Aim: The aim was focused on compiling a comprehensive
overview of the extrinsic tooth bleaching and its mechanisms
including in vitro and in vivo measurement methods and analyzing
factors affecting the efficacy of the bleaching process
on restorative materials and tooth structures.
Background: The importance of tooth bleaching for patients
has notably gained importance and been accompanied by a
dramatic increase in the number of relevant products and procedures
over the past two decades, with a concomitant rise
in publications on this topic. Literatures have put forth that the
mechanisms of tooth bleaching by peroxide agents occur by
the diffusion of peroxide through the enamel to cause oxidation,
and hence, lightening of colored species, particularly, within
the dentinal regions.
Results: An electronic search was conducted across Ovid
Medline, complemented by a manual search across individual
databases, such as Cochrane, Web of Science databases, and
Google Scholar for the purpose of literature analysis on the
mentioned topic. The studies were reviewed and compared.
This article summarizes the current scientific and clinical opinions
through a brief review with regards to the preferred way
of bleaching and its impact on restorative materials. There are
controversies in terms of performing tooth bleaching. Regarding
extrinsic tooth bleaching, certain literature have pointed out
that the in-office method is being followed by a high number of
dental practitioners, whereas it should be practiced based on
selection of the right cases.
Conclusion: Based on previous findings, it is concluded that
at-home bleaching technique appears to be the safest technique
currently available, which is rapid, easy, and cheap. However,
the correct selection of the cases is mandatory. The in-office
method provides good outcomes, while it may be insufficient for
correcting extreme discoloration. It should be considered that
time and concentration are two crucial parameters that have
a great influence on the successful bleaching process. These
techniques are not entirely free from hazards, and therefore,
using these agents under appropriate supervision and consultation
with dental professionals is highly essential.
Clinical significance: In-office tooth bleaching is a great
method for providing rapid tooth bleaching, while it is not as safe as the home bleaching method. With the presented data
over the past two decades, at-home bleaching has also become
an accepted and integrated procedure. However, long-term
health risks are also associated with professional at-home tooth
bleaching using 10% carbamide peroxide (CP) gels, which is
equivalent to 3.5% H2O2. Hence, it is recommended that the
latter method should be mindfully approached when preferring
long-term bleaching processes.