Relationship of subgingival plaque flora to lysosomal and cytoplasmic enzyme activity in gingival crevicular fluid

Examining the relationships among indicators of the acute inflammatory response in gingival crevicular fluid (GCF) and specific bacterial species in subgingival plaque may provide indications of which bacterial species or groups of species may be associated with potentially destructive host-derived processes. Here we report on the relationship of the subgingival plaque flora to the activity of mammalian forms of the enzymes beta-glucuronidase (beta G), lactate dehydrogenase (LDH), and arylsulfatase (AS) in GCF from a total of 54 4-6 mm periodontal sites from 13 periodontitis patients. Sites were scored for probing depth (PD) and bleeding on probing, and GCF was collected using filter paper strips inserted into the sulcus for 30 s, eluted in buffer and assayed for enzyme activity. 1 week later, the patients were again evaluated for PD and bleeding, and subgingival plaque was removed with a curette oriented toward the pocket epithelium. Plaque samples were examined by darkfield microscopy and cultured anaerobically on selective and non-selective media. Various groups of bacteria, including species of black pigmenting Bacteroides (BPB), Fusobacterium sp., Capnocytophaga sp, Streptococcus sanguis, and total facultative organisms were enumerated. Relationships among the enzymes and bacterial groups expressed as colony-forming unit (CFU) counts or as a % of the total cultivable flora were assessed by Spearman correlation analysis. beta G levels were significantly correlated with populations of spirochetes, B. intermedius, B. gingivalis, and total lactose negative BPB's. Correlation between beta G and F. nucleatum sp. or Capnocytophaga sp. approached but did not reach statistically significant levels. In contrast, LDH activity showed a significant positive correlation with levels of B. gingivalis and total lactose negative BPB's. AS levels were significantly correlated only with B. gingivalis. beta G and LDH showed a significant negative correlation with levels of coccoid forms. Thus, beta G, an acid hydrolase which can serve as a marker for primary granule release from polymorphonuclear leukocytes, was most closely correlated with the micro-organisms found in other studies to be associated with chronic adult periodontitis.     

The effect of sequential sampling on crevicular fluid volume and enzyme activity

Gingival crevicular fluid (GCF) volume and constituents in static samples were compared to volume and constituents in subsequent GCF samples collected during a 60-min interval. Using deep intracrevicular placement of precut filter paper strips, GCF was collected from interproximal and facial sites from patients with gingivitis (N = 14; 28 interproximal sites, 28 facial sites) and chronic adult periodontitis (N = 11; 26 interproximal sites, 18 facial sites). The strips were inserted for 30 s at 0, 4, 8, 30 and 60 min. The amount of fluid on each strip was determined and microspectrophotometric techniques were used to assess cytoplasmic and lysosomal enzyme activity. Within each group of sites, mean GCF volume showed minimal fluctuation with repeated sampling. In contrast, the static GCF sample contained the greatest amount of total enzyme activity, and differences were detected between groups. The interproximal sites and the gingivitis-facial sites displayed a similar pattern of change in total enzyme activity during the test period. The highest total enzyme activity was observed in the first sample and decreased at 4 and 8 minutes. At 30 and 60 min, the amount of enzyme either remained at the level detected at 8 min, or displayed a mild tendency to recover towards baseline. A different pattern of total enzyme activity was observed for the periodontitis-facial sites, where a significant decrease was first observed at 30 min. Enzyme concentration was higher in the facial sites than the interproximal sites, and enzyme concentration was generally highest in the static samples. The concentration data, however, is difficult to interpret since a number of sites demonstrated a converted GCF volume of 0 microliter. Our data suggests that total enzyme activity and enzyme concentration are generally greater in the static GCF samples compared to subsequent samples.(ABSTRACT TRUNCATED AT 250 WORDS)     

Alkaline phosphatase activity in gingival crevicular fluid during canine retraction

OBJECTIVES: The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. SETTING AND SAMPLE POPULATION: Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. EXPERIMENTAL VARIABLE: Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. OUTCOME MEASURE: Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. RESULTS: The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. CONCLUSIONS: The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.     

