This study aimed to assess the prevalence of use and need for dental prostheses (UNDP) by individuals at age 24 and their life-course determinants. A representative sample (n = 720) of all 5914 births occurring in Pelotas in 1982 were prospectively investigated, and the UNDP were assessed in 2006. Exploratory variables included demographic and socio-economic, oral health, and dental service utilization patterns during the life-course. The prevalence of UNDP was 2.1% and 29.7%, respectively. Multivariable Poisson regression analysis showed that low socio-economic status through the life-course [Prevalence Ratio (PR) = 1.56 (95% CI: 1.08-2.26)], lower maternal schooling in childhood [PR 2.79 (1.34-5.79)], no oral hygiene instruction by a dentist at age 15 [PR 1.64 (1.11-2.41)], and caries presence at age 15 (high DMFT tertile) [PR 2.90 (1.98-4.24)] were associated with prosthetic treatment needs. These results support the hypothesis that life-course socio-economic, behavioral, and clinical determinants are associated with the need for dental prostheses.