Objectives: Long term follow-up data based on randomised clinical trials are needed in relation to deep caries treatment. The aim of the present trial is to investigate the beneficial and harmful long term effects of stepwise excavation during two visits versus one completed excavation of deep caries in permanent teeth in adults. Methods: Consecutive patients contacting clinical units in Sweden and Denmark were included. The trial is a centrally randomised patient- and observer-blinded multicenter trial, with two parallel intervention groups. A sample size calculation showed that 134 patients were needed in each group. Taking dropouts into account, a total of 314 patients fulfilled well-defined inclusion and exclusion criteria and were centrally block-randomised stratified by age and pain. Inclusion criteria: (i) Person ≥ 18 yrs having deep caries with or without pain (ii) x-ray showing primary caries into the inner 1/4 of the dentin, with the presence of a radiopaque zone at the pulpal wall. Success was defined as unexposed pulp with sustained pulp vitality without apical radiolucency after follow-up. Blinded evaluation of 1½ follow-up has previously been carried out in 106 patients (stepwise excavation group) and 93 patients (direct complete excavation) (Bjørndal et al. 2010, EJOS). Results: At 3-5 yr follow up there was a statistically significantly higher success with stepwise excavation [difference: 11.5%, 95% confidence interval (0.5; 22.2)] versus a direct complete excavation procedure, being similarly with the short term follow-up data. 53.3% (n = 102) of the material has been controlled and no significant differences were noted between the two intervention groups in terms of patients not yet controlled, lost patients and failures (Table). Conclusion: A stepwise excavation procedure still seems preferable after a long term follow up and presumably related to the reduced risk of exposing the inflamed pulp associated with deep caries.