Orthodontic treatment modifies the oxidant-antioxidant balance in saliva of clinically healthy subjects

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.

Salivary biomarkers as key to monitor personalized oral healthcare and precision dentistry: A scoping review

Personalized Oral Healthcare has recently become the new trend word in medicine and dentistry. In this context, saliva diagnostics using various biomarkers seem to be the gateway to personalized dental diagnostics and therapy. But the terminology is not (yet) uniformly defined, furthermore it is unclear to what extent which salivary markers play a relevant role in the therapeutic decision making. In this Scoping Review, an electronic search was conducted in PubMed and Web of Science databases using medical subject headings (MESH terms) “saliva”, “biomarker”, “personality/persons”, and “dentistry”. Only human studies were included, in which repeated salivary measurements were performed to analyze monitoring effects with at least ten patients per group. PRISMA-ScR and Tricco guidelines were followed: (i) to examine what salivary biomarkers have been explored in terms of personalized oral healthcare and precision dentistry, (ii) to investigate the clinical relevance for oral health and its correlation to systemic health, and (iii) to summarize an outlook for future developments based on these results. Out of 899 studies, a total of 57 were included for data extraction in this Scoping Review, mainly focusing on periodontal therapy and patient monitoring. Salivary biomarkers have shown the potential to change the field of dentistry in all dental disciplines as a key for personalized workflows. The increasing interest in dental research is obvious, demonstrated by the growing number of publications in recent years. At this time, however, the predominant discipline is periodontology, which allows biomarker-based monitoring of the disease prevention and progression. The studies included showed heterogeneous methods using manifolds biomarkers. Therefore, no uniformly accepted concept can be presented today. Further clinical research with well-defined outcomes including standardized procedures is necessary.

Salivary Markers of Oxidative Stress in Patients Undergoing Orthodontic Treatment with Clear Aligners versus Self-Ligating Brackets: A Non-Randomized Clinical Trial

The aim of this work was to determine advanced the oxidative protein products (AOPPs), total antioxidant capacity (TAC), and myeloperoxidase activity (MPO) in the saliva of patients undergoing orthodontic treatment with clear removable aligners in comparison with another group in treatment with fixed passive self-ligating brackets applying light forces, before treatment, after 30 days, and after 90 days of treatment. This non-randomized clinical trial recruited patients consecutively, all of which were over 18 years of age and due to undergo orthodontic treatment. They were divided into two groups according to treatment type: Group A, 48 patients treated with clear aligners (Invisalign^®); and Group B, 19 patients treated with Damon System^® 0.22″ self-ligating brackets applying light forces. Saliva samples were collected by a single clinician following the same protocol and underwent three analyses—AOPPs, TAC, and MPO levels–at baseline before placing the apparatus, after 30 days, and after 90 days treatment. Orthodontic treatment, whether with clear aligners or fixed self-ligating brackets and light forces, increased AOPPs after the first 30 days of treatment. During the initial phases of orthodontic treatment, neither clear aligners nor fixed self-ligating brackets applying light forces showed changes in TAC and MPO. Orthodontic treatment with both clear aligners and fixed apparatus self-ligating brackets applying light forces increases oxidative stress (AOPPs) after the first 30 days of treatment. There are no differences in AOPP levels between treatment with clear aligners and self-ligating brackets during the first 90 days of treatment. The antioxidative capacity of saliva during the initial phases of orthodontic treatment, whether with self-ligating brackets or clear aligners, does not undergo significant changes. With either orthodontic technique, the patients’ salivary antioxidant capacity is similar.

