Non-surgical periodontal therapy influences salivary melatonin levels

Arrestin beta-2 deficiency exacerbates periodontal inflammation by mediating activating transcription factor 6 activation and abnormal remodelling of the extracellular matrix

AIM

To investigate the specific role of arrestin beta-2 (ARRB2) in the progression of periodontitis and the underlying mechanisms.

MATERIALS AND METHODS

Single-cell RNA sequencing data were used to analyse gene expression in periodontal tissues from healthy controls and patients with periodontitis. Real-time quantitative polymerase chain reaction, Western blotting and immunohistochemical staining were performed to detect the expression of ARRB2. Furthermore, a ligature-induced periodontitis model was created. Using radiographic and histological methods, RNA sequencing and luciferase assay, the role of ARRB2 in periodontitis and the underlying mechanisms were explored. Finally, the therapeutic effect of melatonin, an inhibitor of activating transcription factor 6 (ATF6), on periodontitis in mice was assessed in both in vivo and in vitro experiments.

RESULTS

ARRB2 expression was up-regulated in inflammatory periodontal tissue. In the ligature-induced mouse model, Arrb2 knockout exacerbated alveolar bone loss (ABL) and extracellular matrix (ECM) degradation. ARRB2 exerted a negative regulatory effect on ATF6, an essential targeted gene. Melatonin ameliorated ABL and an imbalance in ECM remodelling in Arrb2-deficient periodontitis mice.

CONCLUSIONS

ARRB2 mediates ECM remodelling via inhibition of the ATF6 signalling pathway, which ultimately exerts a protective effect on periodontal tissues.

Therapeutic applications of melatonin in disorders related to the gastrointestinal tract and control of appetite

Most animals have large amounts of the special substance melatonin, which is controlled by the light/dark cycle in the suprachiasmatic nucleus. According to what is now understood, the gastrointestinal tract (GIT) and other areas of the body are sites of melatonin production. According to recent studies, the GIT and adjacent organs depend critically on a massive amount of melatonin. Not unexpectedly, melatonin's many biological properties, such as its antioxidant, anti-inflammatory, pro-apoptotic, anti-proliferative, anti-metastasis, and antiangiogenic properties, have drawn the attention of researchers more and more. Because melatonin is an antioxidant, it produces a lot of secretions in the GIT's mucus and saliva, which shields cells from damage and promotes the development of certain GIT-related disorders. Melatonin's ability to alter cellular behavior in the GIT and other associated organs, such as the liver and pancreas, is another way that it functions. This behavior alters the secretory and metabolic activities of these cells. In this review, we attempted to shed fresh light on the many roles that melatonin plays in the various regions of the gastrointestinal tract by focusing on its activities for the first 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.

Effect of Non-surgical Periodontal Therapy on Salivary Melatonin Levels

Objective: Melatonin, a hormone secreted predominantly by pineal gland in a circadian manner, has antioxidant and anti-inflammatory effects. The current research is conducted to explore the influence of non-surgical periodontal therapy (NSPT) on levels of salivary melatonin in subjects with gingivitis and periodontitis. Methods: Sixty systemically healthy participants were included in this study; the groups are as follows: gingivitis (G), chronic periodontitis (CP), generalized aggressive periodontitis (GAP) and periodontally healthy (H). NSPT was applied to G group patients for 2 sessions, to CP and GAP group patients for 4 sessions. Plaque and gingival indices, probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL) were documented at baseline and 3 months post – treatment and early morning salivary samples were collected. ELISA was used to detect melatonin levels in saliva. Pittsburgh Sleep Quality Index (PSQI) questionnaire was performed to evaluate of sleep quality of patients. Results: At baseline, significant difference in gingival index, PD, BOP and CAL values was detected among all groups (p

Clinical efficacy of melatonin as adjunctive therapy to non-surgical treatment of periodontitis: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the effect of adjunctive melatonin supplementation on clinical outcomes after non-surgical periodontal treatment.

METHODS

PubMed, Embase, and Web of Science databases were systematically searched for randomised controlled trials (RCTs) of melatonin adjuvant therapy for periodontitis from inception until May 2021. The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered on The International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021250630). The risk of bias of included studies was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions. The pooled effect estimates were calculated by a random-effects model, and results were expressed as weighted mean differences (WMD).

