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

Abstract

Objective This study examined methods used for reprocessing endodontic instruments in general dental practice and determined the degree of residual visual contamination and blood contamination on 250 reprocessed files collected from 25 general dental practices. Materials and methods A questionnaire was administered to 25 general dental practitioners to obtain information on the re-processing of used endodontic files. Ten files which had been used and reprocessed were also collected from each practice. These were examined visually under a dissecting light microscope for residual contamination and then tested for blood deposits using the Kastle-Meyer test. Results Nineteen of the 25 practices used stainless steel hand files. No practitioners used endodontic files as single use devices. Ninety-two per cent of the practitioners discarded and replaced files when they were bent or damaged. Several decontamination methods were reported. The two combinations employed most frequently were manual cleaning and autoclaving or manual cleaning, followed by ultrasonic cleaning and autoclaving. Of the 250 files, 75% showed some degree of visual contamination and seven percent tested positive for residual blood. Blood contaminated files were significantly more heavily contaminated when examined visually. Large variations were found in residual contamination of files collected from practices using the same methods of decontamination. Conclusions While all practitioners re-used endodontic files, the variations in decontamination methods reported indicate a lack of clarity on best practice. This study demonstrates that endodontic files are not reliably decontaminated by methods currently employed in dental practice.

Prion Disease: The Implications for Dentistry

“…Achieving reliable decontamination of endodontic files intended for reuse is difficult (101)(102)(103)(104)(105)(106)(107)(108)(109). Therefore, there is a possibility that these inadequately decontaminated dental instruments that have been in contact with dental pulp may transfer prion proteins from patients with subclinical, suspected, or confirmed cases of vCJD.…”

“…Some dental instruments are difficult to clean after contamination with blood or neurovascular tissue, and, even after routine decontamination and sterilization, they may carry significant residues of material (51,104). This is especially important for endodontic files (because they have intimate contact with terminal branches of the trigeminal nerve and are difficult to clean by virtue of their design) (101)(102)(103)(104)(105)(106)(107)(108)(109), matrix bands, retainers (because they frequently become contaminated with blood and other proteins) (101,116,117), and used dental burrs (because they too are difficult to decontaminate) (101,118). It should be noted that thus far, there has been only one study (119) that reported a successfully tested clinical cleaning protocol for rotary nickel-titanium endodontic files before sterilization, comprising 10 vigorous strokes in a scouring sponge soaked in 0.2% chlorhexidine solution, a 30-minute presoak in an enzymatic cleaning solution, 15 minutes of ultrasonication in the same solution, and a 20-second rinse in running tap water.…”

Endodontic instrument fracture: causes and prevention

“…70,71 Within other European jurisdictions no such regulation exists and the number of file uses is at the discretion of the operator. File manufacturers have recently advocated that files should be single use only and have introduced features into new files which distort when autoclaving, hence preventing reuse (WaveOne™, Dentsply Maillefer, Ballaigues, Switzerland) (Fig.…”

An investigation of the decontamination of Siqveland matrix bands

“…8,12,[18][19][20] The method used in these investigations involved sampling test items by wiping the point of a folded piece of fi lter paper over their surface; the Kastle-Meyer test was then done on the fi lter paper. This method, though capable of detecting a 1:6,400 dilution of horse or sheep blood, may fail to detect blood should a contaminated area not be sampled.…”