Dental instrument sterilization status in different packing systems

A thorough knowledge about the shelf life of various types of instrument packing is necessary in order to avoid unnecessary re-sterilization of dental instruments. The aim of this study was to evaluate the shelf life of five commonly used packing systems in routine dental practice. This experimental study was conducted with 1400 orthodontic wires. They were divided into five groups (n=280) in order to be packed by Steriperfect (St), TECNO-GAZ (TG), SOGEVA (SO), E-Line (E) and linen (L) brand materials. These packs were then stored in an active dental office environment after proper sterilization by autoclave. Forty packs of each group underwent culture test at 7 different time intervals of 0, 1, 2.5, 4.5, 7 and 9 months. Fisher’s exact test was used to compare group differences. Only 5 packs of L, 6 of St, 3 of TG, 1 of SO and 2 of E showed positive culture results at 0 month samples. Likewise positive culture results were reported for 2 of (L), 1 of (St), 2 of (TG), 3 of (SO) and 1 of (E) in the first month. No significant difference was detected among different packing materials. The findings of this study support the previous findings that contamination is more of event related, not time related; meaning that, sterile instrument packs remain sterile for at least 9 months unless the integrity of pack is violated.