Purpose: To assess and compare prosthodontic treatment needs and the related manpower requirements using the normative and sociodental needs approaches for adult Koreans aged 30 to 64 years. Materials and Methods: Data were obtained from 1,029 30- to 64-year-old adults who were a subsample of the 2003 Korean National Oral Health Survey. Subjects were clinically examined for normative needs and interviewed using an oral health-related quality of life (OHRQoL) measure, the Oral Impacts on Daily Performance. Their oral health behaviors were also assessed. The sociodental approach includes impact-related needs, in which normative needs are integrated with OHRQoL, and propensity-related needs, in which oral health behaviors are used to determine appropriate treatments. Prosthodontic treatment needs and number of clinicians needed to treat those needs were estimated using normative needs, impact-related needs, and propensity-related needs. Results: Compared to normative needs, significant decreases of 74.1% to 78.5% were found for prosthodontic treatment needs using impact-related needs and propensity-related needs, respectively. Differences in manpower requirements to deal with prosthodontic treatment were large; per 100,000 people, 86.5 dental clinicians would be needed using normative needs, compared to 22.4 clinicians using impact-related needs and 18.6 clinicians using propensity-related needs. Conclusions: The sociodental approach for assessing dental needs for prosthodontic treatment indicated much lower levels of treatment needs than the normative approach. The sociodental approach should be applied to dental workforce planning.