Short tandem repeat (STR) instability in the oral mucosa of patients submitted to fixed orthodontic therapy: a limitation of STR profile quality for human identification

The purpose of this study was to evaluate changes in short tandem repeat (STR) profile quality before and after fixed orthodontic therapy. Samples of oral epithelial cells were obtained from 28 volunteers who had an indication for orthodontic treatment. The samples were collected before and three months after starting orthodontic treatment with fixed appliances. DNA extraction and integrity were evaluated by electrophoresis, and STR profiles were obtained by polymerase chain reaction amplification and STR typing via capillary electrophoresis. DNA electrophoresis showed a higher proportion (7/28, 25%) of DNA degradation in the samples collected after fixed orthodontic treatment compared to those obtained before starting orthodontic therapy (3/28, 11%), however, changes in DNA were not significant (p=0.289). In concordance all STR profiles showed complete genotyping; however, imbalances in the size of heterozygotes and in the signal were detected in 25% of STR profiles after orthodontic therapy. Moreover, STR instability was demonstrated by an increase in stutter bands detected in 60% of the DNA profiles after treatment and a spurious allele of the D195433 marker was found in one sample after treatment. The STR profiles of samples obtained from the oral cavity with orthodontic appliances should be interpreted with caution. STR instability increases the incidence of artifacts that could compromise the quality of the results of tests performed in forensic DNA laboratories.

In vivo investigation of gingival health and oxidative stress changes in patients undergoing orthodontic treatment with and without fluoride use

Background and Aims:

We aimed to investigate gingival index changes and oxidative stress in orthodontic patients with and without the use of fluoridated agents over a 6-month period.

Materials and Methods:

Ninety subjects divided into three groups (30 untreated controls, 30 with fixed appliances using nonfluoridated toothpaste, and 30 with fixed appliances using fluoridated toothpastes and mouthwashes ) comprised the sample. The Loe gingival index was used to rank gingival health at four specific time periods in the groups to determine differences (before, at 7 days, 30 days, and 6 months). Gingival crevicular fluid was evaluated for cytokines (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) to determine differences in oxidative status between the groups.

Results:

Controls showed no changes in gingival index throughout the 6-month observation period. There was a deterioration in gingival health in both the fluoridated and nonfluoridated groups till 6 months. IL-1β levels in the fluoridated group increased from the 7^th day, reached a peak at 30 days, and remained slightly elevated at 6 months. The nonfluoridated group also showed elevated levels at all tested time periods, but levels were lower as compared to fluoridated samples. The differences in IL-1β values between the fluoridated and nonfluoridated treated groups were significant. TNF-α levels in the three groups also showed a similar pattern with elevated levels seen in both the treated groups at the 7^th, 30-day, and 6-month periods. The fluoridated group showed the highest levels at three time periods which was statistically significant.

Conclusions:

Gingival health of subjects treated with fixed orthodontic appliances deteriorated from appliance placement till a 6-month time period. Cytokines such as IL-1β and TNF-α associated with oxidative stress during orthodontic treatment increased in both the treated groups, with higher levels in fluoridated subjects. Long-term consequences of oxidative stress changes need further investigation.

Causation of Oxidative Stress and Defense Response of a Yeast Cell Model after Treatment with Orthodontic Alloys Consisting of Metal Ions

Misaligned teeth have a tremendous impact on oral and dental health, and the most efficient method of correcting the problem is orthodontic treatment with orthodontic appliances. The study was conducted to investigate the metal composition of selected orthodontic alloys, the release of metal ions, and the oxidative consequences that the metal ions may cause in the cell. Different sets of archwires, stainless steel brackets, and molar bands were incubated in artificial saliva for 90 days. The composition of each orthodontic material and quantification of the concentration of metal ions released were evaluated. Metal ion mixtures were prepared to determine the occurrence of oxidative stress, antioxidant enzyme defense system, and oxidative damage to proteins. The beta titanium alloy released the fewest metal ions and did not cause oxidative stress or protein damage. The metal ions from stainless steel and the cobalt-chromium alloy can cause oxidative stress and protein damage only at high concentrations. All metal ions from orthodontic alloys alter the activity of antioxidant enzymes in some way. The determined amounts of metal ions released from orthodontic appliances in a simulated oral environment are still below the maximum tolerated dose, and the concentrations of released metal ions are not capable of inducing oxidative stress, although some changes in antioxidant enzyme activity were observed at these concentrations.

