Objective: Clinical, radiographic, and microbiologic changes in deep caries lesions were assessed after incomplete carious dentin removal and tooth sealing. Method and materials: Thirty-two teeth with deep caries lesions were studied. Treatment consisted of incomplete excavation of the demineralized dentin, application of calcium hydroxide, and sealing for a 6- to 7-month period. The color and consistency of the dentin were clinically assessed. Differences in radiographic density were assessed by digital image subtraction. Microbiologic samples were obtained from the demineralized dentin before the temporary sealing and after the experimental period. The samples were cultivated on blood agar under aerobic and anaerobic conditions, in Mitis Salivarius agar, and Rogosa selective Lactobacillus agar. Results: Two cases were lost during the study; one presented pulpal necrosis. In the other case, there was pulpal exposure during removal of provisional sealing. In all teeth, the initial demineralized dentin was soft and wet; one lesion was yellow, 21 were light brown, and eight were dark brown. After treatment, the dentin was dry, and 80.00% of specimens were hard, 16.67% were leathery, and 3.33% remained soft. The dentin was light brown in five teeth and dark brown in 25. There was a statistically significant mean difference in radiographic density (pixel intensity), 88.77 ±(plus/minus) 7.02 in the control areas and 94.66 ±(plus/minus) 6.75 in the test areas. The counts of anaerobic and aerobic bacteria, lactobacilli, and Streptococci mutans had decreased significantly by the end of treatment. Conclusion: Incomplete removal of carious dentin and subsequent tooth sealing resulted in the arrest of the lesions, suggesting that complete dentinal caries lesion removal is not essential to the control of caries lesions.