The purpose of the pilot study was to investigate whether an interactive online module improved third-year dental students' radiographic caries diagnosis abilities and conceptual understanding. Third year dental students were given online tutoring modules and assessed afterward to determine whether their diagnostic skills improved, whether they perceived and improvement in their diagnostic skills, and whether following the modules with interactive group discussions was a more effective teaching method. The choice to use the module was left to each individual. Thirty-one students completed an assessment consisting of three full-mouth series (FMX) radiographs of varying number and severity of carious lesions first individually and then in teams. Performance was evaluated quantitatively and qualitatively. A T-test analysis revealed that the students who accessed the module did not perform significantly better than students who did not access the module; however, a ?[superscript 2]-test showed that students who accessed the module correctly diagnosed yet over- and under-diagnosed more frequently. Survey responses showed that students believed the module helped clarify lecture topics. The online radiographic caries diagnosis module has introduced a promising and beneficial adjunctive resource for dental students.