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.

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.

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.

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.

[Aortic valve replacement in a renal transplant recipient].

A 65-year-old male was admitted to our hospital for surgical treatment of congestive heart failure with aortic regurgitation. He had received renal transplantation 15 years before in the United States, and had been under immunosuppressive regimen with ciclosporin and mycophenolate mofetil. Although the renal allograft function had been gradually deteriorating, and preoperative serum creatinine level was 1.8 mg/dl, and it decreased to 1.5 mg/dl after aortic valve replacement. Cryopreserved aortic allograft was needed for the aortic valve replacement. The reasons are; the patient may need hemodialysis (HD) or retransplantation of the kidney in the future, and the immunosuppressive therapy for kidney will provide good immunologic environment for second allograft, i.e.--aortic valve. He tolerated the operation well and the immunosuppressive agents were continued in the perioperative period. He is now in New York Heart Association (NYHA) class I.

[Secondary left main trunk coronary artery shock syndrome].

A 71-year-old male patient was admitted to our hospital and diagnosed as inferior wall acute myocardial infarction (AMI). Coronary angiogram revealed 3 vessel disease and left main trunk coronary artery (LMT) lesion. Because right coronary artery (RCA) had been recanalised, he was scheduled to operation. On the 6th day after admission, another attack made him fell into secondary LMT shock syndrome and lung edema. Emergency operation was performed and he recovered from heart failure. Here we report the case and added some considerations.

Effects of recombinant human erythropoietin therapy on blood coagulation and fibrinolysis system.

This study was designed to examine the effects of recombinant human erythropoietin (rHuEPO) therapy on blood coagulation and fibrinolysis in patients scheduled for elective heart surgery and undergoing preoperative autologous blood donation. Twenty-seven patients were studied, of whom 16 patients received rHuEPO (group E) and 11 patients no rHuEPO therapy (group N). The patients in group E were given 6000 units of rHuEPO intravenously every other day, three times a week, beginning from two weeks prior to the operation. In both groups, 400 ml of blood was collected preoperatively for predeposit once a week for two weeks, and the self-donated blood was returned to the patient intra- and postoperatively. Blood samples were drawn at the beginning of the study, immediately before the operation and two weeks after the operation. They were analyzed to assess blood coagulation, fibrinolysis, platelet function and vascular endothelial cell function, in order to examine the effects of the administration of rHuEPO. No significant difference was observed between the two groups in the degree of changes in these parameters following the operation. As enhancement of blood coagulability and fibrinolytic activity was evident postoperatively in both groups, changes in these parameters during the preoperative autologous blood donation period were also assessed excluding the postoperative data. Again, there was no significant intergroup difference in any of the markers evaluated. It was concluded that the administration of rHuEPO during preoperative autologous blood donation is unlikely to affect coagulation and fibrinolysis.

[Notification of unexpected patients' death to the police].

Controversies continue to exist in what situation the surgeons are obliged to report the perioperative patients' death to the police. With regard to this issue, Japan Surgical Society and twelve other Japanese Surgical Societies have declared that 1) patients' death due to evident malpractice must be reported to the police, 2) patients' death resulting from anticipated surgical complications need not be reported to the police, 3) an independent organization be founded for collection and investigation of medical accident/incident reports. Japan Surgical Society will take a responsibility of making a practical guideline as to the notification of accidents to the police and take a leadership in establishing the independent medical accident/incident center.

Favorable results in patients with small size CarboMedics heart valves in the aortic position.

Hemodynamic performance of the CarboMedics heart valve in the aortic position and its clinical impacts were investigated in 126 consecutive patients. The actuarial survival rates of patients who had undergone isolated aortic valve replacement and concomitant aortic and mitral valve replacement were 82.6+/-5.7% and 71.0+/-9.2% at 8 years, respectively. Morbid events were rare, and almost all late survivors were free from evident cardiac symptoms regardless of the valve size. Echocardiography revealed suboptimal transvalvular pressure gradients and effective orifice areas of 19 mm and 21 mm valves. However, relief of the left ventricular overload and improvement of the clinical symptoms as well as cardiac function were comparable to those of patients with larger valves. Valve function measured by echocardiography did not show significant correlation to late outcome. Good results can be expected even in the presence of echocardiographic data such as peak pressure gradient over 40 mmHg, effective orifice area less than 1.0 cm(2), and effective orifice area index less than 0.7 cm(2)/m(2).

Experimental study of small arterial anastomosis with gelatin-resorcin-formaldehyde glue and collagen sheet.

