Abstract
PURPOSE: Marginal bone loss (MBL) around dental implants is a critical factor for long-term success. Convergent abutments have been suggested to improve peri-implant tissue stability. However, previous reviews have not specifically isolated the role of convergent abutments when comparing bone-level (BL) and tissue-level (TL) implant platforms. Therefore, this review aims to clarify whether the implant-abutment connection configuration (BL vs. TL) affects MBL when restored with convergent abutments. OBJECTIVE: To systematically compare MBL around convergent abutments placed on BL versus TL implants. METHODS: This systematic review followed PRISMA guidelines. Electronic databases (PubMed, Scopus, and Web of Science) were searched up to May 2025 for randomized controlled trials (RCTs), cohort, or case-control studies comparing MBL on convergent abutments for BL and TL implants. Two reviewers independently performed screening, data extraction, and risk of bias assessment. RESULTS: Seven studies (three RCTs and four cohort studies) involving 528 implants were included. Overall, TL implants with convergent abutments showed slightly lower MBL (mean 0.42 mm) compared to BL implants (mean 0.53 mm) after 1 year. Differences were statistically significant in three studies but considered clinically marginal. Risk of bias was moderate to low. CONCLUSIONS: Both BL and TL implants with convergent abutments demonstrate minimal MBL after 1 year, with a slight advantage for TL implants. Further long-term, high-quality RCTs are recommended to confirm these findings.