RESULTS

Seven RCTs comprising 412 participants were included in the meta-analysis. The pooled results showed that adjuvant use of melatonin for non-surgical periodontal treatment significantly improved the probing depth (PD) [WMD = - 1.18, 95% CI (- 1.75, - 0.62) I² = 85.7%], clinical attachment loss (CAL) [WMD = - 1.16, 95% CI (- 1.60, - 0.72) I² = 76.7%] and gingival index (WMD = - 0.29, 95%CI [- 0.48, - 0.11], I² = 63.6%) compared with non-surgical treatment alone. In addition, subgroup analysis showed that higher doses of melatonin (3-10 mg) significantly improved PD [WMD = - 1.32, 95%CI (- 2.31, - 0.15) I² = 93%] and CAL [WMD = - 1.30, 95%CI (- 1.80, - 0.81) I² = 73.7%] compared with lower doses of melatonin (< 3 mg).

CONCLUSIONS

We found that adjunctive melatonin supplementation can significantly improve the periodontal status after non-surgical treatment, suggesting that melatonin may be a new adjuvant therapy for periodontitis when non-surgical periodontal treatment alone cannot achieve the desired improvement.

Saliva as a Source of Biomarkers for Periodontitis and Periimplantitis

Saliva has the potential to be used as a diagnostic and monitoring tool for various diseases if biomarkers of an adequate sensitivity and specificity could be identified. Several reviews and even meta-analyses have been performed in recent years, which have found some candidate biomarkers for periodontitis, like macrophage inflammatory protein-1 alpha, interleukin-1ß, interleukin-6, matrix metalloproteinase-8, or hemoglobin. However, none of those are currently in use to replace conventional periodontal diagnostics with a periodontal probe. For periimplantitis, to date, heterogeneity of different study protocols and implant types did not permit to discover clear biomarkers, which were able to distinguish between healthy and diseased implants. Few proinflammatory cytokines, similar to periodontitis, have been characterized as adjunct tools to clinical diagnosis. The additional determination of antimicrobial peptides, bone turnover markers, and bacteria could help to enhance sensitivity and specificity in a combined model for periodontitis and periimplantitis. Furthermore, proteomic approaches might be preferred over single biomarker determinations. A global consensus is also needed to harmonize salivary sampling methods as well as procedures of biomarker analysis to ensure future comparability.

The Effect of Melatonin on Periodontitis

BACKGROUND

Periodontitis is a chronic disease with a complex etiology that includes bacterial colonization, excessive inflammation, and oxidative stress. The hormone melatonin has antioxidant properties and might contribute to alleviating chronic conditions by reducing oxidative stress. The aim of this study was to analyze the effect of exogenous melatonin on periodontitis in an animal model of the disease as well as in patients with periodontitis.

METHODS

In rats with ligature-induced periodontitis, melatonin was administered in drinking water for two weeks. In the human study, patients with treatment-resistant periodontitis were asked to rinse their mouths with a solution containing melatonin or placebo every evening for two weeks. Periodontal status as well as salivary markers of oxidative stress were assessed at the end of the study.

RESULTS

Neither radiography nor μCT revealed any significant effects of melatonin on alveolar bone loss. Gum recession was the only improved macroscopic measure in rats (p < 0.05). Analysis of salivary markers of oxidative stress revealed no effects of treatment in rats or humans despite clearly elevated melatonin concentrations in melatonin treated groups.

CONCLUSION

Our results do not support the use of melatonin for the treatment of periodontitis. However, the negative outcome is limited by the short duration of the study and the chosen route of application as well as the dose of melatonin.

Study on the Effects of Melatonin on Glycemic Control and Periodontal Parameters in Patients with Type II Diabetes Mellitus and Periodontal Disease

Background and Objectives: There is evidence that melatonin could improve the periodontal status and also glycemic control of patients with diabetes mellitus. Therefore, the aim of this study was to assess the effects of scaling and root planing plus adjunctive systemic treatment with melatonin on periodontal parameters and glycemic control in patients with type 2 diabetes and chronic periodontitis. Materials and Methods: The study was conducted on 54 subjects with periodontitis and diabetes mellitus randomly assigned to the study group (n = 27, subjects with scaling and root planing + melatonin) or control group (n = 27, subjects with scaling and root planing + placebo). Periodontal parameters (probing depth—PD; clinical attachment loss—CAL; bleeding on probing—BOP; and hygiene level) and glycated hemoglobin (HbA1c) were assessed at baseline and 8 weeks after. Results: At baseline, there were no significant differences between groups, but at the second evaluation 8 weeks later the association of melatonin with the non-surgical periodontal therapy exerted statistically significant improvements, both in periodontal parameters, with a significant decrease in periodontal disease severity, and glycated hemoglobin when compared to the control subjects. Conclusions: In our study, combined non-surgical periodontal treatment and systemic treatment with melatonin provided additional improvements to severe periodontal condition and the glycemic control of patients with diabetes type 2 when compared to non-surgical periodontal treatment alone.

