Genotoxic assessment of chlorhexidine mouthwash on exfoliated buccal epithelial cells in chronic gingivitis patients

Impact of age-related changes in buccal epithelial cells on pediatric epigenetic biomarker research

Cheek swabs, heterogeneous samples consisting primarily of buccal epithelial cells, are widely used in pediatric DNA methylation studies and biomarker creation. However, the decrease in buccal proportion with age in adults remains unexamined in childhood. We analyzed cheek swabs from 4626 typically developing children 2-months to 20-years-old. Estimated buccal proportion declined throughout childhood with both increasing chronological and predicted epigenetic age. However, buccal proportion did not associate with age throughout adolescence. Variability in buccal proportion increased with age through the entire developmental range. These trends held inversely true for neutrophil proportions. Correcting for buccal proportion attenuated the weak association with PedBE age acceleration to non-significance during initial estimation. Notably, correcting for buccal proportion attenuated the association of PedBE age acceleration with obsessive-compulsive disorder and strengthened the association with diurnal cortisol slope. Thus, the age-related change in children's oral cells is a crucial consideration for cell type-sensitive research.

Does Mouthwash Use Affect Oral Cancer Risk? A Comprehensive Systematic Review and Meta-Analysis

Studies indicate a strong correlation between the length and degree of alcohol and tobacco use and the risk of oral cancer (OC). However, there has been debate concerning the usage of mouthwashes and associated higher risk of OC for many years. The purpose of this study was to gain insight into how using mouthwash influenced the risk of OC. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was used when searching the PubMed/MEDLINE, Scopus, and Web of Science databases. Observational studies that addressed the relationship between mouthwash use and OC and involved adult or older adult populations were included. The Newcastle-Ottawa Scale was employed to check the methodological quality, and random effects meta-analysis, along with other subgroup analyses and meta-regression, were utilized to synthesize quantitative data. Out of 5,132 papers identified, 15 case-control studies comprising 6,515 cases and 17,037 controls were included in the review. Seventeen effect measures from these 15 studies were included in the meta-analysis. For individuals who used mouthwash three or more times a day, the pooled OR for OC was 1.00 (95% CI: 0.79-1.26; n = 17 studies). Among those who had used mouthwash for more than 40 years, the OR was 1.30 (95% CI: 1.58-4.82; p = 0.05; n = 2 studies). Some studies suggest that frequent mouthwash use may increase the risk of OC. Given the biological plausibility of this link, we exercise caution in interpreting these findings. It is important to note the limited research on the frequency and duration of mouthwash use. Thus, for the strengthening of the evidence for a possible dose-response effect of mouthwashes on OC risk, we suggest that future research should be focused on the frequency, duration, and substance of mouthwashes in depth.

Colloidal chitosan-silver nanoparticles-fluoride nanocomposite as an antibacterial mouthwash against salivary Streptococcus mutans in orthodontic patients (a randomized clinical trial)

OBJECTIVES

This study aimed to synthesize and characterize colloidal chitosan-silver nanoparticles-fluoride nanocomposite (CCAgNPF) and evaluate its efficacy compared to chlorhexidine on salivary Streptococcus mutans in orthodontic patients.

MATERIALS AND METHODS

AgNPs stabilized with chitosan were synthesized by chemical reduction of AgNO3. The nanoparticles were characterized with SEM, FTIR, DLS and ICP-OES. The MIC and MBC against S. mutans and IC50 concentration of CCAgNPF were obtained for antibacterial and cytotoxicity evaluations, respectively. For the clinical study, a total of 45 orthodontic patients were divided into three groups of 15 and used the following mouthwashes twice a day for 1 month: CCAgNPF, chlorhexidine 0.2% and the combination of these mouthwashes. The colony count of salivary S. mutans was evaluated before and after using the mouthwashes. The data were analyzed using One-way ANOVA and Tukey's test.

RESULTS

Stabilized AgNPs were spherical with a diameter of 25.3 ± 3.3 nm. The MIC, MBC and IC50 of CCAgNPF were 4.42, 8.85 and 18.89 µg/ml. All mouthwashes reduced the salivary S. mutans of the orthodontic patients, however, no significant difference was found between the efficacy of CCAgNPF and chlorhexidine (P-value > 0.05). The best results were achieved by the combination of CCAgNPF and chlorhexidine mouthwashes (P-value < 0.05).

CONCLUSION

The CCAgNPF and its combination with chlorhexidine present potent bactericidal, biocompatible and effective anti-carious mouthwashes for orthodontic patients.

CLINICAL RELEVANCE

This study proved CCAgNPF as an antibacterial mouthwash with lower cytotoxicity and side effects for patients undergoing orthodontic treatments to maintain oral hygiene and reduce salivary S. mutans.

