Drilling is the process of using a rotating tool to cut into or through a material, creating holes, removing damaged sections, or shaping surfaces. In everyday life, most people encounter drilling in two contexts: construction and dentistry. If you’re searching this term, there’s a good chance you have a dental appointment coming up. Dental drilling remains the most common method for removing tooth decay and preparing a tooth for a filling, and understanding how it works can take some of the anxiety out of the experience.
How Dental Drilling Works
When a cavity forms, bacteria eat through the hard outer enamel and into the softer layer underneath called dentin. A dentist uses a drill (formally called a handpiece) to cut away that infected tissue, then fills the resulting space with a restoration material to rebuild the tooth’s structure. The goal is simple: remove every trace of decay while preserving as much healthy tooth as possible.
Dental drills come in two main varieties. High-speed handpieces spin at 200,000 to 400,000 revolutions per minute and are used for cutting through hard enamel quickly. Low-speed handpieces run at 5,000 to 40,000 RPM and give the dentist finer control for finishing work, polishing, and shaping softer tissue. During a typical cavity filling, your dentist will likely use both: the high-speed drill to open the tooth and remove the bulk of the decay, then the slower one to refine the edges and prepare the surface for the filling.
What You Feel During the Procedure
Tooth pain from drilling happens because of fluid movement inside tiny tubes that run through the dentin layer. When the drill contacts these tubes, the rapid shift in fluid stimulates nerve endings just below the surface, producing that characteristic sharp, quick sting. This is the reason local anesthesia is standard for anything beyond the most superficial work.
Once the numbing injection takes effect, you won’t feel pain from the drill itself. What you will notice is pressure, vibration, and noise. Modern high-speed drills produce sound levels around 91 to 102 decibels, roughly comparable to a lawnmower or a loud motorcycle. The high-pitched whine is the signature sound of dentistry, and while it’s not dangerous for patients during a short visit, it’s loud enough that dental professionals who hear it all day need hearing protection.
If a cavity is deep and the drill gets close to the pulp (the soft tissue at the center of the tooth containing nerves and blood vessels), a different type of nerve fiber activates. These deeper fibers produce a slower, more diffuse, burning sensation rather than a sharp sting. When this kind of pain shows up, it can signal that the damage has reached the inner nerve tissue, which sometimes means a more involved treatment is needed.
Risks of Drilling
The main risk during dental drilling is heat. Friction from a spinning drill tip generates significant warmth in the surrounding tissue. In bone surgery, temperatures above 47°C (about 117°F) sustained for even one minute cause the bone cells to die permanently. Dental drills carry a similar concern for tooth structure, which is why modern handpieces spray a constant stream of water onto the contact point. That water serves double duty: cooling the tissue and flushing away debris so the dentist can see clearly.
Drilling too close to the pulp chamber can also inflame the nerve inside the tooth, a condition called pulpitis. In mild cases, the inflammation resolves on its own after the filling is placed. In more severe cases, the nerve damage becomes irreversible and a root canal is the next step. Skilled technique and imaging help minimize this risk, but it’s inherent to any procedure involving deep decay.
Laser Dentistry as an Alternative
Lasers offer a newer approach that uses focused light energy instead of a spinning bit to remove decay, reshape gum tissue, and sanitize surfaces. Because the beam targets only the treated area, it tends to leave more surrounding healthy tissue intact. Patients typically experience less noise, less vibration, and a gentler overall sensation compared to a traditional drill. Some small cavities and minor soft-tissue procedures can even be treated with little or no local anesthesia, which means less post-visit numbness.
Lasers do have limits. They work best on small lesions, early-stage decay, and minor gum reshaping. Deep cavities, cracked teeth, and large failing restorations still require traditional drilling because the mechanical drill can reach difficult angles and remove damaged tissue more thoroughly. For complex dental work, the conventional handpiece remains the more reliable tool.
Drilling in Bone Surgery
Outside of dentistry, drilling plays a critical role in orthopedic and trauma surgery. Surgeons drill into bone to place screws, pins, and plates that stabilize fractures or anchor joint replacements. The physics are similar to dental drilling but scaled up: a rotating bit cuts through the hard outer layer of bone (cortex) while the surgical team manages heat buildup to prevent tissue death.
The 47°C threshold for bone cell death is the key safety benchmark. Surgical drill bits are designed with specific geometry, including angled tips, thinned central edges, and stepped profiles, to reduce the force and friction needed to penetrate bone. Lower force means less heat. Irrigation with saline solution during the procedure serves the same cooling purpose as the water spray in a dental handpiece. When bone overheats during drilling, the dead tissue can’t support the implanted hardware properly, leading to loosening or failure of the repair.
A Brief History of the Dental Drill
For most of human history, treating a decayed tooth meant pulling it out entirely. Hand-operated drills existed in various forms, but they were slow, imprecise, and painful. The breakthrough came in 1875, when George F. Green, a dentist from Kalamazoo, Michigan, patented the first electric dental drill. Powered by a small electric motor, it dramatically reduced both drilling time and patient discomfort while improving precision. The patent was assigned to Samuel S. White, then a major dental manufacturing company, and electric handpieces quickly became the standard. The air-turbine drill followed in the mid-20th century, pushing speeds into the hundreds of thousands of RPM and enabling the fast, water-cooled procedures used today.