The effects of megadoses of ascorbic acid on PMN chemotaxis and experimental gingivitis

Can vitamins improve periodontal wound healing/regeneration?

Periodontitis is a complex inflammatory disorder of the tooth supporting structures, associated with microbial dysbiosis, and linked to a number if systemic conditions. Untreated it can result in an irreversible damage to the periodontal structures and eventually teeth loss. Regeneration of the lost periodontium requires an orchestration of a number of biological events on cellular and molecular level. In this context, a set of vitamins have been advocated, relying their beneficial physiological effects, to endorse the biological regenerative events of the periodontium on cellular and molecular levels. The aim of the present article is to elaborate on the question whether or not vitamins improve wound healing/regeneration, summarizing the current evidence from in vitro, animal and clinical studies, thereby shedding light on the knowledge gap in this field and highlighting future research needs. Although the present review demonstrates the current heterogeneity in the available evidence and knowledge gaps, findings suggest that vitamins, especially A, B, E, and CoQ10, as well as vitamin combinations, could exert positive attributes on the periodontal outcomes in adjunct to surgical or nonsurgical periodontal therapy.

Effect of non surgical periodontal therapy and vitamin C supplementation on total antioxidant capacity in patients with chronic generalised periodontitis - A randomised controlled trial

Background

Periodontal inflammation are inflammation of supporting tissues of periodontium. The microbial factor can cause infection which is polymicrobial in origin and causes dysbiosis and shift in oxidative stress with compromised antioxidant capacity. This study focused at determination of the effect of nonsurgical periodontal therapy (NSPT) and vitamin C supplementation on total antioxidant capacity (TAOC) in chronic periodontitis patients (ChP).

Material & method

A total of 70 ChPand 35 periodontally healthy subjects (control) were recruited in this study. Further, ChP group was subdivided into ChP1 group (n = 35) which received NSPT only and ChP 2 group (n = 35) which received NSPT with vitamin C 500 mg once daily for 3 months. Serum and saliva samples were taken at baseline and at 3 months postNSPT for measurement of TAOC. Clinical parameters measured were measured at 1-, 3-, 6- and 12-month interval.

Results

Lower levels of serum and salivary TAOC levels were observed in ChP patients than healthy subjects (p < 0.05). Improvement in Clinical parameters was observed in both the groups ChP1 and ChP 2 group post therapy (p < 0.05). The periodontal treatment showed insignificant changes in serum and salivary TAOC levels (p > 0.05). The supplemental dose of vitamin C didn't have any additional benefits (p > 0.05).

Conclusion

There lies an association of oxidative stress with periodontitis, low serum and salivary TAOC levels were seen in chronic periodontitis patients. NSPT improved the periodontal inflammatory status. However, benefits of vitamin C as an adjunct to NSPT remains inconclusive and needs to be further explored by multicentre longitudinal studies.

Nutritional approach for increasing public health during pandemic of COVID-19: A comprehensive review of antiviral nutrients and nutraceuticals

Background: The novel coronavirus (COVID-19) is considered as the most life-threatening pandemic disease during the last decade. The individual nutritional status, though usually ignored in the management of COVID-19, plays a critical role in the immune function and pathogenesis of infection. Accordingly, the present review article aimed to report the effects of nutrients and nutraceuticals on respiratory viral infections including COVID-19, with a focus on their mechanisms of action. Methods: Studies were identified via systematic searches of the databases including PubMed/ MEDLINE, ScienceDirect, Scopus, and Google Scholar from 2000 until April 2020, using keywords. All relevant clinical and experimental studies published in English were included. Results: Protein-energy malnutrition (PEM) is common in severe respiratory infections and should be considered in the management of COVID-19 patients. On the other hand, obesity can be accompanied by decreasing the host immunity. Therefore, increasing physical activity at home and a slight caloric restriction with adequate intake of micronutrients and nutraceuticals are simple aids to boost host immunity and decrease the clinical manifestations of COVID-19. Conclusion: The most important nutrients which can be considered for COVID-19 management are vitamin D, vitamin C, vitamin A, folate, zinc, and probiotics. Their adequacy should be provided through dietary intake or appropriate supplementation. Moreover, adequate intake of some other dietary agents including vitamin E, magnesium, selenium, alpha linolenic acid and phytochemicals are required to maintain the host immunity.

