Connectors and attachments in the survival of fixed dental prostheses: a comprehensive review

Abstract

Connectors and attachments are critical components that unite retainers and pontics in fixed dental prostheses (FDPs). This review synthesizes current evidence on various connector types (rigid, semi-rigid, non-rigid) and attachment systems (precision, stress-breaking) and their impact on FDP longevity. We conducted a broad literature search of PubMed, Embase, and related databases (up to 2025) using terms like “fixed dental prosthesis,” “connector,” “non-rigid connector,” and “precision attachment.” Studies were selected based on relevance to FDP design and survival (clinical trials, in vitro studies, reviews). Overall, FDPs exhibit high long-term survival (~89% at 10 years), but mechanical complications can arise at connector sites. Larger connector cross-sections generally increase fracture resistance (e.g. zirconia FPDs with 12 mm² connectors withstood significantly higher loads than those with 9 mm²), though oversize connectors risk hygiene issues. Rigid connectors maximize stiffness and even load distribution, whereas semi- and non-rigid designs (e.g. tenon–mortise, split-pontic) allow limited movement to relieve stress in misaligned abutments. Precision attachments (male–female fittings) improve load sharing and esthetics by eliminating clasps, and stress-breaking attachments (e.g. bars, clips) can absorb occlusal forces. Digital workflows (intraoral scanning, CAD/CAM) and 3D printing now enhance connector accuracy. Despite these advances, evidence is largely from lab studies and retrospective series, highlighting a need for more controlled trials. In conclusion, careful connector/attachment design – balancing strength, prosthesis fit, esthetics, and hygiene – is vital for FDP success. Emerging materials and technologies promise further improvements but must be validated in long-term clinical research.