Effects of melatonin in wound healing of dental pulp and periodontium: Evidence from in vitro, in vivo and clinical studies

INTRODUCTION

Database research has revealed that melatonin has beneficial effects in pulpal and periodontal regeneration. Several studies reported protective effects of melatonin against inflammation in several organs including the heart, brain, and teeth. In addition to inflammation reduction, melatonin has been involved in tissue regeneration and wound healing. The aim of this review is to summarize the evidence from in vitro, in vivo and clinical studies on the effects of melatonin in wound healing of dental pulp and periodontium. This review gives a thorough summary of the possible role of melatonin in wound healing of dental pulp and periodontium in connection with anti-inflammatory and antioxidant effects, cell proliferation, and cell differentiation. Any contradictory evidence is also assessed.

METHODS

The PubMed database was searched for all research articles published before April 2020 with the search terms "melatonin" and "dental pulp". Articles with the search terms "melatonin", "periodontal disease" and "bone" published before October 2019 were also included. Non-English articles were excluded.

RESULTS

Melatonin has been shown to reduce inflammation, inhibit cell proliferation and regulate differentiation of pulp cells. Melatonin increased odontoblast activities, resulting in the differentiation in the dental pulp. However, melatonin did not initiate differentiation in undifferentiated pulp cells but seemed to have beneficial effects in periodontitis by promoting periodontium's wound healing.

CONCLUSION

Those findings suggest that melatonin could have beneficial effects on pulpal and periodontal cells under inflammatory conditions. However, discrepancies remain between in vitro and in vivo findings regarding the effect of melatonin on dental pulp and periodontium.

Measuring melatonin by immunoassay

The pineal gland hormone melatonin continues to be of considerable interest to biomedical researchers. Of particular interest is the pattern of secretion of melatonin in relation to sleep timing as well as its potential role in certain diseases. Measuring melatonin in biological fluids such as blood and saliva presents particular methodological challenges since the production and secretion of the hormone are known to be extremely low during the light phase in almost all situations. Active secretion only occurs around the time of lights out in a wide range of species. The challenge then is to develop practical high-throughput assays that are sufficiently sensitive and accurate enough to detect levels of melatonin less than 1 pg/mL in biological fluids. Mass spectrometry assays have been developed that achieve the required sensitivity, but are really not practical or even widely available to most researchers. Melatonin radioimmunoassays and ELISA have been developed and are commercially available. But the quality of the results that are being published is very variable, partly not only because of poor experimental designs, but also because of poor assays. In this review, I discuss issues around the design of studies involving melatonin measurement. I then provide a critical assessment of 21 immunoassay kits marketed by 11 different companies with respect to validation, specificity and sensitivity. Technical managers of the companies were contacted in an attempt to obtain information not available online or in kit inserts. A search of the literature was also conducted to uncover papers that have reported the use of these assays, and where possible, both daytime and night-time plasma or saliva melatonin concentrations were extracted and tabulated. The results of the evaluations are disturbing, with many kits lacking any validation studies or using inadequate validation methods. Few assays have been properly assessed for specificity, while others report cross-reaction profiles that can be expected to result in over estimation of the melatonin levels. Some assays are not fit for purpose because they are not sensitive enough to determine plasma or saliva DLMO of 10 and 3 pg/mL, respectively. Finally, some assays produce unrealistically high daytime melatonin levels in humans and laboratory animals in the order of hundreds of pg/mL. In summary, this review provides a comprehensive and unique assessment of the current commercial melatonin immunoassays and their use in publications. It provides researchers new to the field with the information they need to design valid melatonin studies from both the perspective of experimental/clinical trial design and the best assay methodologies. It will also hopefully help journal editors and reviewers who may not be fully aware of the pitfalls of melatonin measurement make better informed decisions on publication acceptability.

