Healing of apical periodontitis in dogs after apicoectomy and retrofilling with various filling materials

Objective. To histologically assess the efficacy of various retrofilling materials in apical surgery. Study design. The pulps of mandibular premolars in seven beagle dogs were infected; this resulted in periapical lesions. Apical surgery was performed without disinfection of the root canals. Super EBA (Harry J. Bosworth Co., Skokie, III.), two formulations of glass ionomer cement, amalgam with varnish, IRM, (Caulk Co., Ltd., Densply International, Milford, Del.) and a light-cured composite resin were the retrofilling materials used. Roots infected and apicoectomized without retrofilling were positive controls. After 6 months the dogs were killed. The experimental roots and surrounding apical tissues were prepared and histologically examined and relative percentages of bone and inflammation were calculated. Results. Super EBA was consistently the best. In overall periapical condition, Super EBA was statistically superior to all materials except IRM. IRM was superior to the glass ionomer cements but not the other materials. As to percentage of bone, Super EBA was the best overall; it was superior to glass ionomer, composite resin, and the positive control but not different from amalgam or IRM. When comparing remaining numbers of inflammatory cells, Super EBA was superior with the lowest number of inflammatory cells present. Conclusion. Although not statistically different from IRM, Super EBA was consistently the best retrofilling material tested when compared with all retrofilling materials studied.