A dental probe that directly measures pH level and temperature of gum pockets and other diseased parts of the oral cavity is provided. The dental probe has a handle and a needle with a pH sensor and a temperature sensor in the needle tip. The handle permits the dentist to manipulate the needle tip to examine a diseased spot in the mouth, where both pH levels and temperature can be analyzed. The rear part of the handle has a light receptor which remains outside the oral cavity when the needle tip is inserted in the diseased part, creating a path for light through the needle part. The dental probe is attached to a dental diagnosis device that enables processing and readout of pH levels and temperature.