The aim of the research project was to test the validity and reliability of new methods of caries diagnostics on extracted human molars in vitro. A total of 375 teeth were examined. Microtomographic images were taken as a reference standard. Radiographs of these teeth and white light images from the occlusal, proximal, buccal and oral directions were taken as a comparative imaging technique to the new methods. As new examination methods, tranisillumination images were taken from the occlusal direction using near-infrared light with wavelengths of 1050, 1200 and 1300 nm with two different indium gallium arsenide (InGaAs) cameras. On the other hand, reflection images of the occlusal, buccal and oral areas were taken using near-infrared light with wavelengths of 1050, 1200, 1300 and 1550 nm, also with two InGaAs cameras. This is the white light image data set of the 375 teeth. Other data publications from the "In-vitro caries diagnostic study": https://doi.org/10.5282/ubm/data.441 (near-infrared transillumination images at 1050, 1200 and 1300 nm from occlusal of 375 extracted human teeth) https://doi.org/10.5282/ubm/data.444 (375 bitewing radiographs of extracted human teeth) https://doi.org/10.5282/ubm/data.445 (375 microtomographic images of the coronal part of extracted human teeth) https://doi.org/10.5282/ubm/data.447 (near-infrared reflection images at 1050, 1200, 1300 and 1550 nm from occlusal, buccal and oral direction of 375 extracted human teeth)