Desarda 2014.

Study characteristics
Methods	Trial design: RCT – split‐mouth design Location: Tatyasaheb Kore Dental College and Research Centre, New Pargaon, Kolhapur, Maharashtra, India Setting: fumigated closed operatory Language: English Number of centres: 1 Study period: not mentioned Funding source: not mentioned Study protocol: not available
Participants	Age: 30 to 60 years Total number of participants: 80 Inclusion criteria: patients aged 30 to 60 years with chronic generalized periodontitis were selected based on International Workshop for Classification of Periodontal Diseases, 1999 (AAP 1999) Exclusion criteria: patients with severely debilitating systemic diseases, with pacemakers, with a history of respiratory diseases, a history of previous periodontal treatment for 1‐year period, or on any antibiotics for 6‐month period Number randomized: 80 Number evaluated: 80 (no missing participants)
Interventions	Comparison: HVE versus no HVE Intervention: Group name: group Y – presence of high‐volume evacuator Number of intervention groups: 1 Number randomized to intervention group: not clear ‐ n = 80 assumed Description of intervention: maxillary incisors and canines were selected as an area for scaling. A piezoelectric scaler (BONARTTM) was used. Scaling was performed in the presence of the high‐volume evacuator in the above‐mentioned area. Power and water flow settings of the scaler were kept the same throughout the procedure. The high‐volume evacuator tip used in this study was stainless steel with a diameter of 12 mm. Nutrient agar plates were exposed for 20 minutes in each group and incubated at 37 °C for 24 hours. Any co‐interventions: no (but saliva ejector was used in both groups) Comparator: Group name: group X ‐ absence of high‐volume evacuator Number of control groups: 1 Number randomized: not clear ‐ n = 80 assumed Description of intervention: maxillary incisors and canines were selected as an area for scaling. A piezoelectric scaler (BONARTTM) was used. Scaling was performed in the absence of the high‐volume evacuator in the above‐mentioned area. Power and water flow settings of the scaler were kept the same throughout the procedure.
Outcomes	Outcome name: reduction in contamination of aerosols (nutrient agar plates were used to check CFU in 2 areas – 20 inches from participant's mouth and 12 inches from participant's mouth) Outcome measurement: reduction in contamination of aerosols (difference in number of CFU) Effect estimate: mean + SD Key conclusions: "within the limitations of the present study, the results showed no difference in reduction of aerosols with or without the use of a high‐volume evacuator when analyzed microbiologically. Thus, it was concluded that high‐volume evacuator when used as a separate unit without any modification is not effective in reducing aerosol count and environmental contamination".
Notes	Study authors contacted for: allocation concealment, blinding of participants and personnel, study protocol and details of statistical tests (authors used Student's t test; for a split‐mouth study, paired t‐test should be used). E‐mail sent on 18 June 2020 but no response received. Scaling was carried out for 10 minutes in both groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Coin toss was used to determine which procedure was to be performed first (i.e. with high‐volume evacuator or without high‐volume evacuator)”
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinding is not possible. However, participants and personnel will not be able to alter their behaviour even if they know the received intervention.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The next day, the nutrient agar plates were examined for colony forming units by a single microbiologist who was unaware of the procedure performed."
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts
Selective reporting (reporting bias)	Unclear risk	We are not sure of reporting selective outcomes as there is no protocol available.
Other bias	Low risk	None