Ask your dentist... how sure are we that dental assistants/dentists would really take time autoclaving or even sterilizing their equipments. Do they really know how infectious and resistant these viruses are to simple sterilizing techniques. Dental procedures are really very invasive with all those blood seeping through the grids in the equipments (analogy: chopping board). Vaccination at birth is the key.
think positive, check all posts there are chances to get rid of hbsag although very rare and hard
cronic hbv comes at birth from infected monthers, as adults it is cleared 100% since only 3% dont clear and this 3% is made of immune depressed because of things that depress immune system like drug addiction, immune suppressive drugs, aids
so the reason you are infected is because your country doesn t have mandatory vaccine at birth, all the countires that have this dont have hbv, the best example is cuba