Over the past decade, propolis has gained recognition in pharmaceuticals and nutraceuticals for its therapeutic properties in the treatment of tumours, inflammatory conditions, bacterial infections, and parasitic infections. Recent experimental evidence regarding the anti-inflammatory mechanism of propolis was reviewed by Zulhendri F. et al. and concluded that it is due to the downregulation of TLR4, MyD88, IRAK4, TRIF, NLRP inflammasomes, NF-κB, and their associated pro-inflammatory cytokines such as IL-1β, IL-6, IFN-γ, and TNF-α that makes propolis an anti-inflammatory agent. Propolis also downregulates the chemokines such as CXCL9 and CXCL10 and reduces the migration of immune cells such as macrophages and neutrophils [
21,
22].
The present study investigated the comparative efficacy of Propolis and chlorhexidine mouthwashes as adjunctive therapy to mechanical periodontal treatment in perimenopausal women with chronic periodontitis. The results indicate that both types of mouthwash demonstrated positive outcomes, with Propolis showing a significantly more pronounced effect on bleeding on probing (BOP).
Periodontal pocket depth (PPD)
In this study, the reduction in PPD is a significant finding in both the Propolis and chlorhexidine groups. The reduction in PPD in the Propolis group is noteworthy, starting from a baseline value of 4.67 mm, which decreased to 4.01 mm at six weeks and further to 3.59 mm at 12 weeks. The chlorhexidine group also experienced a reduction, albeit to a slightly lesser extent, from 4.65 mm at baseline to 4.44 mm at six weeks and 4.25 mm at 12 weeks.
These results align with previous studies that have demonstrated the efficacy of Propolis in reducing PPD [
23,
24]. Propolis, known for its anti-inflammatory and antibacterial properties, has been investigated for its potential in periodontal therapy [
25]. Several studies have reported reductions in PPD when using Propolis-based products, attributed to its ability to inhibit inflammatory processes and microbial growth within periodontal pockets [
7,
26].
Bleeding on probing (BOP)
Bleeding on Probing (BOP) is a crucial clinical parameter in periodontal evaluation, reflecting the inflammatory status of periodontal tissues. The study found that BOP significantly decreased in both the Propolis and chlorhexidine groups, with a slightly greater reduction observed in the Propolis group. In the Propolis group, BOP decreased from a mean value of 77.20 to 46.30 at six weeks and 14.60 at 12 weeks. In the chlorhexidine group, BOP reduced from 77.30 to 49.60 at six weeks and 22.80 at 12 weeks.
The results of this study align with previous research findings on the efficacy of propolis as a natural therapeutic agent in the treatment of periodontal disease [
22,
27]. Propolis has been known for its antimicrobial, anti-inflammatory, and antioxidant properties, which can contribute significantly to the healing process after mechanical periodontal therapy [
28]. This might explain the more pronounced reduction in BOP observed in the propolis group.
Clinical attachment loss (CAL)
Clinical Attachment Loss (CAL) is another essential parameter for assessing periodontal health. The study’s results reveal a significant reduction in CAL for both groups, indicating improved attachment between the teeth and surrounding tissues. In the Propolis group, CAL decreased from 4.45 mm at baseline to 4.15 mm at six weeks and 3.77 mm at 12 weeks. The chlorhexidine group showed a reduction from a baseline value of 4.80 mm to 4.50 mm at six weeks and 4.19 mm at 12 weeks.
These findings corroborate previous research indicating the efficacy of Propolis in reducing CAL [
29]. Propolis, with its anti-inflammatory and tissue regenerative properties, has shown promise in promoting attachment between the periodontal tissues and teeth [
17]. Studies have suggested that Propolis can stimulate fibroblast activity and collagen synthesis, contributing to improvements in CAL [
24,
30].
On the other hand, chlorhexidine, a widely accepted antiseptic in dentistry, also showed a considerable reduction in PPD, CAL, and BOP, consistent with the existing literature [
11]. The mechanism of action mainly lies in its ability to cause bacterial cell death by disrupting the cell membrane [
9].
