Naghsh 2020.

Study characteristics
Methods	Study type: RCT (double‐blinded, 3 groups) Duration of trial: not mentioned in the study Duration of follow‐up: 2 months
Participants	Setting: Faculty of Dentistry, Isfahan University of Medical Sciences, Iran Inclusion criteria: patients who had cervical dentine hypersensitivity in at least 3 teeth in 3 separate quadrants. The selected teeth were free of calculus and plaque and if necessary, the subjects underwent a scaling procedure before the study Exclusion criteria: patients with teeth showing evidence of irreversible pulpitis or necrosis, carious lesions, crown fractures, cracks, caries or restorations, facets of attrition, premature contact, active periodontal disease, use of analgesics during the 72‐hour period before laser application and individuals who had used anti‐sensitivity toothpaste during the previous 3‐month period. Pregnant women and smokers were excluded from the study Total number: 7 patients with 96 teeth enrolled and completed Age range: 25 to 45 years Sex (M/F): 3/4
Interventions	Sensitive teeth of 7 patients were divided into 3 groups with a randomized matching method Group 1: 660 nm diode laser beams were applied to the hypersensitive teeth. The power of 30 mW, in contact with and perpendicular to the surface, continuous irradiation for 120 s with a forward and backward (sweeping) movement Group 2: 810 nm diode laser beams were applied. The power of 100 mW, in contact with and perpendicular to the surface, continuous irradiation for 120 s with a forward and backward (sweeping) movement Group 3: not laser‐irradiated and were only exposed to index radiation (control group). Treatment was rendered in 4 sessions with a 1‐week interval in a similar manner in all the 4 sessions
Outcomes	Responses to applying dry ice sprayed on a small cotton pallet over the tooth surface recorded sing the VAS index (0 to 10). The VAS was evaluated before treatment and immediately after laser irradiation at the first, second, third, and fourth sessions (immediately after it and at 1‐week, 30‐day, and 60‐day postoperative intervals)
Notes	Baseline characteristics: to register the severity of pain in the affected teeth the VAS was used. An attempt was made to carry out random assignment (randomized allocation) based on the baseline VAS scores of the teeth after they were recorded Sample size calculation: not mentioned in the study Source of funding: none. Quote: "The authors declare no conflict of interest" Ethics approval: quote: "The present randomized clinical trial was approved by the Isfahan University Ethics Committee under the code 396228 and registered on the Iranian Registry of Clinical Trials website (identifier: IRCT2017062022699N4; https://www.irct.ir/)" Informed consent: quote: "All the subjects signed informed consent forms in order to be included in the study" Adverse events: not mentioned in the study
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided Quote: "An attempt was made to carry out random assignment (randomized allocation based on the baseline VAS scores of the teeth after they were recorded"
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided Quote: "An attempt was made to carry out random assignment (randomized allocation based on the baseline VAS scores of the teeth after they were recorded"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "The teeth in the control group were not laser‐irradiated and for the purpose of blinding, they were only exposed to index radiation"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information provided Comment: although the authors stated that this is a double‐blinded study, the method of blinding the examiner was not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information provided
Selective reporting (reporting bias)	Low risk	All intended outcomes were reported in the study
Other bias	Low risk	No other sources of bias were identified