Bleeding tendency and ascorbic acid requirements: systematic review and meta-analysis of clinical trials

CONTEXT

The World Health Organization set the recommended daily vitamin C intake, henceforth referred to as ascorbic acid (AA), on the basis of scurvy prevention. Double-blind AA depletion-repletion studies suggest that this recommended AA dose may be too low to prevent microvascular fragility.

OBJECTIVES

(1) To conduct a systematic review and meta-analysis of controlled clinical trials on whether AA supplementation leads to a reduced gingival bleeding tendency, a manifestation of microvascular fragility; and (2) to relate AA plasma levels to retinal hemorrhaging, another manifestation of microvascular fragility.

DATA SOURCES

Data were reviewed from 15 trials conducted in 6 countries with 1140 predominantly healthy participants with measures of gingival bleeding tendency, and from the National Health and Nutrition Examination Survey (NHANES) III of 8210 US residents with measures of retinal hemorrhaging.

RESULTS

In clinical trials, AA supplementation reduced gingival bleeding tendency when estimated baseline AA plasma levels were < 28 μmol/L (standardized mean difference [SMD], -0.83; 95%CI, -1.16 to -0.49; P < 0.002). Supplementation with AA did not unequivocally reduce gingival bleeding tendency when baseline estimated AA plasma levels were >48  μmol/L or unknown (respective standardized mean differences: -0.23, 95%CI, -0.45 to -0.01, P < 0.05; and -0.56; 95%CI: -1.19 to 0.06, P < 0.08). In NHANES III, prevalence of both retinal hemorrhaging and gingival bleeding tendency increased when AA plasma levels were within the range that protects against scurvy (11-28 μmol/L; respective prevalence ratios adjusted for age and sex: 1.47; 95%CI: 1.22-1.77; and 1.64; 95%CI: 1.32-2.03; P < 0.001 for both).

CONCLUSION

Consistent evidence from controlled clinical trials indicates that setting human AA requirements based on scurvy prevention leads to AA plasma levels that may be too low to prevent an increased gingival bleeding tendency. Gingival bleeding tendency and retinal hemorrhaging coincide with low AA plasma levels and thus may be reflective of a systemic microvascular pathology that is reversible with an increased daily AA intake.

Efficacy of vitamin C supplementation as an adjunct in the non-surgical management of periodontitis: a systematic review

BACKGROUND AND OBJECTIVE

The antioxidant potential of vitamin C is useful in reducing oxidative stress, free radicals, and reactive oxygen species, which may assist in the improved outcomes of periodontal therapy. This systematic review was aimed to evaluate the effectiveness of vitamin C supplementation as an adjunct to non-surgical periodontal therapy, in the management of periodontitis.

DATA SOURCES

PubMed, EMBASE, Cochrane Library, and Web of Science.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials published between January 1990 and March 2020.

PARTICIPANTS

People 18 years and older with periodontitis.

STUDY APPRAISAL AND SYNTHESIS METHODS

The Critical Appraisal Skills Programme (CASP) quality appraisal tool.

RESULTS

The initial search yielded 441 articles out of which six studies fulfilled the inclusion criteria. Vitamin C supplementation helped improve bleeding indices in gingivitis but did not significantly lead to reduction of probing depths or clinical attachment gain for periodontitis.

CONCLUSION

Administration of vitamin C as an adjunct to non-surgical periodontal therapy did not result in clinically significant improvements in pocket probing depths at 3 months in periodontitis patients. With the limited evidence available, no recommendation can be made for supplementation of vitamin C in conjunction with initial periodontal therapy for subjects with periodontitis to improve primary treatment outcome measures.

