ABSTRACTthe study aims to evaluate the efficacy of CHX-gel, Ca(OH) 2 and diode laser in eliminating C.albicans from the root canal system and hence to eliminate the chances of reinfection and minimize treatment time. Materials and methods: 180 single rooted anterior teeth were prepared and divided into 4 equal groups, the first was prepared to ISO 60 while the 2 nd -4 th were prepared only to ISO40, all the teeth were then sterilized and inoculated with C.albicans suspensions for 14 days, followed by evaluation of the starting bacterial counts in each tooth by means of colony forming units (CFU/ml), after this the groups 2-4 were prepared to ISO 40 MAF, using NaCl 9% in the 2 nd group, NaOCl 1% in the 3 rd and CHX 0.2% in the 4 th . Finally each of the 4 groups was divided into three subgroups (n=20), the first irradiated with diode laser, the second with injected with Ca(OH) 2 paste and the third injected with CHX-gel for 7 days, followed by estimation of the end bacterial counts in CFU/ml in canal lumen and in dentin. Results : the reduction of C.albicans was higher in all the groups after Ca(OH) 2 and CHX gel injection than with diode laser irradiation (p<0.001, Chi-square test). After chemomechanical preparation a higher effectivity of the laser disinfection was shown and more specimen could reach the lower limit values, the effectiveness was also increased by the use of NaOCl or CHX as irrigants (p<0.001).