Orthodontic adhesive is a specialized material used to secure orthodontic appliances, such as braces, to teeth. It creates a strong, lasting bond that withstands chewing and orthodontic forces. It allows brackets to remain firmly in place, anchoring wires to guide teeth into desired positions for a straighter smile.
What is Orthodontic Adhesive?
Orthodontic adhesive is a dental cement or resin specifically formulated for bonding orthodontic brackets to tooth enamel. It ensures a secure attachment between the bracket and the tooth surface. The material is highly biocompatible, meaning it is safe for oral use. This adhesive provides the stable foundation for controlled forces to effectively move teeth.
The adhesive must withstand daily mechanical stresses, including those from eating and the continuous pressure from archwires and elastic bands. Despite strong bonding, it is engineered for eventual removal without damaging tooth enamel. Its composition ensures minimal water absorption and a thin film thickness, contributing to its effectiveness.
How Orthodontic Adhesives Work
Applying orthodontic adhesives involves several steps to ensure a strong bond. First, the tooth surface is cleaned to remove plaque or debris, creating an optimal bonding environment. Next, an acidic solution, often 37% orthophosphoric acid, is applied to the enamel. This etching roughens the microscopic tooth surface, creating tiny pores that enhance mechanical interlocking with the adhesive.
After etching, the tooth surface is rinsed and dried, followed by primer or bonding agent application. This liquid penetrates the etched enamel, preparing it for the main adhesive. The adhesive is then applied to the back of the bracket, which is positioned onto the tooth. Excess adhesive is removed, and a special blue light, typically around 470 nanometers, hardens or “cures” the adhesive through light curing.
The bond combines mechanical and chemical adhesion. Mechanical bonding occurs as the adhesive flows into microscopic irregularities created by etching on the tooth surface and the bracket’s mesh base, interlocking the materials. Chemical bonding also contributes, as the adhesive forms molecular attractions with both the treated enamel and the bracket. This dual mechanism ensures a secure attachment that withstands orthodontic forces.
Types of Orthodontic Adhesives
Orthodontic adhesives fall into two main categories: resin-based adhesives and glass ionomer cements. Resin-based adhesives, such as composite resins and light-cured resins, are widely used due to their strong bond strength and aesthetic qualities. These materials are activated by a special light, allowing orthodontists ample time to position brackets before hardening. They offer reliable adhesion and are often clear or tooth-colored, making them less noticeable.
Glass ionomer cements (GICs) and their modified versions, RMGICs, offer an alternative. GICs are known for their ability to release fluoride, which helps prevent demineralization around the brackets, a common concern during treatment. While conventional GICs may have lower initial bond strength than resin composites, RMGICs combine properties of both, aiming for improved bond strength while retaining fluoride-releasing benefits. These hybrid materials are useful where moisture control is challenging or for patients at higher cavity risk.
Maintaining and Removing Orthodontic Adhesives
Maintaining oral hygiene is important when orthodontic adhesives are in place, as the brackets and adhesive can create areas where food particles and plaque accumulate. Thorough brushing around each bracket and along the gumline is necessary to prevent plaque buildup and maintain gum health. Flossing with specialized tools for braces also helps clean between teeth and under archwires, minimizing cavity and gum inflammation risk throughout treatment.
Once orthodontic treatment is complete, the brackets are carefully removed using specialized instruments that gently separate them from the tooth surface. While bracket removal is usually quick and painless, some residual adhesive often remains on the teeth. This leftover adhesive is then cleaned off by the orthodontist or dental professional. Tools like dental scalers, polishing burs, or ultrasonic scalers remove the adhesive without damaging the underlying enamel.
The professional removal process ensures that the tooth surface is restored to its smooth, natural state. Attempting to remove adhesive at home with abrasive methods can risk scratching or damaging the enamel, leading to tooth sensitivity or increased susceptibility to decay. Therefore, professional debonding and adhesive removal are important steps to protect dental health and ensure a clean, healthy smile after braces are taken off.