Dental veneers are thin, custom-made shells bonded to the front surface of teeth to correct issues like discoloration, chips, or minor misalignments. These porcelain or composite layers create a uniform and aesthetically pleasing smile. The process requires a permanent alteration to the natural tooth structure to ensure the final result looks seamless and not bulky.
The Necessary Tooth Preparation
Traditional veneer placement requires reducing the tooth’s outermost layer, the enamel, to create adequate space for the porcelain shell. This meticulous preparation allows the final veneer to sit flush with adjacent teeth and the gum line. Without this reduction, the added thickness would result in teeth that look unnaturally large or protruding. Dentists carefully remove a minimal amount of enamel, often ranging from 0.3 to 1.0 millimeter, depending on the veneer material and the tooth’s original position.
The amount of enamel removed is generally equal to the intended thickness of the veneer, typically about 0.5 millimeters. The primary goal is to preserve as much natural tooth structure as possible while ensuring a strong bond and an aesthetically natural outcome. Precision is paramount; removing too much enamel can weaken the tooth, while removing too little leads to a poor fit.
Visualizing the Altered Enamel
After preparation, the tooth surface is significantly altered before the final veneer is bonded. The previously smooth, glossy outer enamel is now a duller, rougher surface. This roughening, often achieved by micro-etching, is intentional, as it improves the mechanical grip and chemical bond of the dental cement. The contoured surface appears slightly smaller and reshaped to better accommodate the porcelain shell.
The most noticeable visual change is the color of the prepared tooth, which appears more yellow or slightly darker than its original shade. This shift occurs because the translucent white outer enamel layer has been reduced, exposing more of the underlying dentin. Dentin is naturally a deeper yellow tissue that makes up the bulk of the tooth structure. The tooth loses its natural luster and appears sculpted where the veneer will be placed.
Protecting the Prepared Tooth
The alteration of the enamel layer makes the underlying tooth structure vulnerable. Exposed dentin contains microscopic tubules leading directly to the pulp, which causes heightened sensitivity to temperature changes and air. This temporary sensitivity is a common side effect of enamel reduction and is managed by covering the prepared teeth while the permanent veneers are fabricated.
Temporary veneers, also known as provisionals, are placed immediately after the preparation visit. They protect the exposed dentin, shield the tooth from external stimuli, and maintain the patient’s ability to chew. They also serve an aesthetic purpose, offering a preview of the new smile, though their color and shape are not identical to the final porcelain veneers.
Since natural enamel does not regenerate, receiving traditional veneers is a long-term commitment. Once a tooth has been prepared, it must always be covered by a veneer or another dental restoration. The temporary covering protects the tooth during the two to three weeks it takes for the dental lab to craft the permanent veneers. During this waiting period, patients are advised to avoid sticky or hard foods that could dislodge the provisional shells.