[Comparative studies of fiberglass and metal brackets].

The demand by patients considered for better esthetics during treatment should be seriously considered. With the introduction of fiberglass brackets one has tried to solve that problem. The purpose of this investigation was: 1. a microscopic examination of the slots of these fiberglass brackets after various periods of wearing; 2. an in vitro investigation of the adhesion of the fiberglass brackets in comparison to metal brackets; The following results were obtained: 1. There are remarkable differences in the slot dimensions between new fiberglass brackets and those which have been in the mouth for varying periods of time. 2. Ligating wires into fiberglass brackets may be difficult because of wing fractures. 3. There are significant differences regarding the adhesion of fiberglass brackets compared with metal brackets. Results of tests carried out under defined conditions (bonding, storage, time-factor) concluded that metal brackets behaved much more favourably; the adhesion of metal brackets was nearly ten times greater than that for fiberglass brackets.