Foods imported into Singapore are strictly tested, so if it has been allowed back on shelves, it means that it has passed testing. I would go for other similar options. There's an organic teething rusk from Bellamy's Organic. http://www.agapebabies.com/agapebabies/formula-milk-feeding/baby-food/teething-rusks-biscuits.html
It used to be taken off the shelves for melamine issues. If it can be placed back and selling in NTUC then it should be safe already. Personally I wouldn't risk it.
Moderation is a key. If you worry about the safety then better don't take risks.
thanks