[An in-vitro study of the interference of orthodontic banding and filling materials]

Discoloring and layers on bands and restorations during fixed orthodontic therapy are well known clinical phenomenon. Because of the complexity of etiological factors an in-vitro model was used in this study. Aim of the study was to examine the amounts and sort of metals which are dissolved. Therefore, respectively 25 normed MOD-cavities in Frasaco-teeth were filled with a non-gamma-2-amalgam (Amalcap plus, Vivadent) and condensed manually or mechanically. In addition, ten crowns of a high golden (Maingold SG, Heraeus) as well as a palladium basis alloy (Albabond A, Heraeus) were casted. Then they were banded with stainless steel bands (Dentaurum) and cemented with a glass ionomer cement (Ketac Cem, Espe). The probes were given into a 0.1 molar lactic acid for seven days at 37 degrees C. Using ICP (ion coupled plasma) analysis the corrosion solution was examined for elements. High levels of Zn- and Al-ion contents were found, which are components of the used cements. The filling materials themselves mainly set free small amounts of Ag, Sn or Cu. The steel band released Fe, Cr, Ni and Ti. The combination of filling material and band resulted in a higher release of most ions.