Construction and application of a nonenzymatic ascorbic acid sensor based on a NiO1.0/polyaniline3.0 hybrid

The schematic diagram for the fabrication process of NiO/PANI.

Effect of Vitamin C as an Adjunct in Nonsurgical Periodontal Therapy in Uncontrolled Type 2 Diabetes Mellitus Patients

Objective  The main purpose of this article is to evaluate periodontal parameters of chronic periodontitis patients with uncontrolled type 2 diabetes mellitus after initial periodontal therapy plus vitamin C.

Materials and Methods  A double-blind, placebo-controlled, clinical trial was conducted. Subjects received initial periodontal therapy plus 500 mg/day vitamin C for 2 months ( n = 15) or placebo ( n = 16). Fasting blood sugar (FBS), hemoglobin A1c (HbA1C), and plasma vitamin C level were assessed at baseline and 2 months post-treatment. Plaque Index, Sulcus Bleeding Index, Gingival Index, pocket depth, and clinical attachment level were measured at baseline, 1 month, and 2 months post-treatment.

Results  Almost all subjects had low level of plasma vitamin C at baseline. In the test group, plasma vitamin C was significantly increased to an adequate level at the end of 2 months. After periodontal treatment, FBS and HbA1c were not significantly different compared with baseline in the test group. In the control group, FBS was significantly decreased from baseline. However, no significant difference between groups was found either in FBS or HbA1c. All periodontal parameters were significantly improved from baseline in both groups. However, no significant difference was found between groups.

Conclusion  Supplementation of 500 mg/day vitamin C did not give an additional benefit in promoting periodontal status in periodontitis patients with uncontrolled type 2 diabetes mellitus.

Effect of guava and vitamin C supplementation on experimental gingivitis: A randomized clinical trial

OBJECTIVE

To study the effect of guava and synthetic vitamin C on the development of gingival inflammation during experimental gingivitis.

MATERIAL AND METHODS

Participants were randomly assigned to three groups supplemented daily with either 200 g guava, 200 mg synthetic vitamin C or water. The study included a 14 days pre-experimental period with oral hygiene instructions, scaling, prophylaxis and supplementation. Thereafter, experiment gingivitis was initiated, while continuing supplementation. At baseline, Day 7 and Day 14 of experimental gingivitis, Plaque Index (PlI) and Gingival Index (GI) were assessed. During the entire study, dietary fruit/vegetables intake was minimal.

RESULTS

PlI increased in guava, vitamin C and control group (ΔPlI: 1.30, 1.61 and 1.79, respectively). However, the guava group developed significantly less plaque compared to the control group. The GI increase in both guava and vitamin C group was significantly less than the increase in the control group (ΔGI: 0.10, 0.24 and 0.87, respectively).

CONCLUSION

In a population of young nonsmoking adults, consumption of either 200 g guava/day or 200 mg synthetic vitamin C/day, prior to and during the oral hygiene abstention period, has a preventive effect on the development of experimental gingivitis as compared to the control group that developed the usual amount of experimental gingivitis.

The association of dietary vitamin C intake with periodontitis among Korean adults: Results from KNHANES Ⅳ

Backgrounds

The association of dietary vitamin C (vit C) on periodontitis requires more valid evidence from large representative samples to enable sufficient adjustments. This study aimed to evaluate the association between dietary vit C intake and periodontitis after controlling for various confounders in the representative Korean adult population

Method

A total of 10,930 Korean adults (≥19 years) from the fourth Korean National Health and Nutrition Examination Survey data set were included in this cross-sectional study. Periodontitis was defined as community periodontal index score of 3 or 4. Dietary vit C intake was estimated from a 24-hour dietary record, and categorized into adequate and inadequate according to the Korean Estimated Average Requirement value. Potential confounders included age, sex, income, frequency of tooth brushing, use of floss, dental visit, drinking, smoking, diabetes, hypercholesterolemia, hypertension, and obesity. A multivariable logistic regression analysis and stratified analysis were applied.

