Relationship between levels of aspartate aminotransferase in gingival crevicular fluid and gingival inflammation

Periodontal disease and emerging point-of-care technologies for its diagnosis

Periodontal disease (PD), a chronic inflammatory disorder that damages the tooth and its supporting components, is a common global oral health problem. Understanding the intricacies of these disorders, from gingivitis to severe PD, is critical for efficient treatment, diagnosis, and prevention in dental care. Periodontal biosensors and biomarkers are critical in improving oral health diagnostic skills. Clinicians may accomplish early identification, tailored therapy, and efficient tracking of periodontal diseases by using these technologies, ushering in a new age of accurate oral healthcare. Traditional periodontitis diagnostic methods frequently rely on physical probing and visual examinations, necessitating the development of point-of-care (POC) devices. As periodontal disorders necessitate more precise and rapid diagnosis, incorporating novel innovations in biosensors and biomarkers becomes increasingly crucial. These innovations improve our capacity to diagnose, monitor, and adapt periodontal therapies, bringing in the next phase of customized and effective dental healthcare. The review discusses the characteristics and stages of PD, clinical treatment techniques, prominent biomarkers and infection-associated factors that may be employed to determine PD, biomedical sensing, and POC appliances that have been created so far to diagnose stages of PD and its progression profile, as well as predicting future developments in this field.

Hepatitis C Infection and Periodontal Disease: Is there a Common Immunological Link?

Hepatitis C virus (HCV) infections could have an important impact on the oral health status of patients, favoring conditions such as periodontal disease and oral cancer. The review of the existing scientific literature written in English was performed, searching for oral and periodontal manifestations of HCV infection and its impact on the oral fluids. HCV infection can determine direct extrahepatic manifestations at the oral and periodontal level including oral lichen planus, Sjögren-like sialadenitis, and oral cancer. The changes caused by the infection in the subjects' immune system, diet, and lifestyle can facilitate the development of oral conditions such as periodontal disease. Important changes also occur in the composition of the infected patients' saliva and gingival fluid. HCV-infected patients need to be carefully monitored in terms of oral health since the infection with the virus can result in oral complications. The cellular and molecular particularities of the gingival fluid of HCV-infected patients can answer some questions regarding its impact upon periodontium impairment and whether this refers to a possible bidirectional relationship, with hepatic biomarker adjustments being induced by the periodontal patients' inflammatory status.

To estimate salivary aspartate aminotransferase levels in chronic gingivitis and chronic periodontitis patients prior to and following non-surgical periodontal therapy: A clinico-biochemical study

Context:

Saliva can be used as a diagnostic fluid in dentistry. Various enzymes have been proposed as markers for periodontal destruction. One of them is aspartate aminotransferase, for which salivary analysis can offer a cost-effective approach for monitoring the disease. Changes in enzymatic activity reflect metabolic changes in the gingiva and periodontium in inflammation.

Aims:

The purpose of this study was to assess the aspartate aminotransferase levels in saliva prior to and following scaling and root planning (SRP) at 1 month and 3 month interval and correlating it with the clinical parameters in generalized chronic gingivitis and chronic periodontitis patients.

Materials and Methods:

Thirty patients with generalized chronic gingivitis and 30 with generalized chronic periodontitis were selected. The activity of aspartate aminotransferase levels in saliva were assessed biochemically before and after SRP at 1 month and 3 months. The aspartate aminotransferase levels were correlated with clinical parameters (gingival index and probing depth).

Statistical Analysis Used:

A paired t test was done.

Results:

A decrease in gingival index, probing depth, and aspartate aminotransferase levels were seen in both the groups at 1 and 3 months which was found to be statistically highly significant (P value 0.00). Aspartate aminotransferase levels were statistically significantly correlated with the clinical parameters at baseline (P < 0.05) but at 3 months, a positive correlation was seen in both the groups which was statistically insignificant (P > 0.05).

Conclusions:

Elevated salivary aspartate aminotransferase levels were seen in generalized chronic gingivitis and chronic periodontitis patients, with higher values recorded in generalized chronic periodontitis correlating to the tissue destruction taking place in these conditions.

Periodontal proteomics: wonders never cease!

Proteins are vital parts of living organisms, as they are integral components of the physiological metabolic pathways of cells. Periodontal tissues comprise multicompartmental groups of interacting cells and matrices that provide continuous support, attachment, proprioception, and physical protection for the teeth. The proteome map, that is, complete catalogue of the matrix and cellular proteins expressed in alveolar bone, cementum, periodontal ligament, and gingiva, is to be explored for more in-depth understanding of periodontium. The ongoing research to understand the signalling pathways that allow cells to divide, differentiate, and die in controlled manner has brought us to the era of proteomics. Proteomics is defined as the study of all proteins including their relative abundance, distribution, posttranslational modifications, functions, and interactions with other macromolecules, in a given cell or organism within a given environment and at a specific stage in the cell cycle. Its application to periodontal science can be used to monitor health status, disease onset, treatment response, and outcome. Proteomics can offer answers to critical, unresolved questions such as the biological basis for the heterogeneity in gingival, alveolar bone, and cemental cell populations.

Presence of Aspartate Aminotransferase in Peri-Implant Crevicular Fluid With and Without Mucositis

The aim of this study was to assess the presence of aspartate aminotransferase (AST) in peri-implant crevicular fluid, with or without clinical signs of mucositis, to determine its predictive diagnostic value, sensitivity, and specificity. The AST levels were determined (at a threshold of 1200 µIU/mL) for 60 clinically successful implants in 25 patients with or without peri-implant mucositis. Samples were taken prior (AST1) to peri-implant probing with a manual constant-pressure probe (0.2 N) and 15 minutes after probing (AST2). Clinical assessments included radiographic determination of preexisting bone loss, probing, and the evaluation of mucositis, plaque, and bleeding upon probing. Analysis was performed at both the level of the implant and the patient as a unit. We detected a significant difference between AST1 and AST2 at both levels. A significant difference was observed at AST1 between implants that bled upon probing and those that did not. However, when we considered the patient as a unit, there were no significant differences. The plaque index was not significant at either level. AST1 had high specificity and positive predictive diagnostic value (80%) for bleeding upon probing. Probing induces a greater release of AST from inflamed tissues compared with healthy tissues in situ but not at the systemic level. At the implant level, the implant position could be responsible for this difference. Aspartate aminotransferase was a reliable predictor of patients with mucositis.

Analysis of aspartate aminotransferase in gingival crevicular fluid: A study with initial therapy

Background and Objectives:

Conventional diagnostic indicators cannot distinguish between disease activity and inactivity but can detect the past tissue destruction. A proper and true periodontal diagnosis is essential in order to have a rational treatment and preventive strategy and to identify sites at risk. The present longitudinal study was designed with an aim to examine the relationship between gingival crevicular fluid (GCF) levels of aspartate aminotransferase (AST) and periodontal disease progression and to analyze the level of AST in GCF before and after the initial therapy in chronic periodontitis patients and determine the relationship between AST and conventional measures of periodontal status.

