**6.5. Electrothermal debracketing**

particularly in an ever-increasing litigious society [56]. Also, the brand of the ceramic bracket should always be recorded on the patient's file. This is of particular importance in the case of

Larmour and Chadwick [57] evaluated the ability of a commercial debonding agent, postdebonding agent (P-de-A) (Oradent Ltd., Eton, Berks, UK). This green gel, containing a derivative of peppermint oil, was claimed to facilitate ceramic bracket debracketing and adhesive residue removal. The manufacturer of P-de-A advised an application time of 1–2 min to soften the resin. Nevertheless, the P-de-A research results did not support these claims [57, 58].

In 1997, Arici et al. [59, 60] proposed the use of a crushable porous ceramic lamella as a means of facilitating debracketing. These porous lamellae were attached to the bracket base with adhesive resin. Subsequently, these bracket/lamella assemblies were bonded to the enamel of the experimental teeth (bovine incisor teeth). The authors [60] of this in vitro study reported the safe removal of these ceramic bracket/lamella assemblies, i.e., no fractures of the ceramic bracket or any evidence of enamel damage was observed. Commercial production of this type

In 1998, Larmour et al. [61] evaluated the possibility of reducing the complications of ceramic bracket debracketing by introducing a notch in the composite bond layer. A section of Mylar® matrix strip (0.01 mm thick and 0.75 mm wide) was placed within the bonding agent in this ex vivo investigation. After the bonding agent had set, the matrix strip was removed creating a "notched" bond layer. Larmour et al. [61] concluded that notching the bonding agent does facilitate ceramic bracket removal. Nevertheless, they emphasized that this modification is not feasible in a clinical setting due to the time needed and the technical difficulty of creating a "notched" bond layer. Furthermore, they cautioned that such a "notched" adhesive layer

In 2003, Carter [62] suggested that a hot-water bath might facilitate ceramic bracket debracketing. Patients were given a cup of hot water, supplied from a coffeemaker, and were asked to hold this water in their mouths for 1 min without swallowing. Subsequently, debracketing with suitable pliers was performed. Carter [62] emphasized that since 1986 no enamel fracture or any other iatrogenic damage occurred with this application in his clinic. Unfortunately, the

It was reported that the ultrasonic debracketing technique presents a decreased probability of enamel damage as well as a decreased probability of bracket fracture. Also, the residual adhesive remaining after debracketing can be removed with the same ultrasonic tip. Nevertheless, the debracketing time is the longest when compared with the mechanical or electrothermal debracketing techniques. It was reported that the debracketing time of the ultrasonic debonding technique is 38–50 s per bracket, when compared with 1 s per bracket with the mechanical debracketing technique. Furthermore, the contact between the "hard" ceramic bracket and the ultrasonic tip has been reported to cause wear of this expensive tip. During the ultrasonic

**6.3. Adjunctive methods proposed for mechanical debracketing**

of ceramic bracket/lamella assembly was not undertaken.

exact temperature of this "hot-water bath" was not stated.

transfer to another orthodontist.

16 Current Approaches in Orthodontics

may lead to plaque accumulation.

**6.4. Ultrasonic debracketing**

In 1986, Sheridan et al. [63] were the first who described electrothermal debracketing (ETD) for the removal of metallic brackets.

With ceramic brackets, ETD has been reported to cause a reduced incidence of bracket fracture. The reduced incidence of bracket fracture is ascribed to the small amount of force needed to break the bond after the heat-induced tip has promoted bond failure by softening/weakening the adhesive material. A relatively short debracketing time per bracket (2 ± 1 s) was reported. The possibility of pulp damage has been mentioned. Fortunately, no signs of irreversible pulp damage with ETD were described [11, 64–66]. Patient acceptance was generally positive [64].

#### **6.6. Laser debracketing**

Different types of lasers have been used for the debracketing of ceramic brackets [67]. The application of laser irradiation causes the softening of the adhesive material. This seems to be quite similar to ETD; however, with laser-assisted debracketing, the amount of thermal energy delivered to the ceramic bracket can be carefully controlled, thereby preventing the possibility of overheating [21, 68]. The time spent for ceramic bracket removal with the laserbased technique is 1–5 s. Debracketing forces are significantly reduced with lasers. As a result, enamel damage and bracket fracture risks are significantly reduced [67, 69]. The high cost of this device may be a disadvantage for the orthodontist [11, 21].
