Veneers are thin, custom-made shells, typically crafted from porcelain or composite resin, which are bonded to the front surface of teeth to improve their appearance. While they are effective for correcting cosmetic imperfections like discoloration or minor chips, successful placement requires a completely healthy and stable foundation. Having pre-existing dental issues does not automatically disqualify someone from receiving veneers, but it nearly always means that preliminary dental work must be completed first. A thorough dental examination is necessary to determine the underlying health of the teeth and gums before any cosmetic treatment can begin.
Eligibility Criteria and Necessary Preliminary Treatments
The primary requirement for veneer placement is a stable oral environment, meaning all active disease must be resolved before proceeding. Active dental decay, or cavities, must be fully treated and filled because bonding requires a clean, solid tooth surface. Placing a veneer over a decaying tooth would trap bacteria, allowing decay to progress unseen beneath the restoration and leading to treatment failure.
Gum health is equally important, as active gum disease, whether gingivitis or periodontitis, creates an unstable foundation. Inflamed or bleeding gums can compromise the chemical bond between the veneer and the tooth due to fluid contamination. If veneers are placed on inflamed gums, the tissue may recede as it heals, exposing the margin and creating an unsightly appearance.
In cases of active gum disease, treatment such as scaling and root planing is necessary to promote healing. Dentists require a period of stable gum health, often several weeks, before proceeding with any cosmetic procedure. Veneers can often correct minor cosmetic issues such as small gaps or slight rotations, provided the overall bite is sound. Existing large fillings or crowns on the teeth being considered may also affect eligibility, sometimes necessitating a full crown instead of a veneer.
Structural Issues That Prevent Veneer Placement
Some dental conditions are considered absolute contraindications, preventing veneer placement even after preliminary treatments. Veneers rely entirely on the strength of the adhesive bond, which is strongest when attached to healthy enamel. Teeth that have suffered severe loss of enamel due to erosion, trauma, or aggressive wear may not retain the veneer effectively, making bonding unstable. In these instances, a full-coverage crown might be recommended instead, as crowns do not rely exclusively on enamel for retention.
Severe malocclusion, or bite issues, also present a significant problem because they place excessive and uneven force on the teeth. A severe crossbite or deep overbite can cause immense pressure that porcelain veneers are not designed to withstand, leading to a high risk of chipping, fracture, or debonding.
Parafunctional habits like uncontrolled bruxism (chronic teeth grinding or clenching) are another structural challenge. The intense, involuntary forces generated by bruxism can quickly destroy veneers. Patients with this habit must first address it, often through the use of a custom-fitted night guard, before cosmetic work can proceed.
The Enamel Reduction and Bonding Process
Assuming a patient is deemed eligible after all preliminary treatments, the first step is tooth preparation. The dentist removes a small amount of enamel from the front surface, typically between 0.3 and 0.7 millimeters, to accommodate the veneer’s thickness. This minimal reduction prevents the final restoration from appearing bulky or unnatural. The precise amount removed is also dictated by the desired final shade, as a dramatic color change requires a slightly thicker veneer.
After preparation, the dentist takes a precise impression or digital scan of the mouth, which is sent to a dental laboratory for custom fabrication. To protect the prepared teeth while the permanent veneers are being made, temporary veneers may be placed. These temporary restorations are spot-bonded with a soft resin to ensure easy removal without contaminating the tooth surface needed for the final bond.
The final appointment involves the permanent bonding process, which begins with etching the tooth surface to create microscopic roughness for mechanical retention. A specialized adhesive cement is applied to the etched surface and the inner surface of the veneer, which is then carefully seated onto the tooth. The cement is then hardened and cured using a high-intensity light, creating a durable chemical bond between the veneer and the tooth.