The effectiveness of lasers to reduce dentinal hypersensitivity remains unclear

Studies were located in a wide spectrum of bibliographic databases including Medline, Science Direct, Cochrane Clinical Trials Register, Cochrane Reviews, ISI Web of Science, LILACS, and IADR. Manual hand searches supplemented the digital search. No language restrictions applied. Independent screening was performed by 2 reviewers before coming to a forced decision of inclusion or exclusion. Kappa statistics were used for measuring agreement. Corresponding authors were contacted for verification of study details if needed.

The review was limited to randomized controlled trials (RCTs) on adult patients with hypersensitive dentin comparing laser intervention versus using a placebo with a follow-up of more than 3 months.

A reference is made to a requirement of the included studies to have used an "assessment of hypersensitivity by scale" and the data reported with a mean and standard deviation. It is not entirely clear whether this should be interpreted as limited to use of VAS scales only, in contrast to categorical Likert-like scales or nominal descriptors. Regardless, the list of excluded studies in the original Table 3 does not include any studies that were excluded because of the lack of fulfilling this requirement.

Out of several thousand titles and abstracts, 63 full-text articles were examined, and 6 of these were identified as RCTs. Three of these reported on less than 3 months, leaving only 3 articles for data extraction. No metaanalyses were done on this limited and somewhat heterogeneous data material. The methodological quality was considered, leaving the authors to conclude that the estimated risk of bias was high for all 3 studies. An exception was one of the studies where the authors were contacted and apparently had produced an inadequate article, but otherwise allegedly had conducted an exemplary trial.

Laser treatment appears to reduce dentin hypersensitivity, but the evidence for this effectiveness is weak, and the placebo effect cannot be ruled out. No pulp damage or major adverse effects were reported in the 3 identified studies.