick cochlea.

We have cloned from the receptor epithelium of the chick cochlea a family of alternatively spliced cDNAs derived from cslo, which encodes a Ca2+-activated K+ channel like those shown to help determine the resonant frequency of electrically tuned hair cells. Our results from PCRs using template RNAs from both tonotopically subdivided receptor epithelia and single hair cells demonstrate differential exon usage along the frequency axis of the epithelium at multiple splice sites in cslo. We also show that single hair cells express more than one splice variant at a given splice site. Since channel isoforms encoded by differentially spliced slo transcripts in other species are functionally heterogeneous, these data suggest that differential processing of slo transcripts may account, at least in part, for the systematic variation in hair-cell membrane properties along the frequency axis of electrically tuned auditory receptor epithelia.

Two-year evaluation of restorations of a packable composite placed in UK general dental practices.

OBJECTIVE: The aim of this study was to assess the clinical performance at two years of 100 Solitaire 2 restorations placed in five United Kingdom dental practices by members of a practice-based research group. METHOD AND MATERIALS: Restorations were assessed after two years by a trained evaluator and the dental practitioner who had placed the material, for anatomic form, marginal adaptation, surface roughness, gingival condition and the presence or absence of secondary caries. In addition, the patients completed a questionnaire requesting details of the comfort and performance of the Solitaire 2 restoration(s). RESULTS: A total of 88 (58 Class II and 30 Class I) restorations of Solitaire 2 placed in 49 patients (mean age 43 years) were assessed. Twelve restorations could not be evaluated because of patient unavailability for the dates of the examinations. Two Class II restorations (2%) had failed by the time of the two-year evaluation and the remaining 86 restorations were found to be intact with no secondary caries. A high percentage of optimal scores were recorded for anatomic form and surface roughness. The colour match of two restorations (2%) was recorded as an obvious mismatch, but otherwise no unacceptable scores were recorded. CONCLUSIONS: After two years of clinical service a high proportion (96%) of the Solitaire 2 restorations that were available for re-examination, placed in general dental practice settings, were found to be performing satisfactorily.

Cost-effectiveness of transaxillary muscle-sparing same-day operative closure of patent ductus arteriosus.

Transaxillary muscle-sparing patent ductus arteriosus closure performed as same-day surgery is described in 10 patients. This approach provides a superb cosmetic result while obviating the need for thoracostomy tube placement.

Ventricular arrhythmias in postoperative tetralogy of Fallot.

Ventricular arrhythmias in patients after total surgical repair of tetralogy of Fallot have been associated with late sudden death. In this large multicenter retrospective study of 359 patients with postoperative tetralogy of Fallot, spontaneous ventricular premature complexes (VPCs) on 24-hour ambulatory electrocardiographic monitoring and laboratory-induced ventricular tachycardia (VT) by electrophysiologic stimulation were analyzed. The mean age at surgical repair was 5 years and the mean follow-up duration after repair was 7 years. Spontaneous VPCs on ambulatory monitoring were found in 48% and induced VT on electrophysiologic stimulation was found in 17% of patients. Both spontaneous VPCs and induced VT were significantly related to delayed age at repair, longer follow-up interval, symptoms of syncope or presyncope and right ventricular systolic hypertension (greater than 60 mm Hg) (p less than 0.05), but not to right ventricular diastolic pressure greater than 8 mm Hg. The VPCs on ambulatory monitoring were more complex with increasing age at repair and follow-up duration. Induction of VT on electrophysiologic stimulation correlated with spontaneous VPCs including VT on 24-hour ambulatory electrocardiographic monitoring. The electrophysiologic stimulation protocol varied and the induction of VT increased with a more aggressive stimulation protocol. While induced sustained monomorphic VT was related to all forms of spontaneous VPCs, induced nonsustained polymorphic VT was related to more complex forms of VPCs on ambulatory monitoring. VT was not induced in asymptomatic patients who had normal 24-hour ambulatory electrocardiographic monitoring and normal right ventricular systolic pressure. (ABSTRACT TRUNCATED AT 250 WORDS)

Safety of patent ductus arteriosus closure in premature infants without tube thoracostomy.

