How an Er:YAG dental laser actually works
Er:YAG stands for erbium-doped yttrium aluminium garnet, the crystal that generates the beam. What matters clinically is the wavelength it produces: 2,940 nanometers, which happens to sit at the peak absorption point for water.
Enamel, dentin, decayed tooth structure, and gum tissue all contain water. When the laser fires a pulse, the water inside a microscopically thin layer of tissue absorbs that energy instantly, expands, and lifts that layer away. The process repeats thousands of times a second, removing tissue in layers finer than a bur can cut, while a cooling water spray runs continuously across the tooth.
Two consequences follow. First, there is no mechanical contact, so no vibration travels down into the pulp and no smear layer is packed into the tooth surface. Second, the energy is spent almost entirely on the tissue with the highest water content, which is decayed tooth structure. Healthy enamel is denser and more mineralized, so it resists the laser more than soft, wet decay does. In practice the instrument is naturally biased toward the part you want gone, which is the core of what minimally invasive dentistry is trying to achieve.
The LiteTouch system carries the laser inside the handpiece itself rather than piping the beam through a fiber or an articulated arm. For the patient, that translates into a lighter, more precise instrument in the mouth and a device that looks and handles more like a normal dental handpiece than a piece of hospital equipment.
What Dr. Mercado uses the laser for
The LiteTouch is cleared by the FDA as an all-tissue laser, which means it is authorized for both hard tissue and soft tissue procedures. Dr. Mercado uses it in two areas of the practice.
Fillings, frequently without an injection
This is the reason most people search for a laser dentist in the first place, so it is worth being precise about it.
A conventional filling is uncomfortable for two reasons that have nothing to do with the cavity itself. A rotary handpiece spins against the tooth at very high speed, which generates frictional heat and transmits vibration straight into the nerve. Anesthetic exists largely to block the response to those two inputs. Take away the friction and the vibration, and the input the nerve was reacting to is mostly gone.
So Dr. Mercado starts many restorative appointments without anesthetic. You sit up, you are asked how it feels after the first few seconds, and the appointment continues that way if you are comfortable. Patients frequently finish a filling, walk out with full sensation in their lip and tongue, and eat lunch normally an hour later.
It is not universal. Decay that has reached close to the pulp, a tooth that is already inflamed and sensitized, and larger or deeper preparations can all still warrant local anesthetic. Comfort thresholds also differ enormously from person to person. The working agreement here is simple: we start without the injection when the case allows it, you say the word at any point, and you get numbed immediately without being asked to justify it.
Gum work without a scalpel
The same wavelength that removes decay also cuts soft tissue, and this is where the laser quietly earns its keep in cosmetic cases.
A beautiful veneer case is not only about the porcelain. If the gum line runs unevenly across the front teeth, or sits low enough to make otherwise well-proportioned teeth look short, the finished smile reads as slightly off even when the ceramics are flawless. Reshaping that gum line with a laser lets Dr. Mercado sculpt the tissue in very small increments while checking symmetry against the tooth proportions he is designing to.
Compared with a blade, laser soft tissue work is generally less bloody, because the laser seals small vessels as it goes, which also means a clearer field to work in and, for many patients, a quieter recovery with no sutures. Because the energy is absorbed within a thin layer, the shaping is precise rather than approximate.
Laser gum recontouring is often performed alongside veneers, bonding, or a full smile makeover, and in those cases it is planned as part of the cosmetic design rather than treated as a separate event.
What a laser appointment is actually like
- Exam and plan. Dr. Mercado looks at the tooth, the radiographs, and the depth of the decay, then tells you plainly whether the laser is a good fit and whether he expects you will want anesthetic.
- Eyewear. You, Dr. Mercado, and the assistant all put on protective eyewear matched to the wavelength. This is standard for every laser appointment.
- Treatment begins. You hear a rhythmic popping and feel a cool water mist. There is no whine, no vibration, and no pressure pushing against the tooth. Most patients report it is the sound and the water they notice, not sensation in the tooth.
- You stay in control. Raise a hand and everything stops. If you want to be numbed, you are numbed, and the rest of the visit continues conventionally.
- The restoration. Once decay is removed, the tooth is bonded and filled with tooth-colored composite, shaped, and polished exactly as it would be otherwise.
- Afterward. With no anesthetic there is nothing to wear off, so you leave with normal sensation and can usually eat right away. Sensitivity for a day or two is possible with any new filling.
Where the laser is not the right tool
The laser is one instrument among several, and using it well means knowing when to reach for a different one.
- Existing metal work. The laser does not cut metal. Old amalgam fillings, metal crowns, and posts are removed with conventional instruments.
- Some crown and bridge preparation. Full-coverage preparations that need very specific margins and taper are often shaped faster and more predictably with a handpiece.
- Deep or inflamed teeth. When decay is close to the nerve or the pulp is already irritated, anesthetic is the right call regardless of the instrument.
- Access. Some surfaces between back teeth are simply easier to reach and shape conventionally.
- Time. Laser preparation can take somewhat longer than a bur on larger restorations. Most patients consider that a fair trade for skipping the injection. Some do not, and that is a legitimate preference.
Dr. Mercado picks the instrument that suits the tooth, and tells you which one he plans to use before he starts.
The equipment, specifically
The studio uses the LiteTouch Er:YAG dental laser from Light Instruments. It is a 2,940 nm erbium laser cleared by the FDA for dental hard tissue procedures including caries removal, cavity preparation, and enamel etching, and for soft tissue procedures including gingivectomy, frenectomy, and the exposure of unerupted teeth. Its distinguishing engineering feature is that the laser source sits inside the handpiece rather than being routed through a fiber or mirrored arm.
Dr. Mercado is trained on the LiteTouch system. If you want to know more about how it will apply to your specific tooth, the fastest answer is a look and a conversation.