The power of free stuff is huge. Whether it is free things that companies are giving to you as a provider so that you will consider buying their products or free things that you can pass on to patients for them to try.
Here is a list of sources for free or almost free things that you may want to look into:
http://www.colgateprofessional.co.uk/ for colgate toothpaste samples.
http://www.dentalcare.co.uk/home.aspx for Oral B samples.
http://www.wrigleyoralhealthcare.co.uk/samples-and-resources for Wrigleys gum samples. Be aware that they only send out a certain number per week so place your order early in the week.
https://www.gsk-dentalprofessionals.co.uk/ For Corsodyl, aquafresh, Poligrip and Sensodyne samples.
http://www.periproducts.co.uk/home For Periproducts samples.
https://www.dental-directory.co.uk/product/PAW085 These are not free but a very reasonably priced way of giving your patients samples of the wisdom brushes.
http://www.oranurse.co.uk/sample_request.html For Oranurse un-flavoured toothpaste.
If I find any other sources I will comment below and please feel free to do the same.