Interfacial fracture toughness of different resin cements bonded to a lithium disilicate glass ceramic

Objectives

To evaluate the effect of HF acid etching and silane treatment on the interfacial fracture toughness of a self-adhesive and two conventional resin-based cements bonded to a lithium disilicate glass ceramic.

Methods

Lithium disilicate glass ceramic discs were prepared with two different surface preparations consisting of gritblasted with aluminium oxide, and gritblasted and etched with hydrofluoric acid. Ceramic surfaces with a chevron shaped circular hole were treated by an optimized silane treatment followed by an unfilled resin and then three different resin cements (Variolink II, Panavia F2, and Multilink Sprint). Specimens were kept in distilled water at 37 °C for 24 h and then subjected to thermocycling. The interfacial fracture toughness was measured and mode of failures was also examined. Data were analysed using analysis of variance followed by T-test analysis.

Results

No statistically significant difference in the mean fracture toughness values between the gritblasted and gritblasted and etched surfaces for Variolink II resin cement was found (P > 0.05). For the gritblasted ceramic surfaces, no significant difference in the mean fracture toughness values between Panavia F2 and Variolink II was observed (P > 0.05). For the gritblasted and etched ceramic surfaces, a significantly higher fracture toughness for Panavia F2 than the other cements was found (P < 0.05).

Conclusions

The interfacial fracture toughness for the lithium disilicate glass ceramic system was affected by the surface treatment and the type of luting agent. Dual-cured resin cements demonstrated a better bonding efficacy to the lithium disilicate glass ceramic compared to the self-adhesive resin cement.

Clinical significance

The lithium disilicate glass ceramic surfaces should be gritblasted and etched to get the best bond when used with Panavia F2 and Multilink Sprint resin cements, whereas for the Variolink II only gritblasting is required. The best bond overall is achieved with Panavia F2.     

Adjacent QT dispersion: A good predictor of ventricular arrhythmias after myocardial infarction

The 12-lead surface electrocardiogram adjacent QTc dispersion, which is the maximum difference of corrected QT interval between two adjacent leads, is a simple method to determine regional variation in repolarization and refractoriness. The aim of this study is to evaluate adjacent QTc dispersion as a marker of susceptibility to ventricular arrhythmias after myocardial infarction. A total of 135 consecutive patients with acute myocardial infarction were enrolled in the study. Adjacent QTc, measured by lens magnifier, was calculated on the first, second and third days after acute myocardial infarction. On the second day after acute myocardial infarction, adjacent QTc dispersion was significantly greater in patients with ventricular arrhythmias (P < 0.001). Adjacent QTc dispersion on the first and fifth day after acute myocardial infarction was not associated with development of ventricular arrhythmias. On the second day after acute myocardial infarction, adjacent QTc dispersion is a simple and feasible method for prediction of ventricular arrhythmias.     

Comparison of miltefosine and meglumine antimoniate for the treatment of zoonotic cutaneous leishmaniasis (ZCL) by a randomized clinical trial in Iran

This study was a randomized, open label comparison that was designed to determine efficacy and safety of miltefosine as the first oral drug for the treatment of zoonotic cutaneous leishmaniasis caused by Leishmania major in comparison with meglumine antimoniate. Complete clinical response was defined as 100% re-epithelialization of the lesion. Definitions of lesion cure and failure were based on both clinical and parasitological criteria two weeks after the end of treatment and clinical recovery three months after this period. Of 32 patients enrolled for miltefosine treatment 28 patients completed treatment, of which 26 were cured at three months, corresponding to a cure rate of 92.9% on a per protocol analysis, and 81.3% according to intention to treat analysis. There was one failure (3.1%), one relapse (3.1%) and four dropouts due to lack of tolerability (12.5%) during the first week of treatment. Of 31 patients who received intramuscular meglumine antimoniate (20mgSb(5)/kg body weight daily for 14 days) 25 were cured (83.3% on a per protocol basis, 80.6% on intention to treat basis), five failed (16.1%) and one was lost (3.2%) at 3-month follow-up. At 6-month follow-up after the end of treatment, no relapse was observed. Both regimens were tolerated but averages of nausea (32.2%) and vomiting (21.5%) were observed in patients during two weeks after initiation of miltefosine treatment. Other gastrointestinal, musculoskeletal, and total adverse events were not statistically different in the two groups during one to four weeks after therapy initiation. No relevant changes were observed in levels of liver enzymes, creatinine and hematological tests before and after end of treatment in both groups. In conclusion, miltefosine is apparently at least as good as meglumine antimoniate for the treatment of cutaneous leishmaniasis caused by L. major in Iran, based on parasitological as well as clinical criteria two weeks, three months, and six months after end of treatment.     

