Polychromatic Restoration of Anterior Fractured Teeth Using a Custom-made Silicone Matrix.

When restoring anterior teeth using resin composites, the use of silicone guide matrices obtained from diagnostic wax-ups is recommended, as this technique facilitates layering and optimizes working time. This is particularly important in polychromatic layering and when more than one anterior tooth is to be restored with resin composites. However, in cases of fractured anterior teeth, it is often not feasible to perform a previous impression and waxing. In these cases, due to trauma and related psychological aspects, patients usually seek immediate esthetic solutions. Therefore, an interesting restorative approach that can simplify the restorative technique is the creation of a silicone guide matrix obtained from the patient's fractured tooth, without the need for prior waxing. This type of personalized matrix was initially proposed by Bertholdo, Ricci, and Barrote. Thus, the purpose of the present work is to demonstrate a modification of the technique for making this type of custom-made matrix for the restoration of two upper central incisors of a 14-year-old patient who fractured his teeth in a bicycle accident.

Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions.

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey's test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

Enamel wetness effects on bond strength using different adhesive systems.

OBJECTIVE: To evaluate, through the application of different dentin bonding systems, the influence of wetness on shear bond strength in enamel. METHODS: This study evaluated three etch-and-rinse adhesive systems (Scotchbond MP [used with and without primer]; Singlebond; and Prime&Bond 2.1) and two self-etching adhesive systems (Clearfil SE Bond; and Xeno IV). Flat bovine enamel surfaces were either air-dried for 30 seconds or blotted with absorbent paper after acid-etching for the conventional bonding agents or before the application of self-etching bonding agents. The resin composite EsthetX was bonded to flat surfaces that had been treated with one of the adhesives, following the manufacturer's instructions. After being stored in water at 37°C for one week, bonded specimens were broken in shear. Data were evaluated with two-way analysis of variance (ANOVA) and Student-Newman-Keuls tests (α=0.05). For comparing each condition individually, regardless of the adhesive or wetness condition, a one-way ANOVA and a Student-Newman-Keuls test (α=0.05) were applied. RESULTS: The two-way ANOVA showed significant differences among adhesive systems. An interaction effect was also observed (p<0.05), but wetness did not influence shear bond strength (p=0.98). The one-way ANOVA showed that the all-in-one adhesive was the only material influenced by the presence of water at the enamel's surface. CONCLUSION: The all-in-one adhesive behaved differently depending on whether the enamel surface was dry or wet.

Using Cross-Polarized Photography as a Guide for Selecting Resin Composite Shade.

The restoration of single discolored maxillary anterior teeth is still a difficult task, as not only shape and surface characterization play an important role in the success of the treatment, but the propagation of light throughout the restorative material does as well. In some cases, small changes in morphology, color, and brightness will be noticeable. These factors are sometimes very tricky, and shade guides alone are difficult to use for color selection. This article proposes a protocol of employing cross-polarization imaging for improving the accuracy of the shade selection of resin composites. The step-by-step technique is presented for the restoration of a single discolored tooth.

Effectiveness of LED/Laser Irradiation on In-Office Dental Bleaching after Three Years.

The present in vivo randomized, triple-blinded, and split-mouth clinical study evaluated the effectiveness of a hybrid light (HL) source on the color change, stability, and tooth sensitivity in patients submitted to different in-office bleaching techniques. Twenty volunteers were divided into two groups and four subgroups. A split-mouth design was conducted to compare two in-office bleaching techniques (with and without light activation): 35% Lase Peroxide Sensy (LPS) + HL: 35% hydrogen peroxide (HP) + HL; 35% LPS: 35% HP; 25% LPS + HL: 25% HP + HL; and 35% Whiteness HP (WHP): 35% HP. For the groups activated with HL, the HP was applied on the enamel surface three consecutive times using a 3 × 2-minute protocol (three HL activations for two minutes each, with a 30-second interval for a total of seven minutes and 30 seconds) for each gel application, totaling 22 minutes and 30 seconds. For the other groups, HP was applied 3 × 15 minutes, totaling 45 minutes. A spectrophotometer was used to measure the color change (ΔE) before the treatment and 24 hours, one week, and one, 12, and 36 months after. A visual analog scale was used to evaluate the tooth sensitivity before the treatment, immediately following treatment, 24 hours, and one week after. Analysis of variance, Tukey's, Kruskall-Wallis, and Wilcoxon tests, all with α = 0.05 were performed. Statistical analysis did not reveal any significant differences (ΔE) between the in-office bleaching techniques with or without HL in the periods evaluated; the activation with HL required 50% less time to achieve such results. The groups without HL presented statistical differences for ΔE when comparing 24 hours with the other follow-up times (intergroup) and an increase in tooth sensitivity in the initial periods. All techniques and bleaching agents were effective on bleaching during a 36-month evaluation of color stability. The groups activated with HL presented lower sensitivity and required a lower activation time.