Intracytoplasmic enzymes in gingival crevicular fluid of patients with aggressive periodontitis

Castro CE, Koss MA, López ME. Intracytoplasmic enzymes in gingival crevicular fluid of patients with aggressive periodontitis. J Periodont Res 2011; 46: 522–527. © 2011 John Wiley & Sons A/S Background and Objective: Biochemical parameters of crevicular fluid could provide evidence of periodontal tissue disease. The aim of this study was to analyze enzymes in crevicular fluid in aggressive localized and generalized periodontitis. Material and Methods: One hundred and twenty‐four subjects were classified as having localized (n = 36) or generalized aggressive periodontitis (n = 38) and subclassified into moderate and severe groups. Controls were 50 periodontitis‐free subjects. Activities of the enzymes lactate dehydrogenase, neutrophil elastase, alkaline phosphatase and aspartate aminotransferase were determined. Data were analyzed using one‐way ANOVA and Tukey’s test. Results: Among the subjects with localized aggressive periodontitis, values of lactate dehydrogenase and alkaline phosphatase increased notably in moderate and severe periodontitis compared with control subjects. Values for aspartate aminotransferase increased with the severity of the disease, and neutrophil elastase was increased in the moderate and severe states. In generalized aggressive periodontitis, lactate dehydrogenase showed higher values than in control subjects in both periodontal subgroups. Alkaline phosphatase and neutrophil elastase showed higher significant differences between moderate and severe periodontitis compared with the control group. Aspartate aminotransferase showed differences between the severe and moderate periodontitis groups compared with the control group. Of all the enzymes analyzed, only lactate dehydrogenase showed higher values in localized than in generalized aggressive periodontitis. Conclusion: Lactate dehydrogenase may distinguish localized and generalized aggressive periodontitis. Alkaline phosphatase increases from moderate to severe states in both types of periodontitis. Aspartate aminotransferase and neutrophil elastase only increase with strong evidence of periodontal destruction.     

Osteopontin in gingival crevicular fluid

Osteopontin (OPN) is a major glycosylated phosphoprotein in bone matrix and is produced by several cells including osteoblasts, osteoclasts and macrophages. OPN levels increase in active sites of bone metabolism. Recently, several bone-related proteins were identified in gingival crevicular fluid (GCF) to seek markers of alveolar bone resorption in periodontal disease. In this study, we investigated the existence of OPN in GCF and the correlation between OPN level in GCF and probing depth (PD) of sampling sites in 98 periodontitis patients and 35 healthy subjects. An immunoblotting analysis using 10% polyacrylamide gel showed that two forms of OPN with molecular masses of 54 and 66 kDa and several degraded fragments were detected in most GCF samples from diseased sites (PD > 4 mm). In GCF samples from healthy sites (PD < or = 3 mm), only one form (54 kDa) was observed, but any degraded fragments were not detected. When OPN amounts in GCF samples were determined by ELISA, a weak. but significant correlation was observed between OPN amount in GCF and PD (r=0.32, p=0.0013). These results demonstrate that OPN exists in GCF and that OPN level in GCF increases with the progression of periodontal disease.     

