Many vegans draw the line at the dentist because it is very hard to have work done that isn't tested on animals as well as not containing animal ingredients.

The latex gloves used by dentists are commonly made of latex which has casein (milk protein) added to increase the stretchy-ness. Nitrile gloves are vegan, less allergy prone and have been said to be more comfortable, if you wish you can supply your dentist, dental assistants, and hygienist with these gloves when you visit.

Tooth paste commonly contains glycerine which I talked about in my personal hygiene chapter but if you missed it:

Glycerine/glycerides/ stearic acid/ palmitic acid/ Lauric acid/ Myristic acid/ Oleic acid (All Tallow) are different fatty acids. They are removed as Suet, hard fat from around kidneys and other organs. These fatty acids can be derived from plants but are most commonly slaughterhouse by products. If you are having trouble grasping that all these little products came from an animal Christien Meindertsma actually spent 3 years tracking down all the products made from 1 pig, Pig 05049. It's amazing what is snuck into all these different products we use and how hidden it is. Thank goodness there is vegan alternatives.

You can also make your own toothpastes, there is lots of recipes on Pinterest, don't worry they work! (I personally use coconut oil, baking soda, Epsom salt, and a peppermint extract). I recommend bringing your own vegan toothpaste to the dentist and asking them to use it instead. Many dentists have their favourite brands so they might not appreciate this but be sure to tell them you are not comfortable using products that are tested on animals that you can easily avoid. At the end of the day your dentist won't want an unhappy patient and I'm sure they will oblige.

Many flosses contain bees wax that coats the string. I already discussed this in my chapter about honey,  bees wax is not vegan.  FYI: ECO-DENT is NOT vegan, they put enzymes (to eat away at plaque) in the floss that are derived from milk. Desert Essence is one popular brand for vegans, I recommend brining this brand or another vegan brand to the dentist when you have check ups, just like toothpaste and gloves ask them to use the vegan alternative.

The point of veganism is to minimise your contribution to animal suffering and exploitation as far as is possible and practical. Different people have different views on what is possible and practical though...?

Of course you should be taking good care of your teeth so you don't need to get dental work done as often. This is possible and practical, if you didn't take care of your oral health you would need to get far more dental work done then someone who does take care of their teeth. This would mean more products would be used (increase in demand for products> containing animal ingredients+ testing). Personally it's not reasonable/practical by my standards to not go to the dentist to avoid the non-vegan products/procedures because your oral health can have an impact on your overall health. Keep in mind Vegans most certainly can get cavities so please take care of you mouth which in turn has an effect on the rest of your bodies health.

So what you can do is use vegan products to care for your teeth so when you do go to the dentist, it will only ever be for checkups (unless you need surgery or braces). When you go to the dentist be sure to bring all the vegan products you would prefer your dentist use.

Now some vegans take it a step further at the dentist... I've already talked of gloves, tooth paste, and floss. Well it should be no surprise those are not the only non-vegan things the dentist uses; But those 3 products are things you can easily control. Some vegans choose not to get freezing when they get a cavity filled or a dental surgery.

Some people might find this 'extreme', but it's not uncommon. Personally I have started doing this at the dentist myself, it's not as scary as you may think the pain doesn't last very long. Commonly the needle the dentist uses is filled with lidocaine, which is most likely tested on animals as all the products dentists use are FDA approved. It's hard to say wether or not it contains animal ingredients (I tried to find out, but no luck). If you can avoid it, please do; remember as far as possible and practical. If I'm getting a surgery on my mouth I fore-sure will use it, but for a cavity or putting a crown on my implant, I don't need it for pain.

Sources:
http://www.veggieboards.com/forum/11-vegetarian-support-forum/42984-dental-floss-vegan.html#/topics/42984?_k=qjgisg