Bonding Polycrystalline Zirconia With 10-MDP-containing Adhesives.

OBJECTIVE: The objective of this study was to evaluate the influence of adhesives with different 10-MDP concentrations on the shear bond strength of a resin cement to zirconia. METHODS AND MATERIALS: Six experimental adhesives were prepared with the following composition: camphorquinone, 1,2-diaminobenzene, butylhydroxytoluene, diphenyliodonium hexafluorophosphate, 2-hydroxyethyl methacrylate triethylene glycol dimethacrylate, ethoxylated bisphenol A glycol dimethacrylate, urethane dimethacrylate, bisphenol A diglycidyl methacrylate, and ethanol. The 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer was added at 0wt%, 3wt%, 6wt%, 9wt%, 12wt%, or 15wt%. Three commercially available adhesives were evaluated: Single Bond Universal, Single Bond 2, and Signum Zirconia Bond. Resin cement cylinders made with RelyX Ultimate were bonded to yttria-stabilized tetragonal zirconia polycrystal with one of the evaluated adhesives and were subjected to the shear bond strength evaluation. Failure modes were analyzed with a stereoscopic loupe. Statistical analyses were performed with one-way analysis of variance and the Tukey's Honestly Significant Difference test (α=0.05). Pearson's was used to correlate the percentage of 10-MDP in the experimental adhesives and shear bond strength. RESULTS: There were significant differences between adhesives (p<0.00001). The highest shear bond strength values were obtained with the Signum Zirconia Bond and Single Bond Universal. Single Bond 2 showed the lowest values. There were no differences between experimental adhesives. All groups showed adhesives failures. A nonlinear correlation was found between bond strength and percentage of 10-MDP in experimental adhesives (r=0.872). CONCLUSIONS: The commercially available adhesives indicated for bonding to zirconia showed the highest bonding values.

Automated diagnosis of heart disease in patients with heart murmurs: application of a neural network technique.

This study was conducted to test a three-layered artificial neural network analysis of phonocardiogram recordings to diagnose, automatically and objectively, the condition of the heart in patients with heart murmurs. The data were recorded simultaneously in each of 49 patients with a heart murmur through eight microphones attached to the skin surface with adhesive tape, and were analysed by computer. The diagnosis was automated using a three-layered neural network technique. The neural network generated correct answers in over 70% of cases. Furthermore, about 80% of cases of two concurrent diseases were identified correctly. However, ventricular septal defects were incorrectly classified as aortic stenosis or aortic regurgitation, and patent ductus arteriosus was not diagnosed correctly. Accurate diagnoses can frequently be obtained using a neural network, but accuracy can be improved with further data accumulation.

Doppler analysis of flow velocity profile at the aortic root.

This study of aortic root flow velocity profiles suggests that the flow velocity pattern is parabolic rather than flat as has been widely supposed. To analyze the distribution of flow velocity, a special ultrasound pulsed Doppler velocity flow meter, with a direct probe on the aortic wall, was designed. Sixteen patients, none with a diagnosis of aortic valve disease, were examined just before undergoing open heart surgery. Parabolic velocity patterns were always found, and it was determined that the parabola was skewed rightward toward the anterior wall. Furthermore, it was shown that the flow velocity vector was initially directed toward the commissure of the right coronary and the noncoronary cusps.

Analysis of cardiac assistance by latissimus dorsi cardiomyoplasty with a time varying elastance model.

OBJECTIVE: The clinical use of skeletal muscle cardiomyoplasty is limited because of its inadequate haemodynamic benefits. To facilitate experimental and clinical efforts to improve the efficacy of this technique, a mathematical model was proposed and its validity was tested in acute experiments. METHODS: The model was based on the assumption that the skeletal muscle wrapped around the heart behaves as a time varying elastance that is connected in series with another time varying elastance representing the native heart. From this model two predictions were made: (1) Skeletal muscle augments the contractility of the heart by increasing the slope (Ees) of the end systolic pressure-volume relation; (2) time varying elastance of the skeletal muscle chamber (Es(t)) can be estimated from that of the assisted heart. These predictions were examined in experiments. In nine anaesthetised, open chest dogs, preconditioned latissimus dorsi muscle was transposed to wrap the heart. Left ventricular pressure (catheter tipped micromanometer), and volume (conductance catheter) were measured while reducing the preload by vena caval occlusion to evaluate Ees with 1:2 (stimulation:heart beat ratio) stimulation of the skeletal muscle. RESULTS: With the stimulation of latissimus muscle, the end systolic pressure-volume relation was linear and Ees increased from 8.6(SEM 2.4) to 11.9(SEM 3.4) mm Hg.ml-1. Estimated Es(t) reflected the stimulation pattern and could account for the mechanism of the cardiac assistance. CONCLUSIONS: Skeletal muscle cardiomyoplasty improved the haemodynamic variable (Ees) as predicted by a mathematical model.

