Prediction and diagnosis of attachment loss by enhanced chemiluminescent assay of crevicular fluid alkaline phosphatase levels

Antioxidant Micronutrients and Oxidative Stress Biomarkers

Chronic inflammatory diseases are the major causes of mortality in humans and recent research has improved our understanding of the major impact of lifestyle factors upon inflammatory diseases and conditions. One of the most influential of these is nutrition, which may drive both pro-inflammatory as well as anti-inflammatory cascades at molecular and cellular levels. There are a variety of model systems that may be employed to investigate the impact of micronutrients and macronutrients upon inflammatory pathways, many of which operate through oxidative stress, either at the level of controlling the redox state of the cell and downstream redox-regulated gene transcription factors, and other acting as free radical generating or scavenging agents. This chapter focuses upon biological sample preparation prior to assay and details methods for analyzing certain antioxidant micronutrients and biomarkers of oxidative stress.

Inflammatory microenvironment-targeted nanotherapies

Inflammatory microenvironments (IMEs) are common pathological characteristics and drive the development of multiple chronic diseases. Thus, IME-targeted therapies exhibit potential for the treatment of inflammatory diseases. Nanoplatforms have significant advantages in improving the efficiency of anti-inflammatory treatments. Owing to their improved therapeutic effects and reduced side effects, IME-targeted nanotherapies have recently drawn interest from the research community. This review introduces IMEs and discusses the application of IME-targeted nanotherapies for inflammatory diseases. The development of rational targeting strategies tailored to IMEs in damaged tissues can help promote therapies for chronic diseases.

Endpoints of active periodontal therapy

Aim

Position paper on endpoints of active periodontal therapy for designing treatment guidelines. The question was as follows: How are, for an individual patient, commonly applied periodontal probing measures—recorded after active periodontal therapy—related to (a) stability of clinical attachment level, (b) tooth survival, (c) need for re‐treatment or (d) oral health‐related quality of life.

Methods

A literature search was conducted in Ovid MEDLINE(R) and Epub Ahead of Print, In‐Process & Other Non‐Indexed Citations and Daily <1946 to 07 June 2019>.

Results

A total of 94 papers were retrieved. From the literature search, it was found that periodontitis patients with a low proportion of deep residual pockets after active periodontal therapy are more likely to have stability of clinical attachment level over a follow‐up time of ≥1 year. Other supporting literature confirms this finding and additionally reports, at the patient level, that probing pocket depths ≥6 mm and bleeding on probing scores ≥30% are risks for tooth loss. There is lack of evidence that periodontal probing measures after completion of active periodontal treatment are tangible to the patient.

Conclusions

Based on literature and biological plausibility, it is reasonable to state that periodontitis patients with a low proportion of residual periodontal pockets and little inflammation are more likely to have stability of clinical attachment levels and less tooth loss over time. Guidelines for periodontal therapy should take into consideration (a) long‐term tangible patient outcomes, (b) that shallow pockets (≤4 mm) without bleeding on probing in patients with <30% bleeding sites are the best guarantee for the patient for stability of his/her periodontal attachment, (c) patient heterogeneity and patient changes in immune response over time, and (d) that treatment strategies include lifestyle changes of the patient. Long‐term large population‐based and practice‐based studies on the efficacy of periodontal therapies including both clinical and patient‐reported outcomes (PROs) need to be initiated, which include the understanding that periodontitis is a complex disease with variation of inflammatory responses due to environment, (epi)genetics, lifestyle and ageing. Involving people living with periodontitis as co‐researchers in the design of these studies would also help to improve their relevance.

Usefulness of hemoglobin examination in gingival crevicular fluid during supportive periodontal therapy to diagnose the pre-symptomatic state in periodontal disease

Objectives

The absence of bleeding on probing (BOP) is a good predictor of disease stability. This study investigated whether detection of hemoglobin (Hb) in gingival crevicular fluid (GCF) indicates minute signs of periodontal disease, even in BOP (−) cases.

Materials and methods

GCF was collected from gingival sulci of 152 sound maxillary and mandibular teeth from 76 patients who had entered supportive periodontal therapy (SPT) using the split-mouth design. As clinical parameters, plaque index, GCF amount, gingival index, probing depth (PD), clinical attachment level, BOP, and alveolar bone resorption ratio were then recorded. As biochemical parameters, Hb amount, alkaline phosphatase (ALP) activity, and protein amount in GCF were measured. Periodontal conditions of diseased sites (PD ≥ 4 mm, BOP (+)) and healthy sites (PD ≤ 4 mm, BOP (−)) were further classified into two groups using the Hb cutoff value determined by PD and BOP and analyzed.

Results

Despite being healthy, ALP activity and protein amount in sulci of the group with Hb level greater than the cutoff value were significantly higher than those in the group with Hb level less than the cutoff value (P < 0.01).

Conclusions

This study indicates that Hb examination is a promising candidate marker of pre-symptomatic periodontal disease because Hb presence in GCF suggests slight tissue damage, even in healthy sites defined as BOP (−).

Clinical relevance

Hb examination of GCF is a powerful diagnostic tool for pre-symptomatic diagnosis of periodontal disease.

