Aggravation of gingival inflammatory symptoms during pregnancy associated with the concentration of plasminogen activator inhibitor type 2 (PAI-2) in gingival fluid

Periodontology and pregnancy: An overview of biomedical and epidemiological evidence

Women are particularly susceptible to developing gingival problems during pregnancy. In addition, periodontal disease in pregnant women may lead to adverse outcomes for both mother and infant, which have serious clinical and public health implications. Both scenarios have been extensively researched, helping to bring attention to pregnant women as an important and vulnerable population as it concerns periodontal health. The increase in gingival inflammation caused by hormonal changes in pregnant women is undisputed and has been studied and documented since the 1960s, although the exact etiology is not fully understood. The relationship between periodontal disease during pregnancy and adverse pregnancy outcomes is less substantiated, because of conflicting evidence. This review of the biomedical and epidemiologic literature provides an overview of both sides of this relationship and examines the potential mechanisms for developing periodontal disease during pregnancy and the proposed mechanisms by which periodontal disease leads to adverse pregnancy outcomes.

PAI-2/SerpinB2 inhibits proteolytic activity in a P. gingivalis-dominated multispecies bacterial consortium

OBJECTIVE

The aim of this study was to investigate the ability of the serine protease inhibitor plasminogen activator inhibitor type 2 (PAI-2/Serpin B2) to inhibit proteases produced by a multispecies bacterial consortium in vitro.

BACKGROUND

Gingival and periodontal inflammation is associated with an increased flow of protein-rich gingival fluid. This nutritional change in the microenvironment favors bacteria with a proteolytic phenotype, triggering inflammation and associated tissue breakdown. PAI-2 is produced by macrophages and keratinocytes and is present in very high concentrations in gingival crevicular fluid; the highest level in the body.

DESIGN

A multispecies bacterial consortium comprising nine bacterial strains, resembling the conditions in a periodontal pocket, was grown planktonically and as a biofilm. After seven days PAI-2 was added to the consortium and the proteolytic activity was assayed with fluorogenic protease substrates; FITC-labeled casein to detect global protease activity, fluorescent H-Gly-Pro-AMC for serine protease activity and fluorescent BIKKAM-10 for Porphyromonas gingivalis-associated protease activity. Protease activity associated with biofilm cells was examined by confocal scanning laser microscopy.

RESULTS

PAI-2 inhibited proteolytic activity of the bacterial consortium, as seen by decreased fluorescence of all substrates. PAI-2 specifically inhibited P. gingivalis proteolytic activity.

CONCLUSION

To our knowledge, this is the first time that PAI-2 has been shown to inhibit bacterial proteases. Given the high concentration of PAI-2 in the gingival region, our results indicate that PAI-2 might play a role for the integrity of the epithelial barrier.

Biofilm community diversity after exposure to 0·4% stannous fluoride gels

AIMS

To test the effect of 0·4% stannous fluoride (SnF2 ) glycerine-based gels on specific portions of the bacterial community in both a clinical observational study and in vitro multispecies plaque-derived (MSPD) biofilm model.

METHODS AND RESULTS

Potential changes to specific portions of the bacterial community were determined through the Human Oral Microbial Identification Microarray (HOMIM). Both the observational clinical study and the biofilm model showed that short-term use of 0·4% SnF2 gel has little effect on the bacterial community depicted by hierarchical cluster analysis. The amount of plaque accumulation on a subject's teeth, which was measured by plaque index scores, failed to show statistical significant changes over the two baselines or after treatment (P = 0·9928). The in vitro results were similar when examining the effect of 0·4% SnF2 gels on biofilm adherence through a crystal violet assay (P = 0·1157).

CONCLUSIONS

The bacteria within the dental biofilms showed resilience in maintaining the overall community diversity after exposure to 0·4% SnF2 topical gels.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study supports that the immediate benefits of using 0·4% SnF2 gels in children may be strictly from fluoride ions inhibiting tooth demineralization rather than delivering substantial antimicrobial effects.

