The answer here is a little complicated. Fluoride has certainly been a key tool in the fight against dental caries (cavities) for well over 60 years. Conventional wisdom would still advocate for the inclusion of fluoride in toothpastes as well as drinking water (in countries including the USA).
However, several studies have found a link (and likely causation effect) between fluoride exposure and developmental (read: among children) neurotoxicity resulting in IQ deficits. The amount of fluoride used in toothpaste by itself is extremely unlikely to cause fluoride toxicity among adults.
However, since the 1980s, advances in dental science have rendered the use of fluoride in toothpaste unnecessary. Ingredients such as hydroxyapatite which occur naturally in the dentin and bones have been shown to be equally effective in preventing cavities while being completely non-toxic. We, at Daybreak, recommend using a fluoride-free toothpaste that contains non-toxic alternatives like HAp, bioactive glass etc. for tooth remineralization.
Resources:
1.Developmental fluoride neurotoxicity: an updated review
2.Developmental Neurotoxicity of Fluoride: A Quantitative Risk Analysis Toward Establishing a Safe Dose for Children