With research increasingly linking poor oral health and gum disease to broader conditions such as cardiovascular disease, diabetes and osteoporosis, experts say it's worth strengthening financial support for dental care, especially in an ageing society.  When Madam Amy Lau was first fitted with dentures nine years ago, she decided against replacing her lower teeth at the same time, as she learnt it would cost another S$700 (US$550) on top of the S$500 she had already paid for the upper set.  "