GV was highly statistically different from the others groups, even when compared with GVI, which means that dentists must use every method they can get to avoid a false-negative diagnosis.

Occiusal surface caries are very difficult to diagnose at early stages, special difficulties are observed when the lesion is formed bilaterally in the pits and fissures walls. Preventive measures have been a constant concerning in the attempt to reduce the installation and progression of incipient occlusal decays. The early canons lesions detection through conventional diagnosis methods are questionable because they can end up with a risk of a false-positive or false-negative diagnosis. Using 22 teeth in vitro, premolars and molars, which suggested carious lesions, the exams were made by 3 examiners calibrated through pre-determined scores. The utilized methods were: GI -visual inspection, Gil -tactile inspection (explorer probe), Gillconventional radiographic exam, GIV -digital radiographic exam (Digora for Windows 1.5 1 and 1.5 iN, Soredex-orion Co.), GV -low intensity laser for diagnosis (DIAGNOdent, KaVo, Germany) and GV1 -histologic section. The examiners did not communicate amoung themselves during the exams. There were significant statistical difference among the evaluated methods. Under Friedman statistical test, GI, Gill and GIV were different from GV at the 0. 1% level; when we have compared Gil with GV, we observed statistical difference at the 1% level. In conclusion, GV was highly statistically different from the others groups, it means that the low intensity laser for diagnosis was the most sensible method to detect decayed tissue.