The decision to remove the brace is made after carefully examining the finishing and detailing procedures are completed. At this point, the plan for retention and the type of retainer to be used should have already been decided. Upper and lower alginate impressions are taken. The lower impression is used to fabricate a flexible spiral wire or rigid retainer. It is essential to accurately record the lingual and occlusal surfaces of the lower anterior segment up to the premolars. After removing the arch wire with brackets on, the upper impression should be taken. A retainer for the upper teeth is made from dental models by scraping the brackets and tubes using a sharp scalpel while the study models are still wet. The maxillary Hawley or Begg-type circumferential retainer is then made on these study models. The retainer should be ready to be given to the patient on the same day the brackets are removed.

The alternate protocol involves making a lower sectional impression of the anterior segment for the fabrication of the flexible wire retainer in the laboratory.

With current digital technology and workflow, an intra-oral scan and 3D-printed lingual retainer is an option for those who can afford the high cost of 3D printing. These aspects are discussed in the chapters 96 and 106 .

The lower flexible or rigid wire retainer is bonded prior to any debond procedure. The maxillary appliance is debonded next, and the retention appliance is issued.

The alternate protocol involves making an upper impression after complete debond. Two models are prepared. The first model is used to create a thermoplastic transparent retainer, which is issued within 2 h of debond. The second model is used for the fabrication of the Hawley’s retainer, which will be issued 1–2 weeks later.

Debanding of molar bands, debonding of the bonded appliance and accessories, and removal of residual adhesive and cement are diligently performed followed by a final cleanup of all tooth surfaces and polishing of teeth.

A review of oral health should involve recording gingival health with complete periodontal assessment, bone loss, assessment of new carious lesions, secondary caries and white spot lesions.

Oral cavity and dentition are critically examined for aesthetic dentistry procedures for improvement of tooth morphology, restoration of fractured enamel edges, aesthetic restoration of small-sized teeth for the creation of contact points and restoration/rehabilitation of missing or carious teeth. The patient is given instructions on oral hygiene and referral for review with his/her general dentist. Treatment of stains and hypoplastic lesions is planned. The upper and lower retention appliances are issued.

The second appointment is organised within a week to review the patient’s compliance with the retention advice in wearing the appliance, settling the occlusion and a review of oral health to prepare post-treatment records. A set of upper and lower study impressions is made to prepare post-treatment study models. Clinical photographs of the face and a set of intraoral pictures are shot. Post-treatment records include lateral cephalogram and panoramic view radiographs of the maxilla and mandible.

The author suggests clinical photographs and intraoral photographs within the first week of debonding which entail sufficient time for gingival bleeding and inflammation to settle down and any residual adhesive/molar band cement and stains left on tooth surfaces become apparent. The patient undergoes the second round of cleanup and polishing before clinical photography. It is important to note that the European Board of Orthodontics suggests that post-treatment models can be prepared within 4 weeks of debonding to be labelled as RED, ensuring the highest standard of care and treatment quality.

A regular follow-up is scheduled at 6 weeks, 3 months, 6 months and a year.

• 1.

  Squeezing brackets to create composite failure with debonding pliers : The mechanical methods require squeezing the mesial and distal wings of the bracket with debracketing instrument thereby distorting the bracket base, causing a bond failure at the bracket mesh and adhesive interface. This method is effective for removal of stainless-steel brackets but leaves them distorted, unsuitable for recycling or reuse. This process cannot be effectively used when an edgewise full-size wire is in place for this does not allow the bracket slot to squeeze.

  • It is also possible to squeeze the bracket wings in gingivo-occlusal direction with a sharp instrument, but it is less efficient than squeezing by holding mesio-distally ( Figs 104.3 and 104.4 ).

    

    Debonding pliers.

    (A) Debonding pliers for anterior teeth. (B) Debonding pliers for premolars. (C) Debonding by squeezing the twin bracket mesiodistally thus causing distortion of the bracket, which facilitates debonding.

    

    Two debonding techniques:

    (A) base method; (B) wings method.

    Source: Cited from Inchingolo F, Inchingolo AM, Riccaldo L, Morolla R, Sardano R, Di Venere D, et al. Structural and Color Alterations of Teeth following Orthodontic Debonding: A Systematic Review. J Funct Biomater. 2024 May 10;15(5):123. doi: 10.3390/jfb15050123. PMID: 38786634; PMCID: PMC11121904 .

• 2.

  Shearing force at composite bracket interface with a sharp-bladed instrument : The other mechanical method is to squeeze the bracket at its base, in occluso-gingival direction, and peel off the bracket. This method utilises use of sharp-edged debonding pliers or a ligature cutter, the sharp blades of which are engaged on each side of the bracket at the junction of bracket base on composite–enamel interface ( Fig. 104.5 ).

  • A careful placement of sharp edges of pliers holding them at the precise locations in a firm grip is required. The squeezing force is then applied which causes enamel composite adhesive failure, and the bracket is peeled off from the tooth surface. The tooth is supported with fingers of another hand at the occlusal or incisal end. The squeeze force is applied from palm grip without any other movement at wrist or elbow, to avoid transmitting jiggling force on the tooth.

  • This method can cause damage to enamel surface due to rubbing of sharp ends of pliers and site of failure being adhesive to enamel interface

  

  Debonding using sharp blades at the bracket enamel interface.

  (A) Ligature cutter as debonding pliers. (B) Ligature cutter being used create shearing forces by holding the sharp edges of pliers at composite bracket interface. (C) Debonding pliers to create shearing forces by holding the sharp edges of pliers at composite bracket interface.

• 3.

