In vivo and in vitro evaluation of Class II composite resin restorations with different matrix systems

PURPOSE: To investigate in vivo and in vitro Class II composite restorations performed with two matrix and wedge systems. MATERIALS AND METHODS: One hundred nine Class II restorations were performed in 23 patients, 59 with metallic matrices and wooden wedges (group 1) and 50 with polyester matrices and reflective wedges (group 2). All cavities were restored using Single Bond and P-60 (3M ESPE). In the metal matrix group, polymerization was performed from the occlusal, and in the polyester group through the reflective wedge. To assess microleakage, 40 proximal standard slot cavities were prepared in 20 noncarious human third molars. In the mesial cavity, the gingival margin was located at the enamel level, and in the distal cavity at the cementum/dentin. Specimens were randomly divided into two groups (n = 20) and restored with Single Bond, Z-250 (3M ESPE), and the same techniques used in the in vivo study: metal matrix/wooden wedge (group 1) and polyester matrix/reflective wedge (group 2). Specimens were thermocycled (500 times, 5 degrees C to 55 degrees C), then isolated with nail varnish and immersed in fuchsin for 8 h. Specimens were sectioned longitudinally and microleakage was assessed under magnification (40X) using a standard scoring system. RESULTS: Data were subjected to the chi-square test, Mann-Whitney U-test, and Kruskal-Wallis H-test. Matrix systems presented similar results in the clinical evaluation and the in vitro microleakage test of Class II composite restorations. Dye leakage was minimal at enamel margins, and statistically lower (p < 0.05) than at cementum/dentin margins. CONCLUSION: The different matrix systems had no influence on clinical performance or in vitro sealing ability of Class II composite restorations.     

22-Year clinical evaluation of the performance of two posterior composites with different filler characteristics

Objectives

This retrospective longitudinal study investigated the longevity of posterior restorations placed in a single general practice using 2 different composites in filler characteristics and material properties: P-50 APC (3M ESPE) with 70 vol.% inorganic filler loading (midfilled) and Herculite XR (Kerr) with 55 vol.% filler loading (minifilled).

Methods

Patient records were used for collecting data. Patients with at least 2 posterior composite restorations placed between 1986 and 1990, and still in the practice for regular check-up visits, were selected. 61 patients (20 male, 41 female, age 31.2-65.1) presenting 362 restorations (121 Class I, 241 Class II) placed using a closed sandwich technique were evaluated by 2 operators using the FDI criteria. Data were analyzed with Fisher's exact test, Kaplan-Meier statistics, and Cox regression analysis (p < 0.05).

Results

110 failures were detected. Similar survival rates for both composites were observed considering the full period of observation; better performance for the midfilled was detected considering the last 12 years. There was higher probability of failure in molars and for multi-surface restorations.

Significance

Both evaluated composites showed good clinical performance over 22 years with 1.5% (midfilled) and 2.2% (minifilled) annual failure rate. Superior longevity for the higher filler loaded composite (midfilled) was observed in the second part of the observation period with constant annual failure rate between 10 years and 20 years, whereas the minifilled material showed an increase in annual failure rate between 10 years and 20 years, suggesting that physical properties of the composite may have some impact on restoration longevity.     

Influence of diabetes on cardiac resynchronization therapy with or without defibrillator in patients with advanced heart failure

