Serum vitamin D levels and chronic periodontitis in adult, Caucasian population-a systematic review

Serum vitamin D, hemoglobin A1c and vitamin B12 levels in patients with gingivitis and periodontitis stages

Aim: To compare the serum vitamin D, hemoglobin A1c (HbA1c) and vitamin B12 levels in patients with gingivitis and four different periodontitis stages diagnosed according to the 2017 Periodontal Disease Classification. Materials & methods: A total of 606 patients were included in the study who were diagnosed with gingivitis and stage I-IV periodontitis. Patients were divided into groups based on disease stage, and the HbA1c, vitamin D and B12 levels of the patients were compared and analyzed. Result: The highest HbA1c level and the lowest vitamin D level were seen in stage III-IV periodontitis. The highest vitamin D and B12 levels were seen in the gingivitis group. Conclusion: Serum HbA1c, vitamin D and B12 levels might vary depending on the presence or severity of periodontitis.Clinical Trial Registration: NCT05745779 (This study was registered and approved by www.clinicaltrials.gov).

Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay

AIM

The study aims is to evaluate the antibacterial effect of vitamin D3 against the red complex bacteria, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia in chronic periodontitis patients.

MATERIALS AND METHODS

The study comprised 98 participants with chronic periodontitis. All clinical parameters including plaque index (PI), gingival bleeding index (GBI), probing pocket depth (PPD), clinical attachment level (CAL), and a microbiological assay of P. gingivalis, T. denticola, T. forsythia were assessed at the baseline. All study participants who underwent scaling and root planning were divided into two groups, A and B, each with 49 patients and only group B patients were advised to take vitamin D supplementation of 60,000 IU granules, once daily for 2 months. All the patients of both the groups were recalled at the end of 2nd month and all the clinical and microbiological parameters were reassessed.

RESULTS

After two months, there was a reduction in all the clinical markers in both groups, but the group B patients showed more improvement following non-surgical treatment vitamin D intake. There was also a statistical reduction in P. gingivalis, T. denticola, and T. forsythia following administration of vitamin D in group B patients compared to group A.

CONCLUSION

These discoveries proposed that vitamin D has a superb antimicrobial impact against red complex periodontal microbes and might be considered a promising compound in the counteraction of periodontal disease.

CLINICAL SIGNIFICANCE

Vitamin D is considered to possess anti-inflammatory and antimicrobial activity, which may help to delay the progression of periodontitis. So, vitamin D3 can be used as a potential supplement that could be employed to stop the advancement of periodontal disease. How to cite this article: Govindharajulu R, Syed NK, Sukumaran B, et al. Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay. J Contemp Dent Pract 2024;25(2):114-117.

Association of vitamin D in individuals with periodontitis: an updated systematic review and meta-analysis

BACKGROUND

There are differences in vitamin D levels between periodontitis and healthy individuals, but the effect of vitamin D on periodontitis is controversial. The purpose of this Meta-analysis is twofold: (1) compare vitamin D levels in individuals with or without periodontitis; (2) assess the effects of vitamin D supplementation during scaling and root planing (SRP) on periodontal clinical parameters in individuals with periodontitis.

METHODS

A systematic search was conducted in five databases (PubMed, Web of Science, MEDLINE, EMBASE, and Cochrane library), published from the database inception to 12 September 2022. The Cochrane Collaboration Risk of bias (ROB) assessment tool, the risk of bias in non-randomized studies of intervention (ROBINS-I) tool, the Newcastle-Ottawa Quality Assessment Scale (NOS), and Agency for Healthcare Quality and Research (AHRQ) were used to evaluate randomized controlled trial (RCT), non-RCT, case-control study, and cross-sectional study, respectively. Statistical analysis was performed using RevMan 5.3 and Stata 14.0 software, with weighted mean difference (WMD), standardized mean difference (SMD) and 95% confidence intervals (CI) as the effect measures, and heterogeneity was tested by subgroup analysis, sensitivity analysis, Meta-regression.

