EFFECT OF HANDEDNESS ON LEARNING SUBGINGIVAL SCALING WITH CURETTES: A STUDY ON MANIKINS

The aim of the present study was to evaluate the influence of systematic manikin-head training and the effectiveness of subgingival scaling applied with hand instruments (curettes) by right- and lefthanded dental students on dental chairs (traditional) designed for right handers. A questionnaire focusing on handedness was administered to 69 voluntary dental students in the third class at the School of Dentistry during preparticipation examination. Handedness was assessed using the Turkish version of the Edinburgh Handedness Inventory. Then, 18 dental students- were specially selected in 2 equal groups according to hand preference: consistent right handers with Geschwind Scores of +100 (5 female- and 4 male) and consistent left handers with Geschwind Scores of –100 (5 female and 4 male). These two untrained dental student groups received 10 weeks manikin head training. Subgingival scaling was performed with hand instruments (Gracey curettes) in manikin head mounted on right sided dental chairs. At 6 test days each dental student had to instrument 12 test teeth. Effectiveness of subgingival scaling was evaluated- by adoption of a grading system. This system had scores from 0 to 3 and was defined by illustrated and described criteria. Statistical analysis- was carried out with SPSS. Two groups were statistically compared on all test days. The yet untrained left handed dental students begin with a relatively high the mean score of 2.25, compared to the yet trained righthanded dental students with 1.93, which was statistically signi-ficant- (p > .05). The right handed dental students reached the mean score of 0.53, whereas the left anded dental students reached the mean score of 0.87 on test day 6. Significant differences in the mean scores were found between the two groups for overall surfaces (p < .05), the distal surfaces (p < .01), lingual surfaces (p < .01), and each group of teeth (p < .05). But there was no statistically significant difference between the 2 groups of students on all test day except for test day 3 in terms of the mean scores for the facial and mesial surfaces (p > .05). Learning success was observed a high level in both groups through -systematical training (p