Clinically, periodontal pocketing was detected in only two specimens, both in the positive control group, where perforations were not repaired. These findings were confirmed histologically.
Radiographs showed evidence of periodontal breakdown in the furcation region in five of the specimens from the unsealed group and in five from the amalgam group. Furcation radiolucencies were not observed in either matrix group.
Histological analysis confirmed that, following pulpotomies, the pulp tissue apical to the calcium hydroxide and the periapical tissues remained normal. All tissues in the negative control group appeared normal and healthy throughout the period of the study. In all the specimens in which a perforation was made, a severe acute inflammatory reaction in the furcal bone was observed at the 1-week time interval. In the amalgam-alone group this severe inflammatory reaction persisted throughout the experimental period (Fig. 2). In the HAPSET and hydroxyapatite groups the inflammatory response diminished with time.
After one month, fibrous encapsulation of both matrix materials was observed. These capsules became thicker and more organized with time. In these groups, at the later time periods, there was evidence of new bone formation. Bone was deposited in direct contact with the matrix materials. There was no intervening connective tissue. There was no apparent difference in the connective tissue and bone response to HAPSET or hydroxyapatite. These results are summarized in Tables 2-4.
Table 2. Inflammation.
Table 3. Connective tissue reaction.
Table 4. Bone reaction.