|Year : 2022 | Volume
| Issue : 4 | Page : 390-393
Evaluating the role of salivary oxidative stress marker malondialdehyde in dental caries—A comparative study
S Sivaranjani, Rameshkumar Annasamy, Amritha James, Rajkumar Krishnan, Ramya Mahalingam, Preethi Arunachalam
Department of Oral Pathology and Microbiology, SRM Dental College, Chennai, Tamil Nadu, India
|Date of Submission||31-Mar-2022|
|Date of Decision||24-Oct-2022|
|Date of Acceptance||24-Oct-2022|
|Date of Web Publication||09-Dec-2022|
Department of Oral Pathology, SRM Dental College, Bharathi Salai, Ramapuram, Chennai - 600 089, Tamil Nadu
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: Free radical-induced damage on the lipids results in the creation of a novel oxidative stress marker—malondialdehyde (MDA). MDA-induced cell damage affects the immune mechanisms of saliva and may lead to the initiation and progression of bacterial diseases like periodontitis and even dental caries. Aim and Objectives: To determine the salivary levels of the oxidative stress marker—malondialdehyde (MDA) in subjects with dental caries before and after treatment to assess the role of MDA in the initiation and evolution of dental caries. Materials and Methods: The study included 40 patients in total. Based on the number of caries teeth present at the time of diagnosis, patients were divided into two groups: Group I: Subjects with dental caries in 1–2 teeth, N = 20; Group II: Subjects with dental caries in 3–4 teeth, N = 20. The patients were further divided into two groups after undergoing treatment: Group III: Group I subjects who undertook treatment for dental caries, N = 20; Group IV: Group II subjects who underwent treatment for dental caries, N = 20. The whole saliva was obtained from all subjects before treatment and one month after treatment. Estimation of MDA levels was done using ELISA. Statistical analysis was conducted using Student's t-test and Pearson's correlation coefficient. A P value ≤ 0.05 was considered significant. Results: Elevated levels of MDA were evident in subjects with greater carious lesions. The levels of MDA decreased significantly in post-treatment subjects. Pearson's correlation analysis also showed a strong positive correlation with the R-value of 0.832 between Group I and Group II. Conclusion: MDA levels increased with an increase in carious lesions and significantly reduced following treatment proving the role of salivary MDA in the evolution of dental caries.
Keywords: Dental caries, lipid peroxidation, MDA, oxidative stress, salivary biomarker
|How to cite this article:|
Sivaranjani S, Annasamy R, James A, Krishnan R, Mahalingam R, Arunachalam P. Evaluating the role of salivary oxidative stress marker malondialdehyde in dental caries—A comparative study. J Indian Acad Oral Med Radiol 2022;34:390-3
|How to cite this URL:|
Sivaranjani S, Annasamy R, James A, Krishnan R, Mahalingam R, Arunachalam P. Evaluating the role of salivary oxidative stress marker malondialdehyde in dental caries—A comparative study. J Indian Acad Oral Med Radiol [serial online] 2022 [cited 2023 Feb 3];34:390-3. Available from: http://www.jiaomr.in/text.asp?2022/34/4/390/363011
| Introduction|| |
Numerous oral conditions have been associated with oxidative stress, including dental caries, periodontitis, and oral squamous cell carcinoma. Oxidative stress arises due to the increasing concentration of free radicals within the cells. Free radicals can alter the cellular components' functions and integrity; one such route is via the peroxidation of lipids.,
Lipid peroxidation results in the degradation of lipids by the oxidative process. In this process, free radicals snip the electrons from the cell membrane-bound lipids leading to cellular damage. This free radical-induced damage on the lipids results in the creation of a novel oxidative stress marker—malondialdehyde (MDA). MDA is a biomarker to assess an organism's oxidative stress level and is considered an indicator of increased lipid peroxidation. MDA-induced cell damage may also affect the immune mechanisms of saliva and lead to the initiation and concatenation of bacterial diseases like periodontitis and even dental caries.,
Oxidative stress plays a central role in the initiation and progression of dental caries. The end products of lipid peroxidation, like MDA, could serve as potential biomarkers to evaluate the progression of dental caries and assess the therapeutic efficacy and response to treatment following the treatment of dental caries.,
Hence, the present research aims to estimate salivary MDA levels in subjects with dental caries before and after treatment to assess the role of MDA in the initiation and progression of dental caries.
| Materials and Methods|| |
The study was conducted in the outpatient department after obtaining approval and ethical clearance from the Institutional Review Board (IRB APPROVAL NUMBER: IRB/2018/MDS/No. 606. Date- 02/12/2020). The study was conducted for a period of one year. Informed consent was obtained in writing from all the participants.
