Effect of Pudilan Keyanning antibacterial mouthwash on dental plaque and gingival inflammation in patients during periodontal maintenance phase: study protocol for double-blind, randomised clinical trial

Pudilan Keyanning mouthwash inhibits dextran-dependent aggregation and biofilm organization of Streptococcus mutans

AIMS

This research aimed to investigate the inhibitory effects of Pudilan mouthwash (PDL) on Streptococcus mutans (S. mutans) biofilms and identify its chemical components.

METHODS AND RESULTS

The impacts of 100% concentrated PDL on S. mutans biofilm were detected by colony-forming unit (CFU) assays, crystal violet staining, confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and quantitative real-time PCR (qRT‒PCR). The biocompatibility with human gingival fibroblasts (HGFs) was evaluated by Cell-Counting-Kit-8 (CCK-8) assay. And chemical components were identified by UPLC-HRMS. PBS and 0.12% chlorhexidine were used as negative and positive controls, respectively. Results indicate early 8-h S. mutans biofilms are sensitive to PDL. Additionally, it leads to a decrease in bacterial activities and dextran-dependent aggregation in 24-h S. mutans biofilms. PDL significantly downregulates the gene expression of gtfB/C/D and smc. And 114 components are identified.

CONCLUSIONS

PDL has an inhibitory effect on S. mutans and favorable biocompatibility. It has potential to be exploited as a novel anti-biofilm agent.

Formulation and Characterization of Mucoadhesive Polymeric Films Containing Extracts of Taraxaci Folium and Matricariae Flos

Taraxaci folium and Matricariae flos plant extracts contain a wide range of bioactive compounds with antioxidant and anti-inflammatory effects. The aim of the study was to evaluate the phytochemical and antioxidant profile of the two plant extracts to obtain a mucoadhesive polymeric film with beneficial properties in acute gingivitis. The chemical composition of the two plant extracts was determined by high-performance liquid chromatography coupled with mass spectrometry. To establish a favourable ratio in the combination of the two extracts, the antioxidant capacity was determined by the method of reduction of copper ions Cu²⁺ from neocuprein and by reduction of the compound 1.1-diphenyl-2-2picril-hydrazyl. Following preliminary analysis, we selected the plant mixture Taraxaci folium/matricariae flos in the ratio of 1:2 (m/m), having an antioxidant capacity of 83.92% ± 0.02 reduction of free nitrogen radical of 1.1-diphenyl-2-2picril-hydrazyl reagent. Subsequently, bioadhesive films of 0.2 mm thickness were obtained using various concentrations of polymer and plant extract. The mucoadhesive films obtained were homogeneous and flexible, with pH ranging from 6.634 to 7.016 and active ingredient release capacity ranging from 85.94-89.52%. Based on in vitro analysis, the film containing 5% polymer and 10% plant extract was selected for in vivo study. The study involved 50 patients undergoing professional oral hygiene followed by a 7-day treatment with the chosen mucoadhesive polymeric film. The study showed that the film used helped accelerate the healing of acute gingivitis after treatment, with anti-inflammatory and protective action.

Enterococcus faecalis rnc gene modulates its susceptibility to disinfection agents: a novel approach against biofilm

BACKGROUND

Enterococcus faecalis (E. faecalis) plays an important role in the failure of root canal treatment and refractory periapical periodontitis. As an important virulence factor of E. faecalis, extracellular polysaccharide (EPS) serves as a matrix to wrap bacteria and form biofilms. The homologous rnc gene, encoding Ribonuclease III, has been reported as a regulator of EPS synthesis. In order to develop novel anti-biofilm targets, we investigated the effects of the rnc gene on the biological characteristics of E. faecalis, and compared the biofilm tolerance towards the typical root canal irrigation agents and traditional Chinese medicine fluid Pudilan.

METHODS

E. faecalis rnc gene overexpression (rnc+) and low-expression (rnc-) strains were constructed. The growth curves of E. faecalis ATCC29212, rnc+, and rnc- strains were obtained to study the regulatory effect of the rnc gene on E. faecalis. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and crystal violet staining assays were performed to evaluate the morphology and composition of E. faecalis biofilms. Furthermore, the wild-type and mutant biofilms were treated with 5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and Pudilan. The residual viabilities of E. faecalis biofilms were evaluated using crystal violet staining and colony counting assays.

RESULTS

The results demonstrated that the rnc gene could promote bacterial growth and EPS synthesis, causing the EPS-barren biofilm morphology and low EPS/bacteria ratio. Both the rnc+ and rnc- biofilms showed increased susceptibility to the root canal irrigation agents. The 5% NaOCl group showed the highest biofilm removing effect followed by Pudilan and 2% CHX. The colony counting results showed almost complete removal of bacteria in the 5% NaOCl, 2% CHX, and Chinese medicine agents' groups.

CONCLUSIONS

This study concluded that the rnc gene could positively regulate bacterial proliferation, EPS synthesis, and biofilm formation in E. faecalis. The rnc mutation caused an increase in the disinfectant sensitivity of biofilm, indicating a potential anti-biofilm target. In addition, Pudilan exhibited an excellent ability to remove E. faecalis biofilm.

Clinical Effectiveness of Herbal Oral Care Products in Periodontitis Patients: A Systematic Review

BACKGROUND

The use of herbal products in oral cavity has shown an increased popularity and potential benefits due to their additional anti-inflammatory and antioxidant properties as well as the lack of side effects related to their use.

OBJECTIVE

To assess the clinical effectiveness of herbal dental products (mouthwash, dentifrice, gel) when compared to conventional products or placebo in periodontitis patients.

MATERIAL AND METHODS

A systematic review with 22 studies was carried out using MEDLINE/Pubmed, EMBASE and Web of Science databases in addition to hand searches. Randomized and non-randomized clinical trials that evaluated the effect of any herbal dental product and compared it with conventional products or placebo in periodontitis patients and published up to March 2022, were screened.

RESULTS

Herbal products used as adjuncts to scaling and root planing (SRP) or supragingival debridement (SPD) led to superior clinical outcomes than placebo or no adjuncts (8 studies). In conjunction with SRP, these products showed comparable outcomes with chlorhexidine (6 studies) or better (4 studies). When used as adjuncts to SPD, herbal oral care products demonstrated comparable outcomes with chlorhexidine and conventional products (4 studies).

CONCLUSIONS

Within the limitations of this systematic review, herbal oral care products may play a key role in the management of periodontal disease. Further well-designed studies are needed to establish their efficacy.