BACKGROUND Almost everyone on the planet has suffered dental caries. It is why dental caries are considered a public health problem. The anticariogenic efficacy of dental sealants for pits and fissures is related to their retention. Air abrasion and acid etching are two current techniques for applying pit and fissure sealants. Our objective was to compare the efficiency of retention a pit and fissure sealant in primary dental organs pre-conditioned with acid etching and air abrasion. METHODS A descriptive, comparative study was conducted in 40 primary dental organs randomly divided into two groups for conditioning the enamel with one or the other technique. Sealants and double-standard mesh for brackets with double ligatures were applied to test shear bond strength with an Inströn testing machine. Student's t-test was used to compare the shear-peel bond strength exerted by the two techniques. RESULTS The average traction tolerated in the group treated with air abrasion was 2.62 kgf, and in the group treated with acid etching was 3.55 kgf, with statistically significant differences (p=0.007). CONCLUSIONS Acid etching demonstrated greater efficiency than air abrasion for retention of dental sealant for small pits and fissures in primary teeth.