Gerschman 1994.

Study characteristics
Methods	Study type: RCT (2 parallel groups) Duration of trial: not mentioned in the study Duration of follow‐up: 8 weeks
Participants	Setting: Oro‐Facial Pain Clinic, University of Melbourne, Australia Inclusion criteria: age 15 to 69 years; even distribution of males and females; mobility of teeth < 1; VAS ≥ 3 Exclusion criteria: active periodontal disease; periodontal surgery within the last 6 months; teeth with carious lesions; large restorations; pulpitis and cracked enamel; chronic, debilitating disease or chronic disease with daily episodes of pain, for example, arthritis; daily doses of medication, for example, analgesics, anticonvulsants, antihistamines, sedatives, tranquillizers, mood‐altering drugs, or anti‐inflammatory drugs; participation in a desensitizing dentifrice study within the last 3 months Total number: 71 participants enrolled and completed Age range: 15 to 69 years (mean age: 37.5 years) Sex (M/F): not mentioned in the study
Interventions	Participants were randomly divided into 2 groups Group 1: placebo group (28 participants enrolled and completed). Details not mentioned in the study Group 2: GaAlAs laser (active group). Details: (1) GaA1As (P‐laser, RHR Marketing Services Ltd, Bentlcigh, Victoria) was used for active treatment. An identical, unpowered placebo laser was also used. The P‐laser system has a power output of 30 mW; and a red aiming beam, with a power output of approximately 0.1 mW. (2) The laser source has a GaAlAs‐diode and a wavelength of 830 nm. (3) The stated power of 30 mW (± 10%) is the precise measure of energy emitted. The diode specification is 50 mW. A linear scale power meter with LCD read‐out designed to measure only light sources at a wavelength of 830 nm was employed. (4) LLLT was applied for 1 minute to both the apex and cervical area of the tooth. Calculation for total irradiance was based on mean power (watts) per time (seconds), for example, 30 mW for 60 s = 1.8 J. The power meter was used to calibrate the laser before each use. LLLT was reapplied at 1 week, 2‐week, and 8‐week intervals and dentinal hypersensitivity was rated on the VAS at the conclusion of each visit Subgroup 2a: tactile sensitivity group (22 participants enrolled and completed) Subgroup 2b: thermal sensitivity group (21 participants enrolled and completed)
Outcomes	Responses to air blast stimuli and tactile stimuli (VAS) at baseline, and 1 week, 2 weeks, 8 weeks after intervention
Notes	Baseline characteristics: 1. baseline hypersensitivity assessment included thermal sensitivity (response to a 1‐second air blast from a dental air unit syringe at a temperature of 18 to 21 ℃) and tactile sensitivity (response to passing a dental explorer over the labial cervical area); 2. the subjects rated their response on a continuous 100 mm VAS. Only 1 tooth per subject was tested. No specific tooth type (that is, incisor, premolar, molar) was selected. A VAS >= 3 was required for inclusion in the study; 3. care was taken so that 1 stimulus did not interfere with the succeeding stimuli, that is, tactile first then thermal. Subjects were instructed to brush their teeth with a non‐desensitizing dentifrice twice daily throughout the study 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: "subjects were drawn mainly from a private practice population and on referral by other dentists and were required to sign an informed consent form" Adverse events: 2 patients reported a temporary, reversible pain sensation in response to lasing
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Subjects experiencing thermal and tactile sensitivity were assigned randomly to an active or placebo group by means of a computer‐generated randomized code"
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Due to use of placebo laser, the study might be free of performance bias
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information provided
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No descriptions on loss to follow‐up
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 Sample size calculation, source of funding and ethics approval were not mentioned in the study