RESULTS

A total of 16 articles were included. The results of Meta-analysis showed that periodontitis was associated with lower serum vitamin D levels compared to normal population (SMD = -0.88, 95%CI -1.75 ~ -0.01, P = 0.048), while there was no significant difference in serum or saliva 25(OH)D levels between periodontitis and normal population. Additionally, the Meta-analysis showed that SRP + vitamin D and SRP alone had a statistically significant effect on serum vitamin D levels in individuals with periodontitis (SMD = 23.67, 95%CI 8.05 ~ 32.29, P = 0.003; SMD = 1.57, 95%CI 1.08 ~ 2.06, P < 0.01). And SRP + vitamin D could significantly reduce clinical attachment level compared to SRP alone (WMD = -0.13, 95%CI -0.19 ~ -0.06, P < 0.01), but had no meaningful effect on probing depth, gingival index, bleeding index, respectively.

CONCLUSION

The evidence from this Meta-analysis suggests that the serum vitamin D concentration of individuals with periodontitis is lower than that of normal people, and SRP along with vitamin D supplementation has been shown to play a significant role in improving periodontal clinical parameters. Therefore, vitamin D supplementation as an adjuvant to nonsurgical periodontal therapy has a positive impact on the prevention and treatment of periodontal disease in clinical practice.

25-hydroxyvitamin D3 generates immunomodulatory plasticity in human periodontal ligament-derived mesenchymal stromal cells that is inflammatory context-dependent

Introduction

Human periodontal ligament-derived mesenchymal stromal cells (hPDL-MSCs) exhibit a tight bi-directional interaction with CD4+ T lymphocytes. The hPDL-MSCs' immunomodulatory abilities are drastically enhanced by pro-inflammatory cytokines via boosting the expression of various immunomediators. 25-hydroxyvitamin D3 (25(OH)D3), the major metabolite of vitamin D3 in the blood, affects both hPDL-MSCs and CD4+ T lymphocytes, but its influence on their interaction is unknown.

Methods

Therefore, primary hPDL-MSCs were stimulated in vitro with tumor necrosis factor (TNF)-α a or interleukin (IL)-1β in the absence and presence of 25(OH)D3 followed by an indirect co-culture with phytohemagglutinin-activated CD4+ T lymphocytes. The CD4+ T lymphocyte proliferation, viability, and cytokine secretion were analyzed. Additionally, the expression of various immunomediators in hPDL-MSCs was investigated, and their implication was verified by using pharmacological inhibitors.

Results

25(OH)D3 significantly counteracted the suppressive effects of IL-1β-treated hPDL-MSCs on CD4+ T lymphocyte proliferation, whereas no effects were observed in the presence of TNF-α. Additionally, 25(OH)D3 significantly increased the percentage of viable CD4+ T lymphocytes via TNF-α- or IL-1β-treated hPDL-MSCs. It also caused a significant decrease in interferon-γ, IL-17A, and transforming growth factor-β productions, which were triggered by TNF-α-treated hPDL-MSCs. 25(OH)D3 significantly decreased the production of various immunomediators in hPDL-MSCs. Inhibition of two of them, prostaglandin E2 and indoleamine-2,3-dioxygenase-1, partially abolished some of the hPDL-MSCs-mediated effects of 25(OH)D3 on CD4+ T lymphocytes.

Conclusion

These data indicate that 25(OH)D3 influences the immunomodulatory activities of hPDL-MSCs. This modulatory potential seems to have high plasticity depending on the local cytokine conditions and may be involved in regulating periodontal tissue inflammatory processes.

Comparison of serum levels of vitamin D in periodontitis patients with and without type 2 diabetes and healthy subjects

OBJECTIVE

The purpose of this study is to find out the levels of serum vitamin D in periodontitis patients with and without type 2 diabetes and to compare them with healthy subjects.

METHODS

In this study, 48 periodontitis patients with type 2 diabetes mellitus (PDM), 53 periodontitis patients (P), and 42 controls who were in the age ranges of 30-50 years and had the entry requirements were selected. Plaque index, calculus index, modified gingival index, pocket depth, clinical attachment loss (CAL), and tooth loss were measured. Serum 25(OH)D level was estimated by electrochemiluminescence immunoassay, and fasting blood sugar and glycosylated hemoglobin were estimated by biochemical colorimetric assays.

RESULTS

The mean serum 25(OH)D level was 17.06 ± 10.73, 15.12 ± 7.74, and 14.17 ± 11.04 ηg/ml for PDM, P, and control groups, respectively, showing no statistical difference. The mean CAL was significantly high in diabetic patients as compared to other groups. Prediabetes prevalence was significantly high in periodontitis patients as compared to controls.

CONCLUSIONS

The prevalence of vitamin D insufficiency was high in the population studied. Serum levels of 25(OH)D showed no significant difference between groups. Periodontitis patients showed an elevated risk for diabetes.

Calcium and Vitamin D Supplementation as Non-Surgical Treatment for Periodontal Disease with a Focus on Female Patients: Literature Review

Periodontal disease is a complex disease that involves an imbalance between the oral microbiota and an individual's inflammatory response. Moreover, the inflammatory response contributes to further imbalance; if left untreated, periodontal disease may result in tooth loss. Vitamin D is intricately involved in the regulation of calcium-phosphate homeostasis and bone mineral metabolism; considering that periodontal surgery usually includes regenerative therapy, adequate vitamin D and calcium levels are essential. The benefits of vitamin D and calcium supplementation have been demonstrated in situations where deficiency is associated with adverse outcomes, such as periodontal disease and maternal health. However, knowledge and attitudes about supplementation, as well as the actual levels of supplementation, vary greatly in the general population; they also differ between men and women. The aim of this review is to discuss how vitamin D and calcium supplementation affect oral and periodontal health, especially in women. Additionally, this review provides suggestions for public health strategies regarding vitamin D and calcium supplementation, as well as the effects of both types of supplementation on maternal oral health.

The Impact of Chronic Kidney Disease on Nutritional Status and Its Possible Relation with Oral Diseases

Several studies have demonstrated a strong relation between periodontal diseases and chronic kidney disease (CKD). The main mechanisms at the base of this link are malnutrition, vitamin dysregulation, especially of B-group vitamins and of C and D vitamins, oxidative stress, metabolic acidosis and low-grade inflammation. In particular, in hemodialysis (HD) adult patients, an impairment of nutritional status has been observed, induced not only by the HD procedures themselves, but also due to numerous CKD-related comorbidities. The alteration of nutritional assessment induces systemic manifestations that have repercussions on oral health, like oral microbiota dysbiosis, slow healing of wounds related to hypovitaminosis C, and an alteration of the supporting bone structures of the oral cavity related to metabolic acidosis and vitamin D deficiency. Low-grade inflammation has been observed to characterize periodontal diseases locally and, in a systemic manner, CKD contributes to the amplification of the pathological process, bidirectionally. Therefore, CKD and oral disease patients should be managed by a multidisciplinary professional team that can evaluate the possible co-presence of these two pathological conditions, that negatively influence each other, and set up therapeutic strategies to treat them. Once these patients have been identified, they should be included in a follow-up program, characterized by periodic checks in order to manage these pathological conditions.

Profile of vitamin D receptor gene polymorphism TaqI in patients with periodontitis

The present study aimed to assess the incidence of the vitamin D receptor (VDR) gene polymorphism TaqI in patients with periodontitis, and the potential association of this polymorphism with the severity of the disease. This was a case-controlled study, which included 162 adults divided into two groups as follows: Case group (81 patients diagnosed with periodontitis) and control group (81 patients without periodontitis). Venous blood was obtained from each sample from which DNA was extracted. The gene polymorphism was determined using restricted fragment length polymorphism-PCR and DNA sequencing to identify endonuclease restrictions in exon 9 (TaqI). The data were analyzed using an independent samples t-test. VDR gene polymorphisms were detected in periodontitis cases with TT (86.4%), Tt (12.4%) and tt (1.2%) genotypes. DNA sequencing confirmed a change in the sequence of the VDR gene nucleotides in patients with periodontitis. The data indicated that the severity of periodontal tissue damage may be influenced by changes in the nucleotide sequence.

Vitamin D3 Serum Levels in Periodontitis Patients: A Case-Control Study

Background: Periodontitis is a multifactorial disease characterized by bacterial-dysbiosis-associated, host-mediated inflammation, which results in the loss of the tooth-supporting tissues. Vitamin D3 plays an important role in the tissue homeostasis and its deficiency might have a negative effect on the periodontitis progression and treatment outcomes. Objectives: The aim of the study was to evaluate the vitamin D3 serum levels among patients with periodontitis and healthy subjects. Materials and Methods: A total of 100 generally healthy adult participants (50 diagnosed with periodontitis, 50 with healthy periodontium) were enrolled in the study. The periodontal clinical parameters were measured, radiographs were performed and the 25-hydroxy vitamin D (25(OH)D) test was used to assess vitamin D3 levels. Results: Vitamin D3 levels were found to be statistically significantly lower among periodontitis patients (31.34; SD = 5.62) compared with healthy controls (39.64; SD = 8.77). Vitamin D3 deficiency was corresponding to the stage and grade of the disease as well as the clinical attachment and bone loss. Conclusion: Adequate monitoring of the vitamin D3 serum levels and supplementation could be of benefit in periodontitis treatment.

Influence of symptomatic periodontal disease on changes in skeletal bone density during medication therapy for osteoporosis in postmenopausal women: the Japanese Osteoporosis Intervention Trial (JOINT)-04 and JOINT-05

Japanese postmenopausal women with symptomatic periodontal disease had a significantly smaller increase in the T-score for total hip bone density than those without periodontal disease during medication therapy for osteoporosis. Intervention to treat symptomatic periodontal disease before and/or during osteoporosis therapy could maintain the effect of osteoporosis medications.

PURPOSE

Women with periodontal disease may be more likely to develop osteoporosis. We evaluated whether the presence of symptomatic periodontal disease can influence changes in skeletal bone mineral density (BMD) during medication therapy for osteoporosis in Japanese postmenopausal women.

METHODS

A total of 4,258 postmenopausal women participated in the Japanese Osteoporosis Intervention Trial protocol number 4 (JOINT-04 trial) and number 5 (JOINT-05 trial), which were multi-center, open-label, randomized controlled trials in Japan. Of these, 3,670 non-edentulous subjects participated in the study. Subjects who had self-reported symptoms of periodontal disease at baseline were defined as having periodontal disease. The study outcome was the difference in BMD changes during the study between subjects with and without periodontal disease. Mixed models for repeated measures after adjusting for covariates were used to investigate the difference in the BMD changes during the study between subjects with and without periodontal disease.

RESULTS

Subjects with periodontal disease had significantly lower T-scores for total hip (p = 0.035) and metacarpal (p = 0.048) BMD than those without periodontal disease at baseline. During medication therapy for osteoporosis, subjects with periodontal disease had a significantly smaller increase in T-score for total hip BMD than those without periodontal disease (p = 0.021), although no significant differences were observed in the changes in T-scores for other skeletal BMD measurements between subjects with and without periodontal disease.

CONCLUSIONS

The presence of self-reported symptoms of periodontal disease may be associated with a decrease in the effect of osteoporosis medications in Japanese postmenopausal women.

The association between vitamin D level and periodontal disease in Saudi population, a preliminary study

OBJECTIVE

Among other regulatory functions, vitamin D has a role in modulating the inflammatory process of periodontal disease. Therefore, this retrospective study aimed to assess the relationship between vitamin D levels and periodontal health in dental patients from the Eastern Province of Saudi Arabia.

METHODS

Radiographs and serum vitamin D levels of patients seeking dental treatment were collected. Exclusion criteria were systemic disease, smoking, recent vitamin D supplementation, and previous periodontal surgery. Gender, age, and alveolar crest height (ACH) were recorded. A total of 67 patients were categorized into three groups according to their serum vitamin D level (<10, <20, and > 20 ng/mL) and their bone loss compared.

RESULTS

Differences in means were compared by t-test. ANOVA was used to compare vitamin D groups and the corresponding ACH, as well as the correlation (p < .05). Patients with vitamin D levels > 20 ng/mL demonstrated a mean ACH of 1.6 mm. The mean ACH was 3.1 mm for those with vitamin D levels < 20 ng/mL, and 4.6 mm for vitamin D levels < 10 ng/mL. A weak negative correlation was found between vitamin D and ACH in all groups (r = -0.055, p = .7).

CONCLUSION

Serum vitamin D level seems to be an important factor that influences oral health, especially the periodontal condition, of both male and female patients.

Mechanisms involved in regulation of periodontal ligament cell production of pro-inflammatory cytokines: Implications in periodontitis

It is well recognized that human periodontal ligament cells (PDL cells) may represent local immune cells of the periodontal tissues. However, it is unclear whether they represent “true” immune cells, since they can produce pro‐inflammatory cytokines not only after stimulation with bacterial lipopolysaccharides but also in response to other stimuli such as mechanical stress. Stimulation with bacterial lipopolysaccharides strongly enhances PDL cell production of pro‐inflammatory cytokines through activation of toll‐like receptors and NF‐κB signaling. Less information is available regarding putative modulators of cytokine production and their mechanisms of action in PDL cells. The anti‐inflammatory glucocorticoid dexamethasone reduces lipopolysaccharide‐induced PDL cell production of cytokines. Recent observations show that vitamin D and the antimicrobial peptide LL‐37 antagonize lipopolysaccharide‐stimulated PDL cell production of pro‐inflammatory cytokines. Secretory leukocyte protease inhibitor is endogenously expressed by PDL cells, and this protein negatively regulates PDL cell‐evoked cytokine production. More information and knowledge about the regulation of PDL cell production of cytokines may clarify the role of PDL cells in oral innate immunity and their importance in periodontitis.

The Effects of 6-Month Vitamin D Supplementation during the Non-Surgical Treatment of Periodontitis in Vitamin-D-Deficient Patients: A Randomized Double-Blind Placebo-Controlled Study

BACKGROUND

This study assessed the effects of weekly vitamin D (VD) supplementation on clinical and biological parameters after scaling and root planning (SRP) in the treatment of periodontitis and served to validate the VD dosage regimen.

METHODS

It was a monocentric, randomized, double-blind, placebo-controlled clinical trial with 6 months follow-up. Healthy Caucasian periodontitis patients presenting serum 25(OH) vitamin D3 below 30 ng/mL were randomly allocated to test group (SRP + VD 25,000 international units (IU)/week) or the control group (SRP + placebo).

RESULTS

A total of 59 patients were screened, 27 were included and 26 completed 3 months (M) and 21 completed 6M control. Test (n = 13) and control groups (n = 14) had similar 25(OH) vitamin D3 levels at baseline (17.6 ± 7.4 vs. 14.4 ± 5.2, respectively). After one month, there was a significant difference between groups (32.9 ± 5.2 vs. 16.1 ± 4.7), also seen at M3 and M6 (t-test, p < 0.001). Periodontal treatment was successful in both groups, since it resulted in a reduction of all measured clinical parameters at M3 and M6 (probing pocket depth (PPD), full mouth bleeding and plaque). However, the reduction in PPD was greater in the test group.

CONCLUSIONS

In this short-term pilot study, no significant differences were observed between two groups. However, supplementation with VD tended to improve the treatment of periodontitis in patients with initial 25(OH) vitamin D3 < 30 ng/mL and proved safe and efficacious. NCT03162406.

Vitamin D and Periodontitis: A Systematic Review and Meta-Analysis

To explore the vitamin D levels of periodontitis patients in comparison with periodontally healthy ones, and to assess the influence of vitamin D supplementation as an adjunctive during nonsurgical periodontal treatment (NSPT). Five databases (Pubmed, Embase, Scholar, Web of Sciences, and Cochrane Library) were searched until May 2020. Mean difference (MD) meta-analysis with corresponding 95% confidence interval (95% CI) and sensitivity tests via meta-regression were used. We followed Strength of Recommendation Taxonomy (SORT) to appraise the strength and quality of the evidence. Sixteen articles were included, fourteen case-control and two intervention studies, all reporting 25-hydroxyvitamin D (25(OH)D) levels. Compared with the healthy controls, the circulating 25(OH)D levels were significantly lower in chronic periodontitis patients (pooled MD = -6.80, 95% CI: -10.59 to -3.02). Subgroup analysis revealed differences among 25(OH)D measurements, with liquid chromatography-mass spectrometry being the most homogeneous method (pooled MD = -2.05, 95% CI: -3.40 to -0.71). Salivary levels of 25(OH)D showed no differences between groups. Due to the low number of studies, conclusions on aggressive periodontitis and in the effect of vitamin D supplementation after NSPT were not possible to ascribe. Compared with healthy controls, 25(OH)D serum levels are significantly lower in chronic periodontitis patients, with an overall SORT A recommendation. Future studies are needed to clarify the effect of vitamin D supplementation and the biological mechanisms linking vitamin D to the periodontium.