Evaluation of gingival crevicular fluid levels of tissue plasminogen activator, plasminogen activator inhibitor 2, matrix metalloproteinase-3 and interleukin 1-β in patients with different periodontal diseases

OBJECTIVES

The purpose of this study was to evaluate the gingival crevicular fluid levels of interleukin-1beta (IL-1β), matrix metalloproteinases-3 (MMP-3), tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor 2 (PAI-2) in patients with chronic periodontitis, aggressive periodontitis (AgP) and healthy individuals (controls).

MATERIAL AND METHODS

Systemically healthy (21 chronic periodontitis, 23 AgP and 20 controls) subjects were included in this study. Plaque index, gingival index, probing pocket depth and clinical attachment level were recorded and gingival crevicular fluid samples were collected. Assays for IL-1β, MMP-3, t-PA and PAI-2 levels in gingival crevicular fluid were carried out by an enzyme-linked immunosorbent assay. The one-sample Kolmogorov-Smirnov test, Mann-Whitney U test and Spearman correlation coefficient were used for data analyses.

RESULTS

Gingival crevicular fluid levels of t-PA and IL-1β were significantly higher in chronic periodontitis and AgP groups than in the control group (p < 0.001). MMP-3 levels in gingival crevicular fluid were detected as significantly higher in the chronic periodontitis and AgP groups compared with the control group (p < 0.05). The t-PA/PAI-2 rate of patients with chronic periodontitis and AgP were significantly higher than the control group (p < 0.05). The positive correlations were found among the PAI-2, t-PA, IL-1β and MMP-3 levels in gingival crevicular fluid. The volume of the gingival crevicular fluid correlated with all of the clinical parameters (p < 0.001). There were positive correlations between the gingival crevicular fluid levels of PAI-2 and the probing pocket depth and between gingival crevicular fluid levels of PAI-2 and the clinical attachment level (p < 0.01). Similarly, significant correlations were found between t-PA levels and probing pocket depth and between t-PA levels and clinical attachment level measurements (p < 0.001).

CONCLUSION

The present data showed that gingival crevicular fluid levels of IL-1 β, MMP-3 and t-PA increased in periodontal disease regardless of the periodontitis type and played a part in tissue destruction.

Oral health education and therapy reduces gingivitis during pregnancy

BACKGROUND

Pregnant women demonstrate increases in gingivitis despite similar plaque levels to non-pregnant counterparts.

AIM

To evaluate an intensive protocol aimed at reducing gingivitis in pregnant women and provide pilot data for large-scale randomized controlled trials investigating oral hygiene measures to reduce pregnancy gingivitis and alter maternity outcomes.

MATERIALS AND METHODS

One hundred and twenty participants between 16 and 24 weeks gestation with Gingival Index (GI) scores ≥2 at ≥50% of tooth sites were enrolled. Plaque index (PI), gingival inflammation (GI), probing depth (PD), and clinical attachment levels (CAL) were recorded at baseline and 8 weeks. Dental prophylaxis was performed at baseline and oral hygiene instructions at baseline, 4 and 8 weeks. Pregnancy outcomes were recorded at parturition. Mixed-model analysis of variance was used to compare clinical measurements at baseline and 8 weeks.

RESULTS

Statistically significant reductions in PI, GI, PD, and CAL occurred over the study period. Mean whole mouth PI and GI scores decreased approximately 50% and the percentage of sites with PI and GI ≥2 decreased from 40% to 17% and 53% to 21.8%, respectively. Mean decreases in whole mouth PD and CAL of 0.45 and 0.24 mm, respectively, were seen.

CONCLUSIONS

Intensive oral hygiene regimen decreased gingivitis in pregnant patients.

Effect of pregnancy on gingival inflammation in systemically healthy women: a systematic review

AIM

To obtain an overall quantitative estimate of the association between pregnancy and gingival inflammation.

MATERIAL AND METHODS

Medline and EMBASE databases were searched through August 2011. Prospective cohort or cross-sectional studies assessing the effect of pregnancy on gingival inflammation evaluated by the gingival index (GI) and/or bleeding on probing were included. Meta-analyses were performed if possible.

