The Prevora coating works in two stages. First, Prevora Stage 1 delivers a very strong (10% w/v) concentration of chlorhexidine to the tooth surface which has been cleaned of any biofilm. Chlorhexidine bonds to the enamel28 and penetrates the tubules of the dentine at the root.29 An in vitro study found that Prevora's chlorhexidine is retained at levels bactericidal to S. mutans for at least 36 days30 while a similar human study found bactericidal concentrations for 2 to 3 days.31
While on the tooth surface, the chlorhexidine reduces the bacteria which are re-forming into biofilm, and is especially effective against cariogenic microorganisms. Chlorhexidine's method of action is the destruction of the bacterial cell wall (Figure 1).
Figure 1: A film of bacteria treated with chlorhexidine. The cell wall has ruptured.
Prevora is effective against the reformation of the biofilm for these reasons:
- It delivers a strong dose to penetrate the biofilm.
- It is deposited on a clean tooth surface after a prophylaxis. This facilitates strong chemical bonding of a high concentration of chlorhexidine, and thereafter a sustained release against the biofilm.
Prevora's second stage, called Prevora Sealant Stage 2, has two functions. First, this inert coating protects the chlorhexidine-enamel bonding process from salivary washings and food abrasion. Secondly, it minimizes tooth discoloration or staining, a common side effect from chlorhexidine. Tooth staining with chlorhexidine most likely results from a bonding of anionic dietary chromogens (e.g. tea, coffee) onto the chlorhexidine;32 Prevora's second stage serves to intervene in this staining process.
Further professional and technical information on Prevora is provided in the Prevora Guide for the Dental Professional, or available by mail by calling 1-800-463-2999.
Approved by Health Canada - Drug Identification Number 02046245