Telehealth Parenting Program and Salivary Epigenetic Biomarkers in Preschool Children With Developmental Delay: NIMHD Social Epigenomics Program

Importance

Children with developmental delays are at a heightened risk of experiencing mental health challenges, and this risk is exacerbated among racially minoritized children who face disproportionate adversity. Understanding the impact of parenting interventions on biological markers associated with these risks is crucial for mitigating long-term health disparities.

Objective

To examine the effect of 20 weeks of an internet-based parent-child interaction training (iPCIT) program on biomarkers associated with aging and chronic inflammation among preschoolers with developmental delay at 12-month follow-up.

Design, Setting, and Participants

An observational secondary analysis of data from a randomized clinical trial conducted from March 17, 2016, to December 15, 2020, to assess changes in salivary DNA methylation (DNAm)-derived biomarkers following iPCIT intervention. Participants were recruited from 3 Part C early intervention sites in a large southeastern US city. Eligible participants included children recruited within 3 months of their third birthday who had a Child Behavior Checklist Externalizing Problems T score greater than 60 and provided saliva in at least 1 study wave. Data analysis was conducted May 2023 to April 2024.

Intervention

Participants received either iPCIT (a telehealth therapeutic intervention focused on enhancing the parent-child relationship and addressing behavioral challenges in young children) or referrals as usual.

Main Outcomes and Measures

DNAm at the 12-month follow-up was assessed using the Infinium HumanMethylationEPIC Bead Chip Assay to derive biomarkers DunedinPACE, C-reactive protein (CRP), and interleukin-6 (IL-6). Analyses were intent-to-treat and used path analysis.

Results

A total of 71 children (mean [SD] age, 36.27 [0.61] months 51 male [71.8%] and 20 female [28.2%]) were analyzed, of whom 34 received iPCIT and 37 received referrals as usual. The iPCIT group had a slower pace of aging (β = 0.26; 95% CI, 0.06 to 0.50; P = .03) and less DNAm-derived CRP (β = 0.27; 95% CI, 0.05 to 0.49; P = .01) relative to the control condition at the 12-month follow-up. These associations remained significant after accounting for baseline DNAm score, child demographics, and symptom severity, and were independent of predicted buccal epithelial cell proportion for both DunedinPACE and CRP. There was no association with DNAm-derived IL-6 (β = 0.14; 95% CI, -0.08 to 0.36; P = .21).

Conclusions and Relevance

In this study of a parenting intervention, iPCIT, the association of intervention with decreased molecular markers of inflammation and biological aging suggests their potential to modify aspects of the biological embedding of stress. Understanding the systemic biological impact of such interventions offers insights into addressing health disparities and promoting resilience among vulnerable populations.

Trial Registration

ClinicalTrials.gov Identifier: NCT03260816.

Effects of fixed orthodontic treatment with and without chlorhexidine mouthwash on vitality of oral mucosal cells reflected by cell nuclear indexes: A preliminary 3-phase before-after clinical trial

INTRODUCTION

Effects of mouthwashes on the vitality of oral mucosal cells have not been determined in orthodontic patients. We aimed to assess, for the first time, the effects of fixed orthodontic treatment with and without chlorhexidine (CHX) mouthwash on the oral mucosal cell vitality.

MATERIALS AND METHODS

All patients meeting the eligibility criteria were consecutively included until the desired sample size was reached. Oral buccal mucosal cell samples were taken immediately before orthodontic treatment. For each patient, 20 metal brackets and 4 bands were installed on the teeth. Cell samples were recollected after one month of treatment. Then, the patients used an ethanol-free 0.12% CHX mouthwash two times a week for one month. Sampling was repeated at the end of the second month. Papanicolaou staining was used for micronucleus screening of the indexes: micronucleus (MIC), karyorrhexis (KR), karyolysis (KL), and broken eggs (BE). The repair index (RI) was calculated as RI=KR+KL/BE+MIC. Comparisons of nuclear changes over 3 intervals were done using the Friedman and Dunn-Bonferroni tests (α=0.05, β<0.05).

RESULTS

This prospective before-after clinical trial was performed on 408 observations of 34 patients (14 males, 20 females, mean age: 16.68±3.75 years) at 3 intervals (×4 parameters each). The means of MIC, KR, KL, BE, and RI were respectively 1.312±1.219, 0.241±0.564, 0.426±0.657, 0.115±0.224, and 0.476±0.360 before treatment. They were 1.348±1.171, 0.215±0.236, 0.406±0.369, 0.124±0.187, and 0.511±0.310 at the first interval and 1.909±1.263, 0.368±0.174, 0.615±0.269, 0.253±0.150, and 0.529±0.195 at the second interval. Friedman showed significant time-dependent changes for all variables (P<0.0005) except RI. Dunn-Bonferroni showed that except MIC (P=0.017), KR/KL/BE changed insignificantly after orthodontic treatment (P≥0.974). MIC/KR/KL/BE increased significantly after the addition of CHX (P<0.0005).

