Clinical Longevity of Direct Dental Restorations: An Umbrella Review of Systematic Reviews

This umbrella review synthesized high-level evidence on the clinical longevity and failure patterns of direct restorative materials, including conventional composites, bulk-fill resins, ormocer-based composites, and glass ionomer cements (GIC/RMGIC) used in posterior restorations and non-carious cervical lesions (NCCLs).

Sixteen systematic reviews and meta-analyses published between 2012 and 2025 were included, representing over 15,000 restorations with follow-up periods ranging from 6 to 120 months. Methodological quality was assessed using AMSTAR 2, and evidence certainty was graded with the GRADE framework. Outcomes included survival rates, failure types, and comparative risk estimates (RR, OR).

Conventional composites demonstrated > 90% 5-year survival, especially with multi-step adhesives. Bulk-fill resins showed similar short-medium-term outcomes (failure rates < 7%), but long-term data remain limited. Ormocer-based composites had significantly higher failure rates (12.1%), primarily due to marginal degradation. GICs exhibited lower survival but remain useful in high caries risk or moisture challenged conditions. The sandwich technique with RMGIC bases improved retention in NCCLs. Adhesive protocol emerged as a key prognostic factor across all materials.

Clinical longevity is influenced by material class, bonding strategy, and patient risk profile. Conventional and bulk-fill composites remain the most reliable options. RMGICs and sandwich approaches are effective in specific indications.

This umbrella review provides clinicians with consolidated, high-level evidence to optimize restorative decisions. The integration of AMSTAR 2 and GRADE strengthens the clinical applicability of findings.