Triangular-neck implants perform well — but nobody has compared them head-to-head

Clinical question: what is the clinical performance of triangular-neck dental implants, specifically in terms of 1-year marginal bone loss (MBL) and survival rate?

Methodology: this PRISMA-guided systematic review and meta-analysis searched PubMed, Scopus, and Web of Science through June 2025. Randomized controlled trials, retrospective and prospective studies, and case series reporting on ≥10 triangular-neck implants were eligible. Risk of bias was assessed with the Cochrane RoB 2 tool for RCTs and the Joanna Briggs Institute checklist for nonrandomized studies; results were pooled with random-effects meta-analysis, and evidence certainty was graded with GRADE.

Main findings: of 115 titles identified after de-duplication, 8 studies met inclusion criteria, with 5 providing sufficient data for quantitative synthesis. The pooled 1-year mean marginal bone loss was 0.35 mm (95% CI: 0.24-0.46), with low heterogeneity (I² = 23.2%), and the pooled implant survival rate was 97.8% (95% CI: 95.4%-99.4%), with essentially no heterogeneity (I² = 0.0%).

Clinical relevance: triangular-neck implant designs — intended to improve mechanical stability and crestal bone preservation through their macro-geometry — show excellent single-arm outcomes: low first-year bone loss and high survival, consistent across the available studies. However, every included study was single-arm; none directly compared triangular-neck implants against other neck or collar designs in the same trial. That means the review can credibly say triangular-neck implants perform well in isolation, but it cannot yet say whether they perform better, worse, or the same as alternative implant geometries. For clinicians evaluating implant systems, this is a useful reassurance on baseline performance, but not yet grounds for choosing a triangular-neck design over another for its bone-preservation properties specifically — that comparative question awaits head-to-head RCTs.