During a 30-month period, 34 premature infants underwent surgical closure of a patent ductus arteriosus. The mean gestational age at birth was 25 +/- 0.3 weeks and the mean age at the time of operation was 3 +/- 0.3 weeks (mean weight, 829 +/- 54 g). Indomethacin therapy had failed in 32 patients, and 2 had contraindications to its use. The initial 8 patients had parascapular incision and ligation of the patent ductus arteriosus; the last 26 patients had a short transaxillary incision and clipping. The average duration of the operation from the time of incision to skin closure was 36 +/- 2 minutes (range, 15 to 65 minutes). One patient (3%) needed chest tube insertion intraoperatively because of visceral pleura disruption. Two patients (5.8%) had a "small pneumothorax" (< 10% of the lung field) that resolved within 24 hours. There was no morbidity or mortality directly related to the operative procedure, although 3 patients (8.8%) ultimately died from problems related to their severe prematurity. We conclude that surgical closure of patent ductus arteriosus without chest tube drainage can be accomplished safely in premature infants. Postoperative nursing care is simplified and the cost is reduced because the need for the chest tube and drainage system is eliminated and the number of chest radiograms needed postoperatively is reduced.

Use of the native aortic valve as the pulmonary valve in the Ross procedure.

The placement of a foreign valve in the pulmonary position using the Ross procedure requires reoperation. To circumvent this problem, we devised a method of reimplanting the native aortic valve in the pulmonary position, and successfully performed this procedure in a 12-year-old diabetic boy operated on for the treatment of aortic insufficiency. Although diseased, the reimplanted aortic valve functioned well, with trivial stenosis and insufficiency. This modification offers patients with aortic valve disease a potentially curative operation.

Regression of hypertrophic cardiomyopathy after modified Konno procedure.

BACKGROUND: Septal myotomy-myectomy has been known to decrease the incidence of sudden death and produce regression in hypertrophic obstructive cardiomyopathy. Use of beta-blockers or calcium-channel blockers generally does not cause regression of the disease. METHODS: Having successfully performed modified Konno procedures in 13 patients with effective relief of diffuse subaortic stenosis, we applied the procedure in 2 patients with hypertrophic obstructive cardiomyopathy. Both patients (18 and 12 years old, respectively) presented with syncope, angina at rest, and dyspnea despite being on calcium channel blocker therapy. The echocardiographic outflow gradients were 66 mm Hg and 88 mm Hg, respectively, with moderate mitral regurgitation. RESULTS: Both patients had uneventful postoperative course. At 2 years and 1.5 years postoperatively, both patients were free of angina and syncopal episodes. Echocardiography showed absence of outflow gradients and mitral regurgitation. In 1 patient the septal and posterior wall thickness decreased from 3.4 and 1.7 cm preoperatively to 2.6 and 0.9 cm, respectively, postoperatively. In the other patient, the thickness decreased from 2.4 and 0.9 cm preoperatively to 0.8 and 0.7 cm, respectively, postoperatively. Left atrial diameter decreased from 5.4 to 4.7 cm in 1 patient, 3.5 to 2.6 cm in the other. CONCLUSIONS: We believe that the modified Konno procedure could produce more effective relief of obstruction and, therefore, significant regression and further reduction in sudden death in hypertrophic obstructive cardiomyopathy. On the basis of our experience, albeit limited, we encourage its application.

Surgical techniques in partial anomalous pulmonary veins to the superior vena cava.

Over a 12-year period, 40 patients underwent repair of partial anomalous pulmonary veins (PAPV) draining to the superior vena cava (SVC) proximal to the sinus node. Mean age was 6 +/- 2 years. In all patients, the SVC was cannulated superior to the PAPV, which were baffled with pericardium to left atrium. Six patients had associated defects repaired. In 18 patients (group I), an incision was made at the crest of the right atrial appendage (RAA) and extended upward through the sinus node and to the SVC. After rerouting of the PAPV, the SVC was enlarged using the RAA (atriocavoplasty). In 17 patients (group II), rerouting of the PAPV was accomplished through a right atriotomy. Superior vena caval enlargement was not done. Drainage of the PAPV was close to the right atrium in 14 patients (low) and to the azygos vein (high) in 3. In 5 patients (group III), an incision was made on the SVC and RAA sparing the sinus node. After rerouting of the PAPV, the RAA was anastomosed to the SVC (end to side), providing another outlet for SVC flow. There was no early or late death. Two patients (10%) in group I had late sinus bradycardia. Obstruction of the SVC and PAPV developed in 1 patient in group II with high drainage. Intermittent complete heart block developed in 1 patient in group III who also had ventricular septal defect repair. We conclude that atriocavoplasty is effective for rerouting of the PAPV and enlarging the SVC, but may predispose to sinus node disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Modified Konno-Rastan procedure for subaortic stenosis: indications, operative techniques, and results.

