Clinical evaluation of low-level laser therapy and fluoride varnish for treating cervical dentinal hypersensitivity S. A. M. CORONA *, T. N. DO NASCIMENTO *, A. B. E. CATIRSE † , R. F. Z. LIZARELLI ‡ , W. DINELLI § & R. G. PALMA-DIBB * * Department of Restorative Dentistry, Ribeira ˜o Preto School of Dentistry, University of Sa ˜o Paulo, Ribeira ˜o Preto, Brazil, † Department of Dental Materials and Prosthesis, Ribeira˜o Preto School of Dentistry, University of Sa˜o Paulo, Ribeira˜o Preto, Brazil, ‡ Sa ˜o Carlos Physics Institute, University of Sa ˜o Paulo, Ribeira ˜o Preto, Brazil, § Department of Restorative Dentistry, Araraquara School of Dentistry, Sa ˜o Paulo State University (UNESP), Ribeira˜o Preto, Brazil SUMMARY The aim of this study was to evaluate in vivo the use of low-level galium–aluminium– arsenide (GaAlAs) (BDP 600) laser and sodium fluoride varnish (Duraphat Ò ) in the treatment of cervical dentine hypersensitivity. Twelve patients, with at least two sensitive teeth were selected. A total of 60 teeth were included in the trial. Prior to desensitizing treatment, dentine hypersensitivity was assessed by a thermal stimulus and patients’ response to the examination was considered to be a control. The GaAlAs laser (15 mW, 4 J/cm 2 ) was irradiated on contact mode and fluoride varnish was applied at cervical region. The efficiency of the treatments was assessed at three examination peri- ods: immediately after first application, 15 and 30 days after the first application. The degree of sensitivity was determined following predefined criteria. Data were submitted to analysis and no statistically significant difference was observed between fluoride varnish and laser. Considering the treatments separately, there was no significant dif- ference for the fluoride varnish at the three exam- ination periods, and for laser therapy, significant difference (P <0®05) was found solely between the values obtained before the treatment and 30 days after the first application. It may be concluded that both treatments may be effective in decreasing cervical dentinal hypersensitivity. Moreover, the low-level GaAlAs laser showed improved results for treating teeth with higher degree of sensitivity. KEYWORDS: low-level GaAlAs laser, fluoride varnish, cervical dentine hypersensitivity Introduction Dentinal hypersensitivity is characterized by short, sharp pain arising from exposed dentine in response to stimuli typically thermal, evaporative, tactile, osmo- tic or chemical and which cannot be ascribed to any other form of dental defect or pathology (Addy, 1990; Wichgers & Emert, 1996; Kimura et al., 2000). The protective enamel layer can be removed by attrition from occlusal wear, abfractions, parafunctional habits, abrasive tooth brushing or erosion from acidic diet. On the other hand, gingival recession, periodontal disease and also improper tooth brushing can expose root surfaces and hence the thin recovering cementum layer (with approximately 20–50 lm) is easily lost. In all these situations, the underlying sensitive dentinal tissue – containing numerous tubules with the odon- toblast processes – is exposed to oral environment and subjected to a great sort of external sources of irritation. Response to these stimuli can range from mild discom- fort to extreme pain (Wichgers & Emert, 1996). Several theories have been proposed to explain the mechanism of dentinal hypersensitivity (Pashley, 1990). According to Bra ¨ nnstro ¨ m’s Hydrodynamics Theory (Bra ¨ nnstro ¨ m, 1962), the most widely accepted, dentine hypersensitivity results when stimuli applied to dentine displace the fluid inside dentinal tubules inwardly or outwardly (Wichgers & Emert, 1996). Fluid movement ª 2003 Blackwell Publishing Ltd 1183 Journal of Oral Rehabilitation 2003 30; 1183–1189