Midterm results of the rotation-advancement flap method for correction of partial anomalous pulmonary venous drainage into the superior vena cava.

Since 1986, a rotation-advancement flap method has been used in 11 patients with partial anomalous pulmonary venous drainage into the superior vena cava. This method consists of atrial partitioning, enlargement of the superior vena cava, and protection of the sinus node. The midterm postoperative sinus node function and hemodynamic changes were examined in this study. Postoperative angiograms showed normal pulmonary venous pathway and no stenosis in the superior vena cava. Cardiac rhythm was normal and no clinical symptoms appeared.

Rotation-advancement flap method for correction of partial anomalous pulmonary venous drainage into the superior vena cava.

Three patients with partial anomalous pulmonary venous drainage into the superior vena cava underwent repair by a rotation-advancement flap method. The technique consisted of atrial partitioning, enlargement of the superior vena cava, and protection of sinus node function. Follow-up studies of all patients were done between 12 and 15 months after the operation. The superior vena cava was not stenosed and its diameter was normal, as demonstrated by cavograms. Pulmonary venous return appeared normal on angiograms, and sinus node function was normal by electrophysiologic studies.

Systemic-to-pulmonary shunt in a patient with isolation of the subclavian artery.

A surgical procedure is described that was carried out to treat an 18-month-old boy with tetralogy of Fallot, right aortic arch, and isolation of the left subclavian artery. The patient underwent a descending aorta-right pulmonary artery shunt using a polytetrafluoroethylene graft, as a systemic-pulmonary shunt. The effectiveness of this procedure in patients with some special conditions is discussed.

Resinous plate for permanent sternal splinting in patients with extracardiac conduits.

During operations on patients with extracardiac conduits, sternal reapproximation occasionally results in critical compression of the conduit and serious deterioration in hemodynamic function. Permanent splinting of the sternum with a methyl methacrylate resinous plate provides an adequate substernal space for the extracardiac conduit.

Intravalvular implantation technique for aortic valve replacement in aortitis syndrome.

BACKGROUND: Paravalvular leakage is one of the most serious complications of aortic valve replacement in patients with aortitis syndrome. The purpose of this study was to compare the effectiveness of the intravalvular implantation technique in preventing paravalvular leakage with that of the conventional technique. METHODS: Since 1982, 14 patients with aortic regurgitation caused by aortitis syndrome have undergone aortic valve replacement at our institute. An intravalvular implantation technique was applied in 7 of the 14 patients. The technique consists of suturing a prosthetic valve to the aortic annulus and sandwiching the leaflets between exogenous felt pledgets and the inflamed aortic annulus. RESULTS: Paravalvular leakage occurred in 3 of 7 patients in the conventionally treated group and in none of 7 in the intravalvular implantation group. CONCLUSIONS: The intravalvular implantation technique is effective in preventing paravalvular leakage in patients with aortitis syndrome.

Tuberculous pseudoaneurysm of the thoracic aorta.

Tuberculous pseudoaneurysm has been reported to be a fatal, but rare complication of tuberculosis. We report a case of a 68-year-old man who underwent successful surgical treatment for a tuberculous pseudoaneurysm of the thoracic aorta with bronchial communication, and review previous reports of patients who also underwent operation for similar lesions, focusing especially on the pathway of infection to the aorta.

Atrial ablation with an IRK-151 infrared coagulator.