Smoking cessation increases gingival blood flow and gingival crevicular fluid

OBJECTIVES: The purpose of the present study was to determine the effect of smoking cessation on gingival blood flow (GBF) and gingival crevicular fluid (GCF). MATERIAL AND METHODS: Sixteen male smokers (aged 22-39 (25.3+/-4.0) years), with no clinical signs of periodontal and systemic diseases, were recruited. The experiment was performed before (baseline) and at 1, 3 and 5 days, and at 1, 2, 4 and 8 weeks after smoking cessation. The status of smoking and smoking cessation was verified by exhaled carbon monoxide (CO) concentration, and by serum nicotine and cotinine concentrations. A laser Doppler flowmeter was used to record relative blood flow continuously, on three gingival sites of the left maxillary central incisor (mid-labial aspect of the gingival margin and bilateral interdental papillae). The GCF was collected at the mesio- and disto-labial aspects of the left maxillary central incisor and the volume was calculated by the Periotron 6000(R) system. The same measurements except for the GBF were performed on 11 non-smoking controls (four females and seven males), aged 23-27 (24.4+/-1.2) years. RESULTS: Eleven of 16 smokers successfully completed smoking cessation for 8 weeks. At 1 day after smoking cessation, there was a significantly lower CO concentration than at baseline (p<0.01). Also, nicotine and cotinine concentrations markedly decreased at the second measurement. The GBF rate of smokers was significantly higher at 3 days after smoking cessation compared to the baseline (p<0.01). While the GCF volume was significantly increased at 5 days after smoking cessation compared to the baseline (p<0.01), it was significantly lower than that of non-smokers until 2 weeks after smoking cessation (p<0.01). CONCLUSION: The results show that the gingival microcirculation recovers to normal in the early stages of smoking cessation, which could activate the gingival tissues metabolism/remodeling, and contribute to periodontal health.     

A rapid spectrophotometric assay for tetracycline in gingival crevicular fluid

AIM: The aim of this study was to investigate a rapid spectrophotometric assay for its potential to measure tetracycline levels in gingival crevicular fluid (GCF). MATERIALS AND METHODS: The technique involves complexation of tetracycline with molybdenum in order to shift the absorbance spectrum away from that region where interference with plasma proteins is a problem. The sensitivity of the assay and reproducibility of elution were examined together with an assessment of the effect of plasma proteins. The assay was also tested in a small pilot clinical project, measuring tetracycline levels in GCF following placement of a test gel formulation in 25 periodontal pockets in 5 patients. RESULTS: The in vitro results showed good sensitivity of the assay over the concentration range tested (0.5-200 microg tetracycline) and with little effect of plasma proteins. Elution from the paper strips was reproducible with a good linear correlation between direct and filter absorbed assays (r=0.9989, p<0.01). The pilot clinical study indicated a mean half-time of tetracycline in GCF of 28 min with confidence intervals of 21 to 34 min, although wide variation between the drug levels of individual periodontal pockets was seen. CONCLUSIONS: The results indicate good sensitivity for this assay to measure tetracycline hydrochloride in vivo. The potential for rapidly processing large numbers of samples contrasts with the assay time and limited sample throughput of other methods such as high pressure liquid chromatography (HPLC) and suggests that the technique may be a useful addition to current techniques for measuring tetracycline hydrochloride in vivo.     

Correlation analysis for clinical and gingival crevicular fluid parameters at anatomically related gingival sites

This study was designed to evaluate the relationship of certain clinical and biochemical measures of periodontal pathology at anatomically related gingival sites. The maxillary first molar--second bicuspid region was studied in patients with gingivitis and periodontitis. The mesiobuccal site on the first molar was compared to the mesiopalatal and direct buccal sites on the molar and the distobuccal site on the second bicuspid. Probing depth, attachment level, gingival index, gingival crevicular fluid (GCF) volume, and GCF levels of the lysosomal enzyme B-glucuronidase (BG), the cytoplasmic enzyme lactate dehydrogenase, IgG and the protease-inhibitor alpha-2-macroglobulin were studied. For the 3 anatomical pairs that were analyzed, the correlation coefficients for the GCF constituents were generally higher than the correlations for the clinical parameters. The mean correlations for the GCF constituents were higher for the periodontitis patients as compared to the gingivitis patients. For the periodontitis patients, BG activity was correlated at adjacent proximal sites, approached significance at adjacent papillary sites, but was not significantly correlated at adjacent facial-proximal sites. This data suggests that sampling of BG activity from a mesiobuccal site provides information about the anterior papillary unit. In contrast, IgG in GCF collected from the mesiobuccal site on the first molar was significantly correlated with the total IgG in the 3 other sites.(ABSTRACT TRUNCATED AT 250 WORDS)     

