Table 3. Comparison of different methods based on different indexes.

Method	Similarity index	Sensitivity	Specificity
Ours
enamel	0.847	0.942	0.840
dentine	0.895	0.950	0.896
pulp	0.792	0.746	0.780
FCM
enamel	0.847	0.942	0.840
dentine	0.853	0.956	0.813
pulp	0.723	0.617	0.657
HCA
enamel	0.847	0.942	0.840
dentine	0.829	0.950	0.802
pulp	0.656	0.560	0.648
DBSCAN
enamel	0.847	0.942	0.840
dentine	0.812	0.951	0.795
pulp	0.642	0.551	0.623
GMMs
enamel	0.847	0.942	0.840
dentine	0.851	0.952	0.809
pulp	0.715	0.610	0.623