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Effective bleaching of discolored resin composites aged in an acidic and alcoholic media rich in staining agents was achieved, improving color and translucency. Carbamide peroxide showed better performance than hydrogen peroxide for the bleaching of stained resin composites. (J Esthet Restor Dent 29:368-377, 2017).

The purpose of this study was to evaluate the compressive strength of two glass ionomer cements, a conventional one (Vitro Fil - DFL) and a resin-modified material (Vitro Fil LC - DFL), using two test specimen dimensions: One with 6 mm in height and 4 mm in diameter and the other with 12 mm in height and 6 mm in diameter, according to the ISO 7489:1986 specification and the ANSI/ADA Specification No. 66 for Dental Glass Ionomer Cement, respectively. Ten specimens were fabricated with each material and for each size, in a total of 40 specimens. They were stored in distilled water for 24 hours and then subjected to a compressive strength test in a universal testing machine (EMIC), at a crosshead speed of 0.5 mm/min. The data were statistically analyzed using the Kruskal-Wallis test (5%). Mean compressive strength values (MPa) were: 54.00 +/- 6.6 and 105.10 +/- 17.3 for the 12 mm x 6 mm sample using Vitro Fil and Vitro Fil LC, respectively, and 46.00 +/- 3.8 and 91.10 +/- 8.2 for the 6 mm x 4 mm sample using Vitro Fil and Vitro Fil LC, respectively. The resin-modified glass ionomer cement obtained the best results, irrespective of specimen dimensions. For both glass ionomer materials, the 12 mm x 6 mm matrix led to higher compressive strength results than the 6 mm x 4 mm matrix. A higher variability in results was observed when the glass ionomer cements were used in the larger matrices.

The increase in the litter size in past decades has caused reduction in the individual piglet birth weight. Therefore, nutritional strategies employed in the last third of gestation in order to improve the piglet birth weight have been studied. This study aimed to evaluate the effects of 2 different feeding levels (1.8 and 2.2 kg/d) in the last third of gestation on the piglet birth weight and the female reproductive performance. A total of 407 females were fed on a diet based on corn-soybean meal (3.25 Mcal ME per kg and 0.65% standardized ileal digestible lysine) from day 90 of gestation until farrowing. The females were weighed on day 90 and day 112 of gestation, and at weaning. Born alive and stillborn piglets were weighed within 12 h of birth. The lactation feed intake and the litter growth rate were measured in a randomly selected subsample of 53 sows from each treatment. The data were analyzed using the generalized linear mixed models, considering the females as the experimental unit. Parity, treatment, and their interaction were analyzed for all responses. The females fed on 2.2 kg/d of diet from day 90 to day 112 exhibited greater body weight gain compared to the females fed on 1.8 kg/d (P < 0.001). No evidence of the effects of feeding levels on the individual piglet birth weight and on the within-litter CV were observed, for both gilts and sows (P ≥ 0.90). Similarly, when the classes of the total born piglets were considered in the analysis (<15 and ≥15 for gilts; <16 and ≥16 for sows), no positive effects of increasing the feeding level were observed on the individual piglet birth weight and the within-litter CV (P ≥ 0.47). Also, no differences in the stillborn rate, mummified-fetus rate, and percentage of piglets weighing less than 1,000 g at birth were observed between the treatments (P ≥ 0.28). The females fed on 1.8 kg/d of diet exhibited greater feed intake during lactation, compared to the females fed on 2.2 kg/d (P < 0.05). Weaning weight, weaning-to-estrus interval, subsequent litter size, and culling rate were not affected by the dietary levels (P ≥ 0.23). In conclusion, increasing the feed intake from day 90 of gestation until farrowing increased the body weight gain in sow, demonstrated no effect on the piglet birth weight, and reduced the lactation feed intake. Furthermore, there was no evidence of the effects of the treatments on the litter growth rate or on the subsequent female reproductive performance.

