Evaluation of salivary total oxidant-antioxidant status and DNA damage of children undergoing fixed orthodontic therapy

Investigation of the cytotoxic and genotoxic effects of removable retention appliances

INTRODUCTION

This study aimed to examine and compare the cytotoxic and genotoxic effects of Hawley and Essix removable retainers on tissues.

METHODS

A total of 50 patients who had completed fixed orthodontic treatment were randomly assigned to 1 of 2 groups based on the type of retainer they would use for retention: Essix group (n = 25) or Hawley group (n = 25). For biochemical evaluation, saliva samples were collected at 3-time points: before appliance use, 1 month after appliance use (TB1), and 3 months after appliance use. The levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), nuclear factor erythroid 2-related factor 2, and Kelch-like ECH-related protein 1 (Keap1) were then analyzed. For cytologic evaluation, swab samples were collected before and 14-21 days after the use of the appliance, and the occurrence of micronucleus, pyknosis, karyorrhexis, and karyolysis were analyzed.

RESULTS

Biochemical evaluation revealed that the 8-OHdG level was higher in the Hawley group at TB1 and TB2. Conversely, no significant differences were observed in nuclear factor erythroid 2-related factor 2 levels between the groups. Although no significant difference in Keap1 value was observed between the 2 groups at TB1, a notable elevation in Keap1 levels was evident in the Hawley group at TB2. A cytologic evaluation revealed that the levels of micronuclei, pyknosis, karyorrhexis, and karyolysis were higher in the Essix group at 14-21 days after appliance use.

CONCLUSIONS

The application of both appliances was observed to increase the number of findings indicating nuclear degeneration. However, the Hawley retainer increased the 8-OHdG level, whereas the Essix retainer showed a decrease in this 8-OHdG level.

Impact of Clear Aligners vs Conventional Brackets on Oxidant and Antioxidant Levels: A Case-Control Study

BACKGROUND The aim of this study was to identify the changes in the levels of total oxidant status (TOS) and total antioxidant status (TAS) in gingival crevicular fluid (GCF) samples of patients treated with conventional brackets (CBs) and clear aligners (CAs) over a 30-day period. MATERIAL AND METHODS Thirty-four patients who received non-extraction treatment with either CBs or CAs were included in the study. GCF samples were obtained at baseline (T0) and on days 7 (T1) and 30 (T2) following initial phase of treatment. Clinical periodontal parameters were used to determine periodontal conditions of patients. ELISA method was used to determine TAS and TOS levels in GCF samples. RESULTS In the group treated with CAs, TOS levels in GCF were significantly high at T1 but approached T0 after the first month (T2) of treatment. In contrast, the group treated with CBs showed significantly high TOS levels in GCF at both T1 and T2 compared with T0. No significant changes were observed in GCF TAS data at T1 and T2 in either group (CA and CB), compared with T0. When comparing TOS data between the groups at T1 and T2, the CA group had lower TOS levels than the CB group (Mann-Whitney U with Bonferroni correction). Additionally, the CA group had lower periodontal clinical indexes than did the CB group. CONCLUSIONS Oxidative tissue damage during orthodontic teeth movements may be lower with CA treatment. In cases in which higher oxidative stress is anticipated, CA treatment may be preferred over CB treatment.

Evaluating the Therapeutic Properties of Natural Products in Orthodontic and Surgical Treatment of Dentofacial Deformities: A Systematic Review of Clinical Trials

The use of natural products as alternatives to traditional pharmacological treatments in orthodontics is gaining interest due to their anti-inflammatory, antibacterial, and antioxidant properties. This systematic review synthesizes evidence from clinical trials to evaluate the efficacy of natural products in reducing inflammation and bacterial presence in orthodontic and orthognathic treatment settings. The database search was conducted across PubMed, Scopus, and Embase up to January 2024. The review focused on randomized controlled trials only. The selected studies centered on the anti-inflammatory, antibacterial, and antioxidant effects of natural products, adhering to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines for data extraction. Nine studies, totaling 358 participants, were included. Significant findings demonstrated a reduction in gingival inflammation by over 40% with the use of Aloe vera compared to chlorhexidine. Another study noted a decrease in bleeding on probing by 13.6 points in the treatment group over placebo. Additionally, honey showed a rapid modulation of plaque pH and significantly reduced bacterial counts of Streptococcus mutans. Furthermore, the use of resveratrol emulgel was linked to substantial improvements in gingival health, with a reduction in the gingival index and probing pocket depth. The results indicate that natural products can significantly enhance orthodontic treatment outcomes by reducing inflammation and bacterial levels. These products offer effective alternatives to traditional treatments and show potential for integration into routine orthodontic care protocols. Further research is encouraged to standardize application methods and dosages to maximize clinical benefits and patient satisfaction.