ObjectivesWe performed a post hoc analysis to determine the influence of cardiac resynchronization therapy with a defibrillator (CRT-D) or without a defibrillator (CRT-P) on outcomes among diabetic patients with advanced heart failure (HF).BackgroundIn patients with systolic HF, diabetes is an independent predictor of morbidity and mortality. No data are available on its impact on CRT-D or CRT-P in advanced HF.MethodsThe database of the Comparison of Medical Therapy, Pacing and Defibrillation in Heart Failure trial was examined to determine the influence of CRT (CRT-D and CRT-P) on outcomes among diabetic patients. All-cause mortality or hospitalization, all-cause mortality or cardiovascular hospitalization, all-cause mortality or HF hospitalization, and all-cause mortality were analyzed among diabetic patients (n = 622). A Cox proportional hazard model, adjusting for age, gender, New York Heart Association, ischemic status, body mass index, left ventricular ejection fraction, heart rate, QRS, left or right bundle branch block, blood pressure, comorbidities (renal failure, carotid artery disease, peripheral vascular disease, hypertension, coronary artery bypass grafting, and atrial fibrillation), medications, and device (with or without defibrillator), was used to estimate hazard ratios (HRs) and significance.ResultsThe overall outcome of diabetic patients was similar to that of nondiabetic patients in the optimal pharmacologic therapy arm. With CRT, diabetic patients experienced a substantial reduction in all-cause mortality or all-cause hospitalization (HR = 0.77, 95% confidence interval [CI] 62–0.97), all-cause mortality or cardiovascular hospitalization (HR = 0.67, 95% CI 0.53–0.85), all-cause mortality or HF hospitalization (HR = 0.52, 95% CI 0.40–0.69), and all-cause mortality (HR = 0.67, 95% CI 0.45–0.99) compared with optimal pharmacologic therapy. Procedure-related complications and length of stay were identical in diabetic and nondiabetic patients.ConclusionIn diabetic patients with advanced HF, there is a substantial benefit from device therapy with significant improvement in all end points.     

Autoimmune thyroid disease and chronic urticaria

We report six cases of autoimmune thyroid disease associated with chronic urticaria and briefly review the literature, including the histopathological nature of such lesions, and their aetiology and pathogenesis. In view of the prevalence of thyroid disease in patients with chronic urticaria, screening measurements of thyrotropin and anti-thyroperoxidase antibodies are recommended, although negative antibodies do not exclude a relationship between urticaria and thyroid autoimmunity. After failure of conventional therapy for urticaria, patients who are apparently clinically euthyroid may be considered for a trial with levothyroxine. Improvement of urticaria was seen with levothyroxine treatment in three of four patients with only marginal abnormalities in thyroid function.     

Shrinkage stress of three composites under different polymerization methods

The aim of this study was to evaluate the shrinkage stress of three composites under different polymerization methods: halogen conventional polymerization (G1), halogen "soft-start" polymerization (G2) and LED polymerization (G3). The composites tested were Filtek Z-100 (3M/ESPE), Filtek Z-250 (3M/ESPE) and Solitaire 2 (Heraeus Kulzer). For G1, an XL-3000 (3M/ESPE) curing unit with light intensity of 507 mW/cm2 was employed. In G2, the same light unit was used, but with a reduced light intensity in the first 20 s (166 mW/cm2). In G3, an Ultrablue I (DMC) LED curing unit with light intensity of 125 mW/cm2 was used. The test was performed with a DL 2000 (EMIC) universal testing machine and two metallic molds with a 1 mm space between them. The composites were inserted in the space between the molds and light cured according to the protocols mentioned above. Stress was registered in different periods of time: 10, 20, 40, 60, 90 and 120 s. A significant linear increase of the shrinkage stress over time was observed, except for Z-100 in G2. Generally, LED polymerization (G3) reduced the generated stress when compared to conventional halogen polymerization (G1). In G3, the composite with the additional co-initiator presented lower stress when compared to the other composites tested. The combination between composite and polymerization method produced different patterns of stress behavior. LED polymerization reduced the initial shrinkage stress of the three materials and was influenced by the presence of co-initiators in the composites.     

Dentin penetrability evaluation of three different dyes in root-end cavities filled with mineral trioxide aggregate (MTA)

The purpose of this study was to evaluate the penetration of three dyes in MTA root-end fillings. In 30 single-rooted teeth, cavities for retrofilling were prepared with an ultrasound appliance and filled with MTA. The specimens were randomly assigned to three groups (n = 10) and immersed in the following solutions: 2% methylene blue (MET), 50% silver nitrate (NIT) and 0.2% rhodamine B (ROD). Two transversal slices (1 mm) of the retrofilling region were obtained and evaluated using the Image Tool 3.0 software to obtain a quantitative evaluation (in mm2) of the dye penetration around the retrofillings. Data were submitted to statistical analysis using Students t-test. The lowest degree of dye penetration was observed for the NIT group, in both slices (p < 0.05). Dye penetration was significantly larger in the ROD group when compared to the NIT group, in both slices (p < 0.05), and to the MET group, only in slice 1 (p < 0.05). Within the limitations of this study, it was concluded that the choice of dye could influence the penetration evaluation in root-end filling studies, and that the NIT had the lowest penetration capacity in the apical dentine.