The effect of a calcium hydroxide paste on wound healing and osseointegration of dental implants. A pilot study in beagle dogs.

The aim of this investigation was to evaluate the effect of a new calcium hydroxide suspension (Osteoinductal) on the healing process of endosseous dental implants after placement. The material, composed of 25% calcium hydroxide, 25% Oleum pedum tauri and 50% vaselinum album, was developed with the intention to accelerate and to increase the mineralized bone to implant contact during the healing phase. Eight adult beagle dogs were used in this study. Prior to the beginning of the study the dogs had all mandibular premolars extracted. After the extraction sites had healed for 3 months, implant osteotomies were performed. On one side of the mandibular premolars extracted. After the extraction sites had healed for 3 months, implant osteotomies were performed. On one side of the mandible Osteoinductal was applied into the osteotomies before placement of the implants, whereas the other side did not receive Osteoinductal. A total of 48 implants were placed with two losses during the entire study period. Two dogs were sacrificed 1 week, 2 weeks, 4 weeks and 3 months after implant placement. The specimens were evaluated histologically and histomorphometrically. In the histological evaluation an intense inflammatory reaction towards the calcium hydroxide suspension was found leading to a destruction of the bone surrounding the implants after 1 and 2 weeks. A giant cell reaction against the test material was visible at 4 weeks. At 3 months no inflammatory and no giant cell reaction could be depicted in the test group. The mean direct bone to implant contact or inflammatory tissue to implant contact showed no differences between test and control group for 1 and 2 weeks. Although statistically not significant, there was a clinical significant difference in the mineralized bone to implant contact between test and control group for the last two timepoints (i.e. 4-week specimens: test group 2.3 +/- 0.9%, control group 26.8 +/- 11.1%; 3-month specimens: test group 10.5 +/- 12.7%, control group 60.7 +/- 13.7%). This study indicates that the use of the calcium hydroxide suspension Osteoinductal has a detrimental effect on wound healing and osseointegration of dental implants and cannot be recommended for use with dental implants.