龈沟液弹性蛋白酶洗提和保存方法的初步研究

目的 :观察不同保存温度、时间和不同缓冲液以及不同洗提方法对龈沟液弹性蛋白酶 (GCF-EA)活性的影响。方法 :采用底物反应法分别于取样即刻和 1、2、3、4周时检测 - 2 0℃和 - 70℃保存的PBS组和Tris-HCl组以震荡法和震荡 +离心法洗提的GCF样本中EA的活性。结果 :不同洗提方法间洗提效果的差异具有显著性 (0 .0 1

0 .5 )。在相同时间内 ,PBS组或Tris -HCl组 - 2 0℃保存的GCF样本EA活性与- 70℃者间的差异无显著性 (P >0 .0 5 ) ,但 - 2 0℃保存者有略高于 - 70℃者的倾向 ,且 - 2 0℃比 - 70℃条件下保持EA活性的时间略长。结论 :将滤纸条上的GCF样本进行洗提时 ,采用“震荡 +离心法”优于“震荡法”。GCF样本的保存过程中 ,缓冲液的种类以及保存温度可影响GCF -EA的活性。以PBS作为缓冲液、- 2 0℃保存可能更利于其中EA活性的稳定。     

Relationship of collagenase and cathepsin G activity in gingival crevicular fluid

Human neutrophil cathepsin G has been identified as a potent proteolytic activator of latent human neutrophil collagenase in vitro. In order to examine the role of cathepsin G in the activation mechanism of latent human neutrophil collagenase in vivo, gingival crevicular fluid was collected from periodontal pockets of patients with adult periodontitis and the relationship of cathepsin G to the proportion of endogenously active collagenase and total collagenase activity was determined. The changes in these parameters were monitored before and after periodontal therapy and compared to control values obtained for periodontal sites without clinical signs of inflammation or increased pocket depth. A significant decrease in cathepsin G and collagenase activity in gingival crevicular fluid collected from initially deep periodontal pockets was observed in response to scaling and root planing ( P < 0.025, Wilcoxon signed rank test). Also the proportion of endogenously active collagenase decreased ( P < 0.05). There was a significant correlation of cathepsin G and total collagenase activity. However, no correlation of cathepsin G activity and endogenously active collagenase was observed. The results indicate the existence of several distinct activation pathways for latent human neutrophil collagenase in vivo and suggest that, apart from cathepsin G, other proteolytic activation cascades and/or non-proteolytic activaton pathways participate in the activation of latent human neutrophil collagenase in vivo.     

Phylloquinone in gingival crevicular fluid in adult periodontitis

Abstract. Phylloquinone is a lipid soluble vitamin which is an absolute growth requirement for black-pigmented anaerobes, many of which are implicated in the aetiology of periodontal diseases. This cross-sectional study aimed to detect the levels of phylloquinone in GCF from healthy and diseased sites in subjects with adult periodontitis, in order to investigate further its potential role in the disease process. The sample consisted of eighteen patients with adult periodontitis. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each subject. GCF was sampled and the amount of phylloquinone in each sample was determined using reverse-phase high performance liquid chromatography coupled to electrochemical detection. The mean amount of phylloquinone in accumulated GCF from diseased sites was 406 pg/site and 80 pg/site from healthy sites ( p =0.013). When the amounts of phylloquinone in GCF were expressed as concentrations the values were 228 ng/ml and 3350 ng/ml for diseased and healthy sites respectively ( p =0.084). These findings suggest the levels of phylloquinone in GCF differs in periodontal health and disease in subjects with adult periodontitis. The total phylloquinone at diseased sites may provide the nutritional requirements favouring the growth of black-pigmented anaerobes.     

