Quercetin as an Auxiliary Endodontic Irrigant for Root Canal Treatment: Anti-Biofilm and Dentin Collagen-Stabilizing Effects In Vitro

Application of photosensitive dental materials as a novel antimicrobial option in dentistry: A literature review

The formation of dental plaque is well-known for its role in causing various oral infections, such as tooth decay, inflammation of the dental pulp, gum disease, and infections of the oral mucosa like peri-implantitis and denture stomatitis. These infections primarily affect the local area of the mouth, but if not treated, they can potentially lead to life-threatening conditions. Traditional methods of mechanical and chemical antimicrobial treatment have limitations in fully eliminating microorganisms and preventing the formation of biofilms. Additionally, these methods can contribute to the development of drug-resistant microorganisms and disrupt the natural balance of oral bacteria. Antimicrobial photodynamic therapy (aPDT) is a technique that utilizes low-power lasers with specific wavelengths in combination with a photosensitizing agent called photosensitizer to kill microorganisms. By inducing damage through reactive oxygen species (ROS), aPDT offers a new approach to addressing dental plaque and associated microbial biofilms, aiming to improve oral health outcomes. Recently, photosensitizers have been incorporated into dental materials to create photosensitive dental materials. This article aimed to review the use of photosensitive dental materials for aPDT as an innovative antimicrobial option in dentistry, with the goal of enhancing oral health.

Characterization, Antimicrobial Activity, and Antioxidant Efficacy of a Pomegranate Peel Solution Against Persistent Root Canal Pathogens

BACKGROUND

The limitations of dental irrigation solutions reinforce the need to explore novel bioactive compounds that are safer and biodegradable. This study aimed to prepare a 10% pomegranate peel solution (Punica granatum extract - PGE) and evaluate its antimicrobial and antioxidant effects for root canal treatment.

METHODS

Lyophilized extracts (1g/10 mL) from pomegranate peels were prepared, and the punicalagin content was assessed by ultra-performance liquid chromatography using pure punicalagin (standard). The antimicrobial activity was tested against common persistent root canal pathogens by the agar diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicide concentration (MCB/MFC). The antioxidant activity (%AA) was assessed by the DPPH radical scavenging method. Data were analyzed by ANOVA and Tukey's test (α = 0.05).

RESULTS

The total phenolic content of the PGEextract was 6.55 µg/mL. Differences were found among the inhibition zone of PGE (23.32 ± 3.65), 1% NaOCl (30.76 ± 4.73), and 50% ethanol (without inhibition) (p < 0.05). The MIC values of PGE ranged between 6.25 and 75 mg/ml, and PGE was effective against the tested pathogens. PGE had antioxidant potential (IC50 = 3.52 µg/mL); however, the mean values were inferior to that of the quercetin (positive control) (IC50 = 0.95 µg/mL). The DPPH scavenging effect (%AA) of PGE (70.98 ± 2.3) had no difference from the positive control (72.94 ± 2.1) (p = 0.253).

CONCLUSION

The PGE extract was successfully biosynthesized and exhibited antimicrobial and antioxidant activity, suggesting its potential use as an adjuvant therapy during root canal treatment.

The comparative evaluation of the effects of quercetin, α-tocopherol, and chlorhexidine dentin pretreatments on the durability of universal adhesives

OBJECTIVE

The aim of this study was to evaluate and compare the effects of chlorhexidine, quercetin, and α-tocopherol on the shear bond strength of universal adhesives in the short (24h) and long term (6 months).

MATERIAL AND METHODS

Ninety-six extracted sound molars were collected and divided randomly into four groups: control (no treatment), 2% chlorhexidine, 10% α-tocopherol, and 1% quercetin. The solutions were prepared and applied to the teeth for 60 s, followed by application of All-Bond universal adhesive and composite build-up. Half of the specimens in each group (n = 12) were tested for shear bond strength (SBS) after 24 h of storage and the other half were kept in distilled water for 6 months and then tested for shear bond strength. The shear bond strength test was performed and the failure modes were determined using a stereomicroscope. The data were analyzed using two-way analysis of variance and Tukey's post hoc tests with p ˂ .05 as the significance level.

RESULTS

The results of the two-way analysis of variance test showed that there was no significant difference in immediate SBS, and after 6 months, α-tocopherol had the lowest SBS in comparison to the control and CHX subgroups (p < .05). The t-test showed that the shear bond strength in the α-tocopherol and quercetin groups was significantly decreased after 6 months.

CONCLUSION

It can be concluded that the solutions used in this study had no adverse effect on immediate SBS. After 6 months, the CHX could preserve SBS in comparison to other groups.

Effects of the Combined Application of Trimethylated Chitosan and Carbodiimide on the Biostability and Antibacterial Activity of Dentin Collagen Matrix

The structural integrity of a dentin matrix that has been demineralized by the clinical use of etchants or calcium-depleting endodontic irrigants, such as endodontic ethylenediaminetetraacetic acid (EDTA), is often deteriorated due to the collagenolytic activities of reactivated endogenous enzymes as well as the infiltration of extrinsic bacteria. Therefore, the biomodification of dentin collagen with improved stability and antibacterial activity holds great promise in conservative dentistry. The purpose of this study was to evaluate the effects of the combined application of trimethylated chitosan (TMC) and 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) on the biostability and antibacterial activity of the demineralized dentin collagen matrix. The morphological changes in the collagen matrix were observed by scanning electron microscopy (SEM), the amount of TMC adsorbed on the collagen surface was detected by X-ray photoelectron spectroscopy, and the elastic modulus was measured by a three-point bending device. Dry weight loss and amino acid release were detected to evaluate its anti-collagenase degradation performance. The antibacterial performance was detected by confocal microscopy. The TMC-treated group had less collagen space and a more compact collagen arrangement, while the untreated group had a looser collagen arrangement. The combined application of TMC and EDC can increase the elastic modulus, reduce the loss of elastic modulus, and result in good antibacterial performance. The current study proved that a dentin collagen matrix biomodified by TMC and EDC showed improved biodegradation resistance and antibacterial activities.