Tissue integration of zirconia and titanium implants with and without buccal dehiscence defects—A histologic and radiographic preclinical study

Objective To histologically and radiographically evaluate soft (primary outcome) and hard tissue integration of two‐piece titanium and zirconia dental implants with/without buccal dehiscence defects. Materials & methods In six dogs, five implants were randomly placed on both sides of the mandible: (a) Z1: a zirconia implant (modified surface) within the bony housing, (b) Z2: a zirconia implant (standard surface) within the bony housing, (c) T: a titanium implant within the bony housing, (d) Z1_D: a Z1 implant placed with a buccal bone dehiscence (3 mm in height, identical width to implant body), and (e) T_D: a titanium implant placed with a buccal bone dehiscence. Two weeks of healing and 6 months of loading were applied on each hemi‐mandible, respectively. Results The median level of the margo mucosae shifted more apically over time in all groups (borderline statistical significance in groups Z1_D: −0.52 mm and T_D: −1.26 mm). The median height of the peri‐implant mucosa in groups Z1_D and T_D was greatest at 2 weeks and 6 months, but the linear change in the peri‐implant mucosa was statistically significant only for group T_D over time (−1.45 mm). Z1 demonstrated a higher bone‐to‐implant contact compared to Z2 and T. Minimal change of radiographic marginal bone levels in all groups was observed (