[Marginal leakage of glass ionomer as filling material for proximal decay in endodontic treatment].

The primary purpose of sealing proximal tooth defects during endodontic treatment is to prevent fluid, organic or bacterial contamination of the root canal system. At times, glass ionomers are used to restore proximal tooth defects between appointments, and after the root canal therapy. The purpose of this study was to evaluate the sealing ability of glass ionomers in teeth having proximal defects during root canal therapy. Sixty lower molars were extracted and prepared with standard endodontic access procedures. The mesial wall was then removed to mimic a proximal defect, and the tooth was filled with a glass ionomer in various thicknesses--0.8, 1.2 and 1.5 mm, respectively. After thermocycline treatment, all of the teeth were partially immersed in a 1% methylene blue dye for two weeks. During this period, the glass ionomer was directly observed to determine if any marginal leakage occurred. The glass ionomer was unacceptable if the dye penetrated to the interior wall of the pulp chamber. If not, it was classified as acceptable. The results indicated that dye penetration or leakage was least likely to occur in a 1.5 mm glass ionomer group.