Presence of cortisol in gingival crevicular fluid A pilot study

Abstract. Cortisol is one of the primary mediators of the stress response, in the main having immunosuppressive effects. An important component of the host response in periodontal inflammation is gingival crevicular fluid (GCF), with constituents mainly derived from serum, Cortisol like many other steroids, is present in saliva but its occurrence in GCF does not seem to be documented, Unstimulated whole saliva was collected and GCF was sampled on filter disks. The samples were analysed by a modified RIA method for serum in such a way that small volumes and low concentrations could be measured. Our findings suggest that the total concentration of cortisol in GCF might be estimated to levels below 1/10 of that in serum. However, what appears as a distinctive feature is the considerable variation of the cortisol concentrations for individual teeth. To our knowledge, this is the first time cortisol has been measured in gingival crevicular fluid, and this opens Ihe prospects for further in vivo research.     

Periodontal variables affecting nifedipine sequestration in gingival crevicular fluid

We previously demonstrated the sequestration of nifedipine in gingival crevicular fluid (GCF), especially in patients exhibiting significant gingival overgrowth. The aim of the present study is to determine the role of site specific periodontal factors in this phenomenon. 10 adult patients exhibiting nifedipine induced gingival overgrowth were studied. In each patient GCF was harvested from two sites that demonstrated inflammation and increased probing depth as well as from two clinically healthy sites. The concentration of nifedipine was determined using gas chromatography. Drug concentrations were significantly increased in the presence of inflammation (p=0.004) and plaque (p=0.029) whilst increased probing depths and gingival overgrowth were not significantly related to drug sequestration. We can conclude that inflammatory changes in gingival tissues appear to be a significant determinant for the sequestration of nifedpine in the GCF.     

Granulocyte elastase activity in static and flow gingival crevicular fluid

OBJECTIVES: This study aimed to evaluate the volume of gingival crevicular fluid (GCF) and granulocyte elastase activity in static GCF (sGCF) and flow GCF (fGCF) from subjects with various periodontal conditions. METHODS: Eleven periodontally healthy, 10 gingivitis and 12 periodontitis subjects were recruited and the sites investigated consisted of healthy sites from healthy subjects (HH); healthy (HG) and gingivitis sites (GG) from gingivitis subjects; and healthy (HP), gingivitis (GP) and periodontitis sites (PP) from periodontitis subjects. fGCF samples were collected either 1 min or 5 min following sGCF collection by paper strip technique. GCF volume was determined by Periotron 6000 and granulocyte elastase activity was assayed with a specific substrate [l-pyroglutamyl-l-prolyl-l-valine-p-nitroanilide(pGluProVal-pNA)]. RESULTS: At baseline, no significant differences existed in clinical and GCF parameters between the two matched sites for subsequent collection of fGCF samples either 1 min or 5 min after sGCF sampling in all subjects. The flow exudate in HG and HP sites quickly replenished to sGCF levels, while a delayed replenishment was found in HH sites, despite the similar sGCF volumes of these sites. The GCF volume and elastase levels in the fGCF at 1 min were higher in GP sites than in GG sites (P < 0.05). Overall, depletion of elastase levels in the fGCF at 1 min was observed in all subjects, whereas elastase levels in the fGCF at 5 min had replenished to sGCF levels in HP, GP, PP sites and GG sites, but had remained at a lower level in HH and HG sites. An overall positive correlation was found between sGCF and fGCF for GCF volume and elastase activity (P < 0.001); however, this correlation varied with GCF parameters and with site conditions of the subjects concerned. CONCLUSIONS: This study shows that patterns of dynamic changes in GCF flow and elastase activity varied under different periodontal conditions. Assessment of both sGCF and fGCF may allow better insight into the dynamic change of the target components in GCF.     

