ISO 22570:2020 pdf download – Dentistry — Spoons and bone curettes.
5.2 Materials The material used for spoons and bone curettes is at the discretion of the manufacturer provided the requirements of this document are satisfied. If stainless steel is used, it shall be in accordance with ISO 7153-1 or ISO 21850-1. The material of the handle is at the manufacturer’s discretion providing it complies with 5.6. Test in accordance with 6.3. 5.3 Handle The shape of the handle for spoons and bone curettes is at the manufacturer’s discretion. 5.4 Working end The shape of the working end of a sharp spoon according to Hemmingway shall be oval. See Figure 1. The shape of the working end of a bone curette according to Lucas shall be pear-shaped. See Figure 2. The labial surface forms the cutting edge at the transition to the rounded back surface. The cutting edge shall extend at least up to the point of the greatest width (see cross-section A-A in Figure 1 and Figure 2). The working end shall have a hardness of 42 HRC to 58 HRC. Test in accordance with ISO 6508-1, Scale C. Alternatively, a Vickers hardness test in accordance with ISO 6507-1 can be performed. The measured values thus determined shall be converted into Rockwell values. NOTE ISO 18265:2013, Table 1 contains practical conversion values. 1 HRC is added to the value thus calculated (empirical values with stainless steel).
5.5? Surface? finish The surfaces of the spoons and bone curettes shall be free from defects and residues. The surface finish of the working ends and the shafts shall be polished. The degree of gloss is at the manufacturer’s discretion. For reasons of hygiene, a surface that facilitates reprocessing of spoons and bone curettes should be selected for the handle surface. Test in accordance with 6.1. 5.6 Resistance to reprocessing The spoons and bone curettes shall withstand 100 reprocessing cycles, as defined by the instructions for use accordance with ISO 17664, without deterioration in performance or signs of corrosion. If the manufacturer states a lower number of permitted reprocessing cycles, then this number shall be used in place of the 100 stated above. The reprocessing cycle shall include the recommended methods for cleaning, disinfection and sterilization. Test in accordance with 6.3. 6 Measurement and test methods 6.1 Visual inspection Carry out visual inspection with normal visual acuity and without magnification. 6.2 Dimensions Measure the dimensions using a measuring device that is accurate to 1/10 of the tolerance to be measured. EXAMPLE Suitable measuring devices are Vernier callipers and micrometres in accordance with ISO 3611.