**6.1. Mechanical debracketing**

Three mechanical debracketing techniques have been described. These are lift-off, wrenching, and delamination [46]. The first technique uses a lift-off debracketing instrument (LODI). This pistol-grip plier is placed over the bracket, and a debracketing force is applied to the tie-wings of the bracket. It has been pointed out that the LODI cannot be used with ceramic brackets due to their brittleness [39]. The wrenching technique uses a special tool that produces a wrenching or torsional force at the base of the bracket [46]. This approach, providing a rotational shear force, can be likened to the turning of a door knob.

The delamination technique was the first technique introduced and is still reported to be the most widely accepted ceramic bracket removal technique [11, 15]. This technique involves the application of a slow squeezing force with the sharp blades of the debracketing pliers placed on the enamel surface and within the adhesive, thereby producing a wedging effect (**Figure 5**).

It has been stated that such a force—produced by a slow, gradual compression—would seem to offer the best chance for inducing crack propagation within the adhesive, leading to a cohesive failure, thus minimizing the risk of enamel damage as well as the risk of bracket fracture. A cohesive bond failure is a failure through a single material, where cohesive forces between the same atomic species are present [2, 11, 21, 46].

a tooth with enamel cracks and/or a large restoration, should be avoided as much as possible. This type of tooth is under greater risk for enamel damage when compared with a healthy tooth during mechanical debracketing [21, 39]. Care also has to be exercised with porcelain

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During the bonding procedure, excess adhesive flash (EAF) must be removed with an explorer before the adhesive has set or with burs after setting. Only meticulous EAF removal allows the sharp-edged plier blades of the debracketing instrument to be fully seated on the enamel during ceramic bracket removal. This produces a safe force transmission and crack propagation through the adhesive, resulting in a cohesive failure within the adhesive, thereby protecting enamel as well as bracket integrity [2, 11, 21]. Furthermore, EAF removal improves

It should be noted that a flash-free adhesive-coated appliance system was introduced. This

Unfortunately, debracketing may lead to bracket fracture. Bracket fragments may detach (loose fragments) or remain attached on the enamel surface. Low-speed or high-speed grinding of the bracket fragments with no water coolant may bring forth permanent damage and necrosis of the dental pulps. Therefore, water cooling is absolutely necessary during the grinding/removal of ceramic bracket fragments [10, 55]. Furthermore, high-volume suction next to the area of grinding has been emphasized in order to minimize the spreading of ceramic particles [10, 55]. These particles have been reported to cause irritation of the eyes as well as itching of the hands [55]. After the removal of these fragments, the clinician can proceed with

Loose, fractured ceramic bracket fragments may create serious problems, such as aspiration or ingestion of these radiolucent fragments. Furthermore, during debracketing, the "popping off" of fragments may occur. This may subject the patient as well as the orthodontist to eye injury. The use of protective eyewear and a mask is indispensable for the orthodontist. The

The force applied during debracketing may cause discomfort. Therefore, the orthodontist should always support the teeth with his or her fingers or make the patient bite firmly into a cotton roll during debracketing. Biting firmly into a cotton roll and/or gauze not only minimizes discomfort but also minimizes the risk of brackets and/or fragments from getting displaced into the oral cavity [21, 34]. Colored cotton rolls may facilitate the detection of frac-

If pliers are used for debracketing, Bishara and Fehr [21] advised the renewal of the plier blades after the removal of 50 brackets. Pliers with nonexchangeable blades should be sharpened on a regular basis [21]. Sharp-edged plier blades are required for safe debracketing, i.e., for the induction of crack propagation within the bonding adhesive rather than the enamel or the ceramic bracket. The orthodontist should never delegate ceramic bracket debracketing to

It has been emphasized that every informed consent form signed by the patient/parents (and the orthodontist) should specifically outline the potential risks of ceramic brackets,

restorations, such as crowns and veneers [51].

esthetics by providing a clean and neat appearance.

adhesive remnant removal.

tured ceramic bracket fragments.

auxiliaries [21, 56].

innovative technology does not necessitate flash removal [54].

patient should be given protective eyewear as well [21, 34, 56].

