ELECTROTHERMAL DEBRACKETING - PATIENT ACCEPTANCE AND EFFECTS ON THE DENTED PULP

Adhesives bond ceramic brackets so effectively that their removal by m echanical forces can fracture the brackets and may damage the tooth su rface. Electrothermal debracketers have been developed to facilitate r emoval; whether the heat generated will damage the underlying pulp is unclear. In our experiment, a prototype device with a high heat tip wa s used to remove brackets from premolars in patients. The following pa rameters were evaluated: (1) time required for removal, (2) patient ac ceptance, and (3) histologic effect on the pulp. Forty-eight experimen tal teeth planned for orthodontic extraction were bonded by a filled B is-GMA composite resin and a monocrystalline sapphire bracket. After t he chemically cured composite set, debracketing was performed accordin g to the manufacturer's recommendations. Seventeen premolars were not etched or bracketed and served as controls. The interval between heat application and removal of the bracket was timed. Patients were questi oned as to sensations during debracketing. Teeth were extracted at 5 t o 7 or 28 to 32 days and histologically prepared. Pulps were evaluated for alterations. Brackets were removed in an average of 2.1 seconds, usually at the bracket/composite interface. Patient acceptance was gen erally positive. Pulpal necrosis was not observed but, in a number of specimens, slight inflammation and odontoblastic disruption occurred a t both observation periods.