Tooth decay, also known as dental caries or cavities, is a breakdown of teeth due to acids made by bacteria. The cavities may be a number of different colours from yellow to black. Symptoms may include pain and difficulty with eating. Microinvasive techniques involve preparing the tooth surface with an acid and then either placing a seal on top of the surface or 'infiltrating' the softer demineralised tissue with resins. These newer methods work by installing a barrier either on the tooth surface or within the demineralised tissue to protect it against acids and avoid the further loss of minerals from within the tooth, thus helping to stop the decay. This book is a comprehensive guide to techniques, technologies and tools used in microinvasive dentistry. Divided into four sections, the text begins with an overview of caries and its prevention. The following sections provide in depth discussion on diagnosis through various imaging devices, then different treatment options and technologies. The final section covers future developments including enamel regeneration and photobiomodulation.