My dentists in Canada, knowing I have CLL, have always used prophylactic (protective) antibiotics for dental work, including cleanings.
There doesn't seem to be much agreement on this subject, and it seems to vary from country to country, but it would be a good idea that CLL patients advise their dentists and dental surgeon that they have a compromised immune system.
The standard dose I get is 2gr of amoxicillin, one hour before dental work...or I don't get in the chair.
~chris
When I was diagnosed with CLL following a rapid drop in neutrophils, my haematologist told me to stop flossing my teeth due to the risk of infection, then when I informed my dental practice I had CLL, they were very quick to drop the regular inspections and cleans. A few years later a broken filling forced the issue and thanks to what I'd read on CLL forums, I knew that antibiotic prophylaxis was an established practice for those with CLL. My dental hygienist contacted my haematologist and arranged a prescription accordingly. I've now got a prescription on hand from my haematologist and through taking a high dose antibiotic prior to seeing the oral hygienist and dentist, I've never had any problems after dental treatment, despite still having low neutrophils, which are currently hovering around 0.8.
Maintaining good dental health should be an integral part of maintaining your overall health - there is a known link between good dental and heart health for example. Definitely get prophylactic cover in place so you are prepared for any urgent dental intervention!
Neil
For 8 years my dentist ( at my UK hospital ) gave me an antibiotic before treatment. However he retired last year and new dentist brought new rules and even after my protest does not use antibiotics. This worried me after an extraction but my consultant apparently accepted the hospitals new rules.
Ernie
There are certainly very good reasons for not providing antibiotics without good reason. Superbugs anyone?
That said, if you have low immunity (e.g. few properly working B-lymphocytes and low Ig factors - which is par for the course as CLL progresses and/or low neutrophils, etc), then you are at higher risk of developing infections from bacteria naturally in your oral environment that will invade through the pretty well inevitable damage to your mouth from dental work.
IF your CLL specialist/consultant can confirm that your infection fighting capacity is satisfactory, then I'd accept the hospital's new rules, otherwise I'd push for a justifiable exemption. After all, if you have a high risk of getting ill from a bacterial infection after any dental work, you are likely to incur additional demands on NHS services which will probably require antibiotic treatment for you anyway - not to mention the additional misery and risk to your health!
Neil
I see a very competent dentist in Ontario, Canada. I have very low Igs and she is aware. She doesn't prescribe antibiotics to me for routine cleaning and fillings. This has not caused me any problems during the 4 years since diagnosis. My neutrophils are still in normal range. I think whether or not they prescribe prophylactic antibiotics varies between dentists.
I have a dental appointment on Monday 8th. My dentist doesn't want to use antibiotics and when I mentioned this last week at my 3 monthly consultation, my haematologist agreed. I was advised to use an antibacterial mouth wash before and after the extraction. The tooth is very loose and gets infected anyway.
I'm in the UK and it seems that this is the accepted policy.
I think it varies widely, perhaps from dentist to dentist, there doesn't seem to be many guidelines. Certainly the risk of infection is probably higher post treatment for CLL, but not always.
Mind you, you probably get more antibiotics in a few steak or chicken dinners than you would get at the dentist... 
I'm seeing my dentist for a check up/scale and polish next week. She's a new, young dentist and had never heard of CLL much less considered precautionary measures from what I could gather.
As I left her surgery she looked at me pitifully and said, 'see you in 6 months.....then added, I hope!'
Hard to get good NHS dentists but I'll be quizzing her more closely this next time before I make a decision about staying with that practice.
Prefer the steak dinner idea for protective cover Chris....
Newdawn
I was just diagnosed with the rear lower molar as abcessed. My dentist was leery of pulling the tooth saying that if it got worse it could swell and cut off my carotid artery blood flow. He has sent me to an oral surgeon. That kind of freaked me out. Any comments? Platelets are now down to 104. See the surgeon tomorrow.
Mike
What symptoms of CLL do I really have to worry about?!
What to avoid eating if you have CLL?
cll/ sepsis/check your prescriptions 
CLL and Problems with Teeth and Gums
