Decontamination procedures for tungsten carbide debonding burs: a cross-sectional survey of hospital-based orthodontic departments.

OBJECTIVE: To determine the current pattern of use and handling of tungsten carbide debonding burs (TCDBs) within UK hospital-based orthodontic departments. DESIGN: Cross-sectional survey. SUBJECTS AND METHODS: Questionnaires were sent to 217 departments within the UK and an overall response rate of 93% was achieved. RESULTS: Most hospital departments (68%) currently use TCDBs designed for a slow handpiece. Just over half (55%) discard their TCDBs after single-use, but only 24% adequately decontaminate new burs prior to initial use. Almost all those that reuse TCDBs decontaminate them in a sterilizer and carry out combinatorial presterilization cleaning. The most common methods are manual cleaning followed by an ultrasonic bath (26%) or washer-disinfector (15%); or alternatively, soaking of burs followed by manual cleaning (13%). For those departments that use only a single method, manual cleaning (29%) or a washer-disinfector (10%) are most common. In terms of sterilizing TCDBs, 58% used a vacuum phase autoclave and 13% a downward displacement. CONCLUSIONS: There is wide variation in the handling of TCDBs in UK hospital-based orthodontic departments. Decontamination of new TCDBs prior to initial use is carried out by less than a third of departments. Despite their classification as reusable devices, just over half discard TCDBs after single use. However, among those that do reuse TCDBs, almost all decontaminate them correctly.

Decontamination of viable Streptococcus mutans from orthodontic tungsten carbide debonding burs. An in vitro microbiological study.

OBJECTIVES: To investigate the effectiveness of currently recommended decontamination procedures on tungsten carbide debonding burs (TCDBs). DESIGN: In vitro microbiological study. SETTING: St George's Hospital NHS Trust, UK. MATERIALS AND METHODS: A total of 240 extracted tooth surfaces were bonded with orthodontic brackets, debonded to leave residual composite and artificially contaminated with Streptococcus mutans. INTERVENTION: Sterilized TCDBs in a slow handpiece were used to remove this composite before random allocation into one of six different decontamination groups of 40 burs each. These included a control group that was not decontaminated and a further five that underwent different methods of presterilization cleaning within the decontamination process (none, manual, ultrasonic, washer disinfector and enzyme soak) followed by sterilization in a vacuum phase autoclave at 134 degrees C for 3 min. MAIN OUTCOME MEASURES: The burs were placed in brain heart infusion (BHI) broths, incubated for 48 h. Following this the broths were inspected for turbidity and microbiological analysis was carried out to detect viable bacterial growth. Data were analysed using the Kruskal-Wallis test for single ordered data. RESULTS: S. mutans was recovered from 39 out of 40 burs in the control group and no burs from the decontamination groups, which was statistically significant (P = 0.001). No differences were found between decontamination groups (P = 0.271). However, skin flora contamination was noted in 17 broths. CONCLUSIONS: The five methods of decontaminating TCDBs investigated in this study were effective in removing viable S. mutans. Other investigations are required to determine if TCDBs can be successfully cleaned of blood and protein residue prior reuse.