Plaque-induced gingivitis: Case definition and diagnostic considerations

OBJECTIVE

Clinical gingival inflammation is a well-defined site-specific condition for which several measurement systems have been proposed and validated, and epidemiological studies consistently indicate its high prevalence globally. However, it is clear that defining and grading a gingival inflammatory condition at a site level (i.e. a "gingivitis site") is completely different from defining and grading a "gingivitis case" (GC) (i.e. a patient affected by gingivitis), and that a "gingivitis site" does not necessarily mean a "GC". The purpose of the present review is to summarize the evidence on clinical, biochemical, microbiologic, genetic markers as well as symptoms associated with plaque-induced gingivitis and to propose a set of criteria to define GC.

IMPORTANCE

A universally accepted case definition for gingivitis would provide the necessary information to enable oral health professionals to assess the effectiveness of their prevention strategies and treatment regimens; help set priorities for therapeutic actions/programs by health care providers; and undertake surveillance.

FINDINGS

Based on available methods to assess gingival inflammation, GC could be simply, objectively and accurately identified and graded using bleeding on probing score (BOP%) CONCLUSIONS: A patient with intact periodontium would be diagnosed as a GC according to a BOP score ≥ 10%, further classified as localized (BOP score ≥ 10% and ≤30%) or generalized (BOP score > 30%). The proposed classification may also apply to patients with a reduced periodontium, where a GC would characterize a patient with attachment loss and BOP score ≥ 10%, but without BOP in any site probing ≥4 mm in depth.

Evaluation of serum and salivary alkaline phosphatase levels in chronic periodontitis patients before and after nonsurgical periodontal therapy

Background:

The traditional method of diagnosing periodontitis includes the assessment of clinical parameters and radiographic aids to evaluate the periodontal tissue destruction. Saliva has the potential to be used as the diagnostic fluid for oral disease. This study aimed at comparing the quantitative levels of alkaline phosphatase (ALP) in saliva and serum before and after scaling and root planing in patients with chronic generalized periodontitis.

Materials and Methods:

A total number of 50 participants (40 with chronic generalized periodontitis and 10 periodontally healthy volunteers) of 30–50 years were included in the study. Clinical parameters such as simplified oral hygiene index (OHI-S), gingival index, probing depth, and clinical attachment loss (CAL) were measured, and then, saliva and blood sample collection was done and analyzed for ALP levels by spectrometry. The clinical parameters along with saliva and serum ALP levels were reevaluated after 30 days following Phase I periodontal therapy. The results were statistically analyzed using paired t-test and one-way ANOVA.

Results:

The saliva and serum ALP levels were significantly increased in patients with chronic generalized periodontitis with an increase in clinical parameters such as OHI-S, gingival index, probing depth, and CAL when compared with periodontally healthy individuals. The saliva and serum ALP levels were significantly decreased following Phase I periodontal, therapy along with improvement in clinical parameters.

Conclusion:

With the limitations of the present study, it could be concluded that ALP levels in saliva can be used for the diagnosis of active phase of periodontal disease and also for evaluation of the treatment outcomes following Phase I periodontal therapy.

Enzymatic Analysis of the Gingival Crevicular Fluid in Hypoxia of High Altitude (Everest)

The aim of this study is to determine the qualitative and quantitative changes of alkaline phosphatase (ALP) that occur in the Gingival Crevicular Fluid (GCF) in hypobaric-hypoxic conditions (high altitude). Hypoxia affects systemic adaptation responses in different organs. We examined 17 Caucasians subjects, of whom 13 were mountain climbers (1 female and 12 males), and 4 Tibetans (2 females and 2 males) following exposure to the hypoxia environment of high altitude. The study was conducted at different altitudes (0 m control, 1000 m, 5200 m above sea level) on Mount Everest. The protocol consisted of withdrawing crevicular fluid through the use of cones made of endodontic paper size 30 sectioned to 15 mm from the apex, inserted for 30 seconds in the gingival sulcus (about 2 mm). The analyzed sites were the mesial and distal, buccal and palatal of tooth 1.1 and 2.1. Blood exams were performed on the subjects using I-Stat, furnishing analysis in real time (about 2 mins). In agreement with other results reported in literature, in all the subjects we found an increase in the hematocrit and hemoglobin with a large range of values between them, and with significant differences, as analysed with the Fisher, Scheffe and Bonferroni/Dunn statistical methods. The enzymatic analysis of the GFC showed an increase of the levels of ALP at each altitude studied. With this preliminary study we show that hypoxic environment determines not only the well known cardiovascular systemic responses, but also crevicular fluid adaptation.

Antioxidant Micronutrients and Oxidative Stress Biomarkers

Chronic inflammatory diseases are the major causes of mortality in humans and recent research has improved our understanding of the major impact of life-style factors upon inflammatory diseases and conditions. One of the most influential of these is nutrition, which may drive both pro-inflammatory as well as anti-inflammatory cascades at molecular and cellular levels. There are a variety of model systems that may be employed to investigate the impact of micronutrients and macronutrients upon inflammatory pathways, many of which operate through oxidative stress, either at the level of controlling the redox state of the cell and downstream redox-regulated gene transcription factors, and other acting as free radical generating or scavenging agents. This chapter focuses upon biological sample preparation prior to assay and details methods for analyzing certain antioxidant micronutrients and biomarkers of oxidative stress.

Gingival Crevicular Fluid as a Novel Potential Source of Biomarkers Distinguishes Pubertal from Post-Pubertal Subjects

Detection of pubertal growth peak is vