Worrall 1987.

Methods	Trial design: CCT Location: Periodontal clinic, Birmingham Dental Hospital, UK Setting: dental operatory Language: English Number of centres: 1 Study period: not mentioned Funding source: not mentioned Study protocol: not available
Participants	Age: not mentioned Sex: not mentioned Total number of participants: not reported Inclusion criteria: patients who require stain removal Exclusion criteria: not mentioned Method of blinding: not mentioned Number evaluated (withdrawals/missing participants): not reported
Interventions	Comparison: Group 1: negative control (air polishing on a sterile stainless steel bowl) Group 2: positive control (air polishing on patient's teeth using conventional saliva ejector) Group 3: preoperative CHX mouthrinse Group 4: high‐volume aspiration with wide‐bore tip Number of intervention groups: 2 Intervention: Group name: high‐volume aspiration with wide‐bore tip Description of intervention: patients' teeth were air‐polished using Prophy Jet and a dental surgery assistant was holding the high‐volume aspiration apparatus Any co‐interventions: no Comparator: Group name: air polishing on a sterile stainless steel bowl Group name: air polishing on patient's teeth using conventional saliva ejector Number of control groups: 2
Outcomes	Outcome name: reduction in level of contamination in aerosols Outcome measurement: CFU (using blood agar plates), aerobic culture were done. Culture plates placed at 1, 2 and 3 metres from the headrest of the chair. Culture was done 10 minutes before the procedure (resting), during the procedure and 20 minutes after the procedure. Effect estimate: mean (SE) Key conclusions: high‐volume aspirator is very effective in reducing airborne contamination produced during air‐polishing. If this is not available, 0.2% CHX pre‐rinsing is recommended prior to air‐polishing.
Notes	Number of participants not reported