BACKGROUND: Diffuse or unresectable subaortic stenosis (SAS) necessitates an aggressive surgical approach for the elimination of left ventricular outflow tract obstruction. In this article we report our experience with the modified Konno-Rastan procedure, with inherent preservation of the native aortic valve and annulus, in the treatment of diffuse or unresectable SAS. METHODS: Sixteen children (age range, 21 months to 18 years) underwent the modified Konno-Rastan procedure through either a transventricular (n = 12) or a transatrial approach (n = 4) to the conal septum. Indications for operation were recurrent SAS (n = 3), hypertrophic obstructive cardiomyopathy (n = 3), tunnel stenosis (n = 2), SAS related to a canal (n = 3), and SAS after ventricular septal defect closure (n = 5). Eleven patients had undergone previous procedures and 5 underwent the modified Konno-Rastan procedure as their primary operation. RESULTS: The mean preoperative left ventricular outflow tract gradient of 50 +/- 17 mm Hg was reduced to 3 +/- 7 mm Hg (p < 0.001) after surgical repair. Postoperative complications included sternal infection (n = 1), heart block (n = 2), mediastinal bleeding (n = 1), and renal and cerebral ischemia (n = 1). There was 1 late postoperative death caused by pneumonia 2 years after operation (6.2% mortality rate). The mean follow-up period was 62 +/- 39 months and all patients had complete relief of preoperative symptoms and were in New York Heart Association class I. One patient underwent a successful redo modified Konno-Rastan procedure 7 years after the first operation for residual left ventricular outflow tract obstruction immediately below the aortic valve. One patient is awaiting reoperation for aortic incompetence unrelated to conal enlargement 1.5 years after the first procedure. CONCLUSIONS: The modified Konno-Rastan procedure represents an excellent therapy for diffuse or unresectable SAS in patients with a normal aortic valve. In addition, it produces excellent results in a limited number of patients with hypertrophic obstructive cardiomyopathy, in whom the Morrow procedure traditionally has been performed. Although it usually is performed through a transventricular approach, the modified Konno-Rastan procedure also can be performed through a transatrial approach; this is particularly useful in patients who have had previous ventricular septal defect closure associated with SAS occurring proximal to the prosthetic patch.

Early pulmonary homograft failure from dilatation due to distal pulmonary artery stenosis.

Early progressive pulmonary homograft insufficiency developed in an 11-month-old infant after repair of truncus arteriosus because of dilatation secondary to the presence of residual distal pulmonary artery stenosis and hypoplasia. Before repair, the pulmonary artery branches were discontinuous, with the right pulmonary artery being somewhat hypoplastic and originating from the trunk, and the left pulmonary artery supplied by a modified Blalock-Taussig shunt created in the newborn period. At repair, a pulmonary homograft was used to connect the branches. Progressive cardiomegaly and oxygen dependance occurred 3 weeks postoperatively. Cardiac catheterization showed systemic right ventricular pressure, severe homograft insufficiency, and residual distal pulmonary artery stenosis and hypoplasia. On reoperation at 3 months postoperatively, the homograft annulus diameter increased from 14 mm to 16 mm. Dilatation and insufficiency probably occurred because the right ventricle and homograft distal to the obstruction functioned as a unit during systole. The problem might have been minimized with the use of aortic homograft, which is thicker, or annular reinforcement with a synthetic material.

Recognition and management of accessory mitral tissue causing severe subaortic stenosis.