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.

Risk Assessment of Oxidative Stress Induced by Metal Ions Released from Fixed Orthodontic Appliances during Treatment and Indications for Supportive Antioxidant Therapy: A Narrative Review

The treatment with fixed orthodontic appliances could have an important role in the induction of oxidative stress and associated negative consequences. Because of the simultaneous effects of corrosion, deformation, friction, and mechanical stress on fixed orthodontic appliances during treatment, degradation of orthodontic brackets and archwires occurs, causing higher concentrations of metal ions in the oral cavity. Corroded appliances cause the release of metal ions, which may lead to the increased values of reactive oxygen species (ROS) due to metal-catalyzed free radical reactions. Chromium, iron, nickel, cobalt, titanium, and molybdenum all belong to the group of transition metals that can be subjected to redox reactions to form ROS. The estimation of health risk due to the amount of heavy metals released and the level of selected parameters of oxidative stress generated for the time of treatment with fixed orthodontic appliances is presented. Approaches to avoid oxidative stress and recommendations for the preventive use of topical or systemic antioxidants during orthodontic treatment are discussed.

Protein carbonylation associated with nickel liberation in orthodontic gingival overgrowth

OBJECTIVE

To determine nickel levels and their impact on protein carbonylation in gum samples from patients with gingival overgrowth by orthodontic treatment.

DESIGN

A retrospective observational study with 33 patients divided into three groups. Group 1 patients with gingival overgrowth by orthodontic appliances; group 2 patients without gingival overgrowth but with a history of orthodontic treatment; group 3 patients without overgrowth and history of orthodontic appliances. Nickel level in gingiva samples was measured by atomic absorption while protein carbonylation was determined by Western Blot. Furthermore, three proteins were identified in carbonylated protein bands by mass spectrometry.

RESULTS

Statistically significant differences (p < 0,05) in tissue nickel levels among groups were established (nickel levels group 1: 1.33 ± 1.52; group 2: 0.33 ± 0.44; group 3: 0.20 ± 0.22 μg Ni/g tissue). Protein carbonylation was higher in patients with gingival enlargement (group 1) and history of appliance use (group 2) than controls (group 3). It was observed that band A of the Western blots presented the highest intensity (Rf 0.23) with an average intensity of 4.133.830 ± 1.958.569 for group 1; 4.420.146 ± 1.594.679 for group 2 and 2.110. 727 ± 1.640.721 for group 3. Also, the proteins Teneurin-4, Bromodomain adjacent to zinc finger domain protein 2B, Lysine-specific demethylase 5B, and Serum albumin, were identified from oxidized bands.

CONCLUSIONS

The gum of patients with gingival overgrowth by orthodontic appliances contains higher nickel residues and carbonylation of its proteins.

The Effect of Selected Dental Materials Used in Conservative Dentistry, Endodontics, Surgery, and Orthodontics as Well as during the Periodontal Treatment on the Redox Balance in the Oral Cavity

Oxidative stress (OS) is a redox homeostasis disorder that results in oxidation of cell components and thus disturbs cell metabolism. OS is induced by numerous internal as well as external factors. According to recent studies, dental treatment may also be one of them. The aim of our work was to assess the effect of dental treatment on the redox balance of the oral cavity. We reviewed literature available in PubMed, Medline, and Scopus databases, including the results from 2010 to 2020. Publications were searched according to the keywords: oxidative stress and dental monomers; oxidative stress and amalgam; oxidative stress and periodontitis, oxidative stress and braces, oxidative stress and titanium; oxidative stress and dental implants, oxidative stress and endodontics treatment, oxidative stress and dental treatment; and oxidative stress and dental composite. It was found that dental treatment with the use of composites, amalgams, glass-ionomers, materials for root canal filling/rinsing, orthodontic braces (made of various metal alloys), titanium implants, or whitening agents can disturb oral redox homeostasis by affecting the antioxidant barrier and increasing oxidative damage to salivary proteins, lipids, and DNA. Abnormal saliva secretion/composition was also observed in dental patients in the course of OS. It is suggested that the addition of antioxidants to dental materials or antioxidant therapy applied during dental treatment could protect the patient against harmful effects of OS in the oral cavity.