However, this study observed a higher degree of reduction in the aforementioned clinical parameters in the Propolis group compared to the chlorhexidine group. These findings can be attributed to the additional anti-inflammatory and antioxidant properties of Propolis that can provide an added benefit in periodontal healing, a hypothesis supported by some recent studies [
20,
31].
Sukhmawati (2021) conducted a study on six participants, and in each participant, two different sites of periodontal pockets were chosen. Group A received 10% propolis after the curettage, and Group B was given 1% tetracycline after curettage. PI, PPD, BOP, and concentration of IL-1β were assessed at baseline and day 21. Significant reductions in IL-1β and clinical parameters such as PPD and BOP were recorded, strengthening the findings of our study [
24].
Propolis was administered as an adjunct to chlorhexidine in two studies, and the results of both groups were comparable, and Propolis reduced the periodontal index equally with chlorhexidine [
29,
32]. Propolis mouthwash was also tested against placebo after mechanical debridement of the pockets. The final visit significantly improved PPD, CAL, and BOP compared to placebo [
26].
The results of this study align with previous research indicating the effectiveness of Propolis in the treatment of periodontal disease [
33,
34]. The reduction in PPD, CAL, and BOP in the Propolis group is in line with earlier investigations that have reported similar outcomes [
35,
36]. This consistency in findings suggests that Propolis may be a valuable adjunct in periodontal therapy.
It is important to note that the present study contributes to the existing body of evidence by providing a well-structured clinical trial with rigorous methodology. By conducting a double-blind, randomized, controlled trial, the authors have addressed potential sources of bias and increased the reliability of their findings. This study has several strengths, including the large sample size and full mouth examinations of all patients. Additionally, all patients were examined by the same examiner, trained to ensure consistency in results. Although measures have been taken to avoid missing follow-up, clinical trials are always limited by participant exclusions and decreases in sample size that researchers cannot control. Other biomarkers in addition to clinical parameters assist in determining the superiority of Propolis over traditional medicaments. For this purpose, salivary biomarker Neopterin was measured in saliva of patients in periodontitis, which will be discussed in Part 2 of this manuscript.
Despite these promising findings, it is crucial to consider the limitations of the study, such as the short follow-up period. Future research with longer follow-up periods can provide more concrete evidence on the comparative efficacy of Propolis and chlorhexidine mouthwashes in the treatment of chronic periodontitis, especially in perimenopausal women. Future studies should offer incentives to participants to improve compliance and make it easier to contact them when evaluations are required.
Based on the findings of the present study, the following recommendations can be made for future research and clinical practice. Considering the chronic nature of periodontitis and its management, future studies should incorporate extended follow-up periods. This would provide more robust data on the long-term efficacy and safety compared to chlorhexidine. The current study focused on perimenopausal women. Future research could consider a more diverse population, including males and females across different age groups, to examine the effects of propolis and chlorhexidine mouthwashes on a broader demographic. As both types of mouthwash demonstrated beneficial effects, their combined use might be worth investigating to understand if simultaneous use can offer synergistic benefits in the treatment of chronic periodontitis. Further research is warranted to understand the exact mechanism through which propolis provides an added advantage in periodontal healing. This could lead to the formulation of more effective therapeutic agents. Given the superior effect of propolis, a cost-effectiveness analysis could be undertaken to examine the potential economic benefits of using propolis over chlorhexidine, considering factors such as production cost, patient compliance, and side effects. In addition to clinical parameters, future studies may incorporate patient-reported outcome measures such as comfort, taste preference, and overall satisfaction to provide a comprehensive evaluation of the effectiveness of mouthwashes. Lastly, based on the results of the current study, it may be recommended that clinicians consider the use of propolis mouthwash as an adjunct to mechanical therapy in perimenopausal women with chronic periodontitis.