Wide-thread implant macrogeometry and immediate implant placement: A systematic review of primary stability, marginal bone loss, and survival outcomes

Abstract

Background: Wide-thread dental implants have been proposed to enhance primary stability and marginal bone preservation in immediate implant placement protocols, particularly in low-density bone. This systematic review aimed to evaluate the influence of wide-thread implant macrogeometry on primary stability, marginal bone loss, and survival outcomes in immediate implant placement.

Material and Methods: A systematic electronic search was performed in PubMed (MEDLINE), complemented by manual screening of reference lists and forward and backward citation tracking, to identify studies published between January 2007 and August 2025. Clinical studies, in vitro experiments, finite element analyses, and reviews assessing the effect of implant macrogeometry, especially wide-thread configurations, on insertion torque, implant stability quotient (ISQ), marginal bone loss (MBL), and survival in immediate placement were included. Studies without biomechanical relevance, non-English publications, case reports, and those lacking quantitative stability or bone data were excluded.

Results: A total of 36 records were initially identified, and 25 studies met the inclusion criteria. Increased thread depth, wider or more aggressive threads, and tapered implant bodies generally improved insertion torque and ISQ values, particularly in D3–D4 bone and post-extraction sockets. Clinical investigations reported high survival rates for immediately placed implants with optimized macrogeometry, while MBL typically remained within clinically acceptable limits when adequate primary stability and appropriate loading protocols were achieved. However, small sample sizes, short follow-up periods, heterogeneity among implant systems, and non-standardized outcome reporting limited the possibility of robust quantitative comparisons.

Conclusions: Wide-thread implant macrogeometry appears to enhance primary stability in immediate placement and supports favorable short- to medium-term survival and marginal bone behavior when combined with careful case selection and controlled loading. Further well-designed prospective randomized studies with long-term follow-up are needed to determine whether these biomechanical advantages translate into superior long-term clinical outcomes.