SUMMARYThis study evaluated the effect of mechanical cycling on the bond strength of fiber posts bonded to root dentin. The hypotheses examined were that bond strength is not changed after fatigue testing and bond strength does not present vast variations according to the type of fiber post. Sixty crownless, single-rooted human teeth were endodontically treated, with the space prepared at 12 mm. Thirty specimens received a quartz fiber post (Q-FRC) (DT Light-Post), and the remaining 30 specimens received a glass fiber post (G-FRC) (FRC Postec Plus). All the posts were resin luted (All Bond+Duolink), and each specimen was embedded in a cylinder with epoxy resin. The specimens were divided into six groups: G1-Q-FRC+no cycling; G2-Q-FRC+20,000 cycles (load: 50N; angle of 45°; frequency: 8Hz); G3-Q-FRC+2,000,000 cycles; G4-G-FRC+no cycling; G5-G-FRC+20,000 cycles; G6-G-FRC+2,000,000 cycles. The specimens were cut perpendicular to their long axis, forming 2-mm thick disc-samples, which were submitted to the push-out test. ANOVA (α=.05) revealed that: (a) Q-FRC (7.1±2.2MPa) and G-FRC (6.9±2.1MPa) were statistically similar (p=0.665); (b) the "no cycling" groups (7.0±2.4MPa), "20,000 cycles" groups Clinical RelevanceWhen adhesively cemented, tested fiber posts are fatigue resistant and appear to have no affect on bond strength to root dentin. Thus, the retention strength of these fiber posts could be maintained for an extended period; however, further studies should be conducted. 580Operative Dentistry (7.0±2.1MPa) and "2,000,000 cycles" groups (7.0±2.0MPa) were statistically similar (p=0.996). It concluded that mechanical cycling did not affect the bond strength of two fiber posts bonded to dentin.

The effects of increasing feed intake (1.8, 2.3, 2.8, and 3.3 kg/d) during late gestation of gilts on piglet birth weight and female reproductive performance were evaluated. A total of 977 gilts were fed a diet based on corn-soybean meal (3.29 Mcal ME per kg and 0.64% standardized ileal digestible lysine) from day 90 of gestation until farrowing. Gilts were weighed on days 90 and 112 of gestation, at farrowing and weaning. Born alive and stillborn piglets were weighed within 12 h of birth. Colostrum yield (CY), lactation feed intake, and litter growth rate were measured in a randomly selected subsample of 245 gilts. The data were analyzed using generalized linear mixed models. As expected, gains in body weight (BW) were different at day 112 (P < 0.001) with the greatest values observed in the 3.3 kg/d treatment. As feed intake increased during late gestation, BW, body condition score (BCS), backfat (BF), and Caliper unit also increased between day 112 and weaning (P < 0.001). No differences were found among treatments in total number of piglets born, mummified fetuses, sum of born alive and stillborn piglets, and within-litter birth weight CV (P > 0.05). Tendencies for quadratic effect of feed intake were observed for born alive piglets (P = 0.079), average birth weight of piglets (P = 0.083), and litter weight (P = 0.059). Gilts with lower feed intake during late gestation had reduced percentages of stillborn piglets than gilts with greater feed intakes. The CY decreased linearly (P < 0.05) as the feed intake was increased. No differences among treatments were found at weaning in individual piglet weight and litter weight, as well as in percentage of weaned piglets (P > 0.05). Lactation feed intake decreased as gestation feeding level increased (P < 0.05). No differences in the subsequent cycle were observed among treatments for farrowing rate, retention rate up to the next farrowing, number of total piglets born, born alive, stillborn piglets, and mummified fetuses (P > 0.05). In conclusion, increased feed intake from day 90 of gestation until farrowing resulted in increased maternal BW gain and stillborn rate, but reduced CY and lactation feed intake. A slight increase in birth weight was observed for the 2.3 kg/d treatment. Furthermore, litter growth and subsequent female reproductive performance were not affected by feed intake during late gestation.

This study aimed to evaluate the effect of repolishing after bleaching on color stability and smoothness of two resin composites aged in a high-staining beverage. Fifty-six disc-shaped specimens (8×2 mm) of each resin composite were fabricated (Filtek Z250, 3M ESPE, microhybrid, and Filtek Z350 XT, 3M ESPE, nanofilled) and then divided according to treatment: bleached or nonbleached. After treatment application, groups were subdivided according to the surface treatment: repolished or unrepolished. A new subdivision was performed according to aging conditions: immersion in red wine for 15 min/d or in artificial saliva for 24 h/d during 30 days. Color (CIE L*a*b* system) and roughness (Ra) were assessed at baseline (P0), after bleaching procedures (P1), after surface treatment (P2), and after aging (P3). Color change (ΔE) was calculated through the CIEDE2000 formula. Statistical analysis was performed using repeated measures analysis of variance and the Tukey post hoc test. Bleached repolished groups presented lower color alteration than the bleached unrepolished groups from both resin composites when aged in red wine. Repolishing (P1 vs P2) promoted a slight decrease in roughness values of almost all groups. Nanofilled composite presented greater ΔE values than microhybrid composite when aged in red wine.