PennWell Dental Community
I’m sure you have heard the claim from some instrument manufactures that they now can produce scalers and curettes that never need sharpening. When you take a moment to think about this is it possibly true? I tend to doubt it. Come on, a blade that never gets dull? Where is the research that supports this outlandish claim? I haven’t seen it but I have seen research that reports the opposite.
A study by independent professional engineers concluded that a standard stainless steel curette has better edge retention than the advertised never need to be sharpened curettes. This claim is based on the results of two methods used to evaluate metallurgical qualities of edge retention:
• HARDNESS: The Rockwell “C” hardness level of a regular stainless steel curette was identical to that of a curette claimed to never need sharpening.
• MICROSTRUCTURE: A consistent microstructure of the steel being used will provide more uniformity throughout the instrument. A 1000X magnification shows that the steel used in standard stainless steel curettes has a more uniform distribution and size of carbides than the steel used in the never need to be sharpened curettes.
A chemical analysis of the different stainless steels showed that the composition of standard stainless steel curettes and the steel used in the never need to be sharpened curettes to be virtually identical.
I have also learned that the process used in treating the “never need to sharpen” curettes requires very high heat. This heat is capable of damaging the structure of the steel actually making it softer.
I am not a metallurgical engineer. I am only reporting what I have learned. My advice to you is simple. When someone on the lecture circuit states that they use curettes that never need sharpening ask them to show you the research to support it!