The goal of this study is to evaluate whether a new 3D-printed dental device can effectively maintain space after premature loss of primary teeth in children, compared to the traditional stainless-steel device. It will also assess safety and comfort. The main questions it aims to answer are:

1. What is the clinical success rate of 3D printed space maintainers compared to traditional metal band and loop space maintainers over a 12-month period?
2. How do 3D printed space maintainers compare in maintaining space and preventing rotation of abutment teeth?
3. What are the differences in gingival health outcomes between the two types of space maintainers?

Participants (13 children aged 6-9 years) will:

Receive both devices in a "split-mouth" design (one on each side of the mouth), totaling 26 treated tooth spaces (13 per group).

Attend checkups every 3 months for a year to monitor the devices' performance.

Inclusion Criteria:

1. Apparently healthy children.
2. Children of both genders aged 6-9 years old.
3. Guardians agree to join the study and sign the informed consent.
4. Recent premature loss of primary first molars or having primary first molars indicated for extraction on both sides.
5. Sound buccal and lingual surfaces of abutment teeth (primary second molar and primary canine).
6. Good oral hygiene.
7. Absence of radiographic periapical pathology related to the abutment teeth.
8. Absence of abnormal occlusal conditions such as posterior crossbite, deep bite, and scissor bite.
9. All the indications for a band and loop space maintainer are met.

Exclusion Criteria:

1. The patient is not able to attend regular follow-up visits.
2. Allergic condition to any of the used materials.