Micropatterned Silica Films with Nanohydroxyapatite for Y-TZP Implants.

This investigation aimed at developing micropatterned silica thin films (MSTFs) containing nanohydroxyapatite (nano-HA) microaggregates that were not completely covered by silica so that they could directly interact with the surrounding cells. The objectives were 1) to evaluate the effect of the presence of 2 films (MSTF with or without nano-HA addition) on the characteristic strength (σ0) and Weibull modulus ( m) of a yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and 2) to evaluate the effect of these 2 films, as applied onto the Y-TZP surface, on the morphology, orientation, and proliferation of MG63 cells. Sol-gel process and soft lithography were used to apply the MSTF onto the Y-TZP specimens. Three experimental groups were produced: Y-TZP, Y-TZP + MSTF, and Y-TZP + MSTF + sprayed nano-HA. All surfaces were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy and tested for 4-point flexural strength ( n = 30) in water at 37 °C. Weibull analysis was used to determine m and σ0 (maximum likelihood method). In vitro biological behavior was performed with human osteoblast-like cells (MG63). Y-TZP was successfully coated with MSFT and MSFT + nano-HA. Scanning electron microscopy micrographs indicated that the microaggregates of nano-HA were not entirely covered by the silica. There was no statistically significant difference among the experimental groups for σ0 and m. In the groups containing the films, the cells were elongated and aligned along the lines. The MSFT + nano-HA group showed significantly higher cell metabolic activity than that obtained for the Y-TZP group at day 7. This investigation was successful in producing an MSTF containing nano-HA microaggregates that remained exposed to the environment. The developed films did not jeopardize the structural reliability of a commercial Y-TZP, as confirmed by the Weibull statistics. The MG63 cells seeded over the films became elongated and aligned along the films' micropatterned lines. Y-TZP specimens coated with MSTF and nano-HA showed a higher cell metabolic activity and proliferation after 7 d of culture when compared with uncoated Y-TZP.

Comparative evaluation of the effect of sustained inflation and rapid inflation/deflation of the intrarectal balloon upon rectoanal inhibitory reflex parameters in asymptomatic subjects.

PURPOSE: The effects of rapid sustained inflation versus rapid inflation/deflation of the intrarectal balloon upon rectoanal inhibitory reflex (RAIR) parameters were evaluated in asymptomatic subjects. METHODS: Forty asymptomatic adults were submitted to anorectal manometry with rapid or sustained inflation with 30 and 60 mL air. The average age was 27.4 years (range, 20-40). The subjects were divided into Group I (20 men) and Group II (20 women) for analysis. RAIR parameters were registered in order to compare the inflation patterns within each group, and Groups I and II were compared for each inflation pattern with regard to RAIR parameters. RESULTS: Sustained inflation significantly increased IAS relaxation time and duration of the reflex in both groups, and IAS tone recovery time in Group I. CONCLUSIONS: RAIR parameters are influenced by the choice of inflation pattern. Further studies are required to establish a standard intrarectal balloon inflation pattern.