Results

Those with inadequate dietary vit C intake were more likely by 1.16 times to have periodontitis than those with adequate dietary vit C intake (adjusted odds ratio [aOR] = 1.16, 95% confidence interval = 1.04–1.29). Lowest and middle-low quartile of dietary vit C intake, compared to highest quartile of dietary vit C intake, showed significant association (aOR = 1.28 and 1.22 respectively), which was in a biological-gradient relationship (trend-p <0.05).

Conclusions

Our data showed that inadequate dietary vit C intake was independently associated with periodontitis among Korean adults. Hence, adequate intake of dietary vitamin C could be substantially important on the promotion of periodontal health among Korean adults.

Intracellular ascorbate tightens the endothelial permeability barrier through Epac1 and the tubulin cytoskeleton

Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species.

Assessment of total antioxidant capacity and the use of vitamin C in the treatment of non-smokers with chronic periodontitis

BACKGROUND

Several recent studies have indicated that total antioxidant capacity (TAOC) of plasma seems to be compromised in chronic periodontitis (ChP). The aim of this study is to investigate plasma TAOC in patients with ChP and to assess the effects of vitamin C as an adjunct to non-surgical periodontal treatment.

METHODS

The study population consisted of 60 subjects: 30 diagnosed with ChP and 30 matched controls. Furthermore, patients from the ChP group were randomly allocated into ChP1 (15 patients received non-surgical treatment with adjunctive dose of vitamin C) and ChP2 (15 patients received non-surgical periodontal treatment alone). Plasma TAOC levels were measured by an ABTS assay at baseline and 1 month post-therapy.

RESULTS

Plasma TAOC levels were significantly lower in ChP patients than controls (P <0.001). The periodontal therapy resulted in increasing plasma TAOC and improvements in clinical measures among both ChP1 and ChP2 groups (P <0.001). However, the adjunctive dose of vitamin C did not offer additional effect (P >0.05).

CONCLUSIONS

ChP is significantly associated with lower levels of plasma TAOC. The non-surgical periodontal therapy seems to reduce the oxidative stress during the periodontal inflammation. However, the use of adjunctive vitamin C still needs further investigation.

The effect of ascorbate on minor recurrent aphthous stomatitis

AIM

Minor recurrent aphthous stomatitis (MRAS) is a common, painful and inflammatory ailment of the oral cavity with juvenile onset and unknown aetiology. The purpose of this study was to evaluate the potential of ascorbate (vitamin C) to reduce the frequency of MRAS and severity of pain.

PATIENTS AND METHODS

Sixteen MRAS patients (9 boys and 7 girls: mean age, 12.0 +/- 2.4 years old) were assigned to take an oral dosage of 2000 mg/m(2)/day ascorbate.

SUBJECTS

Their baseline frequency of outbreaks and the level of pains were compared during the treatment; in addition, a crossover clinical trial was performed. Polymorphonuclear leucocytes play a role in the pathogenesis, and then superoxide anion production was evaluated in prior to ascorbate treatment.

RESULTS

The data indicated a statistically significant 50% reduction in oral ulcer outbreaks and a decline of pain level. Neutrophils were primed for superoxide anion production in the patients with MRAS.

CONCLUSION

Ascorbate may modulate the generation of reactive oxygen species and augment neutrophil apoptosis, which could prevent neutrophil-mediated inflammation. Ascorbate seems to be effective, but the findings of our study were preliminary and it should be re-evaluated with a larger randomized controlled clinical trials.

Java project on periodontal diseases: the relationship between vitamin C and the severity of periodontitis

OBJECTIVE

To study the relationship between vitamin C and the severity of periodontitis.

