Statement of problem. Patient satisfaction and maximum biting force from patients who wear 2-implant-retained overdentures with different constructed bar attachments can be improved.

Purpose. This randomised controlled clinical trial assessed patient satisfaction and maximum biting force with three differently constructed bar-retained overdentures (conventional casting, Milling and 3D printing CAD/CAM techniques) within a one-year follow-up.

Material and methods. A total of 60 implants were placed in 30 mandibular jaws(30 participants). The jaws were randomly assigned to 1 of the 3 treatment groups: a 10 conventional technique cast Co-Cr bar attachment, a 10 Co-Cr CAD/CAM milled bar attachment, and a 10 Co-Cr CAD/CAM 3D-printed bar attachment all groups were connected to 2 implants in the canine area. Patient satisfaction was tested after 6 months, and 12 months for each group; the results were collected, tabulated, and statistically analysed using a Pair-wise comparisons test and the Kruskal-Wallis test. Maximum biting force was tested at baseline,3 months, 6 months, and 12 months for each group; the results were collected, tabulated, and statistically analysed using a Pair-wise comparisons test and ANOVA test.

A total of 60 implants were placed in 30 mandibular jaws(30 participants). The jaws were randomly assigned to 1 of the 3 treatment groups: a 10 conventional technique cast Co-Cr bar attachment, a 10 Co-Cr CAD/CAM milled bar attachment, and a 10 Co-Cr CAD/CAM 3D-printed bar attachment all groups were connected to 2 implants in the canine area. Patient satisfaction was tested after 6 months, and 12 months for each group; the results were collected, tabulated, and statistically analysed using a Pair-wise comparisons test and the Kruskal-Wallis test. Maximum biting force was tested at baseline,3 months, 6 months, and 12 months for each group; the results were collected, tabulated, and statistically analysed using a Pair-wise comparisons test and ANOVA test.

Inclusion Criteria:

1. Patients with sufficient residual alveolar bone quantity and quality anterior to the mental foramen to receive self-taping root form titanium implants.
2. Maxillary and Mandibular residual alveolar ridges covered with healthy mucosa without any remaining roots or local inflammation.
3. Patients with sufficient inter-arch space (at least 15 mm) to have overdenture and bar attachment.
4. U-shaped lower ridge to avoid the lingual placement of the bar that occurs with a V-shaped ridge.
5. Patients with skeletal and dental class I.

Exclusion Criteria:

1. Patients with systemic diseases such as cardiovascular diseases, any disease of immunity, febrile conditions such as epilepsy, metabolic disorders, osteoporosis, hyperparathyroidism, and impaired psychological conditions that might affect the oral tissues or the bone metabolic rate.
2. Patients with local and general contraindications for surgical procedures.
3. Patients with TMJ or neuromuscular disorder.
4. Patients with Para functional habits such as bruxism and clenching.
5. Patients with impacted teeth or remaining roots.
6. Alcoholic patients.
7. Patients with a history of radiotherapy in the head and neck region.
8. Non-cooperative patients.
9. Patients with a history of bisphosphonate intake.
10. Patients with flabby tissues, bony undercuts, sharp bony edges, thin ridges or abnormalities at the lower alveolar ridge and recent extraction.

This randomised controlled clinical trial assessed patient satisfaction and maximum biting force with three differently constructed bar-retained overdentures (conventional casting, Milling and 3D printing CAD/CAM techniques) within a one-year follow-up.