The investigators aim will be to compare the diagnostic performance of clinical visual examination (ICDAS II), intraoral/bite wing radiography (BW), near infrared light transillumination (NIR-LT), and laser fluorescence (LF), in comparison to microcomputed tomography (micro-CT) for the detection of non-cavitated occlusal enamel and dentin caries in third molar teeth. Potential participants will be consecutively recruited.

Studies regarding comparison of diagnostic techniques for caries detection are generally conducted under in vitro conditions due to ethical concerns. Considering the many recently published in vitro studies which attempted to assess the diagnostic ability of different caries diagnosis systems, it is not possible to know at what rate in vitro findings are applicable to the clinical situation.The investigators would like to assess initial occlusal caries lesions by using different diagnostic methods under in vivo conditions. In the present study, the investigators will assess diagnostic accuracy of clinical visual examination (ICDAS II), digital intraoral radiography, near infrared light transillumination (NIR-LT), and laser fluorescence (LF), by examining third molar teeth in comparison to gold standard micro-CT images. The null hypothesis of the study is that no significant difference exists for the clinical performance of the evaluated methods in detecting non-cavitated occlusal caries in either the enamel or the dentin. This prospective study will include 101 third molars of 101 patients with non-cavitated occlusal caries requiring extraction. ICDAS II, BW, NIR-LT and LF examinations will be carried out by two examiners. Gold standard will be determined by micro-CT imaging after extraction. Intraclass correlation coefficient (ICC) value will be calculated for examiner agreement. Accuracy rate, sensitivity, specificity, predictive values and areas under receiver operating characteristic curves (Az) will be calculated. Clinical application time and patient comfort/pain analysis will be compared. Nonparametric variables will be assessed by Kruskal Wallis Test. Significance level will be set at p<0.05.

Inclusion Criteria:

• According to the American Society of Anesthesiologists (ASA) only status 1/ healthy patients
• Completely erupted permanent dentition,
• No fixed orthodontic apparatus, prosthetic restoration and filling material,
• A minimum age of 18 years,
• At least one third erupted molar teeth (third mandibular or third maxillary molar from each patient was included),
• Non cavitated occlusal caries,
• Teeth with no hypoplasia or hypomineralization,
• Third molar teeth that require extraction for surgery, orthodontics and prosthetic reasons,
• If clinical indicators suggest a current caries risk or activity that required additional diagnosis, the patients will be asked to participate in this additional examination.

Exclusion Criteria:

• Patients younger than 18
• Patients that can not be recruited according to the inclusion criteria.

The study sample will be comprised of 100 third molars requiring extraction with non-cavitated but suspected occlusal caries from 101 patients.