An intra-oral imaging apparatus having a fringe pattern generator energizable to emit a fringe pattern illumination having a predetermined spatial frequency, with light in the approximate 350 - 500 nm range. A polarizer in the path of the fringe pattern illumination has a first polarization transmission axis. A projection lens is disposed to direct the polarized fringe pattern illumination as incident illumination toward a tooth surface. An imaging lens is disposed to direct light reflected and scattered at the tooth surface along a detection path. An analyzer is disposed along the detection path, having a second polarization transmission axis. A detector disposed along the detection path obtains image data from the light provided through the analyzer. A control logic processor is responsive to programmed instructions and actuable to adjust the intensity over one or more portions of the fringe pattern illumination according to the image data obtained from the detector.