Sample size determination was done using G*Power 3® software. The sample size was calculated with the power of the study set at 80%, the alpha error set at 5%, and the effect size at 0.4. Simple random sampling was done to recruit participants for the study. Based on the sample size estimated and the sampling technique used, a total of 40 patients were finally recruited for the study.
Inclusion and exclusion criteria
The study included a total of 40 patients. The patients were separated into two groups based on the number of caries teeth present at the time of diagnosis: Group I included subjects with dental caries involving dentin in 1–2 teeth, N = 20. Group II included subjects with dental caries involving dentin in 3–4 teeth, N = 20. Patients between the age-group of 20–35 years, patients with a full complement of permanent teeth excluding third molar, and an OHI-S of 0–1.2 were only included in the study.
Individuals with deleterious habits such as tobacco use, patients with oral inflammatory conditions such as gingivitis, periodontitis, oral ulcers, and mucositis, patients with pulpal and periapical pathologies, and patients with systemic illnesses were omitted from the study.
The patients were further separated into two groups after undergoing treatment: Group III: Group I subjects treated for dental caries, N = 20; Group IV: Group II subjects treated for dental caries, N = 20.
Unstimulated whole saliva was obtained from all subjects before treatment and one month after treatment for dental caries. The saliva was collected in a sterile container and centrifuged immediately in a cooling centrifuge at 2500 rpm for 15 min at 4°C to eliminate squamous cells and cellular debris. The supernatant was separated and collected in 1 ml aliquots and then stored at –80°CC until further analysis.
Human malondialdehyde (MDA) ELISA Kit assay obtained from BioAssay Technology Laboratory was used to estimate the salivary MDA levels. The reaction mixture was measured at 540 nm using Microplate Reader. The absorbance results obtained from the ELISA reader were then converted to μ Mol/L.
Statistical analysis was conducted using SPSS software for Windows, version 22 (SPSS Inc., Chicago, Ill., USA). Student's t-test (two-tailed) was used to statistically analyze the level of significance between each group; the t-test was also used for comparisons of means between the two groups.
Pearson's correlation was applied to analyze the correlation between salivary MDA among different groups. Linear regression analysis was done to assess the perusal of relationships between the variables. The relationship between groups was evaluated by R2 of simple linear regression. P value was considered to be statistically significant if it was less than 0.05.
| Results|| |
The mean salivary MDA level in Group I was 1.46 μmol/L, while the mean salivary MDA level in Group III was markedly lower at 0.98 μmol/L. On comparing the mean MDA levels between Group I and Group III, the P value was found to be 0.001, indicating that the levels of MDA were significantly decreased in the post-treatment subjects (Group III) when compared to pre-treatment subjects Group I [Table 1].
|Table 1: Comparison of salivary MDA levels (μmol/L) between Group I and Group III|
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The mean salivary MDA level in Group II was 1.69 μmol/L, whereas the mean salivary MDA level in Group IV was considerably lower at 1.20 μmol/L. On comparing Group II and Group IV, the P value was found to be 0.001, indicating that the levels of MDA were significantly decreased in the post-treatment subjects (Group IV) when compared to pre-treatment subjects (Group II) [Table 2].
|Table 2: Comparison of salivary MDA levels (μmol/L) between Group II and Group IV|
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On comparing the mean salivary MDA of Group I and Group II, the P value was found to be significant (p < 0.05), suggesting that the levels of MDA increased with an increase in the number of carious lesions [Table 3]. Pearson's correlation analysis also showed a strong positive correlation with the R-value of 0.832 between Group I and Group II [Table 4], [Graph 1].
