Although different materials of mandibular fixed retainer were discussed in the literature, there is contradicting evidence regarding the bond failure of Titanium fixed metal retainer, whether immediate or after 12 months. Moreover, insufficient evidence is present regarding 3D metal printed fixed mandibular retainers.

In recent years a new possibility is available for dental practitioners: CAD-CAM technology and 3D printing, which find their application in all aspects of orthodontics. Orthodontists are already familiar with several products that use 3D printers (i.e. invisible aligners), also known as additive manufacturing, 3D printing is a technology whereby sequential layers of material are layered on top of one another to form an object23. Two recent articles reported the fabrication of a custom lingual retainer cut from a nickel-titanium block with CAD/CAM technology and a CAD/CAM Zirconium bar as a bonded mandibular fixed retainer.

Inclusion Criteria:

• Patients with properly finished orthodontic treatment.
• No sex predilection.
• The presence of 4 permanent mandibular incisors and 2 permanent mandibular canines.
• No active caries, restorations, fractures, or periodontal disease of previously mentioned teeth
• Patients with good oral hygiene.

Exclusion Criteria:

• Patients with no need of fixed mandibular retention.
• Enamel hypoplasia or hypocalcification of mandibular anterior teeth.
• Abnormal morphology of mandibular anterior teeth
• Periodontal disease that contraindicates fixed orthodontic retention.
• No or poor patient's compliance & bad oral hygiene.
• Psychological problems.