Microbial adhesion on different bracket types in vitro.
OBJECTIVE
To test the hypothesis that there are differences in total bacterial counts and capacity for biofilm formation between seven different bracket types.


METHODS
By means of an in vitro experiment, seven commercially available bracket systems (Damon [A], Clarity [B], Mystique [C], Speed [D], Victory MBT [E], Micro-loc [F], and Generus [G]) were compared. A total of 25 premolar brackets of each bracket system were incubated in brain heart infusion medium containing the saliva and bacteria of two orthodontic patients. After 72 hours, the amounts of aerobe and anaerobe bacteria were determined by counting the colony-forming units (CFU). The CFU ratio (aerobe/anaerobe) also was calculated, and the black pigmented bacteria were analyzed.


RESULTS
Significant differences between the different bracket types in terms of biofilm formation were found. Bracket types can be arbitrarily divided into low, intermediate, and high plaque-retaining brackets. The group with low adhesion consists of bracket types E, F, and G; the group with high adhesion of bracket types A, B, and C; and type D exhibits intermediate adhesion. The group with high microbial adhesion (A, B, and C) did present significantly lower CFU ratios (aerobe/anaerobe) than were exhibited by the other bracket systems (P < .05).


CONCLUSIONS
The hypothesis is accepted. Orthodontic brackets serve as different loci for biofilm formation; in this in vitro study, significant differences were noted between the different types of brackets.
van Gastel
Jan
J
Department of Orthodontics, Catholic University, Leuven, Belgium. Johannes.vanGastel@med.KULeuven.ac.be
Quirynen
Marc
M
Teughels
Wim
W
Pauwels
Martine
M
Coucke
Wim
W
Carels
Carine
C
D001422:Bacterial Adhesion; D018441:Biofilms; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology; D006801:Humans; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D018713:Prevotella intermedia / Q000302:isolation & purification; D012463:Saliva