MATERIAL AND METHODS

The study population consisted of subjects from the Malabar/Purbasari tea estate on West Java, Indonesia. In 2002, clinical measurements were performed in 128 subjects, including evaluation of plaque, bleeding on probing, pocket depth and attachment loss. In 2005, 123 out of 128 subjects could be retrieved who were present at the examination of 2002. Blood samples were taken to measure plasma vitamin C levels. Information about the subject's dietary habit was obtained by means of a personal interview guided by a questionnaire.

RESULTS

Plasma levels of vitamin C ranged from 0.02 to 34.45 mg/l with a mean of 7.90 mg/l (+/-5.35). The correlation coefficient between plasma vitamin C level and periodontal attachment loss was -0.199 (p<0.05); stepwise linear regression revealed that vitamin C levels explained 3.9% of the variance in periodontal attachment loss. Subjects with vitamin C deficiency (14.7% of the study population) had more attachment loss compared with those with depletion or normal plasma vitamin C values.

CONCLUSION

The negative association between plasma vitamin C levels and periodontal attachment loss suggests that vitamin C deficiency may contribute to the severity of periodontal breakdown.

Nutrition and periodontal disease

This article discusses general concepts of nutrition and provides an overview of the current understanding of the relationship between nutrition and periodontal disease.

Effects of Vitamin-B Complex Supplementation on Periodontal Wound Healing

BACKGROUND

Reports have demonstrated that nutrient supplements, in particular vitamin-B complex (Vit-B), can positively influence wound healing processes. However, limited information is available on the effects of Vit-B on periodontal wound healing.

METHODS

A total of 30 patients (13 males, 17 females) presenting with generalized moderate to severe chronic periodontitis were enrolled in this study. All subjects presented > or = two teeth in the same sextant with probing depth (PD) > or =5 mm and bleeding upon probing (BOP) in need of access flap surgery (AFS). This study was a randomized, double-masked, placebo-controlled clinical trial. Subjects were instructed to take one capsule a day of either Vit-B (50 mg of the following: thiamine HCl, riboflavin, niacinamide, d-calcium pantothenate, and pyridoxine HCl; 50 microg each of d-biotin and cyanocobalamin; and 400 mcg of folate) or placebo for 30 days following AFS. Clinical attachment levels (CAL) and N-benzoyl-dl-arginine-2-naphthylamide (BANA) test scores were measured at baseline and at 90 and 180 days following surgical intervention. Assessments of the healing response were also performed using BOP, gingival index (GI), and plaque index (Pl) at baseline and 7, 14, 30, 90, and 180 days. The mean results of each parameter were averaged within a group. Differences between groups were analyzed by using repeated measures analysis of variance (ANOVA).

RESULTS

Both groups experienced comparable levels of PD reduction following AFS (test: -1.57 +/- 0.34; control: -1.50 +/- 0.21). Changes in mean CAL were more favorable in Vit-B supplemented subjects (test: +0.41 +/- 0.12; control: -0.52 +/- 0.23; P = 0.024). Stratified data demonstrated significantly better results for the test group in both shallow (test: -0.08 +/- 0.03; control: -1.11 +/- 0.27; P = 0.032) and deep sites (test: +1.69 +/- 0.31; control: +0.74 +/- 0.23; P = 0.037). No significant differences were observed between groups regarding PI, GI, and BOP. BANA test values were significantly reduced in both groups after surgical treatment and no significant differences were noted between groups.

CONCLUSION

Vitamin B-complex supplement in combination with AFS resulted in statistically significant superior CAL gains when compared to placebo.

Effects of specific nutrients on periodontal disease onset, progression and treatment

OBJECTIVES

The aim of this paper is to review the available literature pertaining to the effects of specific nutritional elements (e.g. vitamin B-complex, vitamin C and dietary calcium) on general wound healing, periodontal disease status and response to periodontal therapy.

METHODS

Critical appraisal of various studies that have evaluated the effects of calcium, ascorbic acid and vitamin B-complex in wound healing and periodontal treatment.

