Preclinical operative dentistry performance and association with introduction of caries

Objectives: After achieving competency in a preclinical operative dentistry course individual differences in students' didactic and manual dexterity performance are observed. The purpose of this study was to examine how these differences translate to their performance when working on non-ideal cavity preparations. Materials and Methods: Thirty-nine first year dental students enrolled in a preclinical Operative Dentistry course were trained in the principals of operative dentistry, practicing ideal cavity preparations and restorations. Two final course assignments were introduced just prior the final practical examination; cavity preparations of #19MO and #30DO using identical caries simulated teeth (Columbia Dentoform). Students were provided with detailed written procedure instructions and pictures. Two calibrated masked instructors evaluated deviations from “gold standard” on ten preparation criteria using calibrated instruments. A composite deviation score was calculated and compared with student course performance. Results: Marked differences were noted among students' deviations from ideal preparation dimensions: occlusal isthmus buccal-lingual (B-L) width (ranged up to 2.5mm), occlusal caries excavation (ranged up to 2.5mm), proximal B-L extension (ranged up to 3.5 mm) and axial caries excavation (ranged up to 4.0 mm). Deviations from ideal, noted in preparations of #19MO as well as #30DO, included both over- and under-extension. Associations were noted between the total deviations and some complex practical examination preparations. Further, students in the top tertile of deviation from ideal scored lower in seven of eight practical examinations but not written examinations. Conclusion: Marked differences were found in student clinical judgment and performance on caries simulated teeth despite satisfactory course performance in preclinical operative dentistry. These results provide evidence that preclinical course performance is related to a simulated clinical environment. The role of caries simulated teeth in preclinical operative dentistry curriculum is warranted to practice students' clinical judgment and help to prevent unnecessary clinical challenges.