A dental filling is a restorative treatment that repairs a tooth damaged by decay or trauma. The procedure involves removing the compromised portion of the tooth and replacing it with a durable material like composite resin or amalgam. This process requires a precise sequence of specialized instruments, serving distinct purposes from initial examination to the final polish.
Initial Assessment and Isolation Instruments
The process begins with diagnostic instruments to confirm the presence and extent of the cavity. A small, angled dental mirror allows the dentist to see areas of the mouth obscured from direct view. The explorer, a slender, pointed instrument, is used to check the surface integrity and detect soft areas of decay in the enamel. This tactile examination supplements X-rays and visual inspection.
Isolation tools are used to keep the treatment area clean and dry, which is important for moisture-sensitive composite materials. A rubber dam is a thin sheet that fits over the tooth, isolating it from saliva and bacteria. Cotton rolls and a saliva ejector or high-volume aspirator are also used to manage moisture and debris.
Tools for Removing Decay and Shaping the Cavity
The physical removal of decayed material begins with a powered instrument called a handpiece. The high-speed handpiece operates at hundreds of thousands of rotations per minute, primarily used to cut through the outer enamel and for bulk decay removal. This device uses a coolant spray to prevent heat damage to the tooth.
Once the enamel is penetrated, the dentist switches to a low-speed handpiece or specialized hand instruments. The low-speed device rotates slower and provides greater tactile control when working close to the pulp, or nerve, of the tooth. Both handpieces utilize rotary cutting tools called burs; diamond burs are used for cutting enamel and carbide burs for preparing the underlying dentin. Spoon excavators, which have a curved, spoon-like tip, are used to scrape away soft, infected dentin.
Instruments for Material Placement and Packing
After the cavity is prepared, the filling material must be delivered and condensed into the space. For amalgam fillings, a specialized amalgam carrier acts like a small syringe, transporting the mixed material into the tooth. Condensers, also known as pluggers, are used to compress the material tightly against the cavity walls. This compression eliminates voids and achieves a dense, strong restoration that can withstand biting forces.
For composite resin fillings, specialized non-stick instruments are used to carry and shape the putty-like material. These instruments often feature a titanium nitride coating to prevent the sticky resin from adhering to the metal surface. Before placement, a matrix band and retainer system is applied. This thin strip encircles the tooth to create a temporary wall, providing the necessary contour and support to shape the filling material.
Sculpting, Curing, and Finishing Tools
Once the material is placed, the dentist sculpts the new filling to match the natural anatomy of the tooth. Carvers, such as the Hollenback or Discoid-Cleoid, are hand instruments used to define the grooves and ridges of the biting surface. These tools recreate the tooth’s contours, ensuring the filling blends seamlessly with the surrounding tooth and opposing teeth.
If composite resin is used, a high-intensity curing light hardens the material almost instantly. This process uses a specific wavelength of blue light to activate photoinitiators within the resin, converting the soft paste into a rigid, durable solid. After the material is set, the patient bites down on articulating paper, which leaves colored marks at points of high contact. These marks guide the dentist in using fine finishing burs and abrasive discs or strips to remove excess material and smooth the surface. Burnishers are used to impart a final polish, preventing plaque buildup.