Quite a lot! There are a couple of options for getting rid of that gap between teeth. But first, let's take a look at why you might have a front tooth gap in the first place.
"The teeth just grew like that". This is the way your teeth developed, and there is no particular reason why you have a gap in front teeth.
Some teeth are missing. Maybe they never grew, maybe you hade them pulled when you were young, and the others didn't line up to completely get rid of the gap.
Gum disease. If you have noticed gaps starting to appear between your front teeth, and you're over 40 years of age, then you might well have gum disease.
What ways can you eliminate a gap in front teeth?
If you DO have gum disease, then any of the following treatments won't last long. Your teeth will continue to drift, and the spaces will start to open up again. So the correct thing is to ask your dentist specifically about gum disease. Get him to check your gums, and refer you to the dental hygienist. In addition, take a look at how to cure gum disease.
Assuming your gums are healthy, you have 2 options to eliminate a gap between teeth. You can either move the teeth to close the gap (or gaps), or else you can leave the teeth where they are and fill in the gaps with something. These are the two ways of eliminating a gap in your front teeth.
Moving the teeth will mean getting braces from an orthodontist. In order to close a gap, this will most likely be a brace that is fixed to your teeth for 6 to 12 months. In some ways, this is the best treatment.
If you have a gap in front teeth closed by moving the teeth together with braces, the result is likely to be very stable (as long as you wear your retainer!), and your front teeth will be as healthy as before, with the surface tooth enamel untouched.
Filling in the gap with something can be done in one of 2 ways.
The quick, simple, and cheaper option is to get "composite bonding" on your teeth. In this procedure, there's no shots and no drilling. The dentist just uses a very strong dental glue (a bonding agent) to build up little sections of tooth-colored filling material.
If he adds just one millimeter of filling material to each tooth on either side of the gap, he will have reduced the space by 2 millimeters!
An additional advantage of this technique is that it is reversible. If you don't like the new look, the dentist can simply polish off the filling material and put you back where you were at the start. He hasn't made any permanent changes to your teeth.
The other way of closing gaps in your front teeth is with veneers (also called porcelain laminates or laminate veneers). These are like thin shells of dental porcelain that are bonded on to the fronts of your teeth.
They are made in a dental laboratory, or sometimes in the dental office with a Cerec machine - read more about this at cerec veneers. They can be made slightly wider than the teeth behind them, so that they close up any gaps or spaces.
But getting veneers DOES mean that the tooth enamel on the fronts of the teeth involved will be ground down. This is usually less than a millimeter, but it is a permanent change. Once you get this done, your teeth will have been changed forever, and you will always need veneers on them. When your first veneers get worn or chipped after 10 to 15 years, you will need to get them removed and get new ones made. And the same again 10 to 15 years later.
So think carefully about getting veneers! They can make a HUGE difference to a person's smile, but they DO NOT last forever, and need re-doing from time to time.
The BEST way of fixing a gap in front teeth is usually by getting orthodontic treatment from an orthodontist. It takes longer than the other methods, but your teeth still have their own enamel on them afterwards, and there's nothing to chip or crack or need replacing in later years. Providing you wear your retainers!