Evaluation of Four Titanium Abutment Materials for Soft Tissue Biocompatibility

Objectives: Creating soft tissue seal is crucial to achieve long-term stability of the dental implant. Cell attachment property of the temporary and prosthetic abutment is one of the important factors for creating optimal peri-implant soft tissue around implant that is also essential to prevent peri-implantitis. Titanium (Ti) has been the most widely used material in implantology. The surface modification of Ti has been applied for better osseointegration. However, little is known about its effect on soft tissue biocompatibility. In this study, we evaluated the effect of four different surface modifications of Ti abutments and their soft tissue biocompatibility by using Human Gingival Fibroblasts (HGFs) and Human Oral Keratinocytes (HOKs) in vitro.
Methods: Four different surface modifications of titanium abutment were tested: Grade 4 Ti Osseotite (A), Machined alloy Ti-6AL-4V-Eli (B), Grade 4 Ti Osseotite with DCD (C), and Machined CP Grade 4 Ti (D). Cell early attachment and growth curve were examined by Cell Counting Kit-8 (CCK-8). Click-iT assay was used for proliferation assay. Wound healing assay was evaluated by using Idibi migration kit.
Results: The clinically used machined CP Gr4 Ti showed superior biocompatibility of keratinocytes compared with other materials with the most early attachment, the highest cell proliferation, and the fastest wound healing. However, machined alloy Ti-6AL-4V-Eli had faster wound healing of fibroblasts compared with machined CP Gr4 Ti.
Conclusions: Ti-6AL-4V-Eli is a promising alternative for clinically used machined CP Gr4. However, further surface optimization is needed in order to provide the best compatibility for both keratinocytes and fibroblasts.