RESULTS

Periodontal disease onset, progression and response to therapeutic interventions have been shown to be influenced by several systemic, local and environmental modifying factors. Nutritional supplementation has been suggested as a possible influencing factor on periodontal status and wound healing. Several studies have reported various degrees of association between nutritional elements/supplements and periodontal status, and others have reported possible positive influences of nutritional supplementation on periodontal therapeutic outcomes. Future research needs to more fully explore the presence and strength of association between nutrition and periodontal health.

CONCLUSIONS

Data collected from the literature suggests that nutrient supplementation causes minimal or no side effects. However, the efficacy of prophylactic nutrient supplementation for the prevention of the onset and progression of periodontal disease, or for the enhancement of periodontal wound healing, remains to be determined.

Nutrition, infection, and periodontal disease

Even though nutrition is not recognized as a risk factor for periodontal diseases, nutrition is acknowledged to have a significant impact on optimal functioning of the immune response. Dental professionals need to routinely assess nutritional status and provide basic nutrition counseling to their patients to ensure optimal functioning of the immune system in combating infection and to promote optimal periodontal health.

Vitamin C function and status in chronic disease

Vitamin C is an essential dietary nutrient required as a co-factor for many enzymes, and humans are among the few animals that lack the ability to synthesize the compound from glucose. The reduced form of the vitamin, ascorbic acid, is an especially effective antioxidant owing to its high electron-donating power and ready conversion back to the active reduced form. Concentrations of the vitamin in body tissues and fluids are regulated through interactions of intestinal absorption, cellular transport, and excretion. The amount of vitamin C needed to prevent scurvy is very small and easily obtained in nearly all Western diets. There is great interest in the clinical roles of vitamin C because of evidence that oxidative damage is a root cause of, or at least associated with, many diseases. Population studies show that individuals with high intakes of vitamin C have lower risk of a number of chronic diseases, including heart disease, cancer, eye diseases, and neurodegenerative conditions. However, these results may simply reflect a more healthful diet or lifestyle for individuals with a high vitamin C intake. At present, data from controlled clinical trials have not established that higher intakes of vitamin C alone will help prevent chronic degenerative diseases. However, the evidence that ascorbic acid acts as an important antioxidant in many body tissues is convincing. The new higher Recommended Dietary Allowance (RDA) for vitamin C of 75 mg for women and 90 mg for men is, for the first time, based on the vitamin's role as an antioxidant as well as protection from deficiency. In healthy people, amounts greater than the RDA do not appear to be helpful. Vitamin C nutriture may be more important for people with certain diseases or conditions. High intakes of the vitamin are generally well tolerated; a Tolerable Upper Level was recently set at 2 g based on gastrointestinal upset that sometimes accompanies excessive intakes.

Dietary vitamin C and the risk for periodontal disease

BACKGROUND

Vitamin C has long been a candidate for modulating periodontal disease. Studies of scorbutic gingivitis and the effects of vitamin C on extracellular matrix and immunologic and inflammatory responses provide a rationale for hypothesizing that vitamin C is a risk factor for periodontal disease.

METHODS

We evaluated the role of dietary vitamin C as a contributing risk factor for periodontal disease utilizing the Third National Health and Nutrition Examination Survey (NHANES III) which is representative of the U.S. civilian, non-institutionalized population.

RESULTS

A sample of 12,419 adults (20 to 90+ years of age), with dental measurements and assessment of dietary information as well as demographic and medical histories were included in the studies. Dietary vitamin C was estimated by a 24-hour dietary record. Individuals with periodontal disease were arbitrarily defined as those who had mean clinical attachment levels of > or =1.5 mm. Using multiple logistic regression analysis, we found a relationship between reduced dietary vitamin C and increased risk for periodontal disease for the overall population (odds ratio [OR] = 1.19; 95% CI: 1.05 to 1.33). Current and former tobacco users who were taking less dietary vitamin C showed an increased risk of periodontal disease with OR of 1.28, 95% CI: 1.04 to 1.59 for former smokers, and an OR of 1.21, 95% CI: 1.02 to 1.43 for current tobacco users. There was a dose-response relationship between the levels of dietary vitamin C and periodontal disease with an OR of 1.30 for those taking 0 to 29 mg of vitamin C per day, to 1.16 for those taking 100 to 179 mg of vitamin C per day as compared to those taking 180 mg or more of vitamin C per day.