Daily apple versus dried plum: impact on cardiovascular disease risk factors in postmenopausal women

BackgroundEvidence suggests that consumption of apple or its bioactive components modulate lipid metabolism and reduce the production of proinflammatory molecules. However, there is a paucity of such research in human beings.ObjectiveWomen experience a lower rate of cardiovascular disease before menopause compared with men. However, after the onset of menopause, the risk of cardiovascular disease increases drastically due to ovarian hormone deficiency. Hence, we conducted a 1-year clinical trial to evaluate the effect of dried apple vs dried plum consumption in reducing cardiovascular disease risk factors in postmenopausal women.DesignOne-hundred sixty qualified postmenopausal women were recruited from the greater Tallahassee, FL, area during 2007-2009 and were randomly assigned to one of two groups: dried apple (75 g/day) or dried plum (comparative control). Fasting blood samples were collected at baseline, 3, 6, and 12 months to measure various parameters. Physical activity recall and 7-day dietary recall were also obtained.ResultsNeither of the dried fruit regimens significantly affected the participants' reported total energy intake throughout the study period. On the contrary, women who consumed dried apple lost 1.5 kg body weight by the end of the study, albeit not significantly different from the dried plum group. In terms of cholesterol, serum total cholesterol levels were significantly lower in the dried apple group compared with the dried plum group only at 6 months. Although dried plum consumption did not significantly reduce serum total cholesterol and low-density lipoprotein cholesterol levels, it lowered their levels numerically by 3.5% and 8%, respectively, at 12 months compared with baseline. This may explain the lack of significance observed between the groups. However, within the group, women who consumed dried apple had significantly lower serum levels of total cholesterol and low-density lipoprotein cholesterol by 9% and 16%, respectively, at 3 months compared with baseline. These serum values were further decreased to 13% and 24%, respectively, after 6 months but stayed constant thereafter. The within-group analysis also reported that daily apple consumption profoundly improved atherogenic risk ratios, whereas there were no significant changes in lipid profile or atherogenic risk ratios as a result of dried plum consumption. Both dried fruits were able to lower serum levels of lipid hydroperoxide and C-reactive protein. However, serum C-reactive protein levels were significantly lower in the dried plum group compared with the dried apple group at 3 months.ConclusionsThere were no significant differences between the dried apple and dried plum groups in altering serum levels of atherogenic cholesterols except total cholesterol at 6 months. However, when within treatment group comparisons are made, consumption of 75 g dried apple (about two medium-sized apples) can significantly lower atherogenic cholesterol levels as early as 3 months. Furthermore, consumption of dried apple and dried plum are beneficial to human health in terms of anti-inflammatory and antioxidative properties.     

Soy protein with or without isoflavones failed to preserve bone density in gonadal hormone–deficient male rat model of osteoporosis

Soy with its isoflavones has been shown to positively influence bone mineral density in female ovariectomized rats; hence, we hypothesized a similar effect in orchidectomized (ORX) male rats. Forty male Sprague-Dawley rats, aged 95 days, were divided into 4 groups and were either sham operated (Sham) or ORX. The ORX groups were fed a soy protein–based diet (SOY), an isoflavone-depleted soy protein diet (SOY?), or a casein based diet for 65 days after surgery. Orchidectomy increased the rate of bone turnover, resulting in reduced bone mineral density and bone mineral content by 3.5% and 14%, respectively, and compromised biomechanical properties. The mean femoral length of ORX animals was also significantly shorter than Sham animals, but ORX rats that were fed SOY diet did not experience this reduction in bone length, implicating a role for soy protein in bone growth (4.02 ± 0.02, 3.93 ± 0.01, 3.99 ± 0.02, 3.91 ± 0.01 for Sham, ORX, SOY, SOY?, respectively). The SOY and SOY? positively influenced the biomechanical properties of bone such as yield and ultimate force, the measures of bone elasticity, and plasticity. In terms of bone histomorphometry, the data indicate that SOY? tends to reduce ORX-induced increase in bone turnover as evidenced by suppressed bone formation rate/mineralized surface by about 9%. Overall, our results indicated that soy protein, regardless of its isoflavone content, was unable to prevent the ORX-induced femoral decrease in bone density and mineral content. However, soy may enhance the quality of bone as indicated by increased yield force.     

Serum Insulin and Cognitive Performance in Older Adults: A Longitudinal Study

Purpose

The aim of this study was to examine the association of serum glucose, insulin, and insulin resistance with cognitive functioning 7 years later in a longitudinal population-based study of Finnish older adults.