I took doxycycline for 2 months when in Mozambique and broke a tooth on a piece of not very hard bread after 5 or 6 weeks so perhaps it's true that antibiotics are very bad for your teeth & bones......
If I ever go again I wouldn't take the tablets but would take the 'curative dose' of malarone.... and cover myself in deet... and invest in a top of the range mozzy net.