**Figure 5.** Schematic presentation of the delamination technique.

In 1993, Bishara and Fehr [47] evaluated the force levels produced with wide and narrow blades during ceramic bracket removal from human maxillary molar teeth. The wide blades and narrow blades were 3.2 and 2 mm, respectively. Polycrystalline ceramic brackets relying on a combination of mechanical and chemical retention were used. The findings of this in vitro study indicated that the narrow blades produced a significantly lower mean debracketing force, namely 120 kg/cm<sup>2</sup> than the wider blades (150 kg/cm<sup>2</sup> ). Bishara and Fehr [47] concluded that such a significant reduction (20%) in the debracketing force places less stress on the enamel surface, thereby reducing the risk of enamel damage. It has been reported and reiterated that debracketing forces larger than 138 kg/cm<sup>2</sup> , i.e., 13.53 MPa should be avoided [11, 48, 49].

In 2000, Arici and Minors [50] carried out an in vitro study with four different methods of debracketing. They pointed out that reducing the contact area, i.e., contact area between the plier blades and the adhesive, to a minimum reduces the force necessary to initiate ceramic bracket removal. Macroscopically, no enamel damage and no bracket fractures were reported. Arici and Minors [50] used primary bovine mandibular incisor teeth and polycrystalline ceramic brackets with chemical retention. They concluded that their findings basically corroborate the findings of Bishara and Fehr [47].

Following the introduction of ceramic brackets, more than 30 years ago, serious complications during debracketing were encountered [4, 7, 11, 13, 51, 52]. Many in vitro studies, to assist in the development of more reliable and clinically safe ceramic brackets, followed. The reduction of ceramic debracketing forces, thereby protecting enamel integrity as well as bracket integrity, was the aim of these studies [11, 47, 48, 50].

Nowadays, the majority of ceramic bracket manufacturers present detailed debracketing instructions. In fact, many manufacturers have introduced debracketing instruments specifically designed for their bracket brand. These manufacturers claim that their brackets can be removed as easily and as safely as metal brackets as long as the orthodontist meticulously follows these instructions [4, 11, 13, 15]. As a risk management strategy, ceramic brackets that are not accompanied by detailed instructions for bonding and debracketing should definitely not be used.

Any shortcomings related to ceramic brackets should be reported immediately to the manufacturer [7]. "First, do no harm" should serve as the fundamental guiding principle for anyone engaged in health care [53].

#### **6.2. Precautions for mechanical debracketing**

Bonding a ceramic bracket to a compromised tooth, such as a brittle, nonvital tooth (endodontically treated tooth), a tooth with developmental defects, a tooth with demineralized enamel, a tooth with enamel cracks and/or a large restoration, should be avoided as much as possible. This type of tooth is under greater risk for enamel damage when compared with a healthy tooth during mechanical debracketing [21, 39]. Care also has to be exercised with porcelain restorations, such as crowns and veneers [51].

During the bonding procedure, excess adhesive flash (EAF) must be removed with an explorer before the adhesive has set or with burs after setting. Only meticulous EAF removal allows the sharp-edged plier blades of the debracketing instrument to be fully seated on the enamel during ceramic bracket removal. This produces a safe force transmission and crack propagation through the adhesive, resulting in a cohesive failure within the adhesive, thereby protecting enamel as well as bracket integrity [2, 11, 21]. Furthermore, EAF removal improves esthetics by providing a clean and neat appearance.

In 1993, Bishara and Fehr [47] evaluated the force levels produced with wide and narrow blades during ceramic bracket removal from human maxillary molar teeth. The wide blades and narrow blades were 3.2 and 2 mm, respectively. Polycrystalline ceramic brackets relying on a combination of mechanical and chemical retention were used. The findings of this in vitro study indicated that the narrow blades produced a significantly lower mean debracketing

that such a significant reduction (20%) in the debracketing force places less stress on the enamel surface, thereby reducing the risk of enamel damage. It has been reported and reiterated that

In 2000, Arici and Minors [50] carried out an in vitro study with four different methods of debracketing. They pointed out that reducing the contact area, i.e., contact area between the plier blades and the adhesive, to a minimum reduces the force necessary to initiate ceramic bracket removal. Macroscopically, no enamel damage and no bracket fractures were reported. Arici and Minors [50] used primary bovine mandibular incisor teeth and polycrystalline ceramic brackets with chemical retention. They concluded that their findings basically corroborate the

Following the introduction of ceramic brackets, more than 30 years ago, serious complications during debracketing were encountered [4, 7, 11, 13, 51, 52]. Many in vitro studies, to assist in the development of more reliable and clinically safe ceramic brackets, followed. The reduction of ceramic debracketing forces, thereby protecting enamel integrity as well as bracket

Nowadays, the majority of ceramic bracket manufacturers present detailed debracketing instructions. In fact, many manufacturers have introduced debracketing instruments specifically designed for their bracket brand. These manufacturers claim that their brackets can be removed as easily and as safely as metal brackets as long as the orthodontist meticulously follows these instructions [4, 11, 13, 15]. As a risk management strategy, ceramic brackets that are not accompanied by detailed instructions for bonding and debracketing should definitely not be used.

