Effect of Instruction on Light Curing Effectiveness

Objectives: This study measured how much light dental students delivered to the same Class I preparation before training, after training, and again 4 months later.

Methods: At the end of their first year preclinical Cariology course, 38 dental students were tested using the MARC-Patient Simulator (BlueLight, Halifax). The MARC-Patient Simulator is a dental mannequin head with a laboratory grade light detector located 4-mm from the cusp tip of tooth #2.7. This laboratory grade detector measured the light delivered by each student to the Class I preparation in tooth #2.7. The same LED curing light (SmartLite iQ2) was used for 10 seconds. The irradiance received was recorded in real-time and the energy (J/cm²) delivered by each student calculated. The students were then given a lecture and instructions on how to optimize their light curing technique. The experiment was then repeated. The students were retested four months later after they had just completed another preclinical course on posterior composites.

Results: Initially the students delivered between 0.1 to 7.2 J/cm² of energy (meanąSD=4.0ą1.7 J/cm²). After additional teaching using MARC-PS, the same students delivered between 5.8 to 7.5 J/cm² of energy (meanąSD=6.7ą0.4 J/cm²).  Four months later the same students delivered between 5.0 to 7.9 J/cm² of energy (meanąSD=6.1ą1.1 J/cm²) to the same tooth using the same light. ANOVA and Fischer's PLSD tests showed that instruction using MARC made a significant improvement in the energy delivered by the students. The students were better when retested four months later compared to their initial results (p<0.01).

Conclusions: Using MARC-PS was a useful means to demonstrate to students how to use a curing light. Students retained the knowledge for at least four months, but there was a significant reduction in the average energy delivered compared to when they were tested immediately after instruction using MARC.

This study was supported by Dalhousie University.