|Table 3: Comparison of salivary MDA levels (μmol/L) between Group I and Group II|
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|Table 4: Pearson's correlation between mean MDA levels in Group I and Group II|
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| Discussion|| |
MDA is the culmination product of lipid peroxidation in the cell membrane and can cause cellular damage by affecting proteins, lipids, and DNA. MDA is usually considered an indicator of oxidative stress in varying disease conditions, including oral disorders like periodontitis and dental caries., Numerous studies have revealed that MDA levels were elevated in children and adults with caries demonstrating a link between MDA and dental caries. Based on the literature search, it was evident that salivary MDA levels should be less than (0.7 μmol/L) in healthy controls, and that was kept as the baseline value.
In the current study, the mean salivary MDA level in Group I was 1.46 μmol/L, while the mean salivary MDA level in Group III was markedly lower at 0.98 μmol/L. On comparing the salivary MDA levels in Group I and Group III, significantly higher values were seen in Group I, which was statistically significant (p < 0.05), indicating MDA levels were higher in pre-treatment subjects (Group I) and significantly reduced one month after treatment (restoration of all decayed teeth) in the same subjects (Group III) representing that MDA may play a role in the pathogenesis of dental caries.
Similarly, the mean salivary MDA level in Group II was 1 μmol/L, whereas the mean salivary MDA level in Group IV was considerably lower at 1.20 μmol/L. On comparing the salivary MDA levels in Group II and Group IV, significantly higher values were seen in Group II, which was statistically significant (p < 0.05), ascertaining that the salivary MDA levels were higher in pre-treatment subjects (Group II).
In a study led by Subramanyam D et al., salivary MDA levels were evaluated for 150 subjects (75 controls and 75 subjects) with early childhood caries, using thiobarbituric acid reaction, which also showed that salivary MDA levels in subjects with dental caries were higher when equated to subjects without dental caries. Pyati SA et al., in their study comparing salivary MDA levels between 50 children with dental caries and 50 controls, also found expressively higher salivary MDA levels in the caries group compared to controls.
The literature search revealed few studies comparing pre- and post-treatment salivary MDA levels in subjects with chronic periodontitis.,,, However, no studies have compared the pre-treatment and post-treatment levels of salivary MDA in dental caries, thus making our study unique.
Our study was also by the research conducted by Rai BS et al., illustrating that elevated salivary MDA levels were seen in dental caries. The study was conducted among the adult population by TBARS assay.
However, the Sarode G et al. study showed that salivary MDA levels increase with a surge in caries activity, but the differences were not significant. Öztürk et al. (2008) concluded that even though the MDA levels increase with a surge in caries activity, the differences were not significant because routine brushing improves oral hygiene and reduces lipid peroxidation end products like MDA levels in saliva.
In contrast to these studies, the present research presented that salivary MDA levels were higher in the pre-treatment group and significantly reduced following treatment indicating that MDA may play a central role in the pathogenesis of dental caries. Nonetheless, further research is needed to settle the “cause or effect” role of MDA in dental caries.
| Limitations and Future Prospects|| |
The current study is not without limitations. Firstly, our sample size was fairly small. Forthcoming studies with larger sample sizes can give us more insight into the role of MDA in dental caries. Secondly, the biomarker is highly sensitive but not specific. Elevation of salivary MDA can occur due to other underlying pathologies beyond dental caries. The quantification of salivary MDA varies with different techniques and hence is not always reproducible. Thirdly, the baseline value for salivary MDA is yet to be established. Further studies establishing the baseline value of salivary MDA and assessing the post-treatment MDA levels at different time intervals will help find the exact association between MDA and dental caries.
| Conclusion|| |
The present study elicits that the mean salivary MDA levels increased with an increase in the number of carious lesions and significantly reduced following treatment proving the influence of salivary MDA in the pathogenesis of dental caries. The research outcome may be helpful in therapeutic applications leading to the prevention of dental caries.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
MDA could serve as a potential biomarker to estimate the progression of dental caries and evaluate the response to treatment following treatment of dental caries.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]