Materials and Methods:

A total of 20 patients with chronic periodontitis were randomly selected. Two diseased sites and one healthy site were selected in each patient. The periodontal status and GCF-AST levels were recorded at baseline and 3 months post-initial therapy and statistically analyzed.

Results:

There was a statistically significant difference in AST levels between diseased periodontal sites and healthy sites (P<0.05), and between baseline and post-initial therapy (P<0.05). Improvements in clinical status were noted following periodontal therapy and there was a corresponding decrease in AST levels.

Interpretation and Conclusion:

In conclusion, it is suggested that AST levels may be a useful adjunct in the clinical assessment of periodontal disease sites since AST level decreases when periodontal status improves.

Screening for periodontitis in pregnant women with salivary enzymes

AIM

To develop a test for the screening of pregnant women for periodontitis using saliva prior to a dental examination.

METHODS

A cross-sectional research design was employed. Whole unstimulated saliva was collected from 221 pregnant women prior to a dental examination at the Amagasaki Public Health Office and levels of activity of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP), and of occult blood in the saliva were measured. The data were compared with Community Periodontal Index of Treatment Needs (CPITN) scores. The diagnostic performance of LDH, ALP, and occult blood was determined in terms of sensitivity, specificity, and the area under receiver operating characteristics (ROC) curves. The optimal combination of parameters for screening periodontitis was determined at maximum sensitivity and specificity.

RESULTS

Periodontitis (CPITN 3, 4) in 19 women (8.6%) and gingivitis (CPITN 1, 2) in 129 women (58.4%) were observed. The activity levels of LDH and ALP were significantly higher in the pregnant women with periodontitis than those with gingivitis or a healthy periodontium. To distinguish between the pregnant women with periodontitis and the others, a cut-off value of 684 IU/L for LDH and of 75 IU/L for ALP were determined by a ROC analysis. The test combining LDH, ALP, and occult blood showed the highest diagnostic performance; with a sensitivity value of 0.90, specificity value of 0.62, positive predictive value of 0.18, and negative predictive value of 0.98.

CONCLUSIONS

A test combining the parameters salivary LDH, ALP and occult blood is useful for screening pregnant women for periodontitis.

Analysis of Aspartate Aminotransferase and Alkaline Phosphatase in Crevicular Fluid From Implants With and Without Peri-implantitis

PURPOSE

The aim of this investigation was to determine the presence of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in crevicular fluid collected from implants with and without clinical and radiographic signs of peri-implantitis.

MATERIALS AND METHODS

There were 17 implants with symptoms of peri-implantitis in 12 subjects, including 4 females and 8 males, compared to 17 implants in 13 subjects, including 5 females and 8 males, with healthy peri-implant tissues. Filter paper strips were used to collect peri-implant crevicular fluid for 30 seconds in the base of the crevice/pocket. SPSS statistical software (SPSS, Inc., Chicago, IL) was used to determine AST and ALP activity.

RESULTS

The results showed that there was a significant difference in the activity of AST and ALP between the 2 study groups (P < 0.0001). AST activity was significantly associated with the amount of bleeding on probing (P = 0.02), but no statistical correlation was found between ALP activity and increased amount of bleeding on probing (P = 0.05).

CONCLUSIONS

Within the limits of this study, our results may suggest that peri-implant crevicular fluid analysis could be further investigated in longitudinal studies as a suitable diagnostic strategy in the evaluation of dental implants.

Association of gingival crevicular fluid and serum intracytoplasmic enzyme levels in periodontally healthy homozygous (major) beta-thalassemia patients

OBJECTIVE

To assess tissue necrosis in beta-thalassemia major patients, as in other areas of medicine, lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been widely used. These markers of tissue degradation have also been studied in the gingival crevicular fluid (GCF) in relation to periodontal disease status. The purpose of this study was to investigate whether periodontal diagnostic tests based on these markers of tissue degradation are influenced from the enzymes' levels in serum and, therefore, could be used in the assessment of the patient's periodontal status.

MATERIAL AND METHODS

Forty-four periodontally healthy, homozygous beta-thalassemia patients were enrolled in the study. GCF and serum samples were obtained and the levels of AST, ALT and LDH were determined; the measurements took place in an automated analyzer (Hitachi 777) using the kits of Roche Company.

RESULTS

Lack of correlations between serum and GCF enzyme levels was demonstrated. Serum LDH and serum AST, serum AST and serum ALT are significantly positively correlated. Concerning the GCF, AST and ALT were proved to be significantly positively correlated.

CONCLUSIONS

Elevated values of LDH, ALT and AST in serum do not constitute a confounding factor in GCF measurements of the respective enzymes.

Systemic use of metronidazole in the treatment of chronic periodontitis: a pilot study using clinical, microbiological, and enzymatic evaluation

The aim of the present parallel, double-blind investigation was to evaluate the effect of using systemic metronidazole alone or associated to scaling and root planing on adult chronic periodontal disease, monitored at baseline, 30, 60 and 90 days. Twelve subjects were divided into three groups: the first group (Group I - 22 sites) was submitted to scaling and root planing (SRP) alone; the second group (Group II - 30 sites) received SRP and 250 mg of metronidazole (3 times a day for 10 days), and the third group (Group III - 31 sites) was treated with metronidazole alone. The clinical parameters evaluated were probing depth (PD), clinical attachment level (CAL), plaque index (PlI), gingival index (GI) and bleeding upon probing (BP). Microbiological (BANA test) and enzymatic (Pocket Watch) tests were also performed. All three proposed treatments produced significant improvements in clinical conditions of subjects, from baseline, 30, 60 and 90-day period, except for clinical attachment level. The results obtained by microbiological and enzymatic tests did not show statistical differences among the groups for the 90-day period (r = 0.7924 and r = 0.7757, respectively). In relation to clinical parameters, statistical differences among groups were observed only for the gingival index (p = 0.0261) between Groups I and II, and probing depth (p = 0.0124) between Group I and the others. We conclude that the use of systemic metronidazole did not produce additional effects on the microbiological conditions of these patients with chronic periodontal disease.

Levels of aspartate aminotransferase (AST) in saliva of patients with different periodontal conditions

OBJECTIVES

The purpose of this study was to evaluate the relationship between aspartate aminotransferase (AST) levels in saliva measured by Reflotron trade mark System of Diagnosis and periodontal condition indicated by Community Periodontal Index of Treatment Needs (CPITN).

