Dental veneers are thin, custom-made shells bonded to the front surface of teeth to improve appearance. The process requires structural alteration of the natural tooth, which fundamentally changes the shape and surface beneath the restoration. Understanding the underlying anatomy after this procedure is important for anyone considering this common dental treatment. This article details the appearance of the prepared tooth and the reasons behind the required structural changes.
Why Teeth Must Be Prepared for Veneers
Tooth preparation is required primarily to ensure the final restoration does not appear bulky or unnatural. Bonding a veneer directly onto an unprepared tooth would create an unnatural protrusion, which could irritate soft tissue near the gum line. The dentist removes a precise amount of tooth structure to accommodate the thickness of the veneer material.
This preparation typically involves the conservative removal of the outermost layer, enamel, ranging from approximately 0.3 to 0.7 millimeters. This reduction allows the new veneer to sit flush within the natural contours of the dental arch.
Preparation also creates an ideal surface texture for the bonding agent. The surface is subtly roughened, or etched, to maximize adhesion between the tooth and the veneer. Since enamel must be altered, the preparation process is considered permanent and irreversible.
The Appearance of the Prepared Tooth
Once preparation is complete, the tooth is noticeably smaller and has a distinct, altered shape. The front surface is smoothed down, but the contour is often slightly boxy or rectangular, lacking the natural curvature of the original tooth. The sides are often tapered inward, creating a smaller structure to which the veneer will attach.
The surface texture is no longer smooth and polished like natural enamel. Instead, it is intentionally left rough or micro-etched, which aids in the mechanical locking of the dental cement. This texture is perceptible to the tongue and makes the prepared tooth vulnerable until it is covered.
The most noticeable change is the color of the prepared structure. Since a portion of the white, translucent enamel is removed, the underlying layer, dentin, becomes exposed. Dentin naturally has a more yellow, brownish, or dull gray hue than enamel.
This exposure causes the prepared tooth to look significantly darker compared to adjacent, untouched teeth. This color difference is a normal result of exposing the dentin layer, which forms the majority of the tooth’s internal structure.
Immediate Care and Managing Sensitivity
The removal of enamel often leads to immediate, temporary sensitivity in the prepared tooth. This occurs because preparation exposes thousands of microscopic channels within the dentin, known as dentinal tubules. These tubules lead directly to the pulp, allowing external stimuli like air or cold to easily reach the nerve, causing discomfort.
To manage this sensitivity and protect the exposed dentin, the dentist places temporary restorations, often called temporaries. These temporary covers act as a physical barrier against bacteria and temperature changes while the permanent veneers are fabricated in a dental laboratory.
Temporaries also maintain the aesthetics and function of the mouth during the one to two weeks required for custom creation. They prevent adjacent teeth from shifting into the newly created space, which could complicate the seating and alignment of the final restoration.
Long-Term Health and Maintenance of the Underlying Tooth
Once the final veneer is bonded, the long-term health of the underlying tooth depends heavily on meticulous oral hygiene. Specific attention must be paid to the margin, which is the junction where the edge of the veneer meets the natural tooth structure near the gum line. This area is the most susceptible to plaque accumulation because it represents a microscopic seam.
The primary long-term concern is the risk of secondary decay, or cavities forming underneath the restoration. This occurs if bacteria penetrate a micro-gap that develops between the veneer and the tooth surface over time, often due to bond failure. The lack of a sealant in this seam allows bacteria to colonize the dentin structure beneath.
If decay occurs, the veneer must be completely removed to access and treat the compromised tooth structure. Treating decay often requires drilling away more of the original tooth, which further weakens the foundation. Extensive decay may mean the tooth is no longer strong enough for a new veneer and requires a full-coverage restoration, such as a dental crown.