Objective: To evaluate if there is any interference when adding coffee or chocolate to cow milk in the enamel des-remineralization process (orange juice/saliva). Material and Methods: 48 specimens of human enamel (4x4 mm) were included in acrylic resin, ground flat, polished and randomly divided into the following experimental groups (n = 8): G1-saliva, G2-orange juice, G3 orange juice / milk; G4-Orange Juice / Chocolate, G5-Orange Juice / Coffee + milk and G6-milk. Each group was immersed for 60 seconds on each solution proposed and then immersed for 30 minutes in saliva. This cycle was repeated 4 times. Prior to these cycles, the Knoop microhardness average of each specimen was obtained. After the challenges proposed, the final microhardness average was calculated. The values obtained from the difference between the initial and final microhardness were subjected to ANOVA followed by Tukey test (p <0,05). Results: The orange juice had the highest change in microhardness and statistically different from all other groups. The microhardness change was statistically similar in the groups submitted to orange juice followed by immersion in milk, in chocolate and in the mixture milk + coffee. The pure milk and saliva caused no change in surface hardness of enamel. Conclusion: Milk or the addition of chocolate and coffee to milk was able to produce a protective effect of the enamel surface against an erosive challenge.

This study aimed to evaluate the capacity of novel experimental hybrid coatings (HC) to reduce dentin permeability and to verify their resistance to erosive and abrasive challenges. Dentin disc specimens (1 mm thick) were treated with 0.5 M EDTA solution and randomly allocated into three experimental groups (n = 10): Control (Saliva); Concentrated Hybrid Coating (TEOS/GPTMS/Y‐APS); and Diluted Hybrid Coating (1:3 ratio with distilled water). Dentin permeability was assessed by hydraulic conductance in the following experimental time periods: post‐EDTA, post treatment, post erosion (5 min in 0.05 M citric acid solution, pH = 3.8), and post abrasion (toothbrushing for 3,900 cycles). Dentin permeability percent was calculated with respect the values of post‐EDTA for each experimental time. The morphology of the surface of extra dentin specimens was examined by scanning electron microscopy (SEM) in the same time periods (n = 3). Permeability data were analyzed by two‐way repeated measures ANOVA and Tukey tests (p < .05). Both HC presented significantly lower dentin permeability than control post treatment and post erosion (p < .05), without difference between them (p > .05). Post abrasion, there were no significant difference among groups (p > .05). Post treatment and post erosion, the HC seemed to flow into the tubules, occluding them, while the tubules in control remained opened. Post abrasion, the tubules appear to be occluded in all groups. In conclusion, the experimental hybrid coatings were capable of reducing dentin permeability after treatment. They were also able to resist to erosive and abrasive challenges, with the advantage of forming thinner and colorless films that can be potentially used to treat dentin hypersensitivity.

The aim of this study was to evaluate, in vitro, quantitatively and qualitatively, the stability of an experimental hybrid with two different concentrations (concentrated and diluted) applied at a simulation of a sensitive dentin. Human molar teeth were selected and their crowns were sectioned below the occlusal groove in order to obtain specimens of dentine disks that were ground flat and polished to achieve a thickness of 1.0 millimeter. The specimens were divided into 4 groups (n = 9) in accordance with proposed surface treatments: Artificial saliva (SAL) dentinal selfetching adhesive (AD), concentrated experimental hybrid (TC) and experimental hybrid diluted in the ratio 1: 3 (TD). Two methods were used to assess the stability: hydraulic conductance (dentin permeability) and scanning electron microscopy. The dentin permeability in 6 experimental times was carried out: Minimum (no treatment), Maximum (with open tubules), treatment (after application of their treatments), erosion (after 5 minutes of immersion in citric acid 0.05M pH 3, 8), brushing (brushing after 3900 cycles) and Post erosion (erosion was repeated after brushing). The scanning electron microscopy was performed on dentin specimens with a central area of application of treatments and natural tissues on the sides to show the film characteristics applied. Readings were made after application of treatments, after erosion, after brushing and after erosion after brushing, for all 4 treatments proposed. The analysis of variance (ANOVA) for repeated measures with two variation factors was applied with the multiple comparisons paired test (Tukey). For dentin all treatments reduced hydraulic conductance (Lp) in relation to Maximum. TC and TD showed the lowest values (24% and 15%) respectively. The TD continued to show statistically similar values after erosion (36%), being statistically similar to TC (55%). In brushing time the TD Lp was statistically similar to Treatment and erosion times. All groups were statistically similar between treatments in brushing and Post Erosion times. The analysis of SEM shows dentinal tubules with content inside on the TC and TD groups, remaining during all experimental period. AD presented a clear film, which began to stand out and show failure from erosion time. It follows that the TD had better behavior being able to decrease permeability of dentin by forming a thin film transparent, imperceptible, capable of sealing (fully or partially) and penetrate within the dentine tubules, resisting the erosive and abrasive challenges.