MATERIAL AND METHODS

Fifteen patients were assigned to one of four groups C0, C1, C3 and C4, based on their largest CPITN code among the examined sites, totaling 60 participants. About 1.0 ml of non-stimulated saliva was collected from the individuals after a mouth rinse with water. Biochemical analyses of saliva samples were carried out using the proposed system in order to quantify their AST concentration.

RESULTS

There were no significant differences between levels (U/ml) of AST (median; interquartile range) from groups C0 (30.9; 14.7-41.7), C1 (30.3; 19.5-39.4) and C3 (35.1; 27.0-63.5). However, group C4 (106.2; 84.4-129.7) differed statistically from the others (p<0.001) and presented AST levels as high as 284.2 U/ml. Gingival bleeding and suppuration were observed in three individuals with concentrations higher than 125.0 U/ml.

CONCLUSION

Levels of AST in saliva from patients presenting CPITN code 4 were higher than from patients coded lower and could be detected by the evaluated diagnostic system. Periodontal destruction such as periodontal pockets, gingival bleeding and suppuration seems to be related to higher AST levels in saliva.

Aspartate aminotransferase activity in gingival crevicular fluid during orthodontic treatment. A controlled short-term longitudinal study

BACKGROUND

During orthodontic tooth movement, the early response of periodontal tissues to mechanical stress involves an acute inflammatory response, with a sequence characterized by periods of activation, resorption, reversal, and formation in both tension and compression sites. This study used a longitudinal design to examine aspartate aminotransferase (AST) activity in gingival crevicular fluid (GCF) in order to assess whether AST in GCF has potential as a possible diagnostic aid to monitor tooth movement and tissue response during orthodontic treatment.

METHODS

Eighteen patients (mean age, 16.1 years) participated in the study. An upper first molar from each patient undergoing treatment for distal movement served as the test tooth (TT), with its contralateral (CC) and antagonist (AC) first molars used as controls. The CC was included in the orthodontic appliance, but was not subjected to the orthodontic force; the AC was free from any orthodontic appliance. The GCF around the experimental teeth was collected from both mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. Clinical gingival condition was evaluated at baseline and at the end of the experimental period. AST activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total AST activity (mU/sample).

RESULTS

Throughout the experiment, AST levels were significantly elevated in all sites from the TT and CC groups compared to the AC group where, conversely, AST activity remained at the baseline level. However, enzyme levels in the TT group were significantly greater than in the CCs at tension sites on day 14, and in compression sites on days 7 and 14. Moreover, AST activity from the TT group was significantly greater in compression sites than in tension sites on day 7; this was not observed for the CCs.

CONCLUSIONS

Our results suggest that AST levels in GCF reflect the biological activity which occurs in the periodontium during controlled occlusal trauma and, therefore, should be further evaluated as a diagnostic tool for monitoring correct orthodontic tooth movement in clinical practice.

Association of early onset periodontitis microbiota with aspartate aminotransferase activity in gingival crevicular fluid

OBJECTIVES

The objective of this study was to determine the relationship between the activity of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) using the colorimetric PerioGard (PTM) test and the subgingival microflora in early onset periodontitis lesions.

MATERIAL AND METHODS

The study population consisted of 25 otherwise healthy individuals exhibiting early onset periodontitis (EOP). In each patient four experimental sites were identified comprising one deep periodontal pocket (PD >5 mm) randomly chosen in each quadrant. Bacterial samples were obtained from the experimental sites, consecutively cultured anaerobically and in 10% CO(2) using selective and nonselective media. Isolates were characterized to species level by conventional biochemical tests and various identification kits. Clinical measurements as well as AST activity, assessed either as positive or negative using the PTM, were recorded at the same sites.

RESULTS

Sixty-two sites exhibited AST positive and 38 AST negative activity. Analysis of bacterial counts using the ANOVA (Mann Whitney U-test) showed that Streptococcus intermedius, Peptostreptococcus micros, Campylobacter concisus, Bacteroides forsythus, Camplobacter gracilis, Campylobacter rectus and Selenomonas sputigena were significantly higher in sites with AST-positive activity. The odds ratio of having high prevalence of S. intermedius, P. micros, C. concisus, B. forsythus, C. gracilis, C. rectus and S. sputigena in the presence of a positive AST site was very high (range: 3.5-17.0). Streptococcus sanguis, Actinomyces naeslundii, Gemella morbillorum, Capnocytophaga gingivalis, Veillonella parvula, Fusobacterium varium, Eubacterium lentum and Prevotella oralis were detected in significantly higher proportions in sites with AST negative activity and manifested a negative odds ratio in the presence of AST positive sites. The logistic regression analysis revealed that smoking and bleeding upon probing showed a significant association with AST activity, while plaque and suppuration were not found to be significant predictors of AST activity. The co-infection of Porphyromonas gingivalis, B. forsythus and P. micros, or P. gingivalis, B. forsythus and C. rectus were found to be significantly associated with the AST activity (p<0.001). AST positive sites revealed significantly higher occurrence of co-infections by P. gingivalis, B. forsythus, S. sputigena or by P. gingivalis, B. forsythus, S. intermedius than AST negative sites (p<0.001). P. gingivalis, B. forsythus, A. naeslundii co-infection was found significantly higher in the AST negative sites (p<0.001).

CONCLUSIONS

The present study found a high level of agreement between the presence of putative periodontal pathogens and positive AST scores at periodontal sites that clinically were considered to be potentially disease active. Prospective studies should be performed to confirm the findings.

Periodontal disease as a specific, albeit chronic, infection: diagnosis and treatment

Periodontal disease is perhaps the most common chronic infection in adults. Evidence has been accumulating for the past 30 years which indicates that almost all forms of periodontal disease are chronic but specific bacterial infections due to the overgrowth in the dental plaque of a finite number of mostly anaerobic species such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola. The success of traditional debridement procedures and/or antimicrobial agents in improving periodontal health can be associated with the reduction in levels of these anaerobes in the dental plaque. These findings suggest that patients and clinicians have a choice in the treatment of this overgrowth, either a debridement and surgery approach or a debridement and antimicrobial treatment approach. However, the antimicrobial approach, while supported by a wealth of scientific evidence, goes contrary to centuries of dental teaching that states that periodontal disease results from a "dirty mouth." If periodontal disease is demonstrated to be a risk factor for cardiovascular disease and stroke, it will be a modifiable risk factor since periodontal disease can be prevented and treated. Since the antimicrobial approach may be as effective as a surgical approach in the restoration and maintenance of a periodontally healthy dentition, this would give a cardiac or stroke patient and his or her physician a choice in the implementation of treatment seeking to improve the patient's periodontal condition so as to reduce and/or delay future cardiovascular events.

Relationship between crevicular aspartate aminotransferase levels and periodontal disease progression

BACKGROUND

Aspartate aminotransferase (AST), an enzyme released from necrotic cells, has been identified in gingival crevicular fluid (GCF), and elevated levels are associated with periodontal tissue destruction. The aim of this study was to examine the relationship between elevated GCF levels of AST and periodontal disease progression.

