Effect of dentin preparation and acid etching on the sealing ability of glass ionomer and composite resin when used to repair furcation perforations over plaster of Paris barriers.

Access openings and furcation perforations were prepared in 60 human extracted teeth and randomly divided into four equal groups. Plaster of Paris barriers were created in all perforations. The defects were obturated using either glass ionomer or composite resin with or without acid etching of the dentin. The pulp chambers and access openings were filled with composite resin. After immersion in 2% methylene blue solution for 2 weeks, the teeth were sectioned longitudinally and dye penetration was measured under a stereomicroscope using the NIH Image 1.47 Macintosh program. The results indicated that light-cured glass ionomer provided a significantly better seal than did the light-cured composite resin with or without dentin preparation and acid etching. The glass ionomer allowed significantly less dye penetration when used on etched dentin than it did on nonetched dentin.