Low compliance and difficulties in flossing among children and adolescents seemed to be more related to lack of motivation, although problems concerning manual skills were also observed.

HMP was the only agent that could match the protection against initial erosion of the commercially available mouthrinse in both analyses.

Recent studies that have used eCG administration either 14 or 22 days after fixed-time AI in dairy and beef cattle have indicated a positive effect on conception rates. The aim of this study was to evaluate conception rates in embryo recipients treated with eCG 7 days after fixed-time embryo transfer (ET). A protocol for synchronization of ovulation was used in 470 Nelore and crossbred embryo recipient heifers (n = 179), dry cows (n = 152), and lactating cows (n = 139; body condition score = 3.0 to 3.5; >40 days in milk). All heifers and dry cows, but only 27.3% of lactating cows, were cycling at the beginning of the synchronization protocol. On Day 0, each female received IM injections of 2 mg of oestradiol benzoate (Gonadiol, Intervet Schering-Plough Animal Health, São Paulo, Brazil) and 0.075 mg of PGF2α (Preloban, Intervet Schering-Plough Animal Health). An intravaginal progesterone-releasing device (DIB, Intervet Schering-Plough Animal Health) was also inserted on Day 0. On Day 8, the DIB device was removed and cows or heifers received another IM treatment of 0.075 mg of PGF2α (Preloban), 300 IU of eCG (Novormon, Syntex S.A., Buenos Aires, Argentina) and 0.6 mg of oestradiol cipionate (Pfizer, Brazil). Transrectal ultrasonography was performed in all recipients on the day of ET (Day 16, 17, or 18 of the protocol) and only those with a corpus luteum greater than 15 mm in diameter were selected (n = 113 heifers, 114 dry cows, and 70 lactating cows). Transfers of fresh, frozen, and vitrified in vivo-produced embryos from Nelore donors were balanced between experimental groups. Seven days after ET, 127 animals received an IM injection of 400 IU of eCG (eCG group), and the 170 remaining cows or heifers were not treated with eCG, and were therefore considered the control group. Pregnancy diagnosis was performed 30 and 60 days after ovulation by transrectal ultrasound. Data were analysed using generalized linear models and results are presented as least squares means ± standard error. Conception rates were similar in the eCG and control groups at Day 30 (35.9 ± 5.5 and 33.5 ± 4.4, respectively; P > 0.10) and at Day 60 (27.6 ± 4.9 and 26.7 ± 3.9, respectively; P > 0.10). Contrary to other results in the literature, especially in dairy cows bred by fixed-time AI, the use of eCG 7 days after ET did not improve conception rates in Bos indicus cattle used as embryo recipients. Financial support from CNPq, FAPESP, and Intervet Schering-Plough Animal Health of Brazil and Syntex S.A. of Argentina.

No abstract

The objective of this study was to compare, in vitro, using different methods of analysis, the effect on surface of an experimental mouthrinse modified with different active ingredients for the prevention / control of dental erosion caused by hydrochloric acid. An experimental mouthrinse without additives, a commercially available mouthwash for erosion Elmex Erosion ® (AmF/NaF/SnCl2) (ELM) and four mouthrinses added 4 different additives were tested for their ability to protect against erosion in a model of erosion-remineralization, where the response variables were the change of micro-and nanohardness and the quantities of released calcium and phosphate in solution, determined by optic emission spectrometry. The additives used were: casein (CAS 5 g/L), sodium hexametaphosphate (HMP 0.2 g/L), titanium tetrafluoride (TiF4 3.4 g/L) and stannous fluoride (SnF2 8.7 g/L). Bovine enamel specimens were embedded in acrylic resin and polished. They were ramdomily distributed in groups (n=8) and submitted to the following cycle: (1) immersion in 20 ml of 0,01M hydrochloric acid (HCl), pH = 2.4 10 s, (2) immersion in 20 ml of saliva artificial for 60 s, (3) immersion in 20 ml of test solution for 30 seconds and (4) immersion in 20 ml of artificial saliva for 60 s. This cycle was repeated three times during the same day and the solutions were stored for later evaluation. For microhardness, the specimens treated with ELM and SnF 2 showed the highest values of hardness, being significant different from TiF4 solution, which presented the lowest value. The ELM, SnF 2 , CAS and HMP were statistically similar to C. For nanohardness, the TiF4 had the lowest value of hardness, being significant different from C. The SnF 2 , ELM, CAS and HMP were statistically similar to C. In the calcium analysis after the last cycle, ELM and HMP resulted in less calcium loss, which was significantly different from C. After the first immersion, all groups tested, except casein, showed statistically lower calcium loss when compared to group C and there was no difference in statistical analysis of loss of phosphate in the second. In analysis of phosphate loss after the final cycle, ELM TiF4 showed the lowest losses being significant different from C. After the first and the second cycles, only ELM was statistically different from C. It can be concluded that the ELM, HMP and TiF 4 protect the enamel surface against ions loss but the hardness tests could not detect this protection.