RESULTS

Forty-four articles representing 33 studies (14 cohort and 19 cross-sectional) were included. Meta-analyses, performed whenever possible, revealed (1) a significantly lower GI in pregnant women in the first term compared with those in their second or third term of pregnancy; (2) a lower mean GI score in post-partum women compared with women in their second [WMD = 0.143; 95% CI (0.031; 0.255); p = 0.012] or third term [WMD = 0.256; 95% CI (0.151; 0.360); p < 0.001] of pregnancy, when considering cohort studies; (3) Non-pregnant women had lower mean GI values than women in their second or third term of pregnancy. Small changes in plaque levels were reported.

CONCLUSION

Despite the limited number of studies included in the meta-analyses, the present systematic review confirms the existence of a significant increase in GI throughout pregnancy and between pregnant versus post-partum or non-pregnant women, without a concomitant increase in plaque levels.

Gingival crevicular fluid IL-6, tPA, PAI-2, albumin levels following initial periodontal treatment in chronic periodontitis patients with or without type 2 diabetes

OBJECTIVES

To evaluate initial periodontal treatment effects on gingival crevicular fluid (GCF) interleukin-6 (IL-6), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-2 (PAI-2), albumin levels in type 2 diabetic patients.

DESIGN AND METHODS

GCF samples were collected from 20 type 2 diabetic, 22 non-diabetic non-smokers all with chronic periodontitis at baseline, 1-, 3-months following initial periodontal treatment. Biochemical analysis was performed by ELISA. Data were tested by Mann-Whitney U, Wilcoxon tests.

RESULTS

The total amounts of albumin, IL-6, tPA, PAI-2 decreased significantly in diabetics after treatment (1- and 3-months) whereas, only PAI-2 decreased in non-diabetic group at 3-months (p < 0.05). There were statistically significant differences between the diabetics and non-diabetics at all time points for albumin, PAI-2 and at 1-, 3-months for GCF volume (p < 0.050) but only at baseline for IL-6 (p < 0.050).

CONCLUSION

Present data suggest clinical improvements are less apparent in diabetic chronic periodontitis patients as reflected by disease markers in GCF and by an increase in concentrations of inflammatory proteins IL-6, tPA, and PAI-2 in GCF of this patient group following initial periodontal treatment.

Perioperative management of the female and gravid patient

Care of female and gravid patients requires a detailed understanding of the unique issues inherent to quality treatment. Increasingly important data continue to accumulate about significant differences in the physiology of men and women and the way they express disease. Furthermore, the gravid patient requires specific alterations and considerations in clinical care that not only affect the mother but also the fetus. This article focuses on key elements that the treating surgeon should consider.

Gingival crevicular fluid PGE2, IL-1beta, t-PA, PAI-2 levels in type 2 diabetes and relationship with periodontal disease

OBJECTIVES

To evaluate if type 2 diabetes mellitus increase gingival crevicular fluid (GCF) levels of prostaglandin E(2) (PGE(2)), interleukin-1beta (IL-1beta), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-2 (PAI-2).

DESIGN AND METHODS

Seventeen type 2 diabetic patients with periodontal disease (DM), 17 otherwise healthy periodontally diseased patients (PD) and 17 systemically and periodontally healthy control subjects (H) were enrolled. Clinical periodontal measurements were recorded at six sites/tooth. GCF samples were analyzed by ELISA. Data were tested by statistical tests.

RESULTS

DM group revealed lower IL-1beta levels than PD group (p<0.01). PGE(2), t-PA and PAI-2 levels were similar in DM and PD groups (p>0.05). PGE(2), t-PA levels were higher in DM and PD groups than H group (p<0.05). PAI-2 level was higher in DM group than H group (p<0.05). GCF total amount of PGE(2) in DM group exhibited significant correlations with all clinical periodontal measurements (p<0.05).

CONCLUSION

Type 2 diabetes in this study seems not to increase GCF levels of the evaluated inflammatory mediators.

Associations between peri-implant crevicular fluid volume, concentrations of crevicular inflammatory mediators, and composite IL-1A ?889 and IL-1B +3954 genotype: A cross-sectional study on implant recall patients with and without clinical signs of peri-implantitis

OBJECTIVES

To assess possible relationships between peri-implant crevicular fluid (PICF) volumes, biochemical markers of the peri-implant immune response, and periodontitis-associated genotype.

