Evaluation of the shear bond strength and adhesive remnant index of color change, fluorescent, and conventional orthodontic adhesives: An in vitro study

Abstract

Aims: To investigate the in vitro performance of colour change orthodontic adhesive (CCOA) or fluorescent orthodontic adhesive (FOA), conventional orthodontic adhesives (COA), and the mixed CCOA and FOA utilizing the shear bond strength (SBS) and adhesive remnant index (ARI).

Material and methods: Ninety extracted first premolars were used in the study. Four manufacturers of orthodontic adhesive were used, including Transbond™ XT (TBXT) and Transbond™ plus (TBP) (3M™ Unitek™, CA, United States), Ormco Enlight™ (OE) and Greengloo™ (GG) (Ormco™, CA, United States), Light Bond Medium™ (LBM), and GoTo™ (GT) (Reliance orthodontic products®, IL, United States), and BracePaste® Adhesive (BPA) and BracePaste® Colour Change (BPCC) (American orthodontics®, WI, United States). The mixed orthodontic adhesive of Transbond™ plus and GoTo™ (TBPGT) was prepared to evaluate the combined effect of colour change and fluorescent orthodontic adhesives. Peak SBS was recorded using a universal testing machine. ARI was measured using a stereomicroscope under 10x magnification. Descriptive statistical analysis and comparative tests were used to evaluate the results.

Results: All CCOA and FOA had higher mean SBS than COA. The highest value of SBS was obtained in BPCC (23.56MPa), and the lowest value in TBPGT (11.41Mpa). One-way ANOVA multiple comparisons and Duncan's multiple range test showed that TBXT and TBPGT significantly differed in SBS with GT, GG, TBP, and BPCC, respectively (P=0.016). Kruskal-Wallis multiple comparisons test showed no significant differences in ARI among the tested adhesives (P=0.089).

Conclusions: Colour Change Orthodontic Adhesive (CCOA) and Fluorescent Orthodontic Adhesive (FOA) showed a higher SBS than conventional orthodontic adhesives. Greengloo^TM had the lowest ARI among the groups tested. All adhesives tested can be safely used in orthodontic practice, and both CCOA and FOA showed better performance than COA. The Transbond^TM plus and GoTo^TM (TBPGT) mixed adhesives showed the lowest performance in terms of SBS and ARI.

Keywords: Adhesive remnant score; Colour change orthodontic adhesive; Fluorescent orthodontic adhesive; Orthodontic adhesive; Orthodontics; Shear bond strength.