IADR Abstract Archives
Effects of Instrumentation on In vitro Periodontitis Biofilm
Objectives: Current treatment for periodontitis focuses on local disruption of oral biofilm using hand or ultrasonic instruments. Disease recurrence is common following treatment and understanding mechanisms of instruments currently used may reveal novel approaches for maintaining oral health throughout life. We sought to identify the effects of hand or ultrasonic instruments on in vitro biofilms.
Methods: We have previously developed a 10-species in vitro periodontitis biofilm model comprising common organisms associated with health (streptococci sp.) and disease (P. gingivalis). Model biofilms were grown on discs which were treated with either a hand or ultrasonic scaler. We then investigated bacterial viability in the supernatant remaining biomass and regrowth in the well, using crystal violet dye, resazurin dye, and Miles Misra colony quantification.
Results: Immediately following treatment, we observed significant reductions in biofilm biomass and supernatant with each instrument (p<0.001 for each, compared with untreated control). We observed that this effect was significantly greater following ultrasonic vs. hand scaling (p<0.001). Additionally, we observed that the removed biofilm (supernatant) was viable following treatment with either instrument although more was removed following ultrasonic than hand-scaling for both anaerobic and aerobic organisms (p<0.001 for both). Furthermore, both biofilms, and removed supernatants, were able to re-grow within a 48-hour period.
Conclusions: Whilst current dental scalers sufficiently disrupt and remove biofilms from a static surface, biofilms and supernatants remain viable and capable of re-growth. Together these data imply that adjuncts targeting dispersed organisms may be useful additions to current therapy.
Methods: We have previously developed a 10-species in vitro periodontitis biofilm model comprising common organisms associated with health (streptococci sp.) and disease (P. gingivalis). Model biofilms were grown on discs which were treated with either a hand or ultrasonic scaler. We then investigated bacterial viability in the supernatant remaining biomass and regrowth in the well, using crystal violet dye, resazurin dye, and Miles Misra colony quantification.
Results: Immediately following treatment, we observed significant reductions in biofilm biomass and supernatant with each instrument (p<0.001 for each, compared with untreated control). We observed that this effect was significantly greater following ultrasonic vs. hand scaling (p<0.001). Additionally, we observed that the removed biofilm (supernatant) was viable following treatment with either instrument although more was removed following ultrasonic than hand-scaling for both anaerobic and aerobic organisms (p<0.001 for both). Furthermore, both biofilms, and removed supernatants, were able to re-grow within a 48-hour period.
Conclusions: Whilst current dental scalers sufficiently disrupt and remove biofilms from a static surface, biofilms and supernatants remain viable and capable of re-growth. Together these data imply that adjuncts targeting dispersed organisms may be useful additions to current therapy.