MATERIAL AND METHODS

PICF samples from 29 implant maintenance patients, 24 wearing overdentures, five having single crowns and bridgework (11 patients with peri-implantitis and 18 individuals with healthy peri-implant conditions), were analyzed for per site and per crevicular-fluid-volume concentrations of interleukin-1beta, plasminogen activator inhibitor type 2, and prostaglandin E2 by ELISA. Associations between the three substance concentrations and to crevicular fluid flow rate were analyzed by linear regression analysis. The possible differentiating influence of the composite interleukin-1A and -1B genotype on the patients' peri-implant health and biochemical inflammatory status was checked formally with t-test statistics and the Wilcoxon' test. One implant per patient was chosen for analysis.

RESULTS

In patients with healthy peri-implant conditions, genotype-positive individuals showed elevated crevicular fluid flow rates and at the same time reduced mediator concentrations. In patients with an implant affected from peri-implantitis, no statistically significant influence of the periodontitis-associated genotype around the fixture can be stated. There was no statistical difference between per site and per crevicular-fluid-volume concentration analyses. All three mediator concentrations were positively related to each other, while there was a strong negative correlation between crevicular fluid volume and plasminogen activator inhibitor 2 or prostaglandin E2.

CONCLUSIONS

The Interleukin-1 polymorphism investigated exerted only little influence on the peri-implant crevicular immune response, and this influence appeared to be of limited impact in sites with established peri-implantitis lesions.

Signal transduction pathways involved in the stimulation of tissue type plasminogen activator by interleukin-1alpha and Porphyromonas gingivalis in human osteosarcoma cells

BACKGROUND

Recently, evidences have shown that tissue type plasminogen activator (t-PA) may play an important role in the pathogenesis of periodontal diseases. However, the mechanisms and signal transduction pathways involved in the production of t-PA in human osteosarcoma cells are not fully understood.

OBJECTIVES

The purpose of this study was to investigate the caseinolytic activity in human osteosarcoma cell line U2OS cells stimulated with interleukin-1alpha (IL-1alpha) or Porphyromonas gingivalis in the absence or presence of p38 inhibitor SB203580, mitogen-activated protein kinase kinase (MEK) inhibitor U0126, and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002.

METHODS

IL-1alpha and the supernatants of P. gingivalis were used to evaluate the caseinolytic activity in U2OS cells by using casein zymography and enzyme-linked immunosorbent assay (ELISA). Furthermore, to search possible signal transduction pathways, SB203580, U0126, and LY294002 were added to test how they modulated the caseinolytic activity.

RESULTS

Casein zymography exhibited a caseinolytic band with a molecular weight of approximately 70 kDa, suggestive of the presence of t-PA. Secretion of t-PA was found to be stimulated with IL-1alpha and P. gingivalis during a 2-day culture period (p < 0.05). From the results of casein zymography and ELISA, SB203580, U0126, and LY294002 significantly reduced the IL-1alpha or P. gingivalis-stimulated t-PA production, respectively (p < 0.05).

CONCLUSIONS

Our findings demonstrated that IL-1alpha and P. gingivalis enhance t-PA production in human osteosarcoma cells, and that the signal transduction pathways p38, MEK, and PI3K are involved in the inhibition of t-PA. SB203580, U0126, and LY294002 suppress t-PA production and/or activity and may therefore be valuable therapeutics in t-PA-mediated periodontal destruction, and might be proved clinically useful agents, in combination with standard treatment modalities, in the treatment of periodontitis.

Evaluation of t-PA, PAI-2, IL-1βand PGE2in gingival crevicular fluid of rheumatoid arthritis patients with periodontal disease

AIMS

This study was undertaken to compare periodontal conditions, gingival crevicular fluid (GCF) levels of tissue-type plasminogen activator (t-PA), its inhibitor plasminogen activator inhibitor-2 (PAI-2), interleukin-1beta (IL-1beta), prostaglandin E(2) (PGE(2)) in rheumatoid arthritis (RA) patients and control groups.

