Comparison of quantitative polymerase chain reaction (qPCR) and digital polimerase chain reaction (dPCR) quantification of subgingival plaque samples.

For inclusion, each subject had to be systemically healthy and aged 20 to 80 years. Subjects were excluded if they: had less than 5 teeth in each jaw quadrant, regularly used a mouthwash as part of their oral hygiene routine, had received antibiotics during the last 6 months or during the study period, were pregnant or lactating, had a known systemic illness (i.e. HIV/AIDS, diabetes mellitus, cancer, diseases of bone metabolism, diseases affecting wound healing) or were treated with immunosuppressants, chemotherapy, radiation, calcium antagonists, antiepileptics and non-steroidal anti-inflammatory drugs.

The study comprised of two subject groups. The first group consisted of 20 subjects with periodontitis, who had at least one probing site in each jaw quadrant with pocket depth (PPD) measuring > 4 mm and positive bleeding on probing (BOP). Periodontitis stage and grade were determined following the 2018 classification system.

The second group consisted of 20 volunteers without periodontal pathologies (healthy group), i.e. plaque index < 10% at baseline visit, absence of periodontal pockets measuring > 4 mm and no prior periodontal treatment.