to investigate whether it was possible using terminal restriction fragment length polymorphism T-RFLP to identify the effect of the radiographic and clinical quality of the coronal restorations on the composition of the root canal microflora in teeth with necrotic pulps and teeth with root fillings associated with apical periodontitis.
Materials and Methods:
– n: 63 pts (F: 43 M: 20 ) samples were taken from untx canals with necrotic pulps n: 28 and filled canals n:35 all with radiographic signs of AP (2x of PDL).
-Coronal restoration recognized as defective if there was deficient margins in the rgs or 2ndry caries or partial or total loss of the restoration or prop penetrated the tooth restoration interphase.
-Samples were collected during RCT and Rcretx. After RD placement and removal of defective restoration RD was disinfected with 30% hydrogen peroxide and 10% iodine tincture. Canals were irrigated with saline and files were used to pump the saline within the canals. The canals fluid was then soaked in a sterile paper point and transferred to the lab within 30 m.
-QIAamp DNA mini kit was used to extract DNA of the bacteria. Followed by PCR of 16S rRNA gene (16S rDNA) of the domain Bacteria and T-RFLP.
Most highlighted results:
-51 of the sample were PCR +ve
-19 teeth showed signs of defective restoration non defective 32
-The number of TRFs (bacterial species) detected per sample was not sig between pulp necrosis group and root filled group.
-Fusobacterium nucleatum/Streptococcus mitis group was the most frequently encountered 58% of the samples.
-Veillonella sp. was the most frequent species in the pulp necrosis group.
-In the root filled group, Fusobacterium nucleatum/Streptococcus mitis group was counted 17 times
-There was a sig difference in the number of TRF between the filled RC with sound coronal restoration and defective restoration.
-Tooth type and quality of RC filling did not sig affect the no. of TRFS in the retx grp.
Ensuring adequate restoration after RCT may reduce the no. of bacterial species.