A Meta-analysis between in-vivo and in-vitro tooth whitening outcomes

Objective:

To assess if tooth whitening with and without LED acceleration performed in vitro using bovine and human teeth are consistent with outcomes of an in vivo human clinical trial.

Methods:

Forty extracted human and 40 extracted, stained, bovine teeth were randomly allocated to in vitro application of Philips Zoom WhiteSpeed (PZW), 25% Hydrogen Peroxide (HP), with and without LED acceleration.  Color change was assessed using L*a*b* immediately following 3x15 minute treatment applications. The results were compared with the results of an IRB-approved clinical trial that evaluated 136 subjects who were randomized to either PZW with 25% HP or Ultradent Opalescence Boost PF (OBF) with 40% HP and no LED acceleration.  Efficacy was assessed using L*a*b* immediately post-bleaching, and at Day 7. Analysis of variance was used to assess overall color change from baseline (DE) and treatment group (i.e. light and no-light) and teeth source (i.e. extracted bovine teeth, human in vivo and extracted human teeth) was treated as a fixed effect. Least squares means and 95% CIs for each treatment were evaluated.

Results:

LS mean DE values and 95% CI are shown in the figure.

Conclusions:

In vitro experiments using extracted human teeth are consistent with the results observed in an in vivo human trial. Testing with artificially stained bovine teeth tends to over-estimate the magnitude of the effect of whitening treatment. The use of LED irradiation significantly enhances the whitening effect in either the in vitro or in vivo condition.