Bond strength of ceramic orthodontic brackets to composite restorative materials
Derêgowska-Nosowicz P.1, Czarnecka B.*1, Paszyñska E1., Limanowska-Shaw H.1
1Department of Biomaterials and Experimental Dentistry, Poznañ University
of Medical Sciences, Poznañ, Poland
Objectives: To evaluate the SBS of ceramic orthodontic brackets to composite restorative materials using various orthodontic bonding systems. Methods: 60 ceramic orthodontic brackets Illusion PlusTM (Ortho Organizers) were used. 20 brackets were bonded to tooth-shaped samples of Filtek A110 (3M-ESPE) composite (Group A). 20 brackets to similar samples with Filtek Z250 (3M-ESPE) composite (Group B) and 20 to human premolars (Group C) as controls. The brackets were bonded to 10 teeth in each group by composite (Illuminate-Ortho Organizers) adhesiveX or resin modified glass- ionomer (Fuji Ortho LC –GC International) adhesiveY. Samples were stored in water at 37oC for 24h then tested for SBS using a Hounsfield tensometer. Failure mode was evaluated
microscopically. The amount of adhesive remained on the tooth surface was evaluated using ARI. The results were analysed with Multifactor ANOVA and the Newman-Keuls post hoc test. Results:
|
Samples |
Bonding system |
SBS (MPa) SD in brackets |
ARI |
|
Group A |
X Y |
7.5 (2.1) 10.4 (3.8) |
1.3 1.2 |
|
Group B |
X Y |
5.9 (1.5) 7.8 (2.3) |
1.6 1.5 |
|
Group C |
X Y |
6.1 (1.2) 8.3 (1.7) |
2.1 1.9 |
Failure for A with X was cohesive/adhesive and with Y mainly adhesive. Failure for B with X was cohesive/adhesive and with Y mainly adhesive. In group C failures with X and Y were cohesive/adhesive. Conclusion: RMGIC adhesive gave a higher SBS in both experimental groups and the control group, compared to that with composite (p<0.02). These values are satisfactory for clinical situations. Failure mode tended to be adhesive/cohesive in most cases.