Backless dresses look great when matched with the right bra. There are a few choices regarding bra type which will generally work with a backless dress.
First is the standard, backless bra. These do not have a back, and they typically do not have any shoulder staps as well. They often use an adhesive. They are often lighter in weight than silicone strapless bras. Some examples of these are shown here:
Some bras for backless dresses are self adhesive such as many of the silicone types. Though some silicon strapless and backless bras use adhesive on the sides. Here are examples of some silicone bras for backless dresses:
Pasties are another good option when looking for a bra for backless dress, such as those shown here:
Hope you have good luck in your search for the perfect bras for backless dresses.