Does visual acuity influence operative skills?

Objectives: The aim of this intervention study was to test if the visual acuity has in impact on operative skills with a dental bur. Methods: Twenty-nine undergraduate students with half a year of phantom head training underwent a classical optical test at an optician. In the first run, the students were instructed to prepare two different geometrical forms on acrylic blocks (A-PTS, Frasaco, Germany) mounted in phantom heads. In a second run two weeks later the students repeated the same task but were provided with dental Galilean loupes (EyeMag, Zeiss; 2.5X magnification) that were individually adjusted. Quality parameters included a) operative accuracy (Neuhaus et al. 2010), b) simple following of a line with a rotating diamond bur, c) preparation depth, and d) preparation angles of a 3D-cavity. Students with an observed natural visus <1 were defined as bad viewers (Eichenberger et al. 2011) Results: The use of dental loupes significantly enhanced the operative accuracy and preciseness of drilling. According to the optical test, two students were classified as bad viewers. A significantly lower accuracy was found in the group of bad viewers. Over-preparation in particular was significantly enhanced in this group. After application of the dental loupes to all students, no difference could be detected between bad and good viewers with respect to operative accuracy. As to preparation depth and preparation angles, the differences that were detected between good and bad viewers or between first and second run showed clear tendencies towards better preparation with better vision, but failed statistical significance. Conclusion: Dental loupes can be recommended to all dental students and particularly benefit students with a bad natural vision. However, accuracy of more complex cavity preparation tasks seem to be dependent on more skills and on individual training than on vision alone.