Oxidative Stress and Natural Products in Orthodontic Treatment: A Systematic Review

In recent years, orthodontics, a specialized branch of dentistry, has evolved considerably in terms of both techniques and materials used. Aimed at correcting dental malocclusions and craniofacial anomalies, it improves the functionality and aesthetics of the face and oral cavity. However, orthodontic treatment, in its developmental stages, may induce oxidative stress (O.S.) phenomena, with an increase in the production of reactive oxygen species (ROS), damaging the dental and periodontal tissues involved, affecting the short-, medium- and long-term results. Studies on the antioxidant effects of natural products (e.g., resveratrol, green tea, turmeric, etc.) in the medical field have aroused considerable interest in recent years. A systematic literature review was conducted on the PubMed, Scopus, and Web of Science databases using natural products (N.P.s), O.S., and orthodontic as keywords. The study aims to consider the determinants of the increase in ROS occurring during orthodontic treatment and the possibility of natural products being able to control and neutralize biochemical phenomena by restoring the physiological process in which the balance between the production of ROS and the ability of the body's antioxidant system to neutralize them is in favor of the latter.

Oxidative stress and genotoxicity in oral epithelial cells from subjects undergoing orthodontic treatment with fixed appliances

OBJECTIVES

The objective of this work was to evaluate the impact of fixed orthodontic appliances on oxidative stress (OS) and genotoxicity from oral epithelial cells.

MATERIALS AND METHODS

Samples of oral epithelial cells were obtained from fifty-one healthy voluntary subjects who had an indication for orthodontic treatment. The samples were obtained before treatment and after 6 and 9 months of treatment. OS was evaluated by quantitating 8-hydroxy-2'deoxyguanosine (8-OHdG) and by performing relative gene expression with antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). DNA degradation and instability were evaluated by multiplex polymerase chain reaction (PCR) and fragment analysis for human identification.

RESULTS

The quantitation results showed that 8-OHdG increased during treatment, although this increase was not statistically significant. SOD increased by 2.5- and 2.6-fold after 6 and 9 months of treatment, respectively. CAT increased by threefold after 6 months of treatment, while after 9 months of treatment, the expression level decreased to a level similar to that before treatment. DNA degradation was found in 8% and 12% of DNA samples after 6 and 9 months of treatment, respectively, while DNA instability was detected in only 2% and 8% of DNA samples after 6 and 9 months of treatment, respectively.

CONCLUSIONS

The results showed that OS and genotoxicity slightly changed after treatment with a fixed orthodontic appliance; in addition, a biological adaptation response to the treatment may occur after 6 months.

CLINICAL RELEVANCE

OS and genotoxicity in the buccal cavity are risk factors for oral and systemic diseases. This risk may be reduced through antioxidant supplementation, by using thermoplastic materials, or by reducing the orthodontic treatment time.

Does puberty affect oxidative stress levels and antioxidant activity of saliva in patients with fixed orthodontic appliances?

PURPOSE

To evaluate and compare patients' oxidative stress parameters and antioxidant status with fixed orthodontic appliances during the pubertal and postpubertal growth periods.

METHODS

Saliva samples of 20 pubertal (mean age: 12.94 ± 0.34 years) and 20 postpubertal (mean age: 16.34 ± 0.45 years) patients were collected just before the application of fixed orthodontic appliances (T0), 4-5 h (T1), and 7 days (T2) after the initial orthodontic activation. Myeloperoxidase (MPO), nitric oxide (NO), 8‑hydroxydeoxyguanosine (8-OHdG) levels, and superoxide dismutase (SOD) activity in the saliva were examined. Repeated measures analysis of variance (ANOVA), least significant difference (LSD) pairwise comparison, and independent sample t‑tests were used to analyze the differences between the time points and growth periods, respectively.

RESULTS

MPO levels in the saliva of patients in the pubertal period showed a significantly higher increase within the first days of treatment (T2-T1) than in patients in the postpubertal period (p < 0.05). The SOD antioxidant enzyme activity decreased in the samples from T0 to T1 in the patients in the pubertal and postpubertal groups and returned to baseline values (T0) at T2 (p < 0.01). No significant differences in the other biochemical parameters between groups were observed.

