• Intervention/ Control: The procedure will be formed by removing the caries tissue till reaching dentin, leaving the deep layer for the application of the step-wise technique. Dentin sample will be taken by a spoon excavator for both groups and stored in a media to be transferred to the microbiological lab for analysis at the time baseline of the study (T1). Liner will be applied in the cavity for Group D1 using Theracal, and D2 using Biner LC. For both two groups, molars will be restored with Glass Ionomer restoration at the time baseline. Patients will be recalled after 6 months for the re-entry of the restored teeth , removing the Glass Ionomer restoration and collect the dentin sample (T2) for evaluation of the microbiological count. Finally restoring the teeth with Composite as the final permanent restoration. the procedure will follow the manufacturer's instructions for every material used.