Comparison between a glass ionomer cement and a compomer concerning bonded acrylic expander retention and white spot formation : A randomized clinical trial.

BACKGROUND: The goal of the present study was to compare a compomer and a glass ionomer cement (GIC) used for full the cementation of acrylic splint-type maxillary expanders with respect to failure rate and white spot lesions (WSLs) in vivo. METHODS: A total of 120 patients with posterior crossbite and transverse maxillary deficiency were included to the study. The patients were randomly allocated to two groups: GIC group (n = 60) and compomer group (n = 60). The hyrax screw in both groups was activated two times a day for the first week then once a day until the desired amount of expansion was achieved. The rapid maxillary expansion (RME) appliance was left in the mouth for an extra month after the active expansion phase as a retention appliance. Then cementation failures were recorded. In addition, the patients were evaluated for white spot lesions (WSLs) before cementation and after removal of the appliance. RESULTS: A total of 12 (20%) and 2 (3.3%) RME devices failed in the GIC and the compomer group, respectively. This difference between groups was statistically significant (p = 0.044). There were also statistically significant differences between the GIC and compomer groups in terms of WSLs on the central (p = 0.06) and lateral (p = 0.011) incisors, and on the first molar (0.028). However, no differences were observed for the canines (p = 0.185), first (p = 0.457) and second premolars (p = 0.116). In total, there was a statistically significant difference between the GIC and compomer groups (p = 0.048), with more WSLs in the GIC group. CONCLUSIONS: Among the products used in the study, the compomer should be preferred over the GIC for cementation of acrylic splint-type rapid maxillary expanders in terms of failure rate and WSLs.