In cardiovascular surgery, the manual continuous suture has often been used for microvascular anastomosis, but the luminal irregularity often causes thrombotic stenosis in the anastomosis sites. The purpose of this study was to examine the feasibility of the combined use of gelatin-resorcin-formaldehyde (GRF) glue and a collagen sheet for the anastomosis of small arteries 3 to 4 mm in diameter in experimental animals. End-to-end anastomoses of the carotid and femoral arteries of mongrel dogs were carried out with the combined use of GRF glue and collagen sheet. The physical strength of the anastomosis, the histopathologic condition of the vassels, and the absorptivity and the inflammatory response of the glue were evaluated. The physical strength of the anastomosis sites was good and their flexibility optimal, the smooth luminal surface appeared excellent for preventing thrombotic stenosis in all follow-up periods, and the glue was absorbed almost completely within 12 weeks postoperatively. The combined use of GRF glue and collagen sheet would be feasible for the anastomosis of small arteries 3 to 4 mm in diameter and could substitute for the conventional suture method.

[What we must learn from recent medical accidents--experiences at the investigation committee].

The current publicity of medical accidents in Japan started with two well-known accidents. On January 11, 1999, a cardiac patient underwent a pulmonary operation, while a pulmonary patient received cardiac surgery at Yokohama City University Hospital. On February 11, 1999, detergent was inadvertently injected into a venous line at Hiroo Hospital in Tokyo. The author was invited as an indifferent specialist to serve on the Investigation Committee for these two accidents. This article describes the lessons to be learned from these two accidents.

'No-Touch' isolation procedure for ruptured mycotic abdominal aortic aneurysm.

The present study reports a case of the successful surgical repair of a ruptured infra-renal mycotic abdominal aorta with Enterobactor cloacae in a 66-year-old man. During the operative procedure, an extra-anatomic bypass was installed before the laparotomy in order to avoid bacterial contamination. A complete resection of the infected aorta, tapering of the arterial stumps, wrapping of the omentum, and ligation of the aorta and arteries with Teflon tapes was carried out. The patient is alive and well 1 year postsurgery.

Cardiac function evaluated by transesophageal echocardiography during cardiopulmonary bypass.

OBJECTIVE: To evaluate cardiac function at cardiopulmonary bypass weaning, we applied a new technique clinically to determine the approximated Emax without using a conductance catheter. METHODS: Subjects were 5 patients. The left ventricular end-systolic pressure was obtained by overlaying the radial arterial pressure curve on the left ventricular pressure curve. Left ventricular end-systolic volume was assessed by a transesophageal echographic apparatus. At cardiopulmonary bypass weaning, volume loading was applied to increase left atrial pressure by a few mmHg while fixing the pump flow rate at half flow. Changes in left ventricular end-systolic volume and approximated left ventricular end-systolic pressure for total heart beat were plotted during this period, and the gradient of the regression line was taken as approximated Emax. RESULTS: Approximated Emax ranged from 1.29 to 3.28 (mean 2.13 +/- 0.72), and its correlation coefficient was 0.80 +/- 0.06. CONCLUSION: Our new technique is useful in evaluating cardiac function during cardiopulmonary bypass.

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.

Atrial ablation using an IRK-151 infrared coagulator in canine model.

BACKGROUND: A method of atrial ablation was developed with the aim of shortening the aortic cross-clamp time during MAZE surgery. The IRK-151 infrared coagulator (Infrarot-Kontaktkoagulator: MBB: Messerschmidt-Bolkow-Blohn, Germany) was employed. Our aim was to electrophysiologically confirm the efficacy of this device. METHODS: The MAZE-III procedure was performed in four mongrel dogs. Instead of a pulmonary vein-encircling incision, IRK-151 was applied several times to create a continuously overlapping circular lesion. After aortic declamping, the potentials of both atria were recorded using 18 bipolar electrodes implanted in the atrial wall. The recording conditions were: 1) sinus rhythm, 2) overdrive pacing from outside the encircling coagulation, and 3) overdrive pacing from inside the encircling coagulation. RESULTS: 1) There was no detectable potential within the pulmonary vein-encircling coagulation. 2) There was no conduction of paced atrial potential inside the encircling coagulation. 3) Only the area within the encircling coagulation was activated by the stimulus. Other parts of the atrium showed sinus rhythm simultaneously. CONCLUSIONS: The left atrium within the pulmonary vein-encircling coagulation was isolated electrophysiologically.