Immediate one-piece zirconia implants with/without xenograft in the buccal gap: A 6-month pre-clinical study

Abstract

Objective: To histologically evaluate healing following grafting a xenogenous bone substitute in the buccal gap around the immediately placed one-piece zirconia implant. Materials and methods: The third and fourth premolars (PM3 and PM4) in both quadrants of the mandible of nine Mongrel Hound dogs were used for this experiment. They have been removed, and the recipient sites were prepared. The implants were placed in a lingual position in the socket. In one side of the jaw, the gap between the implant and the socket walls was grafted (test) while no grafting was performed in the contralateral side (control), randomly selected. After 6 months of healing, biopsies were obtained and prepared for histological analysis. Vertical and horizontal measures were recorded in buccal and lingual surface. Results: The hard tissue was in a coronal position on the test side compared with the control side. The bone thickness around ZLA (zirconia large-grit sandblasted and acid-etched surface) level was larger on the test side. On the test side, the first bone-implant contact and bone crest, at the buccal aspect, were more coronal to ZLA in PM4 while in PM3 the same happened with the bone crest. The width of the buccal bone wall was larger in PM4 than in PM3 at the ZLA level and 1 mm apical to ZLA. Conclusion: The placement of a xenograft in the gap between 1-piece zirconia implant and the buccal wall in dogs modified the process of hard tissue healing, providing additional amount of hard tissue.