Prolonged Suppressive Effects of Periodontitis on Salivary TFF3 Production

Objective As a follow-up to our previous study that demonstrated decreased salivary trefoil factor family 3 (TFF3) peptide levels in chronic periodontitis patients, this current study aimed to observe the effects of nonsurgical periodontal treatment on salivary TFF3 peptides in patients with periodontal diseases.

Materials and Methods Eighty-seven volunteers that comprised of 30 individuals with healthy periodontium, 31 with gingivitis, and 26 with chronic periodontitis were considered for the study. Prior to periodontal treatment, a general periodontal examination was performed along with collection of saliva samples from each volunteer. Nonsurgical periodontal treatments were provided to patients with gingivitis and periodontitis. Two weeks post-treatment, saliva samples were recollected, and the periodontal status was re-evaluated. Salivary TFF3 concentrations were measured by enzyme-linked immunosorbent assay.

Statistical Analysis Mann–Whitney U test was used when the investigated data were not normally distributed. Chi-squared test was used when dealing with categorical data. Kruskal–Wallis test with post-hoc corrections was used to compare data among the three investigated groups. Two-tailed p < 0.05 was considered as statistically significant.

Results Prior to the periodontal treatment, salivary TFF3 concentrations in patients with gingivitis and periodontitis were significantly lower than those with healthy periodontium. Two weeks post-treatment, increased levels of salivary TFF3 were observed in patients with gingivitis, whereas the concentrations decreased in patients with chronic periodontitis.

Conclusion This study demonstrated the effects of periodontal disease on the production of salivary TFF3 peptides. Interestingly, nonsurgical periodontal treatment also affected the recovery of salivary TFF3 peptides but varied in their outcomes between gingivitis and periodontitis patients.

Melatonin expression in periodontitis and obesity: An experimental in-vivo investigation

BACKGROUND AND OBJECTIVE

Melatonin deficiency has been associated with obesity and systemic inflammation. This study aims to evaluate whether melatonin could interfere with the mechanisms of co-morbidity linking obesity and periodontitis.

MATERIAL AND METHODS

Twenty-eight male Wistar rats were randomly divided in 4 groups: control group (Con) (fed with standard diet); high-fat diet group (HFD) (fed with a diet containing 35.2% fat); Con group with induced periodontitis (Con-Perio) and HFD group with induced periodontitis (HFD-Perio). To induce periodontitis, the method of oral gavages with Porphyromonas gingivalis ATCC W83K1 and Fusobacterium nucleatum DMSZ 20482 was used. Circulating melatonin levels were analyzed by multiplex immunoassays. Periodontitis was assessed by alveolar bone loss (micro-computed tomography and histology) and by surrogate inflammatory outcomes (periodontal pocket depth, modified gingival index and plaque dental index).

RESULTS

Plasma melatonin levels were significantly decreased (P < .05) in the obese rats with periodontitis when compared with controls or with either obese or periodontitis rats. Alveolar bone loss increased 27.71% (2.28 µm) in HFD-Perio group compared with the Con group. The histological analysis showed marked periodontal tissue destruction with osteoclast activity, particularly in the HFD-Perio group. A significant negative correlation (P < .05) was found between periodontal pocket depth, modified gingival index and circulating melatonin levels.

CONCLUSION

Obese and periodontitis demonstrated significantly lower melatonin concentrations when compared with controls, but in obese rats with periodontitis these concentrations were even significantly lower when compared with either periodontitis or obese rats. These results may indicate that melatonin deficiency could be a key mechanism explaining the co-morbidity effect in the association between obesity and periodontitis.

Melatonin and periodontal tissues: Molecular and clinical perspectives

Periodontal disease is a frequent chronic inflammatory pathology that implies the destruction of the tissues supporting the teeth, which represents a high sanitary cost. It usually appears associated with other systemic conditions such as diabetes, metabolic syndrome, depression and Alzheimer disease among others. The presence of melatonin and its receptors in the oral cavity supports the hypothesis that this hormone could play a role in homeostasis of periodontal tissues. In the present review we will discuss the potential role of melatonin, a circadian synchronizing hormone, with proved antiinflammatory and antioxidant profile, in the pathogenesis and treatment of periodontitis. Particular emphasis will be placed on the role of the indolamine in the treatment of periodontal disease when this oral condition is comorbid with other pathologies that would also benefit from the therapeutic potential of melatonin and its analogs through diverse mechanisms.

