Photos show exactly how a dentist fixes a broken tooth using drills, chemicals, and blue light

This front tooth, on a mannequin, is broken. The edges of the tooth are jagged, and the break has created a gap between this tooth and its neighbor.

It's important to fix a cracked tooth to prevent any further damage. The crack could also expose the nerve, which could make the tooth more sensitive.

This process can feel very scary and mysterious when you don't know what's happening inside your mouth. But Shahhal explains this process step by step.

And it's surprisingly similar to construction work.

Shahhal explains how he starts by using a diamond burr — the shrill drill that makes the dreaded whirring noise when you go to the dentist.

He does this to smooth down the damaged edge of the tooth and give the material he uses to fix the tooth a better surface to grab to.

He creates a smooth surface, beveled on a 45-degree angle, to help chemicals stick to the tooth.

Shahhal then places white Teflon tape, the same kind of tape you'd use to fix plumbing or electronics, on the tooth next to the broken one.

That protects the healthy tooth from the chemicals he'll use for the repair.

Shahhal then places a blue chemical, called phosphoric acid etchant, onto the damaged edge of the tooth, using a thin-tipped curved syringe.

The etchan is slightly acidic, so it eats away a little bit at the surface of the tooth.

This acts like a microscopic sandpaper: it creates a porous surface that will make it easier for something to stick to the tooth.

The excess etchant is washed away to avoid damaging the tooth.

Then Shahhal applies a clear bonding agent to the tooth using a fine-tipped brush.

This is a resin, essentially plastic, that can seep into the tiny nooks created by the etchant. As the resin hardens, it creates a strong sublayer that is easy to build on.

The resin contains special molecules so that it only hardens when it's exposed to a certain color of light. That's the next step.

The tooth is then blasted with a stick that emits blue LED light. This is called a curing light.

Curing light activated the agents in the bonding agent to make it harden very quickly.

The blue putty on this picture is called an impression material.

This is the stuff your dentist asks you to bite into to get a mold of your teeth and how they fit together.

Shahhal can use this template to start building up the liquid resin that will make up the bit that is replacing the chipped part of the tooth.

The composite resin, used to replace the chip in the tooth, is built up in layers.

Resin doesn't easily stick to the material that makes up the teeth, which is smooth. But it loves binding to other resin, which is why it's important to build a sublayer.

Shahhal will keep building up the resin in layers. Every so often, he comes in with the blue light to harden the resin before he moves on to another layer.

At this point, the dentist may be reaching for scary, pointy tools.

What they're doing is using these fine-tipped tools to smooth out the resin and give it a nice shape and make sure it fills all the gaps.

The tongue is incredibly sensitive — for many, it's more sensitive than the fingertip.

It can feel tiny imperfections on the tooth, so it's important that the finish on the filling be silky smooth.

"I use a series of disks, that go from coarse to fine, to polish the filing, to make sure there's no ledges, and make sure it's as smooth as possible," said Shahhal.

"A lot of these have different colors that allow us to pick a shade that closely matches our patient's teeth," he said.

The resins can also be more or less opaque. Enamel wears away over time, which can make the tooth look more translucent.

"This allows us to create a filling that looks as natural as possible," he said.

You can watch Insider's full video with Shahhal here: