Prefabricated versus Customised Space Maintainers in the Era of Evidence-based Dentistry: A Comprehensive Narrative Review

Premature loss of primary teeth continues to be one of the most common challenges in paediatric dentistry, with wide-reaching consequences if left untreated. Space loss, midline deviations, crowding, and subsequent malocclusion often develop or develop frequently, often necessitating complex orthodontic treatment during adolescence. Space Maintainers (SMs) have therefore become a cornerstone of preventive paediatric dentistry. Customised appliances historically have been regarded as the gold standard because of their adaptability, long-term stability, and versatility across different clinical scenarios. In contrast, prefabricated SMs were developed as chairside alternatives that require less clinical time, eliminate laboratory steps, and improve feasibility for uncooperative children or in community settings. With the introduction of fibre-reinforced composite resin and Three-dimensional (3D) printing, the paradigm is shifting towards minimally invasive and aesthetic solutions. However, concerns remain regarding their longevity, adaptability, and impact on gingival health. The reviewed articles highlight the distinct advantages and limitations of both prefabricated and customised appliances, along with emerging evidence supporting fibre-reinforced and digitally fabricated SMs. Studies involving animal models and non-clinical narrative reviews were excluded. This narrative evaluation serves as a clinical reference for dental professionals and researchers seeking evidence-based guidance in appliance selection for paediatric space management and insight into future digital advancements in preventive orthodontics.