Placebo-Controlled Trial Evaluating Immediate Efficacy of 1.5% Oxalate Strips

Objectives: A randomized placebo-controlled trial was conducted to evaluate the initial effects of a 1.5% oxalate strip on dentinal hypersensitivity.
Methods: IRB approval and informed consent were obtained, baseline measurements were collected, and 45 adults were randomly assigned to one of two strip groups: 1.5% oxalate gel (Crest® Sensi-Stop™ Strips, The Procter & Gamble Co.) or vehicle. Each 10X30 mm flexible plastic strip was carried on a plastic release liner, and individually packaged within a foil pouch. Strips were identical except for the presence or absence of oxalate-containing gel (59 mg) on the experimental or vehicle strips, respectively, and each strip was labeled blind to treatment. Subjects were instructed to apply the assigned strip to the sensitive tooth/gingiva for 10 minutes, after which, the strip was discarded. Sensitivity was measured before and after treatment following stimulation with a single drop of refrigerated (~2^oC) water. Efficacy was assessed by each subject before and immediately after treatment using a 100-point pain-ranking scale (VAS) on a tablet-based application, while safety was assessed from clinical examinations by a trained examiner, always blind to treatment. Between-group comparisons used an ANCOVA logit transformation with a baseline VAS covariate.
Results: The predominantly female (87%) population ranged from 29-60 years of age. Subjects exhibited considerable variation in pain, with baseline VAS ranging from 15.5 to 97.0 (mild-to-very severe pain), and an overall VAS mean (SD) of 65.9 (18.2). Relative to baseline, the 1.5% oxalate strip group had a highly significant (p<0.001) immediate reduction in VAS (32%). Between-group comparisons showed significant (p<0.05) differences between strips, favoring the experimental strip over vehicle control. Both treatments were well-tolerated.
Conclusions: A randomized, placebo-controlled clinical trial in an inclusive sensitivity population demonstrated a causal immediate reduction in dentinal hypersensitivity with a 1.5% oxalate strip.