METHODS

Over a 12-month period, 8 to 10 interproximal sites in 41 periodontitis subjects (PS) and 15 healthy subjects (HS) were monitored. Clinical measurements included relative attachment level (RAL), probing depth, and bleeding on probing (BOP). Semiquantitative levels of GCF AST (< 800 microIU, > or = 800 microIU, and > or = 1,200 microIU) were determined using a chairside assay. At the 6- and 12-month visits, scaling and root planing and prophylaxis were performed in the PS and HS, respectively. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) were calculated for 2 diagnostic criteria (AST > or = 800 microIU, AST > or = 1,200 microIU) utilizing 4 thresholds of disease progression as determined by 2 methods (absolute change in relative attachment level and cumulative sum [CUSUM]).

RESULTS

The percentage of sites exhibiting AST > or = 800 microIU, AST > or = 1,200 microIU, and BOP in the PS was significantly (P<0.02) lower at 6 and 12 months compared to baseline. The use of crevicular AST activity to monitor periodontal disease progression was associated with many false-positive results. Overall, low specificities, PPV, and odds ratios were demonstrated by the assay when using 2 diagnostic criteria and 4 thresholds of disease progression. The high NPV suggest that a negative AST test result was indicative of a periodontally stable site.

CONCLUSIONS

These results demonstrate that elevated levels of AST were present at sites that did not subsequently exhibit disease progression. The high prevalence of AST-positive sites due to gingival inflammation diminished the test's ability to discriminate between progressive and stable, but inflamed, sites.

Aspartate aminotransferase activity in crevicular fluid from dental implants

BACKGROUND

Aspartate aminotransferase (AST) is an enzyme normally confined to the cytoplasm of cells, but released to the extracellular environment upon cell death. Its levels are associated with the severity of experimental gingivitis and the loss of periodontal attachment. The aim of the present study was to investigate the presence and activity levels of AST in peri-implant crevicular fluid (PCF) from healthy and diseased endosseous implants in order to assess if AST in PCF can be further studied as a possible objective diagnostic aid in oral implantology.

METHODS

Eighty-one fixtures from 81 systemically healthy subjects were divided into 3 groups, 27 healthy implants (HI), 27 implants with mucositis (MI) and 27 implants affected by peri-implantitis (PI) according to well-defined clinical and radiographic criteria. PCF was collected by the insertion of a #40 standardized endodontic paper point to the base of the crevice or pocket for 30 seconds. AST activity was determined spectrophotometrically at 25 degrees C. The results were expressed as AST Units/ml in PCF.

RESULTS

An AST activity was detected in each sample from HI, MI and PI. The mean AST activity in HI was 0.26 +/- 0.16 U/ml; in MI, 0.38 +/- 0.27 U/ml; in PI, 0.62 +/- 0.29 U/ml. ANOVA showed that the difference among HI, MI, and PI was statistically significant at P <0.01 level. Post-hoc tests demonstrated that a significant difference in AST activity existed between HI/PI (t = 5.14; P<0.01) and MI/PI (t = 3.09; P<0.01). No statistically significant difference was found between HI/MI (t = 1.07; P >0.1) AST activity was significantly (P <0.01) associated with probing depth (r = 0.55), the amount of bone loss (r = 0.60) and bleeding on probing (r = 0.67). When the threshold for a positive AST test was set > or =0.4 U/ml, a sensitivity = 0.81 and a specificity = 0.74 were found in the detection of peri-implantitis; the positive predictive value was 61% and the negative predictive value was 88%.

CONCLUSIONS

Within the limits of this study, our results may suggest that PCF analysis could be further investigated in longitudinal studies as a suitable diagnostic strategy in the evaluation of dental implants.

The association of calprotectin level in gingival crevicular fluid with gingival index and the activities of collagenase and aspartate aminotransferase in adult periodontitis patients

BACKGROUND

Calprotectin, a major cytosol protein of leukocytes, exists in plasma and other body fluids of healthy human subjects. Since the calprotectin concentration rises markedly in some inflammatory diseases including rheumatoid arthritis, this protein has been thought to be a marker of inflammatory disease. Recently, we identified calprotectin in human dental calculus and gingival crevicular fluid (GCF), and found that the calprotectin concentration in GCF from patients with periodontitis was significantly higher than that in GCF from healthy subjects. In the present study, the association of GCF calprotectin level with GCF volume, gingival index (GI), and levels of biochemical markers including collagenase and aspartate aminotransferase (AST) in GCF was investigated to clarify the relationship between GCF calprotectin level and periodontal inflammation.

METHODS

Ninety GCF samples collected from periodontal pockets with a probing depth of more than 4 mm in 54 patients with adult periodontitis were used for these assays. The GCF volume was measured, and GI in each site was recorded. The calprotectin content in GCF samples was determined by ELISA using a specific antibody. The activity of collagenase or AST was measured by a respective assay kit.

RESULTS

The total amount of calprotectin and GCF volume showed a highly significant correlation (r = 0.64, P <0.0001), whereas the calprotectin concentration had no correlation with the GCF volume (r = 0.01, P= 0.924). The mean calprotectin concentration in GCF increased with the degree of GI, and the concentration in individual samples was significantly correlated with the GI score (r = 0.56, P<0.0001). Significant positive correlations were observed in GCF calprotectin versus collagenase (r = 0.57, P <0.0001) and GCF calprotectin versus AST levels (r = 0.40, P <0.005).

CONCLUSIONS

From the present results and our previous findings, it is shown that the GCF calprotectin level significantly correlates not only with clinical indicators but also with current biochemical marker levels and that calprotectin may be a useful marker for periodontal inflammation.

Changes in gingival crevicular fluid levels of immunoglobulin A following therapy: association with attachment loss

BACKGROUND

In previous studies, we demonstrated that increased levels of immunoglobulin A (IgA) in gingival crevicular fluid (GCF) may be "protective", while increased levels of the polymorphonuclear lysosomal enzyme, beta-glucuronidase, in GCF were associated with increased risk of disease activity. In this study, we examined the effect of scaling and root planing (SRP) on the levels of beta-glucuronidase, IgG, and IgA in GCF over a 24-week period and compared these to clinical attachment loss (CAL).

METHODS

Twenty-nine patients with periodontal disease were examined for attachment level, probing depth, plaque, and bleeding on probing at 6 sites per tooth. GCF was collected from the mesial aspect of all teeth excluding third molars and analyzed for beta-glucuronidase, IgG, and IgA. After baseline data were collected, each patient received SRP, and GCF was collected again at 2, 4, 6, 8, 12, and 24 weeks post-SRP while clinical data were obtained at 4, 8, 12, and 24 weeks. In addition, we analyzed whether the magnitude of the IgA response to SRP would affect the rate of periodontal disease progression by examining GCF IgA levels at 2 time intervals: 2 to 4 weeks post-SRP and 6 to 12 weeks post-SRP.