Levels of Selected Matrix Metalloproteinases-MMP-1, MMP-2 and Fibronectin in the Saliva of Patients Planned for Endodontic Treatment or Surgical Extraction

OBJECTIVES

Composition of saliva reflects the condition of the oral cavity.

THE AIM OF THE STUDY

Investigation of the concentrations of MMP-1 (Matrix metalloproteinase-1), MMP-2 (Matrix metalloproteinase-2) and fibronectin in the saliva of patients planned for endodontic treatment or surgical extraction.

MATERIAL AND METHODS

Seventy-five patients with caries and 14 healthy subjects were included in the study. Subjects were divided into group 1, in which 50 patients were planned for endodontic treatment, and group 2, in which 25 patients were planned for surgical extraction. For the measurements, we used a surface plasmon resonance imaging biosensor.

RESULTS

We found higher levels of MMP-1, MMP-2 and fibronectin in the saliva of patients planned for dental treatment than in healthy donors. We found lower concentrations of MMP-2 in subjects planned for surgical extraction, than in patients planned for endodontic treatment; however, there were no such differences in salivary concentrations of MMP-1 and fibronectin. There were no statistically significant differences in MMP-1 concentrations in the saliva before and after any type of dental treatment, but contrary to that, we found a statistically significant decrease in MMP-2 concentrations after endodontic treatment and after surgical extraction. We found a significant rise in the concentrations of fibronectin after surgical extraction but not after endodontic treatment.

CONCLUSIONS

The concentrations of MMP-1 and MMP-2 in the saliva of our patients with caries were increased in comparison to healthy individuals, but after the treatment-so sanation of the oral cavity-we noted a decrease in matrix metalloproteinases (MMPs) levels. MMPs can be found in gingival crevicular fluid and saliva, carious dentin and plaque. According to our observations, the main source of MMPs in patients with caries is probably carious dentin. Increase in the salivary levels of fibronectin (FN) after surgical extraction may be connected with soft tissue injury caused by surgical extraction. Our results are another example of the fact that higher salivary concentrations of MMP-1, MMP-2 and FN can reflect the health status of the oral cavity in patients with caries.

Effects of diabetes on oxidative stress, periodontal ligament fiber orientation, and matrix metalloproteinase 8 and 9 expressions during orthodontic tooth movement

OBJECTIVES

To evaluate the influence of diabetes on oxidative stress, periodontal ligament (PDL) orientation, and matrix metalloproteinase (MMP) 8 and 9 expressions during orthodontic tooth movement in a rat model.

MATERIALS AND METHODS

An orthodontic appliance was placed in 60 Sprague-Dawley rats divided into three groups: normoglycemics (n = 20) and two streptozotocin-induced diabetic groups, one untreated (n = 20) and one insulin-treated (n = 20). At 24, 48, and 72 h and 1 week, rats were sacrificed. At each time point, myeloperoxidase (MPO) and malondialdehyde (MDA) were quantified by spectrophotometry, tooth movement was evaluated by micro-CT analysis, and hematoxylin and eosin staining was used to evaluate PDL fiber orientation and immunohistochemistry staining with semi-quantitative H-score analysis of MMP-8 and MMP-9 was performed..

RESULTS

At 24 h, MPO activity was significantly higher in untreated-diabetics than normoglycemics. At 24 and 48 h, the MDA level in untreated-diabetic rats was significantly higher than in normoglycemics and insulin-treated animals. At 72 h and 1 week, PDL fibers were oriented significantly more irregularly in untreated-diabetics than in normoglycemics. At all time points, MMP-8 and MMP-9 expressions were significantly higher in both diabetic groups than in the normoglycemic group. After the second day, tooth movement was significantly greater in untreated-diabetics than in the insulin-treated and normoglycemic groups.

