RETROGRADE ROOT FILLING WITH DENTIN-BONDED MODIFIED RESIN COMPOSITE

A retrograde root-end cover with a special resin composite (Retroplast ) combined with the dentin bonding agent Gluma (Bayer AG) has been use d since 1984 by the authors. Its content of silver, added to promote r adiopacity, has been found to lower the working time and storage stabi lity of the composite and might cause discolorations. Since 1990, silv er has therefore been replaced with ytterbium trifluoride, which elimi nates these side effects. The purpose of this study was to compare the clinical results obtained with these two resin composites and to eval uate the healing results after several years in function. Apical filli ngs (351) with the modified Retroplast showed the following radiograph ic healing pattern 1 yr after surgery: 80% complete healing, 2% scar t issue, 12% uncertain healing, and 6% failure. No significant differenc e in this healing pattern was found, compared with that obtained with the silver-containing Retroplast. Cases with ytterbium trifluoride cla ssified as scar tissue and uncertain healing at 1 yr when examined at 2 to 4 yr postoperatively showed 89% complete healing. 0% scar tissue, 1% uncertain healing, and 9% failure. This result is significantly di fferent from that obtained 1 yr after surgery. Based on calculations, it was predicted that with time 90% will become complete healing, wher eas 10% will become failure.