Vitamin D3 and Dental Mesenchymal Stromal Cells

Vitamin D3 is a hormone involved in the regulation of bone metabolism, mineral homeostasis, and immune response. Almost all dental tissues contain resident mesenchymal stromal cells (MSCs), which are largely similar to bone marrow-derived MSCs. In this narrative review, we summarized the current findings concerning the physiological effects of vitamin D3 on dental MSCs. The existing literature suggests that dental MSCs possess the ability to convert vitamin D3 into 25(OH)D3 and subsequently to the biologically active 1,25(OH)2D3. The vitamin D3 metabolites 25(OH)D3 and 1,25(OH)2D3 stimulate osteogenic differentiation and diminish the inflammatory response of dental MSCs. In addition, 1,25(OH)2D3 influences the immunomodulatory properties of MSCs in different dental tissues. Thus, dental MSCs are both producers and targets of 1,25(OH)2D3 and might regulate the local vitamin D3-dependent processes in an autocrine/paracrine manner. The local vitamin D3 metabolism is assumed to play an essential role in the local physiological processes, but the mechanisms of its regulation in dental MSCs are mostly unknown. The alteration of the local vitamin D3 metabolism may unravel novel therapeutic modalities for the treatment of periodontitis as well as new strategies for dental tissue regeneration.

Pleiotropic effects of vitamin D3 on CD4+ T lymphocytes mediated by human periodontal ligament cells and inflammatory environment

Aims

Both, vitamin D₃ and human periodontal ligament cells (hPDLCs) possess immunosuppressive properties, but their combined effect on immune cells has never been investigated. Here, we analysed the impact of vitamin D₃ on the immunosuppressive properties of hPDLCs towards CD4⁺ T lymphocytes.

Material and Methods

Allogenic CD4⁺ T lymphocytes were activated by phytohemagglutinin either in monoculture or co‐culture with hPDLCs, in the presence or absence of IFN‐γ and 1,25(OH)₂D₃. After 5 days, CD4⁺ T‐lymphocyte proliferation, CD4⁺ CD25⁺ FoxP3⁺ regulatory T lymphocytes (T_regs) proportion and IL‐10, TGF‐β1 and IL‐17A production were analysed.

Results

In monoculture, 1,25(OH)₂D₃ suppressed CD4⁺ T‐lymphocyte proliferation, increased the percentage of CD4⁺ FoxP3⁺ CD25⁺ FoxP3⁺ T_regs and enhanced IL‐10 and TGF‐β1 production. In the presence of IFN‐γ treated hPDLCs, 1,25(OH)₂D₃ significantly increased CD4⁺ T‐lymphocyte proliferation and decreased the percentage of CD4⁺ CD25⁺ FoxP3⁺ T_regs. IL‐10 and IL‐17A expression was significantly diminished by 1,25(OH)₂D₃, whereas TGF‐β1 was slightly increased. The effects of 1,25(OH)₂D₃ in co‐culture were reversed by inhibition of indoleamine‐2,3‐dioxygenase‐1, prostaglandin‐endoperoxide synthase and programmed cell death 1 ligand 1. 1,25(OH)₂D₃ also suppressed the expression of these proteins in hPDLCs.

Conclusion

Effects of vitamin D₃ on CD4⁺ T lymphocyte are modified by hPDLCs depending on the microenvironment.

Evaluation of Salivary Cytokines and Vitamin D Levels in Periodontopathic Patients

Periodontal disease (PD) is an inflammatory condition of the tissues supporting the teeth, which is widespread among the adult population. Evidence shows a relationship between PD and vitamin D levels, which is involved in the regulation of bone metabolism, mineral homeostasis, and inflammatory response. This study aimed to perform a simultaneous evaluation of inflammatory mediators and vitamin D levels in saliva in periodontopathic patients to better understand their role in periodontal disease. In this observational study, clinical periodontal parameter examination was performed for each patient. Moreover, the saliva levels of 25(OH)D₃, TGFβ, IL-35, IL-17A, and MMP9 were evaluated using an ELISA assay. An increase in TGFβ, IL-35, MMP9, and IL-17A salivary levels and a reduction in 25(OH)D₃ levels were observed in periodontopathic patients with respect to the healthy controls. The present study revealed significant positive correlation between cytokines and highly negative correlation between 25(OH)D₃ and salivary cytokine levels. Further studies are needed to better understand if salivary cytokines and vitamin D evaluation may represent a new approach for detection and prevention of progressive diseases, such as PD.

