Objectives Recent studies in undergraduate medical education have demonstrated the advantage of repeated testing over repeated practice with regard to knowledge and skills retention. The aim of this study was to investigate whether this “testing effect” also applies to skills retention in undergraduate dental education. Methods In this prospective, randomised controlled trial, fourth‐year dental students at Göttingen University Medical Centre participated in a training session on surgical suturing in winter term 2014/2015. Following this, they were either assigned to two sessions of additional skills training (group A) or two sessions of skills assessment with feedback (group B). These sessions were spaced over a period of 4 weeks. Skills retention was assessed in a summative objective structured clinical examination (OSCE) at the end of term, that is 6 months after the initial teaching session. Results A total of 32 students completed the study. With regard to suturing, OSCE performance was significantly better in group B than group A (81.9±13.1% vs 63.0±15.4%; P=0.001; Cohen's d=1.33). There was no significant OSCE performance difference in the two groups with regard to other learning objectives that were addressed in the end‐of‐term examination. Thus, the group difference was specific to suturing skills. Conclusions This is the first study to demonstrate that in dental education, repeated testing produces more favourable skills retention than repeated practice. Test‐enhanced learning might be a viable concept for skills retention in undergraduate dentistry education.