Sethi 2019.

Study characteristics
Methods	Trial design: RCT – 3‐arm parallel design Location: MGV's K.B.H. Dental College and Hospital, Mumbai, India Setting: closed operatory Language: English Number of centres: 1 Study period: not mentioned Funding source: none mentioned Study protocol: not available
Participants	Age: 18 to 55 years Total number of participants: 60 (20 per group) Inclusion criteria: participants having minimum of 20 permanent teeth participants diagnosed with moderate‐to‐severe gingivitis having a gingival index (GI) score of 2 to 3 systemically healthy patients participants indicated for full‐mouth scaling in single sitting Exclusion criteria: presence of any systemic disease received antibiotics or nonsteroidal anti‐inflammatory drugs in the past 9 to 11 weeks oral prophylaxis within the past 3 months pregnant and lactating mothers smokers Number randomized: 60 (20 per group) Method of randomization: computer‐generated random sequence table Method of allocation concealment: allocated into 3 groups by 1 examiner while the treatment was performed by another examiner. Method of blinding: not mentioned Number evaluated (withdrawals/missing participants): 60 (none)
Interventions	Comparison: chlorhexidine coolant versus distilled water or cinnamon extract coolant Intervention: Group name: Group I: chlorhexidine used as ultrasonic coolant (20 participants) Group II: cinnamon extract used as ultrasonic coolant (20 participants) Number of intervention groups: 2 Number randomized to intervention group: 20 per group Description of intervention: dental chairs with self‐contained water system were selected. The agents were added in the dental unit waterlines. Strict asepsis was observed. Participants were prepared to enter the operatory by wearing headcaps and autoclaved gowns. Participants were instructed to refrain from all actions that would generate aerosols e.g. conversation, sneezing, and coughing. Single‐sitting ultrasonic scaling was done for all patients for 20 minutes, using ultrasonic scaler. During each scaling procedure, saliva ejector was used. After the procedure, participants were asked about any discomfort noticed such as alteration in taste or burning sensation during debridement. Participants were asked to report to dental office if any adverse effects were experienced after treatment. Any co‐interventions: no Comparator: Group name: group III: distilled water used as ultrasonic coolant (20 participants). Number of control groups: 1 Number randomized to control group: 20 Description of control: same as above except that in the control group distilled water was used as the coolant.
Outcomes	Outcome name: reduction in contamination of aerosols (measured at distance of 1 foot from mouth to patient's chest, right side and left side) Outcome measurement: CFU Effect estimate: mean (SD) Key conclusions: no difference between the 2 intervention groups (chlorhexidine and cinnamon groups) but significant difference between both intervention groups and control (distilled water group) Within the limitations of this study, both cinnamon and chlorhexidine when used as an ultrasonic coolant effectively helped in the reduction of bacterial contamination in dental aerosols, which was seen by reduction in the CFU, after adding these agents in the DUWL.
Notes	Study authors were contacted for: allocation concealment and study protocol. E‐mail sent on 26 July 2020 and reply received on 27 July 2020. The protocol was not published anywhere and was only submitted to ethics committee. Allocation concealment was carried out by an independent investigator who took care of the groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random sequence was used
Allocation concealment (selection bias)	Low risk	Quote: “..allocated into 3 groups by one examiner while the treatment was performed by another examiner” Quote from the personal communication: "Regarding allocation concealment: One of the authors was appointed for this work. The operator and the patient were blind regarding the groups. Only the author responsible for the concealment would take care of the groups."
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	Unclear risk	It is not clear if the CFU were manually counted or any automated colony counters were used – there is subjectivity if manually counted.
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 published protocol available.
Other bias	Low risk	None