METHODS

Twenty-three RA patients, 17 systemically healthy patients with periodontal disease (PD), and 17 systemically and periodontally healthy subjects were recruited. GCF samples were obtained from two single-rooted teeth. Full-mouth clinical periodontal measurements were recorded at six sites/tooth. GCF samples were analysed using relevant ELISA kits. Data were tested statistically by appropriate tests.

RESULTS

Total amounts of t-PA, PAI-2 and PGE(2) in GCF samples of the healthy control group were significantly lower than the other groups (p<0.05). The RA group exhibited a higher total amount of t-PA in GCF samples than the PD group (p<0.05). PAI-2, IL-1beta and PGE(2) total amounts were similar in RA and PD groups (p>0.05).

CONCLUSION

The coexistence of RA and periodontitis does not seem to affect clinical periodontal findings or systemic markers of RA. Similar inflammatory mediator levels in RA and PD groups, despite the long-term usage of corticosteroids, non-steroidal anti-inflammatory drugs, suggest that RA patients may have a propensity to overproduce these inflammatory mediators.

A clinical study of plasminogen activator activity in gingival tissue in dogs with gingivitis and periodontitis

The aim of the present study was to evaluate plasminogen activator activity (PAA), tissue-type plasminogen activator (t-PA) antigen level and plasminogen activator inhibitor-1 (PAI-1) antigen in normal canine gingival tissue samples, gingivitis as well as in different stages of periodontal disease. Gingival tissue from 141 adult dogs were analysed spectrophotometrically in order to determine PAA. The tissues were also examined histopathologically. The Sulcus Bleeding Index was used to evaluate the active and inactive phase of periodontal disease. T-PA antigen as well as PAI-1 antigen level was measured by ELISA. There was a significant increase of PAA and t-PA antigen in samples from inflamed gingival tissue compared with normal gingival tissue, while PAI-1 antigen was not detected in either normal or inflamed gingiva. As the severity of periodontal disease was increasing, PAA and t-PA antigen values were significantly higher in periodontitis tissue sample groups, according to the pattern: gingivitis<early periodontitis<moderate periodontitis<severe periodontitis (P<0.001). PAA and t-PA antigen were increased in samples from the inflamed gingival tissue with higher Bleeding Index, (heavy bleeding>moderate bleeding>slight bleeding, P<0.001). In conclusion, this study indicates that PAA and t-PA antigen level may be used to evaluate the evolution of periodontal disease in dog.

Plasminogen activator system in smokers and non-smokers with and without periodontal disease

BACKGROUND

The present study assessed levels of plasminogen activator (PA) system proteins in gingival crevicular fluid (GCF) and serum of chronic gingivitis, chronic periodontitis patients and periodontally healthy subjects and evaluated how smoking influenced these levels.

METHODS

Twenty chronic gingivitis; 20 chronic periodontitis patients and 20 periodontally healthy volunteers were consecutively recruited according to the inclusion criteria so that exactly half of the subjects in each category were smokers. GCF samples from four sites together with serum samples were obtained from each subject. GCF levels of tissue type PA (t-PA), urokinase type PA (u-PA), PA inhibitor-1 (PAI-1) and PA inhibitor-2 (PAI-2) and serum concentrations of cotinine, u-PA and PAI-1 were analysed by enzyme-linked immunosorbent assay.

RESULTS

The only statistically significant difference between smokers and non-smokers was a lower GCF PAI-2 concentrations in healthy smokers compared with healthy non-smokers (p<0.01). Gingivitis and periodontitis patients had higher GCF concentrations of PAI-2 than healthy subjects (p<0.002 and p<0.02 respectively). The ratio of u-PA:PAI-1 and t-PA:PAI-1 were significantly higher in GCF of smokers with periodontitis compared with "healthy" smokers, whereas the ratio of t-PA:PAI-2 was significantly lower in smokers with periodontal disease (p<0.05).

CONCLUSIONS

GCF levels of the PA system proteins are increased in chronic gingivitis and periodontitis compared with healthy gingiva. Smoking had only subtle effects on the GCF PA system proteins with the exception of PAI-2, and the balance of activators and inhibitors. These findings suggest one mechanism whereby smoking may exert detrimental effects on the periodontal tissues.

