The hidden dangers of metal braces: what patients need to know

Metal braces remain the most widely used orthodontic tool in the world. Yet their use carries a set of documented medical risks that patients are not always informed about before starting treatment. This article reviews the main clinical complications associated with conventional fixed appliances.

One of the most common — and least discussed — complications is enamel demineralisation, clinically known as "white spot lesions." These spots appear around metal brackets due to the accumulation of bacterial plaque in areas that are difficult to clean. Plaque produces acids that progressively dissolve minerals from the enamel, leaving opaque, whitish and rough areas on the tooth surface.

• Estimated prevalence of 38 to 72% of patients wearing braces (Cochrane meta-analysis)
• Lesions appear as early as 4 to 8 weeks after bracket placement
• Some stains are permanent and require remineralisation or aesthetic restoration
• Molars and canines are the most exposed

Metal brackets, arches and ligatures cause repeated mechanical friction against the oral mucosa — the cheeks, lips and tongue. These microtraumas give rise to canker sores, ulcerations and areas of chronic irritation that make chewing painful and diminish daily quality of life, sometimes throughout the entire duration of treatment (12 to 24 months on average).

Contrary to popular belief, these pains do not "go away with time" for all patients: 30% of fixed appliance wearers report persistent mucosal discomfort throughout treatment, according to orthodontic literature.

Fixed appliances create ecological niches favourable to the proliferation of periodontopathogenic bacteria. The accumulation of plaque and tartar around brackets leads to gingival inflammation (gingivitis), which can progress to periodontitis if pre-existing periodontal health is compromised. Studies show a significant increase in gingival pocket depth in orthodontic patients wearing metal braces.

• 80% increase in gingival bleeding in the first 3 months of wear
• Gingival hyperplasia (abnormal gum growth) possible around brackets
• Risk of permanent gingival recession if therapy is not rigorously monitored
• Patients with active periodontal disease: conventional orthodontic treatment contraindicated

The metal alloys used in conventional brackets contain nickel (8 to 12%) and chromium. Nickel allergy is the most common contact dermatitis in Europe and North Africa, affecting approximately 12% of the female population and 2% of the male population. An allergy not detected before placement can manifest as oral ulcerations, peri-oral skin rashes, swelling and uncontrollable chronic inflammation.

Bracket debonding is a common complication in fixed orthodontics — it is estimated that between 5 and 20% of brackets detach during a standard treatment. Each debonding interrupts the orthodontic mechanism, delays treatment and exposes the tooth surface to the risk of enamel fracture during rebonding. If accidentally swallowed, small metal components can in rare cases pose a risk to the airways of young patients.

Clear aligners — such as those developed by Infinity Aligner — eliminate or drastically reduce all of these complications. The absence of brackets removes plaque niches and mucosal trauma. The removability of the trays allows normal brushing and flossing, reducing the caries risk to a level comparable to patients without treatment. Medical thermoplastic materials contain no nickel or chromium. Precise digital monitoring minimises unplanned movements. This is why a growing number of certified orthodontists direct eligible patients towards this alternative.

Metal braces are not without risk. Demineralisation, trauma, periodontal complications and allergies represent real medical risks. If your clinical case allows it, ask your dentist to present alternatives — particularly certified clear aligners — before initiating conventional orthodontic treatment.