EFFECTIVENESS OF CAD/CAM-FABRICATED VERSUS CONVENTIONALLY FABRICATED FIXED ORTHODONTIC RETAINERS: A SYSTEMATIC REVIEW WITH SUBGROUP ANALYSIS BY DENTAL ARCH

Abstract

Background: Orthodontic retention is essential for maintaining post-treatment stability, particularly in the mandibular anterior region where relapse commonly occurs. Recently, computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have been introduced for customized fixed orthodontic retainers, but their clinical effectiveness compared with conventional multistranded retainers remains unclear. Objective: To systematically evaluate and synthesize evidence comparing the clinical effectiveness of CAD/CAM-fabricated and conventionally fabricated fixed orthodontic retainers in maintaining post-treatment stability. Methods: A systematic search of four electronic databases (PubMed/MEDLINE, Scopus, and ScienceDirect) identified clinical studies published between 2020 and January 2026. Study selection followed PRISMA 2020 guidelines. Methodological quality was assessed using the RoB 2 tool for randomized controlled trials and ROBINS-I for non-randomized studies. A random-effects meta-analysis was conducted, and evidence certainty was evaluated using the GRADE approach. Results: Eleven studies involving approximately 825 orthodontic patients were included in the qualitative synthesis, with nine studies eligible for meta-analysis. Findings showed no statistically significant difference between CAD/CAM and conventional retainers in post-treatment stability. Statistical heterogeneity was low to moderate, and funnel plot analysis indicated a low risk of publication bias. Evidence certainty for orthodontic stability outcomes was rated as moderate. Conclusion: Current evidence suggests that CAD/CAM-fabricated fixed retainers provide clinical outcomes comparable to conventional multistranded retainers during the early retention phase, representing a practical alternative in digital orthodontic workflows. However, further long-term randomized clinical trials are needed to clarify their advantages in long-term retention.

Keywords: Orthodontic Retainers, CAD/CAM Technology, Post-treatment Stability