Prophylactic laser produced a better outcome than when patients did not receive any preventive intervention, and red laser (660 nm) was better than infrared (830 nm) in the prevention and treatment of OM.

Adesivos denti nários; Dente decíduo; Infi ltração dentária. Objecti ve: To evaluate in vitro the microleakage in restorati ons placed in primary molars using diff erent adhesive techniques. Method: Caviti es prepared in the buccal and lingual faces of the teeth were randomly assigned to four groups: G1 (n=10) selfetch adhesive system (Adper Prompt L-Pop); G2 (n=10) etchand-rinse adhesive system (Adper Single Bond 2); G3 (n=10) 37% phosphoric acid etching plus self-etch adhesive system (Self-Etch Bond); G4 (n=10) self-etch adhesive system (Self-Etch Bond). Groups 1 and 2 were restored with the composite resin Concept Advanced (Vigodent), while groups 3 and 4 were restored with the composite resin Z100 (3M). The teeth were subjected to a thermocycling regimen of 125 cycles between ±5 o and ± 55 o with dwell ti me of 10 seconds, and were rendered waterproof (quick-setti ng adhesive + nail polish), immersed in 0.5% basic fuchsine and secti oned in a buccolingual directi on. The specimens were examined by three calibrated examiners under a stereomicroscope (Coleman) at ×25 magnifi cati on, according to a pre-established scoring system (0-1). Descripti ve stati sti cal analysis was done and the chi-squared test was used with a signifi cance level of 5%. Results: The adhesive techniques did not prevent the occurrence microleakage. In the occlusal margin, group 4 presented signifi cantly higher microleakage than the other groups. In the cervical margin, group 1 presented signifi cantly higher microleakage than the other groups. Comparing the groups irrespecti vely of the margins, groups 2 and 3 presented lesser microleakage and diff ered signifi cantly from the other groups. Conclusion: None of the adhesive systems was capable of sealing the cavity margins completely. Denti n-bonding agents; Tooth, deciduous; Dental leakage.