  The lift-off debonding instrument (LODI) (3M Unitek, Minnesota, USA): It is a specially designed instrument to be used for debonding of winged brackets. It has a wire loop that engages beneath a tie-wing and applies a shear force when the handles are squeezed. The feet of the instrument rest occlusal/gingival to the bracket on the labial tooth surface of the tooth crown. For the removal of orthodontic brackets, lift-off instrument is better accepted by patients compared to the ligature cutting pliers. Patients report two times lower pain compared to ligature cutters, but the amount of remaining adhesive on the teeth is same. Pithon et al. investigated the level of discomfort reported by patients during the removal of orthodontic metallic brackets performed with four different debonding instruments. The lower level of pain and discomfort was reported when metallic brackets were removed with the LODI and the use of a straight cutter plier caused the highest pain and discomfort scores during debonding.

• 4.

  Ultrasonic debracketing : Ultrasonic KJS and KJC tips used with Cavitron 2002 ultrasonic unit (Dentsply Sirona, North Carolina 28277, USA) were designed for removal of bonded Maryland bridges. The same technique has been inducted for debracketing of the orthodontic appliance. The KJS instrument tip is used at high power to create a purchase point within the adhesive between the bracket base and the enamel surface. ^, In this technique, the brackets are debonded with a decreased chance of enamel damage, a decreased likelihood of bracket failure and the ability for the removal of the residual adhesive with the same instrument after debracketing. The drawbacks of the ultrasonic technique include a notably prolonged debonding time, substantial wear of the expensive ultrasonic tips, the necessity of applying moderate force levels, which may induce discomfort in sensitive teeth, and the potential for soft tissue injury if the operator is not diligent. Using a water spray is imperative to mitigate heat build-up and reduce the likelihood of pulpal damage. While effective, the ultrasonic method is time-consuming and indicated when a ceramic bracket fractures and part of it remains affixed to the tooth during the use of the conventional bracket removal method.

Most ceramic brackets are made of either polycrystalline alumina, single-crystal alumina or zirconium. Polycrystalline brackets with metal slots are also commercially available. The porcelain brackets pose significant problems with their removal due to their physical properties, which are much different from stainless steel.

• •

  Porcelain brackets are harder than stainless steel brackets (nine times or more).

• •

  Porcelain brackets have higher tensile strength compared to SS brackets. Monocrystalline brackets have higher strength than polycrystalline ceramic brackets.

• •

  Porcelain brackets have low fracture toughness. Therefore, they quickly break after the application of force for debonding.

• •

  Ceramic brackets exhibit a high bracket bond strength, which necessitates the use of high forces to remove brackets, which is higher than mean linear tensile strength of enamel (14.5 MPa).

Therefore, debonding of porcelain brackets is associated with a high risk of damage to tooth enamel.

Mechanical debonding of porcelain brackets : Ceramic bracket debonding pliers are recommended by the manufacturers of porcelain brackets. The bracket can be squeezed with Weingart pliers, followed by sharp debonding pliers to create adhesive enamel bond failure ( Fig. 104.6 ).

Debonding using a squeeze action.

(A) Weingart pliers. (B) Debonding ceramic brackets by squeezing the bracket mesiodistally.

Some manufacturers supply and recommend pliers specially designed to work with their brand of brackets. It is important to follow the manufacturer’s guidelines specific to their product regarding debonding.

For example, 3M Unitek has patented a debonding slot and ‘stress concentrator’ located on the base of their clarity brackets. The manufacturer recommends debonding pliers REF 900–850 for clarity brackets. The debonding slot concentrates stress at this point, causing the bracket to collapse under gentle pressure from Howe or Weingart pliers ( Fig. 104.6 ).

This technique allows debonding in a similar method to metal brackets, with most of the residual adhesive remaining on the enamel surface. Their guidelines for debonding are as follows:

• •

  The arch wire is removed.

• •

  It is recommended to remove all composite adhesive around the base of brackets to be debonded especially on mesial and distal sides.

• •

  The debonding pliers are placed against mesial and distal sides in such a manner that edges of the instrument are symmetrically positioned against the labial surface of the bracket.

• •

  The pliers are pressed to squeeze the bracket till it collapses.

• •

  Once collapsed, it is presumed that bond failure has occurred. Rock the bracket gently to remove it from tooth.

• •

  The pliers’ beak may carry tiny pieces of ceramic brackets. Clean it or wipe it before using it on another bracket, to ensure even contacts and force distribution.

Problems associated with debracketing of porcelain brackets ^, : The high bonding strength of porcelain brackets with enamel necessitates the use of high shear stress when mechanical methods of bracket removal are used. The hard and brittle porcelain brackets have little scope for deformation under the debonding pliers’ squeeze pressure, causing their fracture with little or no possibility of bracket/adhesive failure. If the enamel adhesive failure occurs, it can cause damage to enamel surface, which may crack, get chipped off or delaminate along with bracket.

Fracture of ceramic bracket during debonding is not uncommon leaving its base attached to the enamel surface leading to great difficulty in its removal from enamel surface. The only option available is the use of a high-speed diamond bur. This process is time consuming and unpleasant for the patient. Grinding of ceramic materials over the tooth surface generates considerable heat with a potential for pulpal damage. Therefore, the use of only fresh high-speed diamond grinding stone with coolant spray is recommended. During grinding, large ceramic fragments may pop-up which pose the risk of aspiration of the radiolucent material by the patient and produce ceramic dust that has been associated with skin and eye irritation. ^,

Therefore, techniques and methods have been evolved whereby debracketing of ceramic brackets can be performed without damage to enamel surface. They are discussed in the following sections.