IADR Abstract Archives
Novel Bioactive Glass-containing Orthodontic Bracket Adhesive: Ca-ion Releasing Capability
Objectives: The use of resin-based orthodontic bonding agents is generally preferred by most clinicians, due to its ease of use and its clinically acceptable bond strength. Incorporation of bioactive filler particles that release calcium and fluoride ions, might help eliminate white spot lesions that often form around the brackets during treatment. This project developed and tested the calcium ion-releasing capability of such an adhesive.
Methods: A mixture of BisGMA and EOBPADMA monomers were combined with 4-(Dimethylamino)-Benzoic Acid Ethyl Ester and Camphorquinone to create a light polymerizable mixture. Bioactive glass (BAG) (85mol% SiO2, 11mol% CaO, 4mol%) was synthesized in our laboratory. BAG was ground to a particle size of <6 micrometer and treated to create and adsorbed coating of xylitol (BAG-X). BAG-X was added and blended into the monomer mixture at a filler load of 55 %.
A custom polyvinyl siloxane (PVS) mold was used to prepare discs 8mm x 1 mm thick. They were polymerized with a Bluephase LED (Ivoclar Vivadent, Amherst, NY) at >100mW/cm2 for 20 sec./side. Discs were also made from Transbond XT (3M Unitek, Monrovia, CA) for comparison. Each disc was individually stored in either 10 mL of RO water or 10 mL of artificial saliva. Ca ion-release was measured daily for up to 7 days, and weekly for up to 91 days using an ion selective electrode (PerfectION, Mettler Toledo, Columbus, OH). A Student’s t-test was used to look at differences between independent groups with α=0.05.
Results: The concentration of calcium ions released from the experimental BAG-X-containing adhesive into both the artificial saliva and the RO water was statistically higher than that released from the Transbond XT at every time point examined.
Conclusions: The experimental adhesive containing BAG-X released high levels of calcium that may be advantageous in vivo by helping to prevent caries formation around orthodontic brackets on teeth.
Methods: A mixture of BisGMA and EOBPADMA monomers were combined with 4-(Dimethylamino)-Benzoic Acid Ethyl Ester and Camphorquinone to create a light polymerizable mixture. Bioactive glass (BAG) (85mol% SiO2, 11mol% CaO, 4mol%) was synthesized in our laboratory. BAG was ground to a particle size of <6 micrometer and treated to create and adsorbed coating of xylitol (BAG-X). BAG-X was added and blended into the monomer mixture at a filler load of 55 %.
A custom polyvinyl siloxane (PVS) mold was used to prepare discs 8mm x 1 mm thick. They were polymerized with a Bluephase LED (Ivoclar Vivadent, Amherst, NY) at >100mW/cm2 for 20 sec./side. Discs were also made from Transbond XT (3M Unitek, Monrovia, CA) for comparison. Each disc was individually stored in either 10 mL of RO water or 10 mL of artificial saliva. Ca ion-release was measured daily for up to 7 days, and weekly for up to 91 days using an ion selective electrode (PerfectION, Mettler Toledo, Columbus, OH). A Student’s t-test was used to look at differences between independent groups with α=0.05.
Results: The concentration of calcium ions released from the experimental BAG-X-containing adhesive into both the artificial saliva and the RO water was statistically higher than that released from the Transbond XT at every time point examined.
Conclusions: The experimental adhesive containing BAG-X released high levels of calcium that may be advantageous in vivo by helping to prevent caries formation around orthodontic brackets on teeth.