Influence of bracket design on microbial and periodontal parameters in vivo

Aim: To compare undisturbed plaque formation on teeth bonded with different types of orthodontic brackets with non‐bonded control teeth, via a de novo plaque growth experiment over a 7‐day period. Material and methods: A randomized controlled trial with split‐mouth design was set up enroling 16 dental students. Within each subject sites with Speed®(S) and GAC®(G), brackets and control sites were followed. Clinical periodontal parameters were recorded at baseline, on days 3 and 7. Microbiological samples were taken from the brackets and the teeth on days 3 and 7. Results: Both anaerobe and aerobe colony‐forming units (CFU) were significantly higher in S‐sites than in G‐sites (p=0.0002, p=0.02). The shift from aerobic to anaerobic species was observed earlier in S‐sites than in G‐sites. The aerobe/anaerobe CFU ratio was significantly lower in S‐sites than in G‐sites (p=0.01). On day 3, the crevicular fluid flow was significantly higher in S‐sites than in control sites (p=0.01). On day 7, S‐sites and G‐sites showed a significantly higher crevicular flow than control sites (both p