Role of Vitamin D Receptor Gene Polymorphisms on the Susceptibility to Periodontitis: A Meta-Analysis of a Controversial Issue

Background: To assess whether vitamin D receptor (VDR) gene polymorphisms influence the susceptibility to periodontitis. Methods: We retrieved 34 relevant studies, comprising a total of 3848 subjects suffering from periodontitis and 3470 controls for this meta-analysis. The pooled data were analyzed using STATA software. Results: Among all ethnic groups examined, the VDR BsmI polymorphism was associated with periodontitis under the recessive model (odds ratio [OR] = 0.722, 95% confidence interval [CI]: 0.532-0.980, p = 0.037). There was also a link between the VDR FokI polymorphism and periodontitis in the overall population (dominant model: OR = 1.459, 95% CI: 1.050-2.028, p = 0.025 and allelic model: OR = 1.386, 95% CI: 1.026-1.874, p = 0.034) and in Chinese participants (dominant model: OR = 1.813, 95% CI: 1.185-2.774, p = 0.006; allelic model: OR = 1.602, 95% CI: 1.044-2.459, p = 0.031) when stratified by race. The FokI variant was also correlated with aggressive periodontitis (AP) (dominant model: OR = 2.204, 95% CI: 1.148-4.231, p = 0.018; allelic model: OR = 2.017, 95% CI: 1.365-2.980, p = 0.000; and recessive model: OR = 2.903, 95% CI: 1.520-5.542, p = 0.001). We also showed a correlation between the VDR TaqI variant and periodontitis susceptibility in Caucasian populations (dominant model: OR = 0.525, 95% CI: 0.318-0.866, p = 0.012). The results revealed that there was no relationship between the VDR ApaI gene polymorphism and periodontitis. Conclusions: There was a link between the VDR BsmI and FokI gene polymorphisms and periodontitis in the overall population. In addition, the FokI polymorphism was correlated with AP. There was a link between the TaqI polymorphism and periodontitis in the Caucasian population. The VDR Apal variant, however, was not correlated with periodontitis.

Low serum vitamin D and early dental implant failure: Is there a connection? A retrospective clinical study on 1740 implants placed in 885 patients

Background. Since osseointegration depends on bone metabolism, low levels of vitamin D in the blood may negatively affect bone formation around dental implants. To date, only a few studies have investigated the possible connection between serum levels of vitamin D and early dental implant failure (EDIF), i.e. failure that occurs within 4 months after placement, before the connection of the prosthetic abutment. The aim of this study was to investigate whether there is a relationship between low serum levels of vitamin D and EDIF.

Methods. Data used for this retrospective study were derived from the records of a private dental clinic. Inclusion criteria were patients who had been treated with dental implants, inserted with a submerged technique from January 2003 to December 2017. EDIF was the outcome of this study. Chi-squared test was used to investigate the effect of patient-related variables (age, gender, smoking habit, history of periodontal disease and serum levels of vitamin D) on EDIF.

Results. Originally, 885 patients treated with 1,740 fixtures were enrolled in this study. Overall, 35 EDIFs (3.9%) were reported. No correlation was found between EDIF and the patients' gender (P=0.998), age (P=0.832), smoking habit (P=0.473) or history of periodontal disease (P=0.386). Three EDIFs (11.1%) were reported in 27 patients with serum levels of vitamin D <10 ng/mL, 20 EDIFs (4.4%) in 448 patients with levels between 10 and 30 ng/mL, and 12 EDIFs (2.9%) in 410 patients with levels >30 ng/mL. Although there was a clear trend toward an increased incidence of EDIF with lowering of serum vitamin D levels, no statistically significant difference (P=0.105) was found among these three groups.

Conclusion. Within its limitations (retrospective design, low number of patients with severe blood levels of vitamin D enrolled), this study failed to demonstrate a significant relationship between low serum levels of vitamin D and increased risk of EDIF. However, since a dramatic increase in EDIFs with lowering of vitamin D levels in the blood has been reported, further clinical studies with appropriate design (prospective or randomized controlled studies on a larger sample of severely deficient patients) are needed to better investigate this topic