Plasminogen activators and plasminogen activator inhibitors in gingival crevicular fluid of cyclosporin A-treated patients

BACKGROUND

The plasminogen activator (PA) system plays many roles in the inflammatory process and tissue remodelling and repair and is considered to play a significant role in periodontal tissue destruction and healing. The aim of this study was to evaluate the role of the PA system in cyclosporin A (CsA)-induced gingival overgrowth in renal transplant patients.

METHODS

Eighteen renal transplant patients exhibiting moderate to severe CsA-induced gingival overgrowth, 10 other renal transplant patients receiving CsA therapy but showing no sign of CsA-induced gingival overgrowth (CsA-H), 16 chronic gingivitis patients (CG) and 16 systemically and periodontally healthy control subjects (H) were included in the study. Gingival crevicular fluid (GCF) samples were obtained from four randomly selected sites in each subject with the exception of the CsA-induced gingival overgrowth group, where four GCF samples were harvested from sites with severe overgrowth (CsA GO+) and from four sites without any gingival overgrowth (CsA GO-). The GCF levels of albumin, tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) were analysed by enzyme-linked immunosorbent assay. The results were tested for statistical differences.

RESULTS

In CsA GO+ sites t-PA levels were significantly elevated in comparison with gingivitis and healthy sites, while PAI-2 levels in these sites showed statistically significant differences only with CsA-H and gingivitis sites (p<0.05). The levels of t-PA and PAI-2 were significantly higher in CsA GO- sites compared with those of CsA-H, gingivitis and healthy sites (p<0.05). The levels of u-PA and PAI-1 failed to show significant differences between the study groups.

CONCLUSIONS

The findings of the present study indicate alterations in GCF t-PA and PAI-2 levels in CsA-induced gingival overgrowth and might suggest involvement of the plasminogen activating system in the pathogenesis of this side-effect of CsA therapy. However, to what extent these molecules contribute to the pathogenesis of CsA-induced gingival overgrowth remains to be determined.

The Effect of Menstrual Cycle on Periodontal Health

BACKGROUND

Fluctuation in estrogen/progesterone levels has been shown to affect the periodontium. The effects of pregnancy, prepuberty, and oral contraceptives on gingival health has been studied extensively, with gingival scores reported to be higher, in most instances, than in controls. Fluctuation in steroid sex hormone is also noticeable through women's menstrual cycle. Many women report an increase in gingival inflammation and discomfort associated with their menstrual cycle, most commonly around the menses period. However, this well-known phenomenon has never been studied. The purpose of this longitudinal, prospective study was to compare the periodontal status of premenopausal women at different times during their menstrual cycle.

METHODS

Eighteen premenopausal women, enrolled in our maintenance program, were recruited. Clinical examination was performed before the recall visit at three different time points in their menstrual cycle: ovulation (OV), premenstruation (PM), and menstruation (M). Plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were examined around the Ramfjord index teeth. Analysis of variance, with Scheffe modification, was used to determine differences between the menstrual time points.

RESULTS

Several women in this study reported appreciable oral symptoms just before or during menses. Mean PI (0.85 +/- 0.06) was almost identical at all time points. Despite this, GI was significantly higher (P = 0.0245) in OV (0.54 +/- 0.07) and in PM (0.5 +/- 0.08) than in M (0.38 +/- 0.07). Mean patient's PD (2.22 +/- 0.08 mm) and CAL (2.92 +/- 0.15 mm) was not significantly different between examinations.

CONCLUSIONS

We observed changes in gingival scores during the menstrual cycles of periodontally healthy women. These changes need to be addressed when analyzing data from epidemiological and treatment studies in premenopausal women.

Common oral manifestations during pregnancy: a review

Pregnancy has far-reaching systemic effects extending beyond the reproductive system. Oral and masticatory changes during pregnancy have been documented for many years; however, their magnitude and frequency have not been stressed. This review highlights the major oral complications during pregnancy. Pregnancy gingivitis and pregnancy tumor are described and presented, and possible preventive strategies are suggested.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to summarize the major oral complications during pregnancy, to outline the etiologic factors associated with each of these conditions, and to explain the role of dental treatment during pregnancy.

