Fluoride is the ingredient that matters: decades of trials show fluoride toothpaste prevents decay. Most other claims are secondary.
Toothpaste combines a mild abrasive (hydrated silica, calcium carbonate) that helps the brush remove plaque and surface stain, a detergent, flavor, and in most products fluoride as sodium fluoride, stannous fluoride or sodium monofluorophosphate. Fluoride helps enamel resist acid from mouth bacteria and repair early damage.
Specialty pastes add a second job: potassium nitrate or stannous fluoride for sensitive teeth, stannous fluoride or zinc for gum health and breath, extra abrasives or low-strength peroxide for whitening, and nano-hydroxyapatite as a fluoride alternative. The actives pages cover fluoride, stannous fluoride, potassium nitrate and the abrasives.
A Cochrane review of 70 trials in 42,300 children found fluoride toothpaste prevented about 24% of decayed, missing or filled tooth surfaces versus non-fluoride paste, with bigger effects at higher concentration and more frequent brushing. A later review found 1,450 to 1,500 ppm slightly outperforms 1,000 to 1,250 ppm, and 1,000 to 1,100 ppm reduces decay in adults. Evidence for sensitivity pastes is weaker, and fluoride-free alternatives such as hydroxyapatite have far fewer trials.
70 trials (42,300 children): fluoride toothpaste prevented 24% of decayed, missing or filled tooth surfaces versus non-fluoride paste. The effect grew with higher fluoride concentration, more frequent brushing and supervised brushing.
96 trials: 1,000 to 1,250 ppm and 1,450 to 1,500 ppm fluoride pastes reduced decay versus non-fluoride paste, 1,450 to 1,500 ppm slightly more than 1,000 to 1,250 ppm, and 1,000 to 1,100 ppm reduced decay in adults. Higher strengths in young children should be weighed against fluorosis risk.
56 trials: powered brushes reduced plaque by 11% at 1 to 3 months and 21% beyond 3 months, and gingivitis by 6% and 11%, compared with manual brushing (moderate-quality evidence). Clinical importance was uncertain.
Six trials: potassium nitrate toothpaste reduced sensitivity to air blasts and touch at 6 to 8 weeks, but participants' own ratings did not improve significantly. The authors found no clear evidence overall, based on few participants.