Aims: Bacteria are one of the main factors involved in the process of tooth decay and are the main cause of pulp and periapical diseases. Their presence in the crown pulp and dental canal causes symptoms in the teeth. This study aimed to investigate the molecular analysis of anaerobic bacteria in primary and necrotic teeth of children and to determine the relationship between these bacteria and clinical signs and symptoms.
Materials & Methods: In this analytical cross-sectional study, 90 children aged 4-12 years were divided into five equal groups (n=18), including reversible pulpitis without irritant pain, reversible pulpitis with irritant pain, irreversible pulpitis, necrosis with abscess, and necrosis without abscess. Clinical symptoms of the patient, such as history of pain, luxation, sensitivity to percussion, status of the dental pulp, and presence of swelling were recorded, and samples were taken from coronal pulp tissue and root canals during pulp treatment using sterile paper points. To identify anaerobic bacteria, clinical samples were cultured under anaerobic conditions. The 16s rRNA sequencing was used for molecular identification of anaerobic bacteria at species level.
Findings: In 90 patients, 9 different Lactobacillus spp. were identified which among them L. fermentum (37.8%), L. rhamnosus (15.6%), L. salivarius (10%), and L. gasseri (5.6%) were the most prevalent. L. fermentum was the most common species found in all clinical samples that was related to pain (p=0.034).
Conclusion: L. fermentum is the most common species found in all clinical samples that is related to pain.