Short- and Long-Term Influence of Fluoride-Containing Prophylactics on the Growth of Streptococcus mutans on Titanium Surface

Acidic pH and high fluoride (F(-)) concentration impair the corrosion resistance of titanium (Ti). Caries-preventive products contain high amounts of F(-) and are applied at low pH. The purpose of this study was to evaluate whether fluoride applied in different forms has different short-, mid-, and long-term effects on the growth of the bacteria Streptococcus mutans.Ti discs with polished surface were treated with a rinse containing 0.025% olaflur, a gel containing 1.25% olaflur, or a 1% aqueous solution of NaF (pH 4.5), and they were incubated with S mutans for 21 days. Control discs did not get prophylactic treatment. Protein assay analysis was performed at regular intervals to estimate the amount of S mutans. Scanning electron microscopic (SEM) images were also taken.Bacterial protein quantity became significantly different only by the 21st day. Fluoride in rinse and gel proved to be superior to NaF in aqueous solution or no treatment (P < 0.01 and P < 0.05, respectively). However, the discs treated with fluoride in gel showed signs of corrosion in SEM images.The results suggest that the use of fluoride-containing mouthwashes might be the best and safest oral hygienic choice for patients with oral implants. Furthermore, olaflur seems to be superior to NaF for long-term use at low pH.