Enamel Remineralization by Calcium and Fluoride Containing Toothpastes in Situ

Objectives: To compare remineralization of enamel subsurface lesions by toothpastes with added calcium phosphate and fluoride in a double-blind, randomized, cross-over in situ study.
Methods: Human enamel specimens with subsurface lesions were prepared and inserted into two intra-oral appliances worn by volunteers located palatal to maxillary posterior teeth and buccal to mandibular posterior teeth. A slurry (2 g product plus 8 ml H₂O) of each toothpaste was rinsed for 60 s, 4 times per day for 14 days. Four toothpastes were tested: (1) GC Tooth Mousse Plus (TMP) containing 10% (w/v) CPP-ACP (Recaldent) and 900 ppm fluoride as sodium fluoride; (2) Sensodyne Repair and Protect toothpaste containing NovaMin (calcium phosphosilicate) and 1450 ppm fluoride as sodium monofluorophosphate (NaMFP); (3) Colgate Sensitive Pro-Relief containing 8% arginine, calcium carbonate and 1450 ppm F as NaMFP; and (4) Premier Enamelon toothpaste containing amorphous calcium phosphate (ACP) and 0.45% SnF₂ (1600 ppm F ion). Calcium, inorganic phosphate and fluoride levels were measured in post-rinse/saliva samples using ion chromatography and AAS. Enamel lesion mineral content was measured using transverse microradiography.
Results: TMP released greater amounts of soluble (bioavailable) Ca, Pi and F in saliva within 60 seconds and produced the highest levels of enamel subsurface remineralization when compared with the other products. The level of remineralization followed the following order: TMP > Premier Enamelon = Colgate Pro-Relief > Sensodyne toothpaste. Remineralization levels were found to be similar in the enamel lesions located at the different intra-oral sites.
Conclusions: TMP released the highest levels of calcium, phosphate and fluoride ions and was superior to the other calcium phosphate and fluoride-containing toothpastes in remineralization of enamel subsurface lesions in situ.