Aim:The International Caries Detection and Assessment System (ICDAS II) is a clinicalscoring method which defines the stage of caries lesions. ICDAS 3,4 and 5 are the scores of teeth which needs to be restored mostly by direct approach. This study aimed to determine the relationship between ICDAS II scores and volumetric tissue loss of teeth after cavities prepared by minimally invasive principle.

Materials and Methods: Total of 42 extracted premolar teeth with ICDAS 3(n=11), ICDAS 4(n=14), ICDAS 5(n=17) were included to study. Digital photographs and radiographic images were taken. Single experienced examiner has diagnosed all teeth in day light, with naked eye by using all diagnostic records. Cavities were prepared with minimally invasive principle, and coronal build–ups were scanned by CAD/CAM. The volumes of these 3D images were calculated in Meshmixer 3.3. Data analyzed by using Regression&Correlation  Analyses.

Results: The mean volume losses were found as following: ICDAS 3= 12,3%; ICDAS 4= 14%; ICDAS 5= 30,4%. There was a significant positive relationship between ICDAS scores and the volumetric tissue loss of teeth (r(40)=.68 , p<.0001). Least standart deviation (LSD) was detected in ICDAS 4 teeth by SD=0,034 which is important in terms of indicating similar cavity dimensions after preparation.

Conclusion: Caries assessments considered according to ICDAS II scores were proportional to volumetic dental tissue losses. Our results can contribute the high performance of ICDAS II in terms of treatment decision and CAD/CAM and Meshmixer software for volumetric analysis being useful methodunder the conditions of this study.