RESULTS

Seventeen patients (58.6%) exhibited at least 1 site losing > or =2.5 mm of CAL during the 24-week study. Beta-glucuronidase in GCF was significantly decreased at 2 weeks following SRP and then demonstrated a gradual increase throughout the study period. Levels of IgA in GCF significantly increased following SRP, reaching a peak at 6 weeks and then gradually decreasing throughout the study. Furthermore, we found an inverse relationship between GCF IgA levels at 6 to 12 weeks post-SRP and the occurrence of CAL.

CONCLUSIONS

These results support the hypothesis that maintenance of high levels of IgA in GCF may be "protective" against periodontal attachment loss. Furthermore, levels of beta-glucuronidase appear to be a more sensitive indicator of gingival inflammation than clinical measures.

Analysis of gingival crevicular fluid intracytoplasmic enzyme activity in patients with adult periodontitis and rapidly progressive periodontitis. A longitudinal study model with periodontal treatment

In the present study, the activity of 3 functionally related enzymes, creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) levels in the rest and flow gingival crevicular fluid (rGCF, fGCF) from patients with rapidly progressive periodontitis (RPP) and adult periodontitis (AP) were determined before and after periodontal treatment, including maintenance. When rGCF and fGCF mean enzyme levels were compared, rGCF was found to contain approximately twice as much enzyme levels than fGCF throughout the study. The findings of the present study revealed that both the rGCF and fGCF samples also contained higher CK, LDH, and AST levels than serum samples. Baseline clinical parameters and GCF enzyme levels presented a significant decline throughout the non-surgical and surgical treatment phases in both patient groups, with surgical treatment being more effective. Despite clinical stability, in the AP group levels of LDH and AST showed a tendency to increase in the third month, while enzyme levels still continued to decrease in the RPP group, who received additional antibiotics during the surgical phase. These findings suggest that GCF intracytoplasmic enzyme profile is related with periodontal status and successful periodontal treatment, in addition to clinical improvement, has a significant effect on this profile. Analysis of biochemical events, more specifically intracytoplasmic enzyme levels in GCF, are likely to offer a sensitive measure of periodontal pathology which may help in overcoming the existing limitations of clinical parameters. For this purpose, analysis of rGCF intracytoplasmic enzymes seems to be more beneficial.

Gingival crevicular fluid lactoferrin levels in adult periodontitis patients

The present study was designed to determine in a cross-sectional study whether there was any relationship between the levels of lactoferrin in gingival crevicular fluid and clinical periodontal parameters. Crevicular fluid was collected from individual sites using standardized filter paper strips (clinically healthy sites, N = 23; periodontitis sites, n = 66) and evaluated for lactoferrin by enzyme-linked immunosorbent assay. The data showed that: (1) the total amounts of lactoferrin were 0.003-0.021 ng (30 second sample) (average 0.009 +/- 0.005 ng) in a clinically healthy periodontium group and 0.016-3.847 ng (30 second sample) (average 0.575 +/- 0.069 ng) in adult periodontitis patients (statistically significantly higher in adult periodontitis patients); and (2) the total amounts of lactoferrin were significantly correlated with clinical parameters, especially a strong positive correlation with gingival crevicular fluid volume (r = 0.85, p < 0.01) and with probing depth (r = 0.71, p < 0.01). These results indicated that quantification of lactoferrin in gingival crevicular fluid may be a more sensitive indicator of periodontal pathology than traditional clinical indices.

Aspartate aminotransferase (AST) levels in human periodontium-derived cells

The ability to objectively assess periodontal disease activity can significantly affect periodontal therapy. Aspartate aminotransferase (AST) is released extracellularly upon tissue destruction which suggests its potential as a key index in a quantitative assay for evaluating periodontal disease activity. The purpose of the present research was to assess the origin of AST in gingival crevicular fluid (GCF) in vitro. An experimental kit was used for the measurement of AST level in human gingival epithelial cells (HGEs), human gingival fibroblasts (HGFs), human periodontal ligament fibroblasts (HPLFs), polymorphonuclear leukocytes (PMNs), and plasma in peripheral blood. AST activity levels were observed in all of the periodontally derived cells, PMNs, and plasma. A significantly high level of AST activity was observed in HGEs (104.93 +/- 8.13 KU/1000 cells). The level of AST activity in HPLFs was 18.09 +/- 3.73 KU/1000 cells. AST activity in PMNs was significantly low, approximately 2% of that observed in HPLFs. These findings may suggest that AST level in GCF is correlated with the destruction of periodontal tissue.

Comparison of a sonic and a manual toothbrush for efficacy in supragingival plaque removal and reduction of gingivitis

A new sonic electric toothbrush (Sonicare) and a traditional manual toothbrush were compared for efficacy in removing supragingival plaque and reducing gingival inflammation in a 12-week, single-blind clinical trial. 60 subjects with a gingival index (GI) of > 1.5 and no probing depths > 5 mm were randomly assigned to use either the manual or sonic brush, instructed in its use, and asked to brush each morning and evening for 2 minutes. Plaque scores were taken at baseline and at 1, 2, 4, and 12 weeks using the Turesky modification of the Quigley-Hein plaque index. Gingival inflammation was assessed by the GI, bleeding tendency score, presence or absence of bleeding on probing, volumetric measurements of gingival crevicular fluid (GCF), and aspartate aminotransferase (AST) levels in GCF. Repeated measures multivariate analyses of variance were used to detect time- and device-dependent differences for all clinical assessments between the 2 groups over the 5 visits. Both types of brush were effective in removing supragingival plaque. The sonic brush was statistically superior, on a percentage reduction basis, in removing supragingival plaque from the dentition taken as a whole (F-statistic; p = 0.012) and was particularly better in hard-to-reach areas such as posterior teeth (F-statistic; p = 0.003) and interproximal sites (F-statistic; p = 0.004). Both devices were equally effective in reducing gingival inflammation. The sonic brush exhibited less tendency to cause gingival abrasion than the manual brush (1 incident with sonic, 5 incidents with manual), confirming the safety of this product as an oral hygiene device.