CONCLUSIONS

Mechanical stress in untreated-diabetic rats produces more inflammatory response, oxidative stress, tooth movement, PDL disorganization, and MMP-8 and MMP-9 expressions than among normoglycemics. Insulin reverses these effects, favoring the reorganization of periodontal ligament.

CLINICAL RELEVANCE

Our results suggest that the application of orthodontic force in diabetic patients would increase inflammation and delay periodontal restructuring. Insulin would partly reverse this situation although glycemic decompensation episodes may occur. For these reasons, the periods between fixed orthodontic appliance activations should be of sufficient duration to allow adequate tissue recovery.

Oxidative Stress Indexes for Diagnosis of Health or Disease in Humans

Oxidative stress (OS) is the imbalance between oxidant and antioxidant molecules, in favor of oxidants, that causes aging and disease. Many studies have been published that demonstrate the relationship between OS and human health and disease; however, the following questions arise: (i) how are we sure that the OS is present in a biological process? (ii) Is the OS reported in the different investigations equivalent? (iii) What are the best oxidant and antioxidant markers for OS diagnosis? (iv) Can we establish the types and the intensity of the OS? (v) Does OS index could be useful for research and/or application in clinical medicine? In this regard, several indexes have been proposed to measure OS in humans relative to the state of health and disease, among which the following can be highlighted: Oxidative Stress Index (OSI), Tiol Ratios (-SH/TT, -SS/-SH, and-SS/TT), Glutathione Ratio (GSSG/GSH), Oxidative Stress Score (OSS), and OXY-index. Therefore, the aim of this review is to present the state of the art of knowledge about OS indexes for diagnosis of health or disease in humans. We searched for articles in English or Spanish in the PubMed/MEDLINE and Scopus electronic databases published up until May 2019. The keywords used were “oxidative stress,” “index,” and “oxidative stress index.” It was identified 11479 records in both databases, and 490 articles were analyzed. Our review suggests that all indexes analyzed allow diagnose and differentiate the OS related to human health and disease. Also, the studies on OSI, Oxy-score, and OSS indexes have proven to be reliable, practical, and with clinical utility. However, it is necessary to continue with longitudinal studies, especially assess the usefulness of the indexes in the clinical prognosis, and make comparative studies between the different indexes.

Systemic Level of Oxidative Stress during Orthodontic Treatment with Fixed Appliances

The aim of the study was to assess the level of selected systemic oxidative stress parameters during the first week of orthodontic treatment with fixed appliances. Fifty-four males with malocclusion and having a similar lifestyle were randomized using a computer based procedure and allocated to either the treatment group (TG; n=27;24.6 ± 1.7 years) or control group (CG; n=27;24.7 ± 1.7 years). Capillary blood was collected at baseline and 6 hours, 24 hours, and 7 days after archwire insertion. At the same time points, capillary blood was retrieved in the CG. In order to determine the oxidative stress, both the reactive oxygen species (ROS) formation and the antioxidative defense (AD) potential were measured using the ROS testing and oxygen free radicals defense (equivalent to antioxidant defense) testing, respectively, by a blinded operator. The ratio between ROS and AD (ROS/AD) was calculated and data were analyzed using nonparametric tests. No drop-outs or harms were detected. At baseline, neither ROS (1.54 [1.22; 2.12] and 1.74 [1.40; 2.01] for the TG and CG, respectively), AD (1.19 [0.66; 1.50] and 1.19 [0.57; 1.42] for the TG and CG, respectively), nor ROS/AD levels were significantly different (p>0.05). After 24 hours, the ROS level significantly increased in the TG (2.05 [1.71; 2.26]) and was higher compared to the CG ROS level (1.67 [1.29; 1.95]; p=0.025), while for the AD level, no marked between and within group differences were detected. A notable change of ROS/AD ratio was observed over time only within the TG (p=0.026). Moreover, a significantly higher ROS/AD ratio was detected 24 hours after archwire insertion in the TG compared to the CG (2.69 [1.44; 3.89] and 1.79 [1.45; 2.35], respectively), followed by a decrease. Orthodontic treatment with fixed appliances might induce systemic oxidative stress in the short-term, since ROS levels and ROS/AD levels are normalized within 7 days after archwire insertion.

