Microbial Load After Apical Enlargement in Asymptomatic Teeth With Periapical Lesion

24 patients will randomly be assigned to two groups according to the apical shaping size during root canal treatment: 25/.04 and 35/.04. Microbiological sampling of the teeth will be done with paper cones in three steps during the root canal treatment: 1. Sterility control samples (SR1) from the tooth surface after cavity preparation, 2. The first microbiological sample (S1) from the root canal after the initial file reaches the working length. 3. The second microbiological sample (S2) from the root canal after the shaping and irrigation of the root canal is finished. 4. The third microbiological sample (S3) from the root canal after the irrigation activation in the root canal is finished.The samples will be sent to the genetic analysis laboratory for further analysis in the cold chain using a Droplet Digital PCR.