Effect of flap design on healing and osseointegration of dental implants.

The purpose of this study was to evaluate soft tissue healing and osseointegration of dental implants after the use of vestibular incision or crestal incision flap designs during placement of the dental implant fixture. A split-mouth design was used in 10 patients. The vestibular flap technique was used for half the implant fixtures and the crestal incision for the other half. Postsurgical healing was monitored for 30 days, and osseointegration at second-stage surgery was evaluated. The short-term results suggest that the use of either the vestibular incision or the crestal incision technique did not affect overall clinical healing or osseointegration.

Retarded growth rate and delayed onset of egg production associated with spirochaete infection in pullets.

Retarded growth rates and delayed onset of egg production were recorded in 22-week-old pullets reared on deep litter and with indirect contact with pigs. Birds reared in cages or transferred to cages were unaffected. Spirochaetes were isolated and identified from the intestines of the pullets reared on deep litter but not from those reared in cages. Birds kept solely on deep litter were more severely affected, with 24 per cent immature birds and 10 per cent mortality compared with those transferred from deep litter to cages where no mortality was recorded but 15 to 22 per cent were found to be immature. The histopathological changes are described and the significance of the findings is discussed.

The calculation of annual limits of intake for plutonium-239 in man using a bone model which allows for plutonium burial and recycling.

Values of the annual limit of intake (ALI) for plutonium-239 in man have been calculated using committed dose equivalent limits as recommended by ICRP in Publication 26. The calculations were made using a multicompartment bone model which allows for plutonium burial and recycling in the skeleton. In one skeletal compartment, the growing surfaces of cortical bone, it is assumed that plutonium deposits are retained and are not subject to resorption or recycling. In the trabecular bone compartment plutonium is taken to be resorbed with either subsequent redeposition onto bone surfaces or retention in the bone marrow. ALIs for plutonium-239 have been calculated assuming a range of rates of bone accretion (0-32 micron yr-1), different amounts of plutonium retained in the marrow (0-60%) and a 20%, 45% or 70% deposition of plutonium in the skeleton from the blood. The calculations made using this bone model suggest that 750 Bq (20 nCi) is an appropriate ALI for the inhalation of class W and class Y plutonium compounds and that 830 kBq and 5 MBq (23 muCi and 136 muCi) are the appropriate ALIs for the ingestion of soluble and insoluble forms of plutonium respectively.