Zinc and Metallothionein in the Development and Progression of Dental Caries

Chronic oxidative stress and reactive oxygen species (ROS) in oral cavity as well as acidic pH on dental enamel surface due to the metabolic activities of bacterial plaque are the major contributors in the development and progression of dental caries. Along with other factors, deposition or dissolution Ca and Mg mostly determines the re- or demineralization of dental enamel. Zn plays an important role for both Ca and Mg bioavailability in oral cavity. Metallothionein (MT), a group of small molecular weight, cysteine-rich proteins (~ 7 kDa), is commonly induced by ROS, bacterial infection, and Zn. In the current review, we evaluated MT at the junction between the progression of dental caries and its etiologies that are common in MT biosynthesis.

Sources of free radicals and oxidative stress in the oral cavity

OBJECTIVE

An oral cavity is a place especially susceptible to oxidative damage. It is subjected to many environmental pro-oxidative factors or factors that have the ability to generate reactive oxygen species (ROS). The aim of this article is to present the main sources of ROS and oxidative stress in the oral environment.

DESIGN

A literature search was performed using the PubMed and Google Scholar databases.

RESULTS

One of the most important ROS sources in the oral cavity is periodontal inflammation. Other sources of ROS include: xenobiotics (ethanol, cigarette smoke, drugs), food (high-fat diet, high-protein diet, acrolein), dental treatment (ozone, ultrasound, non-thermal plasma, laser light, ultraviolet light), and dental materials (fluorides, dental composites, fixed orthodontic appliances, and titanium fixations). It has been shown that excessive production of ROS in the oral cavity may cause oxidative stress and oxidative damage to cellular DNA, lipids, and proteins, thus predisposing to many oral and systemic diseases.

CONCLUSIONS

Recognition of the exogenous sources of ROS and limitation of exposure to the ROS generating factors can be one of the prophylactic measures preventing oral and systemic diseases. It is suggested that antioxidant supplementation may be helpful in people exposed to excessive production of ROS in the oral cavity system.

Salivary Electrolytes in Patients with Metallic and Ceramic Orthodontic Brackets

Objectives

It is known from the existing literature that metal ions within orthodontic appliances are prone to corrosion due to the salivary and bacterial interplay in the oral cavity. The results from the most studies show that levels of salivary nickel and chromium do not increase after the installment of orthodontic appliances.

Material and methods

However, there are no studies on salivary levels of titanium, cobalt, copper and zinc in these patients. Salivary levels of nickel (Ni), titanium (Ti), chromium (Cr), cobalt (Co), copper (Cu) and zinc (Zn) were measured in 42 patients with ceramic brackets and in 42 patients with metal conventional brackets prior to insertion of orthodontic appliances and six months after insertion of orthodontic appliances by means of inductive coupled plasma/mass spectrometry. Statistical analysis was performed by use of Wilcoxon signed rank test and Mann Whitney test with level of significance set at 0.05.

Results

The results showed that salivary level of titanium increased significantly six months after installment of orthodontic appliances. Salivary level of chromium and zinc significantly decreased after installment of orthodontic appliances. There were no significant differences in salivary levels of nickel, titanium, chromium, copper, cobalt and zinc between the patients with metallic and those with ceramic brackets.

Conclusion

We might conclude that the salivary level of titanium increased significantly six months after installment of orthodontic appliances unlike salivary levels of chromium and zinc which significantly decreased after installment of orthodontic appliances, regardless of bracket type which was used.

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.