Failure to recognize the presence of accessory mitral tissue causing subaortic stenosis can lead to not only the performance of inappropriate operations, but the persistence and recurrence of obstruction or even death. Over a 12-month period, we treated 2 children with severe subaortic stenosis caused by accessory mitral tissue. In 1 patient, who was 4 years old, the echocardiogram showed the accessory mitral tissue to be attached to the anterior mitral leaflet and ballooning into the subaortic area. The other patient, as a newborn, underwent simultaneous repair of a complete canal defect and coarctation. Two years later, the patient was seen because of syncopal episodes, progressive mitral insufficiency, and subaortic stenosis thought to be caused by anterior displacement of the anterior mitral leaflet. Mitral valvuloplasty and a conal enlargement procedure were planned. Intraoperatively, after the mitral valvuloplasty had been done, the subaortic stenosis was found to be due to a tight subaortic ring formed by accessory mitral tissue located at the septum and its fibrous extension to the anterior mitral leaflet. In both patients, excision of the accessory mitral and fibrous tissues resulted in a wide-open subaortic area. Both patients had an uneventful hospital course, and follow-up echocardiography showed no noteworthy residual left ventricular outflow gradient. We believe that increased awareness and sophisticated echocardiographic techniques should lead to an increased recognition of accessory mitral tissue causing subaortic stenosis. Simple resection of the accessory mitral tissue and its secondary fibrous tissues can be curative.

Recognition and management of obstructed pulmonary veins draining to the coronary sinus.

BACKGROUND: Obstruction of the pulmonary veins in total anomalous pulmonary venous drainage to the coronary sinus is generally considered rare. However, if it is present, the usual treatment of unroofing the coronary sinus will lead to a poor result. METHODS: Four patients with total anomalous pulmonary venous drainage to the coronary sinus with obstruction were identified over a 14-month period. Three patients in whom the diagnosis of obstruction was not made underwent coronary sinus unroofing. Retrospective review of the preoperative echocardiograms and Doppler studies showed the presence of obstruction in the vertical vein in 2 patients and in the branches in the other. In the fourth patient, obstruction in the vertical vein was recognized preoperatively with echocardiography and Doppler study. This patient underwent direct common pulmonary vein-left atrial anastomosis. RESULTS: All 3 patients who had coronary unroofing were seen with obstructed pulmonary veins 2 to 7 months postoperatively. After reoperation, 1 died, and the other 2 have done relatively well 3 1/2 and 15 months postoperatively. The patient who had an anastomosis between the common pulmonary vein and the left atrium is doing well 18 months postoperatively. CONCLUSIONS: Obstruction in total anomalous pulmonary venous drainage to the coronary sinus is not as rare as previously reported. To improve outcome, its presence should be sought using complete echocardiography including Doppler studies. When obstruction is present, transection of the vertical vein and common pulmonary vein-left atrial anastomosis through the superior approach is an attractive technique that also eliminates the right-to-left shunting associated with coronary sinus unroofing and simplifies closure of the atrial septal defect.

Obligatory Glenn shunt in fenestrated Fontan.

Five high-risk patients undergoing the Fontan operation required large fenestration (1 cm) because of high central venous pressure and low cardiac output. Because of major arterial desaturation, obligatory Glenn shunts were performed. Three patients had pulmonary atresia, 1 had tricuspid atresia 1-B, and the fifth had single ventricle with subaortic stenosis. The age ranged from 16 to 40 months (mean age, 25 +/- 9 months) and weight from 7.9 to 14.6 kg (mean weight, 11 +/- 2 kg). One patient had single and 3 had bilateral subclavian pulmonary artery shunts. The fifth patient had pulmonary artery banding and coarctation repair followed by an aortopulmonary window and central shunt. The first 2 patients repeatedly had to go back on cardiopulmonary bypass for a larger fenestration and subsequently had an obligatory Glenn shunt because of arterial desaturation. The last 3 patients had planned obligatory Glenn shunt and large fenestration. The first patient died on the second postoperative day of a combination of prolonged operation, repeated cardiopulmonary bypass, and periods of hemodynamic instability. Three patients had closure of the adjustable fenestration under local anesthesia at 4, 5, and 8 weeks postoperatively. The last patient is awaiting closure. We believe that in certain high-risk patients, a large fenestration combined with an obligatory Glenn shunt should be considered to minimize repeated cardiopulmonary bypass and urgent tightening or closure of fenestration in the immediate postoperative period.

Clinical improvement after revision in Fontan patients.