The periodontal status of pregnant women and its relationship with socio-demographic and clinical variables

The aims of this study were to assess the periodontal health and oral hygiene status of pregnant women and non-pregnant controls and to evaluate the effect of socio-demographic and other variables on such periodontal status. A total of 400 women, of whom 200 were pregnant (mean age=30 years, s.e.m.=0.05) and 200 non-pregnant controls (mean age=32 years, s.e.m.=0.05) were chosen at random from four health centres. The clinical parameters used were the Silness and Loe plaque index (Pl.I), Loe and Silness gingival index (GI), probing pocket depth (PPD), probing attachment level (PAL), any relationship to socio-demographic (age, level of education and professional level) and clinical variables (gestation period, previous pregnancy and vomiting during pregnancy) was evaluated. The results showed that pregnant women had significantly higher GI and PPD scores (P < 0.005) but with no statistically significant differences in PAL or Pl.I (P > 0.01) compared with non-pregnant controls. Increased age, lower level of education and non-employment were associated with significantly higher GI and PPD scores (P < 0.01). All these clinical parameters increased in parallel with the increase in the stage of pregnancy, reaching their maximum at the eighth month. Women with previous or multiple pregnancy had statistically significantly higher GI and PPD scores than those who were pregnant for the first time (P < 0.01), but with no statistically significant differences in Pl.I or PAL scores (P > 0.05). Also, women who vomited during pregnancy had significantly higher GI and PPD scores compared with those who did not vomit (P < 0.05). It is concluded that gingival inflammatory symptoms are aggravated during pregnancy and are related to increased age, lower level of education and non-employment. Therefore periodontal preventive programmes are very important for pregnant women.

Effect of pregnancy on periodontal and dental health

Clinical studies have shown that oral tissues can be affected by pregnancy. Pregnancy-related changes are most frequent and most marked in gingival tissue. Pregnancy does not cause gingivitis, but may aggravate pre-existing disease. The most marked changes are seen in gingival vasculature. Characteristic of pregnancy gingivitis is that the gingiva is dark red, swollen, smooth and bleeds easily. Women with pregnancy gingivitis may sometimes develop localized gingival enlargements. The gingival changes usually resolve within a few months of delivery if local irritants are eliminated. The inflammatory changes are usually restricted to the gingiva and probably do not cause permanent changes in periodontal tissues more often than those in the non-pregnant state. Although it is widely believed that pregnancy is harmful to the teeth, the effect of pregnancy on the initiation or progression of caries is not clear. Previous studies, however, indicate that the teeth do not soften, i.e. no significant withdrawal of calcium or other minerals occurs in the teeth. It is mainly the environment of the tooth that is affected. The number of certain salivary cariogenic microorganisms may increase in pregnancy, concurrently with a decrease in salivary pH and buffer effect. Changes in salivary composition in late pregnancy and during lactation may temporarily predispose to dental caries and erosion. Although their underlying mechanisms of action are not fully understood, pregnancy-related changes in the oral environment may have some untoward temporary or permanent effects on oral health. Most of these effects could be avoided by practising good oral hygiene.

The plasminogen activating system in periodontal health and disease

The plasminogen activating system is important for extracellular proteolysis and plays a regulatory role in interactions with other tissue degrading systems. Studies on the plasminogen activating system in gingival crevicular fluid (GCF) as well as gingival tissue are reviewed. t-PA, u-PA, PAI-1 and PAI-2 have all been detected in GCF. Especially t-PA and PAI-2 are found in high concentrations. In tissue studies fibrinolytic activity has been found in the gingival pocket epithelium in humans and in animal studies. t-PA and PAI-2 have been detected there immunohistochemically. Local production of the PAs and PAls has been verified with in situ hybridization. In inflammation, a more intense and widespread immunohistochemical staining of t-PA and PAI-2 is seen. Higher concentrations of t-PA and PAI-2 are found in GCF but the balance between them seems to be constant. A systemically disturbed balance of the plasminogen activating system in GCF has been observed during pregnancy, with a possible protective function of PAI-2. In studies of periodontitis, the production of PAI-2 seemed to be locally lowered at impaired sites. In a study of children, a higher inflammatory response to bacterial plaque was accompanied by a higher fibrinolytic ativity in GCF samples. Bacterial LPS has been found to change the ratio of t-PA to PAI-2 in cultured gingival fibroblasts. Interactions between PAI-2 and a protease in the gingival epithelium has been verified through the immunohistochemical detection of relaxed PAI-2.