CONCLUSION

Dietary intake of vitamin C showed a weak, but statistically significant, relationship to periodontal disease in current and former smokers as measured by clinical attachment. Those taking the lowest levels of vitamin C, and who also smoke, are likely to show the greatest clinical effect on the periodontal tissues.

Enhanced production of mineralized nodules and collagenous proteins in vitro by calcium ascorbate supplemented with vitamin C metabolites

BACKGROUND

Vitamin C or ascorbate is important in wound healing due to its essential role in collagen synthesis. To study wound healing in the periodontium, cells adherent to expanded polytetrafluoroethylene (ePTFE) augmentation membranes, recovered from edentulous ridge augmentation procedures, have been established in culture in our laboratories. The objective of this study was to determine whether treatment of these cells with a calcium ascorbate, which contains vitamin C metabolites (metabolite-supplemented ascorbate), would increase the production of collagenous protein and mineralized tissue in vitro, as compared to unsupplemented calcium ascorbate (ascorbate).

METHODS

Cells derived from ePTFE membranes were cultured with beta-glycerophosphate and the test agents for 2 to 5 weeks, and the surface areas of the cell cultures occupied by mineralized nodules were measured using computerized image analysis. One experiment tested the effects of calcium threonate, one of the vitamin C metabolites in metabolite-supplemented ascorbate. Incorporation of radioactive proline and glycine was used as a measure of total protein (radioactivity precipitated by trichloracetic acid) and collagenase-digestible protein (radioactivity released by collagenase digestion.) Co-localization of collagen and fibronectin was examined by immunofluorescence.

RESULTS

In vitro treatment of these cells with metabolite-supplemented ascorbate increased the area of the cell cultures occupied by mineralized nodules after 5 weeks. Cell cultures treated with metabolite-supplemented ascorbate also exhibited significant increases in total protein. The increase in collagenous proteins in these cultures accounted for 85% of the increase in total protein. The greatest difference between treatment groups was observed in the cell-associated fraction containing the extracellular matrix. The additional collagen exhibited normal co-distribution with fibronectin. In cultures treated with ascorbate spiked with calcium threonate, the area of mineralized tissue was significantly greater than in ascorbate-treated cultures, but was less than that observed in cultures treated with metabolite-supplemented ascorbate.

CONCLUSIONS

In vitro treatment with ascorbate containing vitamin C metabolites enhanced the formation of mineralized nodules and collagenous proteins. Calcium threonate may be one of the metabolites influencing the mineralization process. Identifying factors which facilitate the formation of mineralized tissue has significant clinical ramifications in terms of wound healing and bone regeneration.

Growth and bone remodelling in a scorbutic rat model

This study used the scorbutic Osteogenic Disorder Shionogi rat model and a specific diet to reliably induce a state of sub-scurvy scorbutus. Under these conditions overall somatic growth was assessed, as well as that of the caudal vertebrae, as an example of scorbutic bone growth. Tail loops were then used to mechanically stress mature caudal vertebrae under scorbutic conditions, and the vertebrae's adaptation to these applied forces was assessed, using measurements of bend deformation and histologic analysis of osteogenesis. Scorbutic animals exhibited significant somatic growth retardation (p < 0.05), and abnormal reductions in osteogenesis and periosteal responsiveness to growth. Scorbutic vertebrae also showed greater bend angles of deformation (p < 0.05), and a marked reduction in cortical osseous remodelling and periosteal differentiation. It appeared that the sub-scurvy scorbutic bones were smaller, weaker and less able to adapt to physical stresses: this pattern was reflected at the histologic level.