A multi-center clinical trial of a new chairside test in distinguishing between diseased and healthy periodontal sites. II. Association between site type and test outcome before and after therapy

The aim of the present study was to evaluate the association between the outcome of a chairside test measuring gingival crevicular fluid (GCF) levels of the enzyme aspartate aminotransferase (AST) and other clinical measures of disease including probing depth, severity of inflammation, and GCF flow before and after therapy. We studied 91 patients with moderate to severe periodontitis. Eight sites with probing depths between 5 mm and 8 mm and obvious signs of inflammation were selected and designated diseased sites. Four sites with probing depth < or = 3 mm with no or minimal signs of inflammation were selected and designated non-diseased sites in patients. Thirty healthy individuals were enrolled and four sites in each were selected and designated healthy controls. Patients were treated with scaling and root planing and control subjects with supragingival prophylaxis. Measurements including GCF volume, gingival inflammation, and probing depth were performed at screening baseline, 1 week later at pretreatment baseline, and at weeks 2 and 4 after treatment. AST content of GCF was measured using a chairside colorometric test. It was concluded that the outcome of the test is an effective objective measure distinguishing between diseased sites and non-diseased sites in patients and control subjects when evaluated both prior to and following application of therapy. Use of this simple chairside test, when combined with other standard diagnostic procedures, provides an objective measurement permitting improved capacity to distinguish between diseased and non-diseased periodontal sites, and to better assess and monitor the outcome of therapy.

Platelet association with gingival tissue inflammation

Platelets (PL) may be involved in the inflammatory process through the release of a variety of factors which could contribute to gingival tissue injury. Thus, conditions which result in the localized discharge of PL constitutents could lead to amplification of the inflammatory process at these sites. The purpose of this study was to determine if there was evidence of PL activation in gingival crevicular fluid and whether the degree of gingival inflammation, as measured by the gingival index (GI), was associated with the degree of platelet activation. This was monitored by assaying for beta-thromboglobulin (beta-TG), a platelet specific protein released from alpha granules of PL when activated. One uL samples of the fluids were obtained from human subjects from gingival sites with various GI scores. Fluid samples were also obtained at probe-induced bleeding gingival crevicular sites. beta-TG levels in the various fluids obtained from the crevice were determined by radioimmunoassay (RIA). The RIA data indicated that detectable beta-TG levels were observed in all samples, the means ranging from 5.5 ng/ml to 45.2 ng/ml. Additionally, a positive association between the GI scores of 0 and 1 and the beta-TG levels where observed. For GI scores of 2 and above the beta-TG concentrations appeared to approach a maximum value. These findings provide evidence for PL activation and suggest a relationship with gingival inflammation.

A multicenter clinical trial of PerioGard in distinguishing between diseased and healthy periodontal sites. (I). Study design, methodology and therapeutic outcome

We designed and performed a multicenter clinical trial to determine the relationship between measurements of the level of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) to other measures used to detect periodontal disease and monitor outcome of treatment, including pocket depth and gingival inflammation. 32 periodontitis patients were enrolled at the University of Washington, Seattle, 30 at the University of Florida, Gainesville, and 34 at the University of Illinois, Chicago. 10 periodontally normal control subjects were enrolled at each location. 8 diseased and 4 healthy sites were designated for study in each patient and 8 healthy sites designated in each control subject. Measures of disease included pocket depth, severity of gingival inflammation, and GCF volume. AST levels were measured using the PerioGard test kit. Clinical measurements were made and GCF samples harvested and tested 2x before and 2x after therapy consisting of scaling and root planing under local anesthetic. Specific design and other issues are discussed, including selection of patients and control subjects, sample size, selection of experimental test sites, methods for assessment of diseased and therapeutic improvement, harvesting of GCF and selection of appropriate biostatistical methods for data analysis. Demographics of the patient populations at the 3 locations are reported. As expected, therapy induced only negligible changes in the measures of disease at healthy sites in control subjects, and relatively minor improvement in healthy sites in patients. In contrast, statistically significant improvement relative to pretreatment baseline status in all 3 measures of disease was observed for diseased sites at all 3 study locations with all p-values less than 0.0002. The magnitude of improvement was comparable to that reported previously by others. The % of PerioGard-positive sites decreased significantly between the screening baseline and both post-treatment visits for patients at all 3 locations, with p values of 0.0001 to <0.0008.

Immunoglobulin isotypes in gingival crevicular fluid: possible protective role of IgA

In order to simultaneously assess the local humoral immune and polymorphonuclear leukocyte (PMN) responses in periodontal disease, IgG, IgM, and IgA, as well as the PMN lysosomal enzyme beta-glucuronidase (beta G), were examined in gingival crevicular fluid (GCF) from patients with varying degrees of periodontal pathology. Evaluations were made before and after conservative therapy (scaling and root planing). Thirty patients with varying degrees of periodontal pathology, ranging from mild inflammatory gingivitis to moderate periodontitis, were studied. GCF was collected from the mesial surfaces of all teeth. The presence of the 3 immunoglobulin isotypes was determined by enzyme linked immunosorbent assays (ELISA), while total beta G activity in GCF was determined by a fluorometric assay. Clinical parameters were obtained from 6 sites per tooth. Our data indicate that prior to treatment, total beta G activity is strongly related to the severity of periodontal disease as measured by mean probing attachment level (AL; r = 0.89; P < .005), mean probing depth (PD; 4 = 0.89; P < .0005) and percentage of sites exhibiting bleeding on probing (% BOP; r = 0.49; P < .005). Following treatment, no statistically significant relationship of disease severity and beta G is found. The concentrations of IgG and IgM in GCF do not follow a specific pattern when related to disease severity. In contrast, prior to treatment the concentration of IgA is negatively correlated to mean AL (r = -0.54; P < .005), mean PD (r = -0.59; P < .005), and % BOP (r = -0.47, P < .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Microcirculatory dynamics in experimental human gingivitis

The purpose of this study was to determine the changes that occur in the gingival microcirculation during the development of experimental gingivitis in humans. There have been no studies published to date combining videomicroscopy and laser Doppler flowmetry to study vascular dynamics in experimental gingivitis. Alterations occurring in the microcirculation of the marginal gingiva in 10 (18-30-year-old), healthy male humans when they suspended oral hygiene procedures in a proscribed area for 12-16 days were monitored. A partial mouth, experimental gingivitis model was employed. Gingival health was evaluated before and after the experimental period by assessing gingival and plaque indices and gingival crevicular fluid volume. Gingival vascular monitoring included measurement of red blood cell velocity in individual gingival microvessels via videomicroscopy and measurement of regional gingival blood flow using laser doppler flowmetry. The number of vessels visible in a given microscopic field in a given subject and the number of vessels exhibiting flow were also determined from the videotapes. Systemic cardiovascular and respiratory parameters were monitored to ensure that gingival vascular changes were not secondary to systemic changes. Gingivitis developed in all subjects; significant increases (Student t-test, p < 0.05) were seen in plaque index, gingival index, bleeding on probing and crevicular fluid volume. No change in superficial capillary blood velocity and a significant decrease in gingival regional blood flow were seen with gingivitis. A significant increase in the number of vessels visible in microscopic fields and a decrease in the % of vessels exhibiting flow were observed. Gingival microcirculation exhibited a dramatic, dynamic change in response to the development and progression of gingivitis.