Granulocyte elastase in gingival crevicular fluid

The granulocyte elastase activity and the immuno-reactive (antigenic) granulocyte elastase of gingival crevicular fluid (GCF) were studied in 16 periodontitis patients and in 10 gingivitis patients. The elastase activity was measured with a low molecular weight substrate specific for granulocyte elastase. The antigenic elastase was determined with specific antibodies against granulocyte elastase. Intracrevicular sampling of GCF with paper strips for 30 s seemed to provide representative values of elastase. The elastase activity correlated with probing depth and attachment loss and appeared to be a measure of the degree of tissue destruction. Antigenic elastase represents the number of granulocytes in GCF and should thus be related to the degree of inflammation. The periodontitis patients and the gingivitis patients both had a similar degree of inflammation as measured by antigenic elastase per microliter GCF and gingival index. The elastase activity per microliter GCF, however, was higher in the periodontitis group. Elevated granulocyte elastase activity in GCF seems to be independent of inflammation and could thus be an indicator of patients at risk for periodontitis.     

Cytokines in gingival crevicular fluid of adolescents and young adults

Background/aim:  The purpose of this study was to compare the levels of the cytokines interleukin-1β (IL-1β), IL-4, and IL-8 in the gingival crevicular fluid (GCF) of adolescents and young adults.
Methods:  Twenty-five adolescents aged between 14 and 16 years (Group A) and 20 periodontally healthy young adults aged between 25 and 35 years (Group B) were selected from two private dental clinics limited to pedodontics and periodontics respectively in Piraeus Greece. All subjects were systemically healthy. Clinical examination included probing pocket depth (PPD), presence or absence of plaque, and bleeding on probing (BOP). GCF was collected from four sites per subject. IL-1β, IL-4, and IL-8, measured as total amounts (pg/30 s), were evaluated in 180 samples using a commercially available sandwich enzyme-linked immunosorbent assay.
Results:  IL-1β mean levels of Groups A and B were adjusted for BOP and PPD. Differences of IL-1β mean levels between the two age groups were statistically significant ( F  = 50.245, P  < 0.001) in favour of Group A. Adolescents showed statistically significantly lower mean levels of IL-4 than young adults in the presence of BOP ( F  = 10.690, P  = 0.001). There was no statistically significant difference between adolescents and adults for the means of IL-8 adjusted for BOP and plaque presence ( F  = 2.032, P  = 0.161).
Conclusions:  Within the limits of this study the differences reported in mean levels of IL-1β and IL-4 may be attributed to the different age status.     

两种普通烤瓷冠对龈沟液内酶活性及内毒素含量的影响

目的：检测钛合金与镍铬合金烤瓷冠龈沟液内酶活性及内毒素含量,了解其对龈沟液内酶活性及内毒素含量的影响。方法：选择需要制作镍铬合金和钛合金烤瓷冠的患者各30例,分别在修复前、戴临时冠1周、戴烤瓷冠1月、3月、6月提取烤瓷牙龈沟液,称其质量,检测龈沟液内AST、ALP活性及内毒素含量。结果：两种烤瓷冠龈沟液内ALP、AST活性值及内毒素值戴临时冠l周后上升,与牙体预备前比较,差异有统计学意义（P〈0．05）,钛合金组与镍铬合金组戴牙1月后龈沟液内ALP、AST活性值及内毒素值下降并趋于平缓,1个月、3个月、6个月ALP、AST活性值及内毒素值随时间延长变化无统计学差异（P〉0．05）;两组烤瓷冠龈沟液内ALP、AST活性值及内毒素值在不同时间段进一步两两比较（q检验）,镍铬组ALP、AST活性值及内毒素值高于钛合金组,差异有统计学意义（P〈0．05）。两种烤瓷冠龈沟液值比较,临时戴牙一周后突然上升,一个月之后下降并趋于平缓,与修复前无显著性差异。结论：两种普通金属烤瓷冠对龈沟内的ALP、AST活性及内毒素的量有一定的影响,但钛合金烤瓷冠较镍铬烤瓷冠影响小,两种烤瓷冠修复6月后龈沟液的量与修复前无显著性差异。     

