Table 8.

Intervention studies regarding the relationship between COPD and periodontal disease.

Ref. No.	Study Country Year Sample Size	Methods	Main Findings
[107]	Agado et al. America 2012 n = 30	Respiratory Questionnaire	Periodontal debridement for chronic periodontitis has no effect on quality of life and illness in patients with COPD.
[108]	Kucukcoskun et al. Turkey 2013 n = 40	Number of exacerbations	Initial periodontal therapy showed a significant reduction in the exacerbation frequency during the follow-up period (P = 0.01).
[109]	Shen et al. China 2016 n = 126,251	Adverse respiratory event	During the 5-year follow-up period, all three types (acute exacerbation, pneumonia, and acute respiratory failure) of incident adverse respiratory events were lower in periodontal treatment group than in the comparison group for ER uses and hospitalizations.
[110]	Sundh et al. Sweden 2021 n = 101	16 S rRNA gene sequencing	Advanced dental cleaning is associated with a reduced frequency of COPD exacerbations.
[111]	Zhou et al. China 2014 n = 306	Periodontal indexes, respiratory function, and COPD exacerbations	FEV1 were significantly higher in both Scaling and SRP groups compared with the control group during the follow-up (p < 0.05).
[112]	Sharma et al. India 2021 n = 75	PI, GI, PPD, CAL, and BOP and spirometry (FEV1/forced vital capacity (FVC)) values	COPD patients have poorer periodontal health as compared to systemically healthy counterparts.