New technologies for the diagnosis of periodontal disease

Historically the initial onset of periodontal disease in an individual was considered slow but continuously progressive over time. It was inferred that an individual would experience progressive destruction of the attachment structures until edentulous. However, several studies in the early 1970s contested the traditional concept of continuous disease progression. These studies suggested that periodontal disease progressed by recurrent acute episodes. In specific individuals, the loss of attachment was faster than the concept of slowly progressing disease. There were also sites in patients that progressed slower (or not at all) than anticipated on the basis of radiographic and clinical history of previous disease progression. These findings clearly indicated the need to explore the nature of periodontal disease progression and to institute a major effort into innovative methods to diagnose periodontal diseases. Dentists and researchers could more effectively prevent and treat periodontal disease and relate pertinent research findings to specific disease initiation and progression.

Design and analytic concepts for periodontal clinical trials

Aspects of the design and analysis of periodontal clinical trials are surveyed from a biostatistical perspective. Design issues discussed include protocol preparation, subject selection and its documentation, randomization, problems associated with the sample versus population paradigm in sampling of microbes and gingival fluid constituents, quality control, cross-over and split-mouth versus parallel-arm designs, blinding, and multicenter trials. Analytic discussion deals with the definition and choice of analytic unit, appropriate methods for the analysis of data from multiple sites within the same subject, the nature and application of randomization tests, interim analyses, subgroup analyses, and multiple comparison issues. Examples are provided to illustrate the feasibility of analyzing site-specific data while accounting for intra-subject correlation, which represents the increased similarity of sites chosen from the same mouth as compared to sites from different patients.

The host response in gingival crevicular fluid: potential applications in periodontitis clinical trials

Traditional clinical variables of periodontal pathology have only limited value as indicators for future disease progression in patients with adult periodontitis. Consequently, other aspects of the periodontal lesion are being examined for their diagnostic utility. Analysis of the host response in gingival crevicular fluid (GCF) is among the most intensely studied of these new diagnostic approaches. Specific indicators of the humoral immune response, cellular immune response, and acute inflammatory response have been identified in GCF. The relationship of indicators of the humoral immune response to active periodontal disease is equivocal. Specific indicators of the cellular immune response in GCF may ultimately prove to be important diagnostically, but the relationship of any specific marker to active periodontal disease has not been reported. In contrast, the acute inflammatory response in GCF has been extensively studied and a number of factors appear to be associated with an increased risk for future disease progression. Indicators of enhanced polymorphonuclear leukocyte activity, (lysosomal beta-glucuronidase, lysosomal collagenase), prostaglandin E2, and an indicator of acute tissue destruction (the cytoplasmic enzymes aspartate aminotransferase) have been associated with the occurrence of clinical attachment loss. An example of the application of a GCF marker in a periodontitis clinical trial is provided by describing the relationship of lysosomal beta-glucuronidase in GCF at baseline and 2 weeks following root planing and scaling to the occurrence of disease activity during the following 6 months. Persistently elevated levels of this enzyme were related to clinical attachment loss. The positive, negative, and total predictive values for beta-glucuronidase as an identifier of clinical attachment loss were 86%, 71%, and 76%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Five parameters of gingival crevicular fluid from eight surfaces in periodontal health and disease

Volume and amounts of myeloperoxidase (MPO), lactoferrin (LF), aryl sulfatase (AS) and lactate dehydrogenase (LDH) were measured in gingival crevicular fluid (GCF) collected from the mesial and distal proximal surfaces of the premolars and first and second molars of 3 subject groups. Group assignment was based on subject mean gingival index (GI) and probing depth (PD) of sampled sites as follows: healthy, GI less than or equal to 0.5, PD less than or equal to 3.0; disease 1, GI greater than or equal to 1.0, PD greater than or equal to 3.0 mm; disease 2, PD greater than or equal to 4.0 mm. Attachment loss (ATL) of most sites in the 3 groups was: healthy, 0-1 mm; disease 1, 1-2 mm; and disease 2, 4-9 mm. GCF volume differed among surfaces and teeth in each of the 3 groups. The greater amount of GCF collected from posterior locations was not related to the GI and PD. Differences with sampling location in amounts of GCF constituents were restricted to MPO and LF. Most of these differences (greater amounts at posterior sites) were associated with more severe disease. Variability in amount and composition of GCF collected from different sites, therefore, should be considered in experiments which include quantitation of GCF parameters. The ratio of MPO in disease group 2 to disease group 1 was greater than similar ratios for GCF volume and LF, AS and LDH. The quantity of MPO was the only measure which differed between the 2 disease groups at all surfaces. MPO thus appears to have the greatest potential, among the measured parameters, to serve as a marker for advanced periodontal disease.

Diagnostic characteristics of crevicular fluid aspartate aminotransferase (AST) levels associated with periodontal disease activity

During a 2-year period pocket depth, probing attachment level, gingival index, and crevicular fluid aspartate aminotransferase (AST) levels were monitored in 25 previously treated periodontitis patients. Probing attachment level change was used retrospectively to identify sites where active periodontal destruction had occurred. The ability of crevicular fluid AST activities at 600, 800, 1000, and 1200 microIU levels to recognize active disease was investigated. Probing attachment level changes observed support the concept that the pattern of periodontal disease activity is episodic and infrequent. A loss of greater than or equal to 2 mm was found at 11% of all studied sites, whereas a gain of greater than or equal to 2 mm was noticed for 15% of sites. 2 subjects had 3 teeth that lost greater than or equal to 2 mm of attachment, whereas 15 subjects demonstrated no teeth with disease activity. The remaining 8 subjects had 1 or 2 sites that lost greater than or equal to 2 mm of attachment. Bayes's theorem and ROC curves were used to exemplify the sensitivity and the specificity of AST assessments. The AST 800 microIU demonstrated a sensitivity of 0.93 and specificity 0.68 and an odds ratio of 15.4 for attachment loss greater than or equal to 2 mm. Under the conditional probability of either 50%, 25% or 10% active disease prevalence, AST 800 microIU has a predictability of 73%, 50% and 24% respectively.