Comparison of gingival crevicular fluid sampling methods in patients with severe chronic periodontitis

Background: The analysis of samplings from periodontal pockets is important in the diagnosis and therapy of periodontitis. In this study, three different sampling techniques were compared to determine whether one method yielded samples suitable for the reproducible and simultaneous determination of bacterial load, cytokines, neutrophil elastase, and arginine‐specific gingipains (Rgps). Rgps are an important virulence factor of Porphyromonas gingivalis, the exact concentration of which in gingival crevicular fluid (GCF) has not been quantified. Methods: GCF was sampled from four sites per patient (one sample per quadrant using two samples per method) in 36 patients with chronic periodontitis. One week later, the procedure was repeated with alternative methods. Variables determined were loads of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) and P. gingivalis, levels of interleukin‐6 and ‐8, activity of neutrophil elastase, and level of Rgps. Results: The detected cytokine levels were higher using paper strips compared to paper points. Bacteria were found in similar loads from paper strips and paper points. Rgps were only detectable in high quantities by washing the periodontal pocket. The level of Rgps correlated with the load of P. gingivalis. Conclusions: The use of paper strips was suitable for the simultaneous determination of microbial and immunologic parameters. Obtaining GCF by washing can be useful for special purposes. The gingipain concentration in periodontal pockets was directly determined to be ≤1.5 μM. This value indicated that most of the substrates of these proteases by in vitro assays identified until now can be easily degraded in P. gingivalis–infected sites.     

The pharmacokinetics of phenytoin in gingival crevicular fluid and plasma in relation to gingival overgrowth

Abstract The aim of this study was to determine whether phenytoin (PHT) could be detected in gingival crevicular fluid (GCF), and to relate its concentration to both plasma level and degree of gingival overgrowth. 23 patients medicated with phenytoin for at least 6 months were clinically examined for signs of periodontal disease and gingival overgrowth. 12 patients out of these demonstrated clinically significant overgrowth and their plaque scores and gingival inflammation were greater than for the non-overgrowth group (p<0.001). Phenytoin concentrations were determined by high performance liquid chromatography, and was detected in GCF. There was a significant correlation between the GCF and plasma phenytoin concentrations (p<0.05), but it was not related to the extent of gingival overgrowth. Inflammation increased the GCF volume, but was not a determinant of GCF phenytoin concentration. It is concluded that effusion of phenytoin into GCF is regulated by the plasma levels of the drug, but its concentration in GCF is not related to the incidence of gingival overgrowth.     

Methodological considerations in the assessment of gingival crevicular fluid volume

In 4 studies on gingival crevicular fluid volume (GCFV) determination, the reliability of measurements, influences of plaque, circadian rhythms and stability over 24 h were examined. Samples were taken at 2 sites with a modified intracrevicular method. Reliability (n=40): repeated GCFV determinations within 5 min revealed good reliability coefficients (r(tt)>0.80). Influences of supragingival plaque (n=80): repeated GCFV determinations within 5 min with plaque removal between measurements in fourty subjects, the other subjects serving as control, revealed no group differences with respect to the differences between measurements. Circadian rhythms (n=20): GCFV was assessed 6x throughout the day. Repeated measures ANOVA revealed no significant time effect. Stability over 24 h under constant clinical conditions (n=20): measures were taken at 16:00 h on 2 consecutive days, several disturbing variables were kept constant. Retest correlations revealed a low stability (i.e., high variability) of GCFV measures under constant clinical conditions (r(tt)=0.38 for tooth 11 and r(tt)= -0.25 for tooth 26). It is concluded that GCFV determination can be done with high reliability, the validity of measurements neither being affected by supragingival plaque nor by diurnal rhythms. The low stability of measurements questions the validity of GCFV for diagnostic purposes.