Lizarelli 2007.

Study characteristics
Methods	Study type: RCT (single‐blinded, split‐mouth design) Duration of trial: not mentioned Duration of follow‐up: 3 months
Participants	Setting: Sao Carlos Federal University, Brazil Inclusion criteria: male and female patients with cervical dentinal hypersensitivity Exclusion criteria: indication for or already performed endodontic treatment, extensive restorative treatment, decay, and severe periodontal disease Total number: 60 patients; 144 teeth Age range: not mentioned (older than 18) Sex (M/F): not mentioned
Interventions	Group 1: treated with light emitting diode laser Details: a twin laser used equipped with 2 handpieces, 1 emitting in infrared (780 nm) and 1 in the red (660 nm) band; the 660 nm handpiece with a power setting of 40 mW was chosen; laser beam spot diameter was 4 mm Group 2: treated with light emitting diode therapy Details: device emits at a spectral band of 630 nm, presenting a constant power of 230 mW. The spot size of 4 mm is equivalent to that of the low‐intensity laser system Both had same delivery tip, in order to focus the light beam from the laser source to the target tissue Group 3: placebo (no irradiation)
Outcomes	Using VAS at baseline, 15, 30, and 60 days after last application
Notes	Baseline characteristics: dentinal hypersensitivity was assessed by 2 to 3 s air blast stimulation; after the stimulus, the patient was asked to mark the intensity of pain on a VAS, which was marked on the left end 'no pain' and on the right end 'extreme pain' Sample size calculation: not mentioned in the study Source of funding: not mentioned in the study Ethics approval: not mentioned in the study Informed consent: quote: "Informed consent describing risk and benefits of the respective treatments was obtained from all subjects before participation in the study" Adverse events: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Use of placebos might reduce performance bias. It was impossible to blind personnel in this study design, but the outcome is not likely to be influenced by lack of blinding Comment: this study was described as a "single‐blind study" in the abstract. However, the details of blinding (study personnel as outcome assessor or patients) was not described in the study
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information provided Comment: this study was described as a "single‐blind study" in the abstract. However, the details of blinding (study personnel as outcome assessor or patients) was not described in the study
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient reporting of attrition/exclusions Incomplete outcome data was not mentioned in the study. However, we can appreciate that they had dropouts by comparing the number of teeth between table 1 and 2. It seems that participants who did not complete the follow‐up sessions were excluded from the study
Selective reporting (reporting bias)	Low risk	All intended outcomes were reported in the study. However, tables with number of teeth with improved or worsened hypersensitivity and only bar charts were reported as a result (Fisher's test was used). They cannot be entered in a meta‐analysis Quote: "A 95% confidence interval was used for all analysis"
Other bias	Low risk	No other sources of bias were identified Source of funding, ethics approval and sample size calculation were not described in the study