Orthodontic bonding is the process of attaching orthodontic appliances, such as braces, to the surface of teeth. This procedure uses a unique adhesive material, often called dental cement, which creates a strong connection between the bracket and the tooth enamel. The bond ensures the appliance remains firmly in place throughout treatment, allowing it to apply continuous, gentle forces for guiding teeth into their desired positions.
The Bonding Process
The process of attaching orthodontic brackets begins with a thorough cleaning of the tooth surfaces. A polishing paste removes plaque or debris, ensuring a clean foundation for the adhesive. The teeth are then gently air-dried, often with a cheek retractor to maintain a dry field, which is important for the adhesive to bond effectively.
Next, an etchant, usually a phosphoric acid gel, is applied to the tooth enamel for 15 to 30 seconds per tooth. This etching creates microscopic pores on the enamel surface, enhancing its roughness for a stronger mechanical bond. After the etchant is rinsed off with water and the tooth is dried again, a primer or bonding agent is applied. This liquid helps prepare the etched enamel to receive the adhesive, promoting a chemical bond.
With the tooth surface prepared, a specialized bonding adhesive, often a resin-based cement, is applied to the back of each bracket. The orthodontist carefully places each bracket onto its precise location on the tooth. Any excess adhesive is removed to ensure a clean finish. Finally, a curing light, which emits a specific wavelength of blue light, is used to harden the adhesive. This light activates a photoinitiator within the adhesive, causing it to rapidly polymerize and create a durable bond between the bracket and the tooth, taking about 10-15 seconds per bracket.
Direct Versus Indirect Bonding
Orthodontic bonding can be performed using two techniques: direct bonding and indirect bonding. Direct bonding, the more traditional method, involves the orthodontist placing each bracket individually onto the patient’s teeth during the appointment. This allows for immediate adjustment of each bracket’s position as it is placed, with the adhesive cured directly in the mouth.
Indirect bonding offers an alternative approach, where the brackets are first precisely positioned on a 3D model of the patient’s teeth in a laboratory setting. Once ideal placement is achieved on the model, a custom-made transfer tray, often made of silicone or plastic, is fabricated to pick up the brackets in their exact positions. This tray is then used to transfer and bond multiple brackets simultaneously during the clinical appointment.
One of the main advantages of indirect bonding is its potential for increased precision in bracket placement, as the lab setting allows for more controlled and detailed positioning. This can lead to more accurate tooth movement. While in-office chair time for the patient may be shorter with indirect bonding, the overall process, including lab work, can take longer than direct bonding. Some studies suggest direct bonding may result in slightly higher shear bond strength, though other research indicates no significant difference.
Caring for Bonded Brackets
Maintaining proper oral hygiene is important when wearing bonded brackets to prevent plaque buildup, tooth decay, and gum issues. Brushing your teeth at least two to three times a day, or after every meal and snack, is recommended. Using a soft-bristled toothbrush and fluoride toothpaste, angle the brush above and below the brackets, moving in small circular motions to clean all surfaces of each tooth and bracket.
Flossing requires more attention with braces, but it remains a necessary part of daily care. A floss threader or specialized orthodontic floss can guide the floss under the archwire and between teeth to remove trapped food particles and plaque. Interdental brushes or water flossers can also be useful tools for cleaning around brackets and wires where a regular toothbrush may not reach effectively.
Dietary adjustments are also important to protect the bonded brackets and wires. Patients are generally advised to avoid hard, sticky, or chewy foods that can damage the brackets or dislodge them. Examples include hard candies, nuts, popcorn, caramel, and chewing gum. If a bracket becomes loose or detached, contacting the orthodontist promptly is recommended to have it re-bonded and avoid treatment delays.
The Debonding Procedure
The debonding procedure marks the final step in orthodontic treatment, involving the removal of brackets and wires from the teeth. This process is quick and designed to be comfortable for the patient. The orthodontist uses a special tool, often a debonding plier, to gently squeeze or lift the base of each bracket. This action causes the adhesive bond between the bracket and the tooth enamel to break, allowing the bracket to be removed.
Patients may experience a feeling of pressure or a slight “pop” as each bracket is dislodged, but it is not painful. After all the brackets and wires are removed, some residual adhesive may remain on the tooth surfaces. The orthodontist then uses a slow-speed handpiece with a polishing bur or pumice to carefully scrape and polish away any remaining adhesive, restoring the smooth surface of the tooth enamel. This final polishing ensures the teeth are clean and ready for the next phase, which usually involves wearing a retainer to maintain the newly aligned smile.