## 5 Topical Curcumin-Based Formulations in Oral Diseases
### Periodontal Disease
[120] also performed a comparative study focusing on the efficacy an adjuvant therapy with either curcumin-loaded nanoparticles or chlorheximide combined with scaling and root planing. The experiment was performed in chronic periodontitis patients who were divided into three groups receiving main treatment only, main treatment with additional topical curcumin formulation or main treatment with combined topical chlorheximide therapy. As a response, three different bacterial strains in the dental plaque were monitored. Similarly to the previous study, it was found that in curcumin- andchlorieidine-treated groups, the therapeutic outcomes were similar, and the levels of three periodontitis bacteria were significantly reduced. Considering the fact that chloriexi-dine is a widely known and applied antiseptic, the described effects are promising in terms of potential applicability of curcumin-based topical products in periodontal disease. A similar study was performed by [PERSON] et al. [121]. Periodontal disease-affected patients were divided into two groups subjected to standard treatment with root scaling and planning with or without additional therapy with curcumin-loaded gel. The efficacy of the applied therapeutic approaches was evaluated by checking the levels of interleukin-1\(\beta\) (IL-1\(\beta\)) in the saliva samples and monitoring the clinical parameters. It was found that the adjuvant therapy provided some benefits for the limited time which was reflected by the clinical improvement. However, the results between the IL-1\(\beta\) in the two investigated groups were not statistically different. In the study performed by [PERSON] [122] the same protocol was applied, and curcumin-loaded nanoparticles prepared with poly(lactic-co-glycolic acid) (PLGA) and poly(lactic acid) (PLA) were applied as an adjuvant therapy to standard periodontal disease treatment procedure. Probing pocket depth, bleeding and clinical attachment levels were investigated as key clinical parameters indicating potential improvements. Moreover, the levels of IL-1\(\alpha\), IL-6, TNF\(\alpha\) and IL-10 in the gingival reticular fluid were monitored after \(3,7\) and \(15\) days after the formulation application. It was found that all clinical parameters improved in both compared groups to the same extent. The levels of biochemical markers were also not significantly different, except for IL-6 which had lower levels in curcumin-treated patients. However, the applied adjuvant therapy did not significantly reduce the inflammation which was reflected both in clinical symptoms and most of the investigated biochemical parameters. It is important to note that the applied curcumin concentration was 0.05 mg/mL which is relatively low value. Moreover, the authors indicate low viscosity of the investigated formulation which could possibly leak from periodontal pockets, decreasing the efficacy of the treatment. The same research group also performed a study involving an animal model for testing the efficacy of curcumin-loaded nanoparticles in periodontal repair [123]. In the laboratory animals, periodontitis was induced, and three types of treatment were tested. The first group was treated with the drug-loaded nanoparticles, the second group with placebo nanoparticles, while in the third group, sterile saline was administered. The degree of bone repair evaluated with the use of microcomputer tomography, as well as collagen content, were the highest in the drug-loaded nanoparticle-treated group. Another study describing application of curcumin-loaded nanoparticles was presented by [PERSON] et al. [124]. The investigated silica-based nanoparticles displayed mesoporous structure and rod-like shape. In the first 5 days, curcumin release was relatively quick, and then, the process followed the sustained release pattern. The obtained system was tested against _Porphyromonas gingivalis_, a microbe associated with periodontal disease occurrence.