Implementing Deflection Loupes in Endodontic Training of General Dentistry Residents: Effects on Treatment Quality, Procedure Time and Ergonomics.

Objective: The objective of this study was to evaluate access cavity preparation quality, procedure time, and working posture of general dentistry residents using different types of magnification (naked eye, traditional loupe and deflection loupe).

Methods: This in vitro study used a randomised cross-over design. Thirty general dentistry residents performed access cavity preparations using naked eye, traditional loupe, and deflection loupe on plastic right maxillary first molars in manikins. The working posture was evaluated using the Posture Assessment Instrument (PAI). The access cavity preparation quality scores, procedure time, and PAI scores were compared between groups. Questionnaire results on residents' perceptions were also analysed.

Results: The access cavity preparation scores were higher for both loupe groups than the naked eye group. Procedure time was not different between groups. Both PAI_total and PAI_neck scores were statistically lower in the deflection loupe group and traditional loupe group than in the naked eye group. The deflection loupe group had lower PAI_neck scores than the traditional loupe group. Both traditional loupe and deflection loupe were rated positively in terms of precision, ergonomics, treatment quality, and adaptability. The deflection loupe was considered superior in ergonomics but less comfortable. Eye fatigue is a common problem for both types of loupes.

Conclusion: Both deflection loupe and traditional loupe can improve working posture and access cavity preparation quality. Deflection loupe had an ergonomic advantage over traditional loupe. The comfort of deflection loupe needed improvement because of its heavy weight. Another perceived problem of deflection loupe and traditional loupe was eye fatigue.