Does the addition of potassium nitrate to carbamide peroxide gel reduce sensitivity during at-home bleaching?

BACKGROUND: A systematic review with meta-analysis was conducted to assess the effect of adding potassium nitrate to carbamide peroxide gels on bleaching efficacy and on reducing the risk and intensity of tooth sensitivity. METHODS: PubMed, Scopus, Web of Science, LILACS, BBO, and Cochrane Library databases and the gray literature were searched. IADR abstracts, records of trials, dissertations and theses were also searched. The Cochrane Collaboration risk of bias tool was used to assess the quality of the studies. RESULTS: Six studies were included in the systematic review and most of them had unclear risk of bias for the key domains, and of these only five were included in the meta-analysis. The risk ratio (RR) for sensitivity was 0.93 (95% CI = 0.73 to 1.19, P = 0.56). The standardized mean difference for pain intensity was -0.10 (95% CI = -0.36 to 0.16, P = 0.45), and for colour change was 0.12 (95% CI = -0.22 to 0.46; P = 0.49). CONCLUSIONS: No significant differences were observed between the groups with and without addition of the desensitizer in the gel. The addition of potassium nitrate to carbamide peroxide gel did not reduce the risk and intensity of tooth sensitivity during at-home bleaching. Colour change was not influenced by the addition of potassium nitrate to the gel.

Dietary inclusion of tomato pomace improves meat oxidative stability of young pigs.

The aim of this study was to assess the nutritional effect of tomato pomace, in combination with two distinct fat sources (lard or soya bean oil), on longissimus lumborum muscle, subcutaneous fat and liver of young pigs. Forty male pigs of 4 weeks old were randomly assigned to four dietary treatments using two fibre sources (wheat bran or 5.0% tomato pomace) and two fat sources (lard or soya bean oil), in a 2 × 2 factorial design for a 5-week trial. Tomato pomace did not improve colour, fatty acid profile, cholesterol content or lipid oxidation, nor did it yield detectable levels in lycopene or ß-carotene in the meat (p > 0.05). However, a positive increase in α-tocopherol content of meat and liver was observed in pigs fed tomato pomace (p < 0.05). Compared with lard, soya bean oil increased MUFA and PUFA proportions and decreased the percentage of SFA (p < 0.05). Our results indicate that 5.0% of tomato pomace increases pork oxidative stability and that 5.0% of soya bean oil, compared with lard, improves its nutritional quality.

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.

Effect of the source of dietary fat on postweaning lipogenesis in lean and fat pigs.

Twenty-four male piglets weaned after 21 days, 12 of the Large White lean breed (LW) and 12 of the Alentejano fat breed (AL), have been used to compare the effects of genotype and source of dietary fat on the activities of enzymes involved in lipogenesis and on the composition of selected fatty tissues. During 4 weeks the piglets were fed isoenergetic and isonitrogenous experimental diets, containing 5 % of either olive oil or tallow. In AL piglets the acetylcoenzyme A carboxylase activity was three- and ninefold higher, the malic enzyme activity six- and fivefold, and the glucose-6-phosphate dehydrogenase activity was four- and fivefold higher in the dorsal subcutaneous and in the perirenal fat, respectively, than in LW piglets. In general, fatty tissues of the AL piglets contained a higher proportion of saturated fatty acids. Olive oil induced a significant increase in the activities of malic enzyme and glucose-6-phosphate dehydrogenase in both tissues, but only slightly increased the acetylcoenzyme A carboxylase activity in perirenal fatty tissues (p < 0.05). The fatty acid profile of the subcutaneous and of the perirenal fat was strongly affected by the composition of dietary fat. These observations showed that the source of dietary fat influenced markedly lipid metabolism and body composition since a very early age.

[Daily and weekly circadian variations in sudden death in Chagas disease]. / Variações circadianas diárias e semanais na morte súbita da doença de Chagas.

PURPOSE: To determinate the circadian daily and weekly variations in the incidence of sudden death due to Chagas' disease. METHODS: In 50 chronic chagasic individuals with sudden death due to Chagas' disease and in 473 individuals with natural, not sudden death, we analyzed both the day of the week and the time of the death. Statistical tests were applied to determine the significance of the difference between proportions and averages. RESULTS: For the chagasic group the values indicated a highly significant excess of lethality for the period between 12 and 6pm. The occurrence of the sudden death was the same in the different days of the week for both groups. CONCLUSION: The observed results suggest that the sudden death associated with Chagas' disease has a circadian pattern with a vespertine peak. Weekly variations in the sudden death of chronic chagasic individuals were not detected.