Any shortcomings related to ceramic brackets should be reported immediately to the manufacturer [7]. "First, do no harm" should serve as the fundamental guiding principle for anyone

Bonding a ceramic bracket to a compromised tooth, such as a brittle, nonvital tooth (endodontically treated tooth), a tooth with developmental defects, a tooth with demineralized enamel,

). Bishara and Fehr [47] concluded

, i.e., 13.53 MPa should be avoided [11, 48, 49].

than the wider blades (150 kg/cm<sup>2</sup>

force, namely 120 kg/cm<sup>2</sup>

14 Current Approaches in Orthodontics

debracketing forces larger than 138 kg/cm<sup>2</sup>

**Figure 5.** Schematic presentation of the delamination technique.

findings of Bishara and Fehr [47].

engaged in health care [53].

**6.2. Precautions for mechanical debracketing**

integrity, was the aim of these studies [11, 47, 48, 50].

It should be noted that a flash-free adhesive-coated appliance system was introduced. This innovative technology does not necessitate flash removal [54].

Unfortunately, debracketing may lead to bracket fracture. Bracket fragments may detach (loose fragments) or remain attached on the enamel surface. Low-speed or high-speed grinding of the bracket fragments with no water coolant may bring forth permanent damage and necrosis of the dental pulps. Therefore, water cooling is absolutely necessary during the grinding/removal of ceramic bracket fragments [10, 55]. Furthermore, high-volume suction next to the area of grinding has been emphasized in order to minimize the spreading of ceramic particles [10, 55]. These particles have been reported to cause irritation of the eyes as well as itching of the hands [55]. After the removal of these fragments, the clinician can proceed with adhesive remnant removal.

Loose, fractured ceramic bracket fragments may create serious problems, such as aspiration or ingestion of these radiolucent fragments. Furthermore, during debracketing, the "popping off" of fragments may occur. This may subject the patient as well as the orthodontist to eye injury. The use of protective eyewear and a mask is indispensable for the orthodontist. The patient should be given protective eyewear as well [21, 34, 56].

The force applied during debracketing may cause discomfort. Therefore, the orthodontist should always support the teeth with his or her fingers or make the patient bite firmly into a cotton roll during debracketing. Biting firmly into a cotton roll and/or gauze not only minimizes discomfort but also minimizes the risk of brackets and/or fragments from getting displaced into the oral cavity [21, 34]. Colored cotton rolls may facilitate the detection of fractured ceramic bracket fragments.

If pliers are used for debracketing, Bishara and Fehr [21] advised the renewal of the plier blades after the removal of 50 brackets. Pliers with nonexchangeable blades should be sharpened on a regular basis [21]. Sharp-edged plier blades are required for safe debracketing, i.e., for the induction of crack propagation within the bonding adhesive rather than the enamel or the ceramic bracket. The orthodontist should never delegate ceramic bracket debracketing to auxiliaries [21, 56].

It has been emphasized that every informed consent form signed by the patient/parents (and the orthodontist) should specifically outline the potential risks of ceramic brackets, 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 transfer to another orthodontist.

debracketing procedure, water spray is mandatory to prevent pulp damage. This method requires further testing and is not yet recommended for clinical use [11, 21]. No clinical stud-

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

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].

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

The physical properties as well as rebonding and debonding of monocrystalline and polycrystalline alumina ceramic brackets were reviewed. Ceramic brackets fabricated from polycrystalline zirconium oxide (zirconia) were not mentioned. Thus, we would like to add a short

Zirconia ceramic brackets, manufactured in Japan and Australia, have attracted interest in the past [12]. Nevertheless, problems concerning color (yellowish tint) and opacity (nontranslucency) were reported approximately three decades ago [12, 70]. Furthermore, no significant advantage of zirconia brackets over alumina brackets with regard to their frictional characteristics were reported [71]. Limited published research on zirconia (zirconium oxide) brackets exists [72].

In an increasingly demanding and litigious society, it is mandatory for the orthodontist to use carefully designed ceramic brackets. As a simple risk management strategy, ceramic brackets

this device may be a disadvantage for the orthodontist [11, 21].

paragraph about these brackets for the interested reader.

ies were encountered upon a literature search.

**6.5. Electrothermal debracketing**

for the removal of metallic brackets.

**6.6. Laser debracketing**

**7. Last but not least**

**8. Conclusion**
