Effects of polyhexamethylene guanidine phosphate on human gingival fibroblasts

A literature review of bioactive substances for the treatment of periodontitis: In vitro, in vivo and clinical studies

Periodontitis is a common chronic inflammatory disease of the supporting tissues of the tooth that involves a complex interaction of microorganisms and various cell lines around the infected site. To prevent and treat this disease, several options are available, such as scaling, root planning, antibiotic treatment, and dental surgeries, depending on the stage of the disease. However, these treatments can have various side effects, including additional inflammatory responses, chronic wounds, and the need for secondary surgery. Consequently, numerous studies have focused on developing new therapeutic agents for more effective periodontitis treatment. This review explores the latest trends in bioactive substances with therapeutic effects for periodontitis using various search engines. Therefore, this study aimed to suggest effective directions for therapeutic approaches. Additionally, we provide a summary of the current applications and underlying mechanisms of bioactive substances, which can serve as a reference for the development of periodontitis treatments.

Dramatic reduction of toxicity of Poly(hexamethylene guanidine) disinfectant by charge neutralization

The current study aimed to investigate the toxicity of positively charged polyhexamethylene guanidine (PHMG) polymer and its complexation with different anionic natural polymers such as k-carrageenan (kCG), chondroitin sulfate (CS), sodium alginate (Alg.Na), polystyrene sulfonate sodium (PSS.Na) and hydrolyzed pectin (HP). The physicochemical properties of the synthesized PHMG and its combination with anionic polyelectrolyte complexes (PECs) namely PHMG:PECs were characterized using zeta potential, XPS, FTIR, and TG analysis. Furthermore, cytotoxic behavior of the PHMG and PHMG:PECs, respectively, were evaluated using human liver cancer cell line (HepG2). The study results revealed that the PHMG alone had slightly higher cytotoxicity to the HepG2 cells than the prepared polyelectrolyte complexes such as PHMG:PECs. The PHMG:PECs showed a significant reduction of cytotoxicity to the HepG2 cells than the pristine PHMG alone. A reduction of PHMG toxicity was observed may be due to the facile formation of complexation between the positively charged PHMG and negatively charged anionic natural polymers such as kCG, CS, Alg. Na, PSS.Na and HP, respectively, via charge balance or neutralization. The experimental results indicate that the suggested method might significantly lower PHMG toxicity while improving biocompatibility.

Comparative evaluation of substantivity of two biguanides - 0.2% polyhexanide and 2% chlorhexidine on human dentin

Background:

Substantivity is one of the desirable characteristics of root canal irrigants. Among conventional endodontic irrigants, only chlorhexidine (CHX) is known to exert significant substantivity on root canal dentin. This study explored the substantivity activity of a polymeric biguanide-poly hexamethylene biguanide (PHMB).

Aim:

The aim of this study was to determine the substantivity of a polymeric biguanide - 0.2% PHMB and compare it with that of 2% CHX.

Materials and Methods:

To evaluate and compare the substantivity of 0.2% PHMB and 2% CHX on root canal dentin, dentin disks were prepared and substantivity after 1 h, 24 h, 7 days and 21 days was measured using spectrophotometry.

Statistical Analysis Used:

The data so obtained were analyzed, and the intergroup comparison was made using unpaired t-test.

Results:

The results of this study indicated that 0.2%. PHMB exerts significantly greater substantivity than 2% CHX on human dentin.

Conclusion:

Within the limitations, this study supports the use of 0.2% polyhexanide as an endodontic irrigant based on its property of substantivity.

Adjunctive Antiseptic Irrigation of Periodontal Pockets: Effects on Microbial and Cytokine Profiles

To evaluate the effect of adjunctive antiseptic irrigation of periodontal pockets on microbial and cytokine profiles. Fifty-nine patients with severe periodontitis were allocated to one of three groups for scaling and root planing facilitated with different adjunctive antiseptics: 1% polyhexamethyleneguanidine phosphate (PHMG-P) (n = 19), 0.2% chlorhexidine (CHX) (n = 21) or distilled water (n = 19). Gingival crevicular fluid and subgingival bacterial samples were collected at baseline, and at 2 weeks, and 1 and 4 months. The levels of interleukin (IL)-1β, IL-8, IL-10, and IL-17A, matrix metalloproteinase (MMP)-8, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum,Aggregatibacter actinomycetemcomitans, and Prevotella intermedia were determined. There were no intergroup differences in cytokine concentrations and bacterial counts at any follow-up, however, varying patterns were observed. In the PHMG-P and water groups IL-1β expression peaked at 2 weeks and then gradually declined. In all three groups, the dynamics of MMP-8 concentration were non-linear, increasing by 2 weeks and then declining to below baseline (p > 0.05). P. gingivalis and T. forsythia declined within the first month and increased thereafter, not regaining the baseline level. Adjunctive antiseptic treatment was associated with changes in biomarkers and bacterial counts in the course of the study. The effects of adjunctive antiseptic irrigation were limited in the applied protocol.

Preliminary in vitro and in vivo evaluation of specific activity of branched oligohexamethyleneguanidine hydrochloride

Branched oligohexamethyleneguanidine hydrochloride (OHMG) possesses great potential for the development of novel drugs for the treatment of diseases caused by bacteria. This study aimed at evaluating the antimicrobial activity of OHMG against potential causative agents of oral and pharyngeal mucosa infections, specifically, the activity against 56 clinical strains, 5 of which were antibiotics-resistant. Also, a preliminary in vivo study of the specific activity of OHMG based on a traumatic stomatitis and gingivitis model in rabbits was carried out. In vitro antimicrobial activity of OHMG was determined by testing the minimal inhibitory concentration (MIC). OHMG displayed excellent activity against Streptococcus pneumoniae, Streptococcus pyogenes (MIC was 0.002-0.25 µg/ml), Moraxella catarrhalis (0.03-0.06 µg/ml), Neisseria gonorrhoeae (0.125-2 µg/ml). Almost complete healing of defects in the groups of animals within the 7-day application of 'OHMG hydrochloride' at concentrations of 0.1% and 0.3% after the thermal formation of the stomatitis and gingivitis model was observed.