CONCLUSION

CHX mouthwash, together with orthodontic treatment, has a strong deteriorating effect on nuclear indexes associated with the vitality of buccal mucosal cells. Nuclear changes caused by orthodontic treatment alone might be negligible.

Age features of buccal epithelium in practically healthy people

Recently, buccal epithelium has been used to study age-dependent processes. This approach is of particular relevance due to its non-invasiveness. The purpose of this study is to establish the normal values of the buccal cytogram in different age groups, including athletes. 200 practically healthy volunteers of different ages were examined, who were divided into 5 groups in accordance with the WHO age classification. In addition, 125 professional athletes took part in the study. All patients underwent a comprehensive dental examination and a standard cytological examination of buccal smears. It has been established that the cytological characteristics of buccal epitheliocytes, indirectly reflecting disorders of the nuclear apparatus of the cell, did not change significantly with age, but there was a certain upward trend in the number of cells with such anomalies (micronucleus, protrusions).The number of binuclear cells and the apoptotic index also slightly increase with age. At the same time, a high positive correlation was found between the apoptosis index and senile age. In young athletes, an increase in the number of buccal epitheliocytes with a perinuclear vacuole (an early sign of cell damage) was foundAnalysis of the cytological examination results of the buccal epithelium in people a slight increase in the level of cytological abnormalities in old age, in particular, signs of apoptosis. In addition, in healthy young athletes (18 years old - 44 years old), an increase in the number of cells with signs of nuclear degradation, which most likely reflects increased mechanical stress on the maxillofacial apparatus during sports activities.

Impact of glycine and erythritol/chlorhexidine air-polishing powders on human gingival fibroblasts: an in vitro study

BACKGROUND

Supra- and subgingival air-polishing has been used in periodontitis and gingivitis therapy for years. Low-abrasive types of powders have facilitated the application in subgingival areas. In this study, the cellular effects of a glycine powder and an erythritol/chlorhexidine (CHX) powder on human gingival fibroblasts (HGF) were investigated.

METHODS

HGF were obtained from sound gingiva of three healthy donors. After 12hours and 24hours of incubation time, cell viability testing and, after 24hours and 48hours, a cell proliferation assay was conducted. Additionally, the individual components erythritol and CHX were investigated for cell viability. In vitro wound healing was monitored for 48hours and scanning electron microscopy (SEM) analysis was performed after 24hours. Statistical analysis was accomplished by ANOVA and post hoc Dunnett's and Tukey's tests (p < 0.05) were performed.

RESULTS

Erythritol/CHX powder and in a lower extent, glycine powder decreased cell viability and cell proliferation. The negative effect of erythritol/CHX was mainly based on the CHX component. In vitro wound healing was negatively influenced in both types of powders compared to control. Cell size was altered in both test groups, whereas cell morphology was affected only in the erythritol/CHX group.

CONCLUSIONS

The investigated powders for subgingival air-polishing can influence cell viability, morphology, and proliferation, as well as wound closure in vitro. These actions on fibroblasts are discernible, with the cytotoxic effect of erythritol/CHX powder being very clear and mainly due to the CHX component. Our results suggest that subgingivally applied powders can exert direct effects on gingival fibroblasts.

Comparative assessment of periodontal status and genotoxicity in orthodontic patients on fixed mechanotherapy with and without adjunct chlorhexidine mouthrinse: A randomized control clinical trial

Background:

Adjunct chlorhexidine mouthrinse is used routinely in orthodontic clinical practice for plaque control. However, chlorhexidine has genotoxic effects on the oral cells. Moreover, orthodontic appliance leach Ni, Cr metals ions into saliva causing toxicity of surrounding mucosa. Hence, the aim of the study was to assess the periodontal status and genotoxicity in orthodontic patients on fixed mechanotherapy with and without adjunct chlorhexidine using micronucleus (MN) test.

Materials and Methods:

A randomized control clinical trial was conducted in 30 patients who were on fixed mechanotherapy. The patients were randomly assigned into two treatment groups; Group-A (Control Group): Included 15 patients who are on fixed orthodontic therapy with mechanical plaque control measures only., Group-B (Experimental Group:) included 15 patients on fixed orthodontic therapy with mechanical plaque control and adjunct chlorhexidine mouthrinse (0.2%) for 2 weeks. Periodontal status and genotoxicity using MN test were done at following time points; T0: Just before start of the orthodontic treatment., T1: 2 weeks after start of the orthodontic treatment., T2: 6 weeks after start of the orthodontic treatment., T3: 12 weeks after start of the orthodontic treatment.

