Adult patients ( n = 130 , = 74 , = 56 ; mean age SD : 56.9 12.9 ) from three participating centers , diagnosed with root caries , were randomly allocated into two groups : Test ( n = 64 , = 37 , = 27 ; lesions = 144 ; mean age : 59.0 12.1 ; intervention : high-fluoride toothpaste with 5000 ppm F ) , and Control ( n = 66 , = 37 , = 29 ; lesions = 160 ; mean age : 54.8 13.5 ; intervention : regular-fluoride toothpaste with 1350 ppm F ) groups .