Merits of Soft Nitriding Scalers

Background: It has been demonstrated that nitriding modifies the physical characteristics of metals. The purpose of this study was to evaluate the changes induced by 3 levels of inexpensive soft nitriding treatments on commercial sickle scalers. Methods: Taglite scalers (NT) were soft nitrided for 30 (SN30), 60 (SN60), or 90 (SN90) minutes. The cumulated scaled material was weighed every 10 strokes × 10 and thereafter every 1,000 to 8,000 strokes by an automatic scaling apparatus against epoxy resin. Weight differences were used to indicate abrasion resistance; the relative efficiency (RE) was calculated as the ratio of scaled amount at a given number of strokes (SN/NT). The hardness and the tensile strengths were determined for each soft nitriding treatment level. The nitrided layer thickness of representative SN scalers was observed by electron probe x-ray microanalysis. Results: The SN60 was not significantly different from SN30 or SN90, but the SN90 was more efficient than SN30 for the first 100 strok...