Results:

Plaque index (PI) and bleeding on probing (BOP) were significantly decreased in Group B as compared to Group A in the time intervals; T0-T2, T0-T3, T1-T3 (P < 0.05). Probing pocket depth (PPD) and Clinical attachment level (CAL) showed no significant change in both the groups. The genotoxicity assessed by MN test was significantly increased in Group B than Group A at time intervals; T0-T1, T0-T2 and T0-T3.

Conclusion:

Adjunct chlorhexidine resulted in decreased PI and BOP scores but nonsignificant change in PPD and CAL. However, the genotoxicity increased significantly in both the groups but more with adjunct chlorhexidine.

Effect of St. John's wort oil and olive oil on the postoperative complications after third molar surgery: randomized, double-blind clinical trial

OBJECTIVES

This multicenter study aimed to evaluate the effects of St. John's wort oil and virgin olive oil on the postoperative complications and compare this with chlorhexidine gluconate plus benzydamine hydrochloride mouthwash after the removal of impacted third molar.

METHODS

A total of 90 patients in need of impacted third molar surgery were included in this study. All included patients were randomly divided into 3 groups. The patients in group 1 received St. John's wort oil; the patients in group 2 received virgin olive oil, and those in group 3 received mouthwash containing chlorhexidine gluconate plus benzydamine hydrochloride. The self-reported pain and difficulty during jaw function, trismus, facial swelling, number of analgesics used during first postoperative week, and postoperative periodontal condition including plaque accumulation, bleeding on probing, and periodontal pocket depth were compared between the groups.

RESULTS

No significant differences were found regarding the study variables.

CONCLUSIONS

The data of the present study supports that the use of essential oils provides efficient alternative to the gold standard chlorhexidine gluconate mouthwash in reducing postoperative complications and improving healing process without adverse effects after surgical removal of impacted third molars.

CLINICAL RELEVANCE

The use of essential oils showed similar results as the chlorhexidine gluconate mouthwash regarding swelling, mouth opening, pain, need for rescue medication, infectious complications (i.e., alveolar osteitis), and periodontal healing. Therefore, essential oils can be an alternative to routine mouthwashes to ensure oral hygiene after impacted third molar surgery.

Quantification of DNA Double Strand Breaks and Oxidation Response in Children and Adults Undergoing Dental CBCT Scan

Assessing the possible biological effects of exposure to low doses of ionizing radiation (IR) is one of the prime challenges in radiation protection, especially in medical imaging. Today, radiobiological data on cone beam CT (CBCT) related biological effects are scarce. In children and adults, the induction of DNA double strand breaks (DSBs) in buccal mucosa cells and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and antioxidant capacity in saliva samples after CBCT examination were examined. No DNA DSBs induction was observed in children nor adults. In children only, an increase in 8-oxo-dG levels was observed 30 minutes after CBCT. At the same time an increase in antioxidant capacity was observed in children, whereas a decrease was observed in adults. Our data indicate that children and adults react differently to IR doses associated with CBCT. Fully understanding these differences could lead to an optimal use of CBCT in different age categories as well as improved radiation protection guidelines.

Re-evaluation of polihexanide use in wound antisepsis in order to clarify ambiguities of two animal studies

OBJECTIVE

Due to classification of the agent polihexanide (PHMB) in category 2 'may cause cancer' by the Committee for Risk Assessment of the European Chemicals Agency in 2011, the users of wound antiseptics may be highly confused. In 2017, this statement was updated, defining PHMB up to 0.1% as a preservative safe in all cosmetic products. In the interest of patient safety, a scientific clarification of the potential carcinogenicity of PHMB is necessary.

METHODS

A multidisciplinary team (MDT) of microbiologists, surgeons, dermatologists and biochemists conducted a benefit-risk assessment to clarify the hazard of antiseptic use of PHMB.

RESULTS

In two animal studies, from which the assessment of a carcinogenic risk was derived, PHMB was administered orally over two years in extremely high concentrations far above the NO(A)EL (no-observed-(adverse-) effect level) in rats and mice. Feeding in the NO(A)EL range resulted in no abnormal effects. In one male in the highest dose group of 4000ppm PHMB, an adenocarcinoma was found, which the author attributed to chronic inflammation of the colon with systemic atypical exposure. The increasing incidence of hemangiosarcomas highly probably resulted from increased endothelial proliferation, triggered by the exceedingly high dosage fed, because PHMB is not genotoxic and there is no evidence for epigenetic effects.

DISCUSSION

It is well known that PHMB is not absorbed when applied topically. Considering the absence of genotoxicity and epigenetic effects together with the interpretation of the animal studies, it is the consensus of the multidisciplinary experts that a carcinogenic risk from PHMB-use for wound antisepsis can be ruled out.

CONCLUSION

On this basis and considering their effectiveness, tolerability and clinical evidence, the indications for PHMB based wound antiseptics are justified.