BACKGROUND: Arrhythmias, decreased exercise tolerance, or malabsorption will develop in a significant number of Fontan patients. Fontan revision consisting of creation of lateral atrial tunnel, reconnection of the Glenn shunt when present, or both appears to improve these patients. METHODS: Over a 34-month period, 9 patients underwent Fontan revision. The mean age was 11 +/- 5 years and the mean interval from Fontan operation to revision was 3 +/- 2 years. The reason for revision included marked impairment in exercise capacity, inability to go to school consistently, and chronic fatigue in 6 patients, 3 of whom also had serious atrial arrhythmias. Five of the 6 patients had a classic Glenn shunt. The mean right atrial pressure was greater than the pressure of the Glenn shunt (20 +/- 1.6 versus 17 +/- 0.8 mm Hg). Three of the 6 patients also showed a significant gradient between the right or left pulmonary artery wedge and ventricular end-diastolic pressure, indicating pulmonary vein obstruction from the bulging atrial septum or partitioning patch (13 +/- 3 versus 6.8 +/- 1 mm Hg). The remaining 3 patients had revision because of malabsorption (1), hepatomegaly and obstructed right pulmonary veins from bulging atrial septum (1), and tricuspid insufficiency (1). Fontan revision was accomplished with creation of a lateral atrial tunnel and Glenn reconnection in 6 patients, Glenn reconnection in 2, and creation of a lateral atrial tunnel in 1. Four patients had additional procedures. RESULTS: One patient died of Pseudomonas pneumonia. Early extubation, chest tube removal, and postoperative hospital discharge were accomplished in 8 patients (mean = 1.4 +/- 1, 2.8 +/- 1, and 8 +/- 3 days, respectively). One patient died 8 months postoperatively of brain damage after ventricular fibrillation from attempted cardioversion for atrial flutter. The remaining patients had marked improvement in exercise capacity with ability to consistently go to school, improvement in duration and tolerance to arrhythmias on less medication, and resolution of malabsorption up to 37 months postoperatively (mean, 20 +/- 12 months). CONCLUSIONS: We conclude that creation of lateral atrial tunnel with excision of a bulging atrial septum or atrial partitioning patch that causes pulmonary venous obstruction, reconnection of the Glenn shunt, which allows better distribution of flow based on the pulmonary vascular bed and resistance of each lung, or a combination of these procedures will improve Fontan patients.

Management of arch hypoplasia after successful coarctation repair.

BACKGROUND: Pronounced arch obstruction can be seen after a well-repaired coarctation, and this probably results from the failure of a somewhat hypoplastic arch to grow or from clamp injury at the time of the initial repair, or from both causes. Because of mediastinal adhesions and minimal collateral circulation, use of extraanatomic bypass grafts appears to be the preferred approach. METHODS: Six children or young adults presented with arch obstruction over a 3-year period. Their mean age was 13.5 +/- 4 years, and the mean interval from the time of the initial repair was 10 +/- 4 years. The mean age of the patients at the time of the initial repair was 3.2 +/- 5 years. Symptoms included exertional headache and chest pain. The mean systolic gradients, as shown by echocardiography and cardiac catheterization, were 34 +/- 7 mm Hg and 33 +/- 6 mm Hg, respectively. Repair was accomplished through a midsternotomy using a polytetrafluoroethylene patch placed in the concavity of the arch, which extended from the ascending to the descending aorta. Dissection was kept close to the aorta and arch to minimize injury to the phrenic and recurrent laryngeal nerves. Cardiopulmonary bypass and moderate hypothermia (25 degrees to 27 degrees C bladder temperature) without circulatory arrest were used. RESULTS: All patients were discharged home 4 to 20 days postoperatively (mean, 7 +/- 6 days). All patients were found to be normotensive at a mean follow-up of 1.3 +/- 1 years. Postoperative echocardiograms, which were obtained in all patients, revealed no residual gradients. Exercise blood pressure was evaluated in 2 patients and found to be normal. CONCLUSIONS: Transsternal arch enlargement using cardiopulmonary bypass and moderate hypothermia without circulatory arrest is an attractive and safe approach for the treatment of arch obstruction after coarctation repair. Unlike the use of extraanatomic bypass grafts, it allows complete relief of the obstruction, unhampered aortic growth, the minimal use of foreign material, and a repair that is protected deep within the mediastinal space.

