Background: Premature loss of primary molars plays a significant role in the malfunction of the masticatory apparatus and considerable malocclusion. Space maintainers referred to appliances that preserve the space for adequate eruption of permanent teeth. In modern civilization, the era of esthetics has the main interest of people; therefore, the introduction of new materials and techniques is required.

Methods: In the present study, clinical and antimicrobial evaluation of two luting types of cement [(glass ionomer cement (group A) and resin cement (group B)] under custom made zirconia space maintainers.

Conclusion: Both luting types of cement provided a sufficient success rate during the clinical evaluation period.

Results: Twenty-four space maintainers (96%) remain in position and function after three months of evaluation for group A and 92% for group B. Also, there was no significant difference in the antibacterial properties between the two groups.

Keywords: Space Maintainers; Zirconia; GIC; Resin Cement; Streptococcus mutans