Effect of Er,Cr:YSGG laser on biofilm adhered on zirconia surfaces

Abstract

Objectives: To determine the adhesion of bacteria on zirconia with different surface treatments and to determine the effect of Er,Cr:YSGG laser on bacteria adhered on zirconia with different surface treatments. Methods: Zirconia blocks were cut into discs which were subsequently polished, sonicated and sintered. The sintered discs were randomly divided into three groups (M: machined surfaces, A: acid-etched surfaces and S: sandblasted surfaces) and colonized by Streptococcus sanguinis and Fusobacterium nucleatum reference strains for 7 days. Discs were then irradiated with Er,Cr:YSGG laser. CFU of the bacterial cells were quantified before and after laser therapy. SEM analysis was performed. Data were analyzed with one-way ANOVA or Kruskal-Wallis test while Bonferroni or Mann-Whitney multiple comparison were performed for post hoc analysis. Differences were considered significant if P<0.05.

Results: Significant differences in CFU of both bacteria were found among 3 groups (p<0.001) after culture with CFU of Group S significantly higher than Group M and A. No significant difference was found among the groups for CFU reduction fraction in both bacteria after laser treatment (p>0.05).

Conclusions: Increasing the surface roughness of zirconia discs by sandblasting and acid-etching has significant effects on adhesion of F. nucleatum and S. sanguinis. YSGG laser is effective in removing both bacteria irrespective the type of surface treated zirconia.