A deep and multi-helix flute threaded implant: a review and clinical analysis.

Objectives: Implant success depends on osseointegration that is influenced by macrogeometry, including thread design. Thread macrogeometry has a crucial role in achieving primary stability, particularly in low-density bone. Our study reviews the thread design's impact on implant stability, focusing on Straumann BLX (Straumann Co.) implants for practical insights.

Materials and methods: We searched the PubMed/MEDLINE and Embase for studies released until August 2023 using the following keywords: "implant", "macrogeometry", "thread", "thread depth", "thread pitch", "thread geometry", "macrodesign", "flute", "osseointegration", and "stability". In addition, 58 Straumann BLX implants with dynamic threads, which feature a deep thread design and incorporate a multi-helix flute structure to enhance primary stability across different bone densities, were reviewed retrospectively at our institute.

Results: The literature demonstrated that thread pitch, depth, and flute design significantly affect stress distribution and initial stability, especially in low-density bone. Implants with deep threads and spiral flutes showed improved primary stability and insertion efficiency. Clinically, retrospective data from 58 cases supported favorable outcomes in challenging bone conditions such as posterior maxilla and implant replacement sites.

Conclusion: We need to determine appropriate designs for implants with the consideration of bone quality and implantation bed condition.