Objective: Periodontitis is known to have multifactorial etiology, involving interplay 
between environmental, host and microbial factors. The current treatment approaches 
are aimed at reducing the pathogenic microorganisms. Administration of beneficial 
bacteria (probiotics) has emerged as a promising concept in the prevention and 
treatment of periodontitis. Thus, the aim of the present study is to evaluate the efficacy 
of the local use of probiotics as an adjunct to scaling and root planing (SRP) in the 
treatment of patients with chronic periodontitis and halitosis.
Methods: This is a randomized, placebo‑controlled, double‑blinded trial involving 
32 systemically healthy chronic periodontitis patients. After SRP, the subjects were 
randomly assigned into the test and control groups. Test group (SRP + probiotics) 
received subgingival delivery of probiotics and probiotic mouthwash, and control 
group (SRP + placebo) received subgingival delivery of placebo and placebo mouthwash 
for 15 days. Plaque index (PI), modified gingival index (MGI), and bleeding index (BI) 
were assessed at baseline, 1 and 3 months thereafter, whereas probing depth (PD) 
and clinical attachment level were assessed at baseline and after 3 months. Microbial 
assessment using N‑benzoyl‑DL‑arginine‑naphthylamide (BANA) and halitosis 
assessment using organoleptic scores (ORG) was done at baseline, 1 and 3 months.
Findings: All the clinical and microbiological parameters were significantly reduced 
in both groups at the end of the study. Inter‑group comparison of PD reduction (PDR) 
and clinical attachment gain (CAG) revealed no statistical significance except for PDR 
in moderate pockets for the test group. Test group has shown statistically significant 
improvement in PI, MGI, and BI at 3 months compared to control group. Inter‑group 
comparison revealed a significant reduction in BANA in test group at 1 month. ORG 
were significantly reduced in test group when compared to control group.
Conclusion: Within the limitations of the study, the present investigation showed that 
the adjunctive use of probiotics offers clinical benefit in terms of pocket depth reduction 
in moderate pockets and reduced oral malodor parameters.