PURPOSE: To study the validity of detection of obscure fissure caries extending into dentine by clinical visual examination, Diagnodent or their combination. MATERIAL AND METHODS: Clinical visual examination on fissures of molars with no obvious cavitation was performed on university students with air drying and under optimal lighting. DIAGNOdent was used to detect dentine fissure caries. Biopsy was then performed during restorative treatment of the studied fissures. This was used as reference standard. The sensitivity and specificity of clinical visual examination, Diagnodent with different cut-off points and their combinations were evaluated. RESULTS: A total of 145 first and second permanent molars in 41 students aged 20±2 years were examined. The sensitivity and specificity of clinical visual detection of caries extending into dentine were 0.89 and 0.44 respectively. The sensitivity and specificity using DIAGNODent with the recommended cut-off point 20 were 0.94 and 0.14 respectively. When the cut off point was increased to 35, the sensitivity & specificity values were both changed to 0.75. Caries detection by a combination of clinical visual examination and DIAGNOdent reading 35 had the highest sum of sensitivity & specificity (0.71 + 0.90). CONCLUSION: The validity of caries detection on obscure fissure caries extending into dentine using DIAGNODent with the commended cut-off point 20 was not substantially better than by clinical visual examination. A combination of clinical visual examination and Diagnodent with a cut-off point 35 gave a satisfactory level on both sensitivity and specificity of detection of fissure caries extending into dentine.

The World Federation for Laser Dentistry (WFLD) Congress, Hong Kong, 28-30 July 2008.