When dentists need to retrieve cement crowns, they can use a sliding hammer or an automatic tool, which is powered by compressed air. Researchers in Italy, however, recently compared the reliability, learnability, and efficiency of these options.
Skilled and unexperienced operators were both involved in the study, where an appositively designed setup allowed the measurement of the pattern of force versus time. Peak applied force was seen as an output variable for evaluating tool performance
The researchers found that the automatic tool improves inter-operator and intra-operator reliability respectively from 79% to 95% and from 69% to 92%. Also, the force pattern is significantly different between the two tools.
The automatic tool produces a sharper peak force, as required to break fragile materials such as dental crown cement, with efficiency estimated at 75% or higher. Both tools have high learnability since the performances of experienced and unexperienced operators are not significantly different.
The researchers further note that their experimental setup and respective testing protocol can be used to characterize any other instrument for crown retrieval, with the advantage of producing objective, numerical data.