Effects of ascorbic acid depletion and supplementation on periodontal health and subgingival microflora in humans

This study describes the relationship between varying ascorbate intake, periodontal status, and subgingival microflora as part of a multidisciplinary investigation of ascorbic acid (AA) metabolism in young men housed for 13 weeks in a nutrition suite that provided controlled periods of ascorbic acid depletion and repletion. Twelve medically healthy non-smoking men, aged 25 to 43 years, ate a rotating four-day diet adequate in all nutrients except ascorbic acid. Following an initial baseline period during which the subjects received 250 mg AA/day, the subjects received 5 mg AA/day for a 32-day depletion period. Eight of the 12 subjects participated in a subsequent 56-day repletion period designed to replace the reduced body AA pool slowly. Plasma and leukocyte ascorbate levels, Plaque Index, Gingival Index, probing depths, and attachment level were monitored at the beginning and end of the depletion and repletion periods. Subgingival plaque samples were obtained and examined for selected organisms by indirect immunofluorescence microscopy. A uniform oral hygiene program was reinforced after each examination. Ascorbate concentrations in plasma and leukocytes responded rapidly to changes in vitamin C intake. There were no significant changes in plaque accumulation, probing pocket depth, or attachment level during the study. In contrast, gingival bleeding increased significantly after the period of AA depletion and returned to baseline values after the period of AA repletion. However, no relationship could be demonstrated between either the presence or proportion of target periodontal micro-organisms and measures of bleeding or ascorbate levels.

Assay of ascorbic acid in human crevicular fluid from clinically healthy gingival sites by high-performance liquid chromatography

The volume of fluid on filter paper strips was measured with a Periotron, eluted, and the ascorbic acid measured by chromatography. In preliminary experiments, pre-impregnation of the strips with citric acid increased the recovery of standard ascorbic acid from 37 to 89% and significantly reduced loss of water from the strips over a 3 min period. Samples of crevicular fluid were then collected from clinically healthy gingival sites of 21 healthy volunteers using pre-impregnated strips and assayed for ascorbic acid concentration, together with samples of blood plasma. The mean ascorbic acid concentration in gingival crevicular fluid (207.3 mumol/l; SD: +/- 81.8) was significantly higher (p less than 0.001) than the corresponding plasma concentration (mean 72 mumol/l; SD: +/- 23.3).

A case-control study of plasma ascorbate and acute necrotizing ulcerative gingivitis

Data from animal studies and from studies of patients with acute necrotizing ulcerative gingivitis (ANUG) have provided suggestive evidence for an association between ascorbate deficiency and disease risk. Further, there is biological plausibility for such an association, due to the role of ascorbate in collagen synthesis and leukocyte function. A case-control study of plasma ascorbate and ANUG was performed on 60 patients with a history of ANUG infection and 60 age-race-sex-matched controls. No cases had had active lesions for at least two months prior to their vitamin assay to avoid any potential reduction of dietary intake of ascorbic acid due to the presence of painful mouth lesions. According to results obtained by use of a modification of the 2,4-dinitrophenylhydrazine method for determination of total plasma ascorbate, the mean and standard error of the mean of plasma ascorbate for all ANUG cases was 0.07 +/- 0.006 mmol/L; the mean for all controls was 0.10 +/- 0.006 mmol/L. Paired differences in plasma ascorbic acid concentrations between cases and controls were significantly different from zero (p less than 0.001). The unadjusted relative risk (RR) of ANUG as obtained by conditional logistic regression for subjects whose plasma ascorbic acid concentration was at or below the median value for controls, relative to subjects with higher values, was 7.3 (90% confidence interval, 3.0 - 17.4; one-sided p value less than 0.001). Patients with a history of ANUG ingested a daily average of 1.2 +/- 0.2 servings of dietary ascorbic acid, as compared with a daily average of 1.9 +/- 0.2 servings for healthy controls.(ABSTRACT TRUNCATED AT 250 WORDS)