Systematic assessment of color removal following vital bleaching of intrinsically stained teeth.

Various treatment variables associated with a standard bleaching technique were systematically recorded in 53 individuals exhibiting intrinsic discoloration of permanent teeth. These variables (predictors) included: (1) etiology (fluoride or tetracycline); (2) age of the patient; (3) the presented color of the stain; (4) the intensity of that color; (5) a long versus short bleaching time technique; and (6) the number of bleaching sessions. These were assessed as to their relationship with the results of treatment (dependent variable). The findings of a multiple regression analysis revealed that the contributions of the individual predictors were significantly different between those stains caused by tetracycline ingestion (N = 27) and those stains due to fluoride ingestion (N = 20). The analysis also revealed that those variables contributing to a significant proportion of the variance in results of treatment when tetracycline was the cause were: (1) the color of the stain and (2) the number of bleaching sessions. When fluoride was apparently the causal agent: (1) the bleaching time technique; (2) age of the patient; (3) color of the stain; and (4) the number of bleaching sessions contributed to a significant proportion of the variance in the results of treatment.