Host mediators in gingival crevicular fluid: implications for the pathogenesis of periodontal disease

During the past few years, a considerable number of studies have examined different aspects of the host response in gingival crevicular fluid (GCF), including the relationship of specific markers to the active phases of periodontal disease. Various indicators of the acute inflammatory response (the lysosomal enzymes beta-glucuronidase and collagenase, the cytoplasmic enzyme aspartate aminotransferase, and the arachidonic acid metabolite PGE2) have been shown to be associated with clinical attachment loss in chronic adult periodontitis in man and experimental periodontitis in animal models. In contrast, the relationship of indicators of the humoral immune response in GCF to active periodontal disease is equivocal. Furthermore, a number of indicators of the cellular immune response have been identified recently in GCF (i.e., Interleukin-1 alpha, IL-1 beta, tumor necrosis factor-alpha), but their relationship to active phases of periodontal disease have not been studied. The polymorphonuclear leukocyte (PMN) is the cellular hallmark of acute inflammation. Evidence from the GCF studies suggests that hyperreactivity of these cells plays a critical role in the active phases of some forms of periodontal disease. Metabolic activation of PMN can be associated with a number of potentially destructive reactions. The major effector mechanism for tissue destruction that can be specifically identified with the PMN is the synergistic effect of the release of PMN proteases and the generation of reactive oxygen metabolites by these cells. Priming of the PMN, where the PMN response is enhanced by agents that do not initiate the response, may be an important mechanism for PMN activation in the crevicular environment; for example, cytokines such as IL-1 beta and TNF-alpha, and lipopolysaccharides released from subgingival Gram-negative bacteria, can serve this function. The hypothesis proposed here argues that in addition to the severe forms of periodontal disease that have been associated with qualitative or quantitative PMN defects, tissue destruction in the periodontum can be observed with hyperreactivity of these cells. These differing conclusions do not create a dilemma, but may represent opposite ends of a balance that is no longer in equilibrium.

Diagnosis of periodontal diseases

This paper reviews current (Fall, 1990) information related to the diagnosis of periodontal diseases. As background, principles of diagnostic decision-making and conceptual shifts during the 1970's and 1980's are reviewed in brief. "Diseases" that appeared in many classification schemes for periodontal diseases in the early 1970's--for example, "periodontosis" and "occlusal trauma"--do not appear in most current classifications. A recent (1989a) classification recommended by the American Academy of Periodontology holds that "periodontitis" includes several different diseases. There is, indeed, evidence for several different forms of periodontitis, but the AAP's classification does not conform to the principles of diagnostic decision-making because of the significant overlap between and heterogeneities within its suggested "diseases". An alternative classification is suggested, based on a concept that the periodontal diseases are mixed infections whose outcome is modified by relative effectiveness of host response. This view suggests that the most usual forms, gingivitis and adult periodontitis, normally occur in persons with essentially normal defense systems. Variation in extent or severity of disease can be understood as a function of the local infection in hosts with various degrees of compromised resistance to the infection. Early-onset periodontitis (EOP) cases could be accounted for by those where host response is abnormal to some significant degree. The greater the abnormality, the greater the extent and severity of disease might be. Localized EOP cases would be those where a relatively effective specific response intervenes to ameliorate progress of disease after the initially rapid progression. Other issues are detection of disease activity and assessment of risk for disease progression. Non-cultural bacteriological tests are available, but have not yet been shown to detect or predict activity or risk. One difficulty in reaching such proof for those or other tests has been the lack of an appropriate "gold standard" for disease activity or progression. This is being remedied by development of improved automated probes and imaging technologies. Considerable effort is being devoted to determining whether factors in gingival crevicular fluid may have diagnostic utility. More evidence is needed before clinical utility is known, but several enzymes and cytokines have potential for aiding diagnostic decisions.

Periodontal diagnosis in the 1990s

Clinicians are usually inclined to reduce data obtained from diagnosis to a simpler form such as "yes or no" answers in order to obtain useful parameters for daily practice. It should be realized, however, that the diagnostic process very rarely exhibits "black and white" situations. Rather the evaluation of numerous "grey levels" is imperative. The diagnostic process, therefore, remains always incomplete and inaccurate, and it represents an evaluation of probabilities rather than certainties. For this reason, the diagnostician should realize and understand the mathematical relations between the information provided by diagnostic tests and the clinical situation actually present at the time of the test. This will allow one to convert diagnostic results into therapeutic procedures with a high degree of confidence. Since results from diagnostic tests are quite often used to decide on treatment, complex data are reduced to simple dichotomy, such as presence or absence of disease, normal or abnormal conditions, etc. In order to react to diagnostic tests in an ordinal, dichotomous manner, the clinician has to choose a particular level of a test at which he initiates treatment without having the assurance that this level represents the one and only standard at which treatment has to be initiated.

Association of gingival crevicular fluid aspartate aminotransferase levels with histopathology during ligature-induced periodontitis in the beagle dog

Previous investigations have shown a clear association between the presence of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) and clinical evidence of periodontal disease in humans, as well as in the beagle dog model. This paper describes a 26-week study that uses the beagle dog model of ligature-induced periodontitis in which GCF-AST (corrected for collection time) was correlated with microscopic evidence of tissue destruction in the periodontium at the sites of fluid collection. GCF and clinical data were collected at baseline, at optimal gingival health, during gingivitis, and after ligation. A cross-mouth design was implemented so that six premolar teeth in each dog were ligated for periods up to five weeks. Formalin-fixed tissues from the sites of GCF collection were prepared for light microscopy and evaluated for the presence of epithelial ulceration, bone resorption, and inflammatory cell infiltration. The relationship between GCF-AST levels and microscopic findings was analyzed by calculation of sensitivity and specificity and by plots of Receiver Operating Characteristics. These data revealed a correlation between elevated enzyme concentration and microscopic evidence of disease activity. Taken together with human studies, these results provide support for the use of AST as a marker of periodontal disease progression.

Effect of sampling time and repetition on gingival crevicular fluid and aspartate aminotransferase activity

Tests based on the composition of gingival crevicular fluid (GCF) for detection of active periodontitis require a better understanding of sampling variables than currently exists. We have studied the effects of sample time and repetition on the presence and activity of aspartate aminotransferase (AST). Two 30-second samples of GCF were harvested within 10-minute intervals from 192 teeth with periodontitis. GCF sample size and AST activity were measured. GCF volume and AST activity of first samples were each approximately 10% greater than for second samples. The differences were significant. AST activity correlated positively with gingival index scores and probing pocket depth. Samples were also harvested from groups of 4 teeth during 5-, 10-, 20- and 30-s periods with 1-min intervals and varying sample order. For these samples, first samples contained the greatest amount of enzyme activity, regardless of sample time. When only first samples were considered, the 5- and 10-s samples showed more total activity than the 20- and 30-s samples, and differences were statistically significant. Flow rate for the 5-s sample was always higher than for all other samples, regardless of its position in the sampling sequence. Our observations are consistent with the existence of a reservoir of AST activity that is, in major part, depleted during the first 5 to 10 s of sampling, and that requires a time period of more than 10 min to reequilibrate. Five- to 10-s samples may distinguish active disease better than 20- or 30-s samples, since most of the activity is taken onto the strip in the first few seconds, and the activity is subsequently partly inactivated or diluted by the uptake of fluid less rich in enzyme activity.