OBJECTIVES: The present retrospective analysis was performed to evaluate the long-term results of initial periodontal and fixed prosthodontic treatment in patients with gingivitis or moderate chronic periodontitis during post-therapeutic irregular maintenance of 5-17 years. MATERIAL AND METHODS: Thirty-four patients participated in the study. Baseline data were taken from the patients' records when the periodontal and the prosthetic treatment was finished. A follow-up examination was performed in conjunction with the radiographic examination including assessment of plaque, bleeding on probing, probing pocket depth, recession and probing attachment loss. Information regarding the oral hygiene habits of the subjects as well as the amount of dental and initial therapy received between the observation time was obtained from the patients' records. RESULTS: The results from the clinical trial revealed that during the mean examination period of 11 years only 31 teeth were lost. The remaining restored and non-restored teeth did not show any significant differences in attachment loss (from 2.9 mm to 3.0 mm) in spite of a higher plaque value at the follow-up examination (from 42% to 48%). The BoP remained stable in the same time period and scored 31% to 28%. CONCLUSIONS: The periodontal attachment levels were maintained during a prolonged period despite irregular maintenance care. This indicates that in a population of obviously decreased susceptibility to chronic periodontitis, it is possible that fixed reconstructions will not - even under suboptimal supportive care - jeopardize the periodontal status.