Immunohistochemical assessment of the peri-implant soft tissue around different abutment materials: A human study.

BACKGROUND Soft tissue reaction to dental implant abutments influences the sustainability of restoration. Several abutment materials, such as titanium and gold alloy, have been introduced for strength and esthetic solutions. Zirconia and titanium-base abutments have also become popular in recent years due to high esthetic demands. PURPOSE To investigate the immune cell infiltration into the soft tissue in response to different abutment materials. MATERIALS AND METHODS Twenty dental implants were placed in the posterior regions of 17 patients. Titanium, zirconia, gold alloy, and titanium-base were randomly selected for each patient on the day of surgery. After 8 weeks of healing, the abutments were removed along with 1 mm of peri-implant soft tissue. Immunohistochemical assessment was performed using labeled streptavidin-biotin to identify T cells, B cells, macrophages, plasma cells, and microvascular infiltration. RESULTS Gold alloy demonstrated an overall higher inflammatory cell infiltration and highest number of CD3+ , CD20+ , and CD 68+ cells (P value <.05). The number of plasma cell and new microvascular infiltrations among abutment materials was not significantly different. CONCLUSION Titanium, titanium-base, and zirconia abutments showed comparable infiltration profiles; gold alloy abutments showed the highest B-cell, T cell, and macrophage infiltration. None of the abutment materials caused clinical inflammation; hence, they can be effectively used.