Economic evaluation of the fentanyl transdermal system for the treatment of chronic moderate to severe pain.

The fentanyl transdermal system (Duragesic) is an opioid analgesic indicated for the management of chronic moderate to severe pain. The purpose of this analysis is to estimate its economic value compared to two long-acting oral opioids. A cost-utility analysis was performed using a three-phased decision analytic model. The transdermal system had the highest expected cost during the first year of therapy ($2,491), moderately higher than the cost of a year of therapy with controlled-release morphine ($2,037) or controlled-release oxycodone ($2,307). The system also had the highest expected number of quality-adjusted life-days (QALDs) (244 compared to 236 for morphine and 231 for oxycodone), despite conservative assumptions. The fentanyl transdermal system achieved incremental cost-utility ratios of $20,709 (vs. morphine) and $5,273 (vs. oxycodone) per quality-adjusted life year (QALY) gained. In a conservative modeled analysis, the fentanyl transdermal system led to increased QALDs at a nominal increased cost. In the absence of head-to-head clinical trials, models help clarify cost and outcome trade-offs and provide a consistent theoretical framework for use by individual decisionmakers.

Adolescent knowledge of bacterial endocarditis prophylaxis.

OBJECTIVE: To determine if adolescents with congenital heart disease have adequate knowledge of bacterial endocarditis prophylaxis. DESIGN: Forty-eight adolescents attending a congenital heart disease summer camp were asked to complete an eight-question survey to assess their knowledge of heart disease, endocarditis, and endocarditis prophylaxis. RESULTS: Forty-five of 48 (94%) completed the questionnaire. Thirty-one (69%) knew the name of their heart disease. Two correctly defined endocarditis. None knew measures which could prevent endocarditis. Although 36 (80%) knew they needed to take "a medicine" prior to dental procedures, only 18 (40%) knew that an antibiotic was needed. There were significant gender differences for knowledge of antibiotics and for knowledge of current medications. However, patient gender and regular use of cardiac medications did not correlate significantly with knowledge of endocarditis or bacterial endocarditis prophylaxis. CONCLUSION: Whereas most adolescents know the names of their heart lesions and current medications, knowledge of endocarditis and bacterial endocarditis prevention and prophylaxis is inadequate.

Bulimia: implications for the practising dentist.

The incidence of eating disorders appears to be increasing, with the dental practitioner potentially being the first healthcare worker to make a diagnosis, due to the characteristic dental signs of tooth substance loss. It is therefore important that members of the dental team are aware of the dental sequelae of anorexia and bulimia and are able to offer advice and treatment to sufferers.

One-year retrospective clinical evaluation of hybrid composite restorations placed in United Kingdom general practices.

OBJECTIVE: The purpose of this study was to assess Pertac II restorations placed in general dental practice. METHOD AND MATERIALS: A total of 86 restorations (14 Class I, 10 Class II, 17 Class III, 5 Class IV, and 40 Class V) using a hybrid composite material (Pertac II) placed in 56 patients (mean age, 39 years) in 5 dental practices in the United Kingdom were assessed after 1 year by a trained evaluator and the dental practitioner who had placed the restoration. All the restorations were assessed for anatomic form, marginal adaptation, surface roughness, sensitivity or discomfort, gingival condition, and the presence or absence of secondary caries. RESULTS: Thirty-five (43%) restorations were placed in load-bearing situations, 9% of which were assessed as being in "heavy" occlusion. Five (6%) of the restorations were lost (all Class V restorations), 4 from premolars and 1 from a molar. Four were in wedge-shaped cavities and 1 small restoration was actually dislodged during examination. The remaining 81 (94%) restorations were found to be intact, with no secondary caries detected. A high percentage of optimal scores were recorded for both anatomic form and surface roughness. CONCLUSION: It is concluded that the evaluation demonstrated satisfactory clinical performance of Pertac II restorations after 1 year of clinical service in the wide variety of clinical situations seen in general dental practice. However, the potential for failure of hybrid composite materials in Class V situations appears high. It may be argued that clinicians who wish to use a resin-based material in a Class V situation should use a compomer or microfilled composite.