ORIGINAL ARTICLE Is photobiomodulation (PBM) effective for the treatment of dentin hypersensitivity? A systematic review Alana Cristina Machado 1 & Ítallo Emídio Lira Viana 1 & Aloisio Melo Farias-Neto 1 & Mariana Minatel Braga 2 & Carlos de Paula Eduardo 3 & Patricia Moreira de Freitas 3 & Ana Cecilia Corrêa Aranha 3 Received: 5 June 2017 /Accepted: 28 November 2017 # Springer-Verlag London Ltd., part of Springer Nature 2017 Abstract The present study aims to evaluate the current scientific data regarding the effectiveness of photobiomodulation (PBM) in the treatment of dentin hypersensitivity (DH) as an alternative method for pain control. A systematic review was conducted to assess the effectiveness of PBM as treatment for DH. A complete literature search was performed up to October 2016. Searches were conducted using Boolean operators and MeSH terms. References of all selected full-text articles and related reviews were scanned. A total of 280 articles were identified (241 articles were excluded by the title and abstract). Of the 39 articles selected for analysis, 36 were excluded because they presented one or more exclusion criteria. Therefore, three articles were qualified for inclusion in this systematic review. PBM may not lead to adverse effects provided that adequately controlled parameters are followed when treating DH. More consistent studies should be conducted in order to adequately observe the advantageous therapeutic effect of PBM. Keywords Dentin . Hypersensitivity . Photobiomodulation . Systematic review Introduction Dentin hypersensitivity (DH) can be defined as short, sharp pain in response to stimuli, by exposed dentin with open den- tinal tubules. This pain that results from applying thermal, evaporative, tactile, osmotic, or chemical stimuli to this ex- posed surface cannot be ascribed to any other form of dental defect or pathology [1–3]. DH is a common problem among the population, being one of the main reasons for patients seeking dental treatment [3–6]. The combination of various factors such as inappropriate or poor oral hygiene, periodontal therapy, non-bacterial acid ex- posure, excessive occlusal force, or premature occlusion can induce loss of enamel leading to coronal or root dentin expo- sure with opened dentin tubules that induce DH [7]. The hydrodynamic theory of pain proposed by Brännström is the most acceptable theory to explain the mechanisms of DH. It explains that dentin exposure with subsequent opening of dentinal tubules allows the fluid flows to enter or leave the tubules, while the incidence of the abovementioned stimuli activates baroreceptors in the pulp, resulting in the generation of impulses and perception of sensorineural pain [8]. DH treatment can be conservatively managed by two strat- egies. The first is related to the use of agents to physically occlude the dentinal tubules, isolating the tubule contents from the oral environment and preventing the flow and move- ment of tubular fluid. This strategy goes directly to the more accepted theory of pain, the hydrodynamic theory. According to this theory, pain receptors are stimulated by the dentinal fluid movement. So, if the dentinal fluid stops due to a phys- ical occluding agent, such as high-power lasers, desensitizers based on glutaraldehyde, oxalates, strontium, varnishes, and bonding systems, no stimulation of pain receptor will occur and pain sensation is hindered. The second strategy is the use * Ana Cecilia Corrêa Aranha acca@usp.br 1 Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil 2 Department of Pediatric Dentistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil 3 Special Laboratory of Lasers in Dentistry (LELO), Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil Lasers in Medical Science https://doi.org/10.1007/s10103-017-2403-7