Purpose: This study investigated the possible relationship between the survival of complete crowns (CCs), 3-unit fixed dental prostheses (3uFDPs), and fixed dental prostheses (FDPs) versus gender and age at initial treatment over a period of 18 to 20 years in an undergraduate clinic. Materials and Methods: Complete treatment and follow-up records of 1,037 CCs (60.5% women/39.5% men; age range: 18 to 82 years), 134 3uFDPs (59.2% women/40.8% men; age range: 33.6 to 93.6 years), and 322 FDPs (62.1% women/37.9% men; age range: 33.6 to 94.2 years) were available for analysis. Failures of the fixed prosthetic restorations were defined as irreversible complications (finish line involved or loss of CCs, FDPs, or abutments). Results: The association between gender versus irreversible complications for the CCs (P = .481), 3uFDPs (P = .814), and FDPs (P = .410) groups was not statistically significant. The relationship between age versus irreversible complications for the fixed prosthetic restorations was statistically significant for all test groups. The patients with the failing restorations (66.2 years; mean range: 64.8 to 67.5 years) were 4.5 to 5.5 years older at initial treatment than the patients with the surviving restorations (61.3 years; mean range: 59.5 to 63.0 years). Conclusions: There was no relationship between gender and irreversible complications. There was a clear statistically significant association between age and irreversible complications. Receiver operating characteristic analysis for all study groups revealed that for age, no clear cutoff point exists with acceptable specificity and sensitivity