CONCLUSIONS

Comparing the pubertal and postpubertal groups, orthodontic force application with fixed orthodontic appliances did not change the final levels (on day 7) of antioxidant status or oxidative stress markers, except for MPO in saliva.

The cytotoxic and oxidative effects of restorative materials in cultured human gingival fibroblasts

The aim of this study was to evaluate the cytotoxic and oxidative effects of the most commonly used dental restorative materials on human gingival fibroblast cells (HGFCs). HGFCs were obtained from healthy individuals. The tested restorative materials were a microhybrid resin based composite, a compomer resin, a glass ionomer cement, and an amalgam alloy. One hundred eight cylindirical samples, 10 mm in diameter and 2 mm in height, were prepared according to ISO 10993-12:2002 specifications (n = 9 in the tested subgroups). Freshly prepared and aged samples in artificial saliva at 37 °C (7 and 21 d) were placed into well plates and incubated. Wells without dental materials were constituted as the control group. After 72 h incubation period, cytotoxicity was determined using the neutral red (NR) assay. Oxidative alterations were assessed using total antioxidant capacity (TAC) and total oxidant status (TOS) assay kits. Data were analyzed using the ANOVA and LSD post hoc tests. All tested materials led to significant decreases in the cell viability rates (33-73%) compared to the control group. Glass ionomer and resin composite were found to be more cytotoxic than amalgam alloy and compomer. The highest TAC level was observed in glass ionomer after seven-day aging and these changes prevented an increase in TOS levels. Increases in TAC levels after seven-day aging in all groups exhibited significant differences with freshly prepared samples (p < 0.05). In all material groups, TOS levels of freshly prepared samples differed statistically and significantly from samples aged for 7 and 21 d (p < 0.05). The data obtained suggested that all the tested materials exhibited cytotoxic and pro-oxidant features. Freshly prepared samples caused higher TOS levels. However, oxidant status induced by materials decreased over time.

Evaluation of interleukin-1β level and oxidative status in gingival crevicular fluid during rapid maxillary expansion

OBJECTIVES

The levels of interleukin-1β (IL-1β), nitric oxide (NO), total antioxidant capacity (TAC), and total oxidant status (TOS) in gingival crevicular fluid (GCF) were determined during rapid maxillary expansion (RME) treatment.

MATERIALS AND METHODS

Fourteen patients (10-13 years old) were included. A modified hyrax appliance was used for the treatment. After periodontal parameters were recorded, GCF was collected from the first molars at each observation [T1:baseline:14 days after periodontal prophylaxis and instructions; T2:1 day later hyrax inserted, at passive position; T3:1 week later; after the first activation; T4:after 2 × 1/4 activation; T5:after 7 × 1/4 activation; T6:after 14 × 1/4 activation; T7:retention period on the 1 st month; and T8:retention period on the 3rd month].

RESULTS

Although the levels of IL1-β, NO, and PD increased significantly from T1 to T2, the GI, BOP%, and PI remained unchanged throughout treatment. GCF volume at buccal and palatal surfaces increased significantly from T1 to T4, T6, T7, and T8. The parameters in GCF and TAC levels were not only higher at palatal side in comparison with buccal, but also TOS levels increased at both buccal and palatal sides.

CONCLUSIONS

In this study, the differences of oxidative status and IL-1β levels during RME treatment could be attributable to orthopedic effect of the heavy forces on maxilla and minimal orthodontic forces on teeth applied by the RME apparatus.

Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans

Total Antioxidant Capacity (TAC) is a biomarker often used in order to investigate oxidative stress in many pathological conditions. Saliva and urine can be collected noninvasively and represent attractive diagnostic fluids for detecting biomarkers of various pathological conditions. The reviewed case-control and intervention studies that measured salivary or urinary TAC revealed that diseases, antioxidant foods, or supplements and age, gender, and lifestyle factors influenced salivary or urinary TAC. Salivary and urinary TAC were particularly affected by oral or renal status, respectively, as well as by infection; therefore these factors must be taken into account in both case-control and intervention studies. Furthermore, some considerations on sample collection and normalization strategies could be made. In particular, unstimulated saliva could be the better approach to measure salivary TAC, whereas 24 h or spontaneous urine collection should be chosen on the basis of the study outcome and of the creatinine clearance. Finally, the uric acid-independent TAC could be the better approach to evaluate red-ox status of body, in particular after nutritional interventions and in diseases associated with hyperuricaemia.