Aims: Reflection on a deeper level is recognized as an important skill to learn for undergraduate students since mastering reflection can be helpful throughout their future careers. The aim with this study was to (i) examine if short structured written reflections could stimulate deep reflection among a group of dental students and (ii) explore specifically how the students reflected on clinical experience in relation to uncertainty when assessing the risk for exacerbation of apical periodontitis in root filled teeth.Methods: Short reflections were written by 52 dental students at Malmö University in 2021. All students first answered some questions associated with the risk for exacerbation of apical periodontitis in a case with a root filled tooth with a diffuse widening of the periodontal ligament space. After this, they were asked to write short reflections following prompts developed specifically to stimulate reflection. For each student, the reflections were analyzed and the level of reflection according to the 4Rs framework (Reporting/responding, Relating, Reasoning, Reconstructing) was assessed. The written content in the reflections were analyzed by a qualitative method, Systematic Text Condensation (STC). Results: Thirteen of the students (25%) reached the deepest level of reflection, Reconstructing. Sixteen students (31%), reached only the most superficial level, Report/respond. Two themes about experience and lack of experience were identified in the reflections: Theme 1 “The meaning of clinical experience” and Theme 2 “Differences and similarities”. The themes were subdivided into nine subgroups and described in more detail the relationship between experience and certainty as perceived by the students.Conclusions: A short reflection exercise stimulated deep reflection in a proportion of, but not all, dental students. The students believed that certainty comes with experience even when there is a lack of scientific evidence.