BACKGROUND: The purpose of this study was to develop a method of atrial ablation. In the IRK-151 infrared coagulator, light from a tungsten-halogen lamp is focused into a quartz rod. The distal exit plane is connected to a tip made of sapphire to allow linear ablation. METHODS: Thirty-six lesions were created in 9 mongrel dogs. The beating ventricular myocardium was ablated from the epicardium. In each dog, 4 lesions were created by using the following durations of application: 3, 9, 15, and 21 seconds. After the ablation, the myocardium was fixed and stained. A linear lesion on the beating right atrial free wall was created. Before and after the ablation, epicardial plaque-electrode mapping was performed. Three months after ablation, remapping was performed. RESULTS: The ablated myocardium had well-demarcated necrosis without carbonization or vaporization. The maximum depth was 10.3 +/- 0.8 mm. The conducting pathway was blocked. The block, once made, continued for 3 months. CONCLUSIONS: The IRK-151 produces well-demarcated lesions that were deep enough for atrial ablation to block the conducting pathway.

Excellent survival in a subgroup of patients with intrapulmonary metastasis of lung cancer.

BACKGROUND: Recently, intrapulmonary metastases in non-small cell lung cancer have been considered to have less influence on prognosis than extrapulmonary metastases. We report a subgroup found among patients with intrapulmonary metastases showing a good prognosis. METHOD: A retrospective study was performed on 236 consecutive patients with non-small cell lung cancer who underwent surgical resection of their tumors. Intrapulmonary metastases were found histopathologically in 50 of them, and their clinicopathologic features were investigated. RESULTS: Analysis of postsurgical results revealed a subgroup of patients showing excellent prognosis (n = 15). They had well-differentiated adenocarcinomas with bronchioloalveolar spread and pT1-2 N0, without vascular or lymphangitic invasion. Their actuarial 5-year survival rate was 100%, with a mean survival interval to date of 28 months. However, none of the other 35 patients survived for 5 years, with a mean survival interval to date of 11 months. CONCLUSIONS: We have clarified that patients with histopathologically diagnosed intrapulmonary metastases from non-small cell lung cancer do not constitute a homogeneous group. Pulmonary metastases with good prognosis, which are considered to be hematogenous metastases, may be benign lesions such as adenomatous or atypical adenomatous hyperplasias mimicking malignant tumors.

Retrograde gastric varices in a patient with total cavopulmonary shunt.

Gastric varices formed in a patient who had undergone a total cavopulmonary shunt operation 7 years previously. The varices were found to be due to development of collaterals from high-pressure systemic vein to low-pressure portal vein. Bleeding gastric varix can be a late complication of total cavopulmonary shunt.

Application of a new tactile sensor to thoracoscopic surgery: experimental and clinical study.

BACKGROUND: We developed a new tactile sensor that could quantify the hardness of objects as changes in the resonance frequency of the sensor (delta f). We have applied it to thoracoscopic operations for the localization of small invisible nodules in the lung. METHODS: When the sensor probe was moved over the lung surface, a delta f curve was depicted on the computer screen. When the sensor tip reached a point directly above a hard object, a sudden upward jump of the delta f curve was evoked. After experimental studies using pigs, the sensor was applied in 8 patients. More recently we produced a needle sensor to distinguish small nodules from bronchi that may evoke similar upward jumps of the delta f curve. Eight nodules and four bronchi in resected human lungs were probed directly using this sensor. RESULTS: In all of the patients, the hardness of various thoracic structures could be quantified. A total of 10 nodules were found using the sensor and resected thoracoscopically. The needle sensor distinguished nodules from bronchi, as the mean delta f of the bronchial walls (-64 +/- 45.9 Hz) was significantly higher than that of nodules (-526 +/- 168 Hz, p < 0.001). CONCLUSIONS: Thoracoscopic detection of small and invisible pulmonary nodules using our new tactile sensor is feasible.

The effect of cardiopulmonary bypass on T cells and their subpopulations.

To investigate the effect of cardiopulmonary bypass (CPB) on T cells, lymphocyte subsets of peripheral blood and lymphoid organs were monitored during and after open-heart surgery (Group 1). As a control, lymphocyte subsets of peripheral blood were measured in patients undergoing thoracovascular operations without CPB (Group 2). In Group 1, analysis of each subset-to-total lymphocyte ratio revealed that observed lymphocytopenia in the early postoperative days was mainly the result of T cell reduction, and that the decrease of helper/inducer T cells contributed to this decrease. In contrast, no significant fluctuation of any lymphocyte subpopulation ratio was observed in Group 2. Analysis of lymphocyte subpopulation ratios in lymphoid organs showed that reciprocal changes of T cells and their subsets were observed in the bone marrow, thus indicating that the redistribution of T cells (especially of helper/inducer cells) seems to occur between peripheral blood and bone marrow in Group 1. Furthermore, there was no relationship between serum cortisol levels and the changes in lymphocyte subset ratios in Group 1 patients.