I'll leave the antibiotic issue alone for the most part - it can be quite important with major dental procedures to avoid serious infections. If you are needing constant dental work then that technically is a "kidney system" issue from a Chinese Medicine perspective (which has little or nothing to do with the physical kidneys - see "My Kidneys Are What?" for more on that).
As for the dangers of metal implants there is a fair amount of research being done to ascertain what risks/issues there may be. At this point much of it is pretty inconclusive. You may find the following research articles worth reading (particularly the first one here):
-- particularly this part:
Systemic effects of metal ions
Most in vitro and in vivo studies that have been published in the Literature are related to the effects induced by Cr and Co. Other known potential toxic ions released by orthopaedic implants are Titanium (Ti), Aluminum (Al), Vanadium (V) and Nickel (Ni). Co, Cr and possibly Ni and V are normal components of some enzymes of our body. They must be introduced with the diet, but become toxic at high dosage.
Co toxicity can affect many organs, and can cause various types of symptoms: neurological (tinnitus, vertigo, deafness, blindness, convulsions); cardiological (cardiomyopathy); haematological (polycythemia); and endocrine (hypothyroidism). Cr seems to be less cytotoxic but more genotoxic than Co (13, 23). It induces tubular necrosis and interstitial cell damage which can result in impaired renal functioning (24). Also potentially severe hepatic lesions have been described, with hepatocellular necrosis and possibly disseminated intravascular coagulation (25). As observed in experimental studies, Cr may compete with Fe in binding to apo-transferrin, causing anaemia. Chronic exposure to Cr has detrimental effects on male and female fertility as a result of decreased sperm production and impaired sperm and ova quality (26).
Al toxicity has been linked to neurological conditions such as memory loss, gait disturbance and involuntary movement, and the development of neuropathological conditions such as amyotrophic lateral sclerosis. Moreover, the accumulation of Al in the brain has been reported as a possible cause of Parkinson’s disease, dialysis encephalopathy and Alzheimer’s disease (27–29). Chronic Al exposure has been related to osteomalacia, pathological fractures, impaired bone remodelling, altered response to vitamin D and proximal myopathy (30).
Another study of interest:
The quick guide is that there does appear to be potentially significant issues but that must be weighed against the issues of chronic pain, immobility, etc. The real issue is to try to do better education and lifestyle counseling long before the joints have passed the point of no return so to speak. In some people with trauma, genetics, etc. this is somewhat unavoidable and it is great to have western medicine surgical techniques to aid this subset of people. Ultimately, however, having high sugar diets, excessive calcium intake, sedentary lifestyles, etc. are known contributors to joint degenerative issues. Stopping it before it starts is where the emphasis needs to be.