Plaque distribution on bonded brackets: a scanning microscope study.

N ew and often extensive patterns of plaque accumulation can develop in association with resin-bonded orthodontic brackets in addition to a subject’s already established plaque pattern.’ Weitman and Eames5 showed that plaque covers the surface of resin restorations within 24 hours of placement and concluded that the resin surface was rough and, therefore, predisposed to the rapid attachment and growth of oral microorganisms. Waerhaug4 demonstrated, histologically, the presence of both supragingival and subgingival plaque on acrylic and other restorations. He also concluded that rough surfaces are likely to encourage the rapid attachment of bacteria and the ultimate promotion of gingival and periodontal disease. Weitman and Eames used erythrocin dye to disclose the plaque but did not correlate their clinical observations with those derived by other methods. However, Jordan and his co-workers,” using the scanning electron microscope, photographed microorganisms on surfaces of composite (filled) restorations as well as acrylic (unfilled) restorations. Their observations supported the Weitman and Eames conclusion and confirmed Waerhaug’s findings. Since filled and unfilled resins are used to bond orthodontic brackets, it was postulated that they may be among the factors contributing to the plaque patterns recorded by ultraviolet photography.’ Because a large number of bonded brackets were available from our study subjects, with significant amounts of resin still attached to them, we undertook their detailed examination for plaque with the scanning electron microscope. The objective of the study was to determine the sites of plaque accumulation and the extent to which plaque accumulated on mesh-back and perforated types of brackets and the resin associated with them.