Localization of plasminogen activators and plasminogen-activator inhibitors in human gingival tissues demonstrated by immunohistochemistry and in situ hybridization

The plasminogen-activating system plays an important part in tissue proteolysis in physiological as well as pathological processes. Plasminogen activators u-PA (urokinase) and t-PA (tissue) as well as the inhibitors PAI-1 and PAI-2 are present in gingival crevicular fluid in concentrations significantly greater than in plasma. This fact, and the finding that the concentrations of t-PA and PAI-2 are higher in areas with gingival inflammation, indicate local production of these components. The present study describes, by means of in situ hybridization and immunohistochemistry, the localization of the plasminogen activators and their inhibitors in gingival tissues from patients undergoing periodontal surgery. t-PA mRNA and t-PA antigen were primarily found in the epithelial tissues, predominantly in the sulcular and junctional regions, although occasionally in the oral epithelium and in blood vessels of the connective tissue. u-PA and u-PA-receptor signals were seen in single cells within the junctional and sulcular epithelia and adjacent to blood vessels close to the junctional epithelium, but rarely in the oral epithelium. Similar to t-PA, the predominant location of PAI-2 mRNA was the gingival epithelia. In the junctional and sulcular epithelia, PAI-2 mRNA was seen throughout the thickness, while in the oral epithelium the strongest signals were seen in stratum granulosum and stratum spinosum. PAI-1 mRNA was invariably found in the connective tissue associated with blood vessels. The present study confirms earlier indications of local production of plasminogen activators and their inhibitors in gingival tissues. In addition, the results demonstrate that t-PA and PAI-2 in these patients are produced predominantly in the epithelial tissues. Furthermore, the presence of t-PA and PAI-2 seems to be most pronounced in the areas likely to be subjected to bacterial assault.

Immunohistochemical demonstration of the plasminogen activator system in human gingival tissues and gingival fibroblasts

The relative distribution of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2) was studied in cultured human gingival fibroblasts, healthy gingival tissues and inflamed gingival tissues by immunohistochemistry. In cultured gingival fibroblasts t-PA, u-PA and PAI-1 were expressed in cytoplasm; u-PA and PAI-1 were more intensely stained than t-PA; PAI-2 was not detectable in gingival fibroblasts. Following interleukin 1 beta (IL-1 beta) stimulation, the intensity of intracellular staining for t-PA was increased and a number of cells staining strongly for PAI-2 were seen; no difference in the intensity of immunostaining level was noted for the expression of u-PA and PAI-1 between IL-1 beta stimulated cells and unstimulated cells. In healthy gingival tissues, u-PA and PAI-1 displayed a wide distribution throughout all the connective tissue and epithelium; t-PA localized mainly in the connective tissue while PAI-2 showed little association with the connective tissue but did faintly stain in the epithelial layer. In inflamed gingival tissues, staining for t-PA was significantly increased in the extracellular matrix of the connective tissue, whereas staining for u-PA, PAI-1 and PAI-2 was found to be slightly increased, but no significant difference was noted for staining when compared with the healthy gingival tissues. A granular distribution of t-PA, u-PA, PAI-1 and PAI-2 was noted around areas of inflammatory cell infiltration. These immunohistochemical findings indicate that the plasminogen activator system produced by fibroblasts may be influenced by the presence of the inflammatory mediator IL-1 beta. In addition, the significant increase of t-PA in inflamed connective tissue and the wide expression of these components around inflamed cells may contribute to connective tissue degradation and may relate to the migration and localization of monocytes/macrophages in inflamed tissue.