Total Antioxidant Capacity and Total Oxidant Status in Saliva of Periodontitis Patients in Relation to Bacterial Load

The detection of salivary biomarkers has a potential application in early diagnosis and monitoring of periodontal inflammation. However, searching sensitive salivary biomarkers for periodontitis is still ongoing. Oxidative stress is supposed to play an important role in periodontitis progression and tissue destruction. In this cross-sectional study, we investigated total antioxidant capacity (TAC) and total oxidant status (TOS) in saliva of periodontitis patients compared to healthy controls and their relationship with periodontopathic bacteria and periodontal disease severity. Unstimulated saliva was collected from 45 patients with generalized severe periodontitis and 37 healthy individuals and the TAC/TOS were measured. In addition, salivary levels of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum in saliva were measured. Salivary TAC was lower in periodontitis patients compared to healthy controls. Moreover, a significant negative correlation of salivary TAC with clinical attachment loss was observed in periodontitis patients. No significant difference in the salivary TOS was observed between periodontitis patients and healthy controls. Bacterial load was enhanced in periodontitis patients and exhibited correlation with periodontal disease severity but not with salivary TAC/TOS. Our data suggest that changes in antioxidant capacity in periodontitis patients are not associated with increased bacterial load and are probably due to a dysregulated immune response.

Melatonin as a candidate therapeutic drug for protecting bone cells from chlorhexidine-induced damage

BACKGROUND

Melatonin was proposed for use in periodontitis and peri-implantitis therapy due to its bone-supportive effects. This issue is of interest because standard adjuvant antiseptics, namely chlorhexidine (CHX), prove damaging for osteoblasts. Thus, the aim of this study is to investigate if melatonin is suitable as an auxiliary agent for protecting osteoblasts from CHX damage.

METHODS

MC3T3 osteoblast response was determined following administration of various CHX concentrations in the absence or presence of melatonin. Osteoblast morphology was evaluated, total reactive oxygen species (ROS) and superoxide levels were quantified, ratios of apoptotic and necrotic cells were identified by flow cytometry, metabolic activity of remaining cells was assessed, and effects were calculated with repeated measures analysis and post hoc P value adjustment.

RESULTS

CHX led to poor morphology, increased total ROS and superoxide levels, and rigorously diminished the number of vital and metabolic active osteoblasts in a concentration-dependent manner. However, simultaneous melatonin supply supported cell morphogenesis and growth, reduced ROS and superoxide generation, shifted the percentage of CHX-damaged cells from necrotic/late to early apoptotic events, and modulated metabolic activity in osteoblasts.

CONCLUSION

These data reveal that melatonin protects osteoblasts in the CHX context, thereby implicating melatonin as a promising drug in periodontitis and peri-implantitis treatment.

Melatonin in the oral cavity: physiological and pathological implications

BACKGROUND AND OBJECTIVES

The purpose of this article was to summarize what is known about the function of melatonin in the oral cavity.

MATERIAL AND METHODS

Databases were searched for the relevant published literature to 30 November, 2013. The following search items were used in various combinations: melatonin, gingiva, periodontium, inflammation, herpes, alveolar bone, periodontal ligament, dental implants, xerostomia, methacrylate, chlorhexidine, cancer. The literature uncovered is summarized herein.

RESULTS

Salivary melatonin levels exhibit a circadian rhythm with highest values at night. Melatonin has both receptor-mediated and receptor-independent actions in cells of the oral cavity. Melatonin is released into the saliva by the acinar cells of the major salivary glands and via the gingival fluid. Functions of melatonin in the oral cavity are likely to relate primarily to its anti-inflammatory and antioxidant activities. These actions may suppress inflammation of the gingiva and periodontium, reduce alveolar bone loss, abrogate herpes lesions, enhance osteointegration of dental implants, limit oral cancer, and suppress disorders that have a free radical component. Sublingual melatonin tablets or oral melatonin sprays and topical melatonin-containing gel, if used on a regular basis, may improve overall oral health and reduce mucosal lesions.

CONCLUSION

Collectively, the results indicate that endogenously-produced and exogenously-applied melatonin are beneficial to the oral cavity.