A study of blood contamination of Siqveland matrix bands

Abstract

AimsTo use a sensitive forensic test to measure blood contamination of used Siqveland matrix bands following routine cleaning and sterilisation procedures in general dental practice. Materials and methods Sixteen general dental practices in the West of Scotland participated. Details of instrument cleaning procedures were recorded for each practice. A total of 133 Siqveland matrix bands were recovered following cleaning and sterilisation and were examined for residual blood contamination by the Kastle-Meyer test, a wellrecognised forensic technique. Results Ultrasonic baths were used for the cleaning of 62 (47%) bands and retainers and the remainder (53%) were hand scrubbed prior to autoclaving. Overall, 21% of the matrix bands and 19% of the retainers gave a positive Kastle-Meyer test, indicative of residual blood contamination, following cleaning and sterilisation. In relation to cleaning method, 34% of hand-scrubbed bands and 32% of handscrubbed retainers were positive for residual blood by the Kastle-Meyer test compared with 6% and 3% respectively of ultrasonically cleaned bands and retainers (P < 0.001). Conclusions If Siqveland matrix bands are re-processed in the assembled state, then adequate pre-sterilisation cleaning cannot be achieved reliably. Ultrasonic baths are significantly more effective than hand cleaning for these items of equipment.

A study of visual and blood contamination on reprocessed endodontic files from general dental practice

“…Materials tested include calcium hydroxide, gutta percha, zincoxide eugenol cement, zinc polycarboxylate cement, zinc phosphate, composite resin materials, glass ionomer cements and amalgam. 11 The fact that 17 re-processed endodontic files tested positive for blood is a reminder that thorough cleaning of used instruments is essential if transmission of a wide range of pathogenic microorganisms is to be prevented.…”

“…9 This well known forensic science test for haemoglobin has been used in previous investigations of residual blood on dental surgery surfaces and equipment. 10,11 The sensitivity of the test allows detection of blood in dilutions of between 1:50,000 and 1:100,000.…”

Decontamination in primary care practice - a curate's egg, good in most parts

“…However, the need for more detailed practical guidance to dental personnel on implementation of the technical requirements implicit in high quality decontamination cannot be overstressed. 18,19 . Although guidance has been issued 20 recommending that the matrix bands must not be re-used there are a number of practitioners who continue to decontaminate and re-use assembled bands for treatment of multiple patients.…”

A national study of cross infection control: 'are we clean enough?'

“…22 The cleaning of surgical instruments is necessary to ensure effective disinfection and sterilisation. 23 Instruments can be handwashed or ultrasonic cleaners and washers can be used. Using automated washing methods rather than manual cleaning is considered to be more effi cient and less likely to cause inoculation injuries.…”