Dental caries and fluorosis prevalence study in a nonfluoridated Brazilian community: trend analysis and toothpaste association.

The main purpose of this study is to compare data from previous surveys to current prevalence rates of dental caries and dental fluorosis in eleven- and twelve-year-olds in a non-fluoridated Brazilian community (< 0.2 ppm F). This study also assesses the possible association between use of fluoride toothpaste and the prevalence of dental caries and dental fluorosis. The sample subjects are randomly selected schoolchildren who were examined with a dental probe and buccal mirror under natural light. The intra-examiner error was calculated, using Kappa statistics (K tau 0.85). The results showed that between 1991 and 1997 there was a 56.7 percent decrease in the prevalence of dental caries and an 80.1 percent increase in dental fluorosis. Children with dental fluorosis were 1.75 times more likely to be free of caries (OR = 1.75-CI:0.43, 6.68). Children who started using fluoride toothpaste before the age of three were 4.43 times more likely to have dental fluorosis than those who started using it after the age of three (OR = 4.43-CI:0.51, 99.61). The results of the cross-sectional surveys conducted with schoolchildren in 1991, 1995, and 1997 suggest a continuing decrease in the prevalence of dental caries and an increase in the prevalence of dental fluorosis in this nonfluoridated Brazilian town.

Development of anthropomorphic upper limb prostheses with human-like interphalangian and interdigital couplings.

This article presents a model for the couplings of the movements between the phalanges and fingers in a hand when they execute certain functions. It also shows the importance of knowing these couplings, suggests methods for obtaining them, and discusses how to apply them to the construction of artificial upper limbs, highlighting the important mechanical aspects for achieving such a goal. Thus, it gives support for projects of upper limb prosthesis with anthropomorphic characteristics.