Available evidence does not support use of oxalates for dentine hypersensitivity

Medline, CENTRAL, LILACS, TRIP Database, National Guideline Clearinghouse, OPENSigle and a number of other medical / dental databases and websites, as well as reference lists.

Randomised controlled trials and controlled clinical trials in any language that compared oxalates with placebo or no treatment were eligible for inclusion.

Three reviewers extracted data with two people assessing quality independently using the Cochrane risk of bias domains. Standardized mean differences (SMD) were estimated by random-effects meta-analysis and heterogeneity between studies was quantified with the I2-statistic.

12 reports were included. Interventions were diverse and included: monohydrogen-monopotassium oxalate, ferric oxalate, di-potassium oxalate, or oxalate containing pre-polymerized resin, and combinations of monohydrogen-monopotassium and di-potassium oxalate. Follow up intervals varied between immediate to 1 year. Hypersensitivity was elicited by tactile, evaporative or thermal stimuli, and a number of outcomes used to measure pain. Risk of bias was high in a number of studies and statistical heterogeneity high. Based on 187 and 179 units (patients or teeth) in the intervention and placebo groups from seven studies, the summary SMD for 3% monohydrogen-monopotassium oxalate was -0.71 (95% Confidence Interval (CI):-1.48, 0.06), which suggests it may not be beneficial. There was no improvement with the other interventions.

The review identified no evidence to indicate benefit from treating dentine hypersensitivity with oxalates beyond a placebo effect.