Glass Ionomer Cements can be used for Bonding Orthodontic Brackets After Cancer Radiation Treatment?

Abstract

Patients undergoing radiotherapy treatment present more susceptibility to dental caries and the use of an orthodontic device increases this risk factor due to biofilm accumulation around the brackets. The objective of this study was to evaluate the shear bond strength to irradiated permanent teeth of orthodontic brackets bonded with conventional glass ionomer cement and resin-modified glass ionomer cement due to the fluoride release capacity of these materials. Ninety prepared human premolars were divided into 6 groups (n=15), according to the bonding material and use or not of radiation: CR: Transbond XT composite resin; RMGIC: Fuji Ortho LC conventional glass ionomer cement; GIC: Ketac Cem Easymix resin-modified glass ionomer cement. The groups were irradiated (I) or non-irradiated (NI) prior to bracket bonding. The specimens were subjected to a fractioned radiation dose of 2 Gy over 5 consecutive days for 6 weeks. After the radiotherapy, the brackets were bonded on the specimens with Transbond XT, Fuji Ortho LC and Ketac Cem Easymix. After 24 h, the specimens were subjected to shear bond strength test. The image of enamel surface (classified by Adhesive Remnant Index - ARI) was also evaluated and its frequency was checked among groups/subgroups. The shear bond strength variable was evaluated with ANOVA and Tukey's post-hoc test. GIC group showed the lowest adhesion values among the groups (p<0.05). There was no statistically significant difference among non-irradiated and irradiated groups (p>0.05). As for the ARI, the CR-I group showed the highest material retention on enamel surface among the irradiated groups. RMGIC group showed the highest values for shear bond strength and presented ARI acceptable for clinical practices.

Impact of Irradiation on the Adhesive Performance of Resin-Based Dental Biomaterials: A Systematic Review of Laboratory Studies

“…The adhesives used in the included studies comprised etch-and-rinse adhesives (two-step, three-step, and four-step), self-etch adhesives (one-step and two-step), and universal adhesives that were applied in self-etch or etch-and-rinse mode. One study assessed a resin-modified glass ionomer material in addition to resin-based composite [ 36 ]. Apart from the study that bonded quartz fiber posts in root canals using dual-curing resin-based luting material, most studies used light-curing resin-based composites to create standardized restorations or cylinders for bond strength testing and other assessments of adhesive performance.…”

“…A decrease in enamel bond strength of orthodontic brackets was observed in three of four studies that compared irradiated enamel specimens with unirradiated specimens [ 45 , 46 , 47 ]. No significant decline in enamel bond strength of orthodontic brackets was found in one study [ 36 ].…”

“…Most of the studies on enamel bonding reported that irradiation reduces the bond strength. However, a few studies found no significant impact of irradiation on bond strength, including one that investigated the bonding of resin-modified glass ionomer cement [ 29 , 36 , 41 ]. The reduced bond strength observed in most studies is likely due to the microstructural changes in enamel caused by irradiation, which can make it more difficult for adhesives to bond effectively.…”

“…Irradiation and the timing of the restorative procedure had no significant impact on the adhesive performance on enamel and dentin. Santin et al, 2018 [ 36 ] Human enamel from premolars 90 teeth (6 groups with 15 specimens each) Flat enamel surface Orthodontic brackets bonded to flat enamel surface Two main groups (irradiation before bonding vs. no irradiation); three subgroups (RBC, GIC, RMGIC) 2 Gy daily for 5 days per week over 6 weeks (total dose 60 Gy) E&R adhesive (XT Primer, 3M, St. Paul, MN, USA); RBC (Transbond XT, 3M, St. Paul, MN, USA); RMGIC (Fuji Ortho LC resin, GC, Tokyo, Japan) Shear bond strength assessment Irradiation had no significant impact on the adhesion of brackets bonded with RBC and RMGIC. RBC and RMGIC achieved higher bond strength than GIC.…”