Thermal debracketing of orthodontic resins.
Ten commercial brands of orthodontic bonding materials representing three modes of delivery systems (two-paste, no-mix, and powder/liquid) were used to bond stainless steel brackets to bovine teeth. Heat was applied to the bracket, and the temperature at debonding was noted for each type of resin. The two-paste systems required a higher temperature to debond than did the no-mix systems. The powder/liquid system required the lowest temperature. There is a direct relationship between filler content and debonding temperature. There is an inverse exponential relationship between debonding temperature and load needed to cause debracketing. Room-temperature debonding showed failure at the bracket/resin interface with evidence of cohesive enamel fracture. Thermal debonding showed no evidence of overt enamel fracture, and failure site shifted toward the tooth/resin interface. Ceramic brackets required almost twice the time to debracket than did stainless steel brackets.
School of Dentistry, Medical College of Georgia, Augusta.
F A
FA
Rueggeberg
P
P
Lockwood
D000818:Animals; D002417:Cattle; D002516:Ceramics; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements; D003799:Dental Stress Analysis; D006358:Hot Temperature; D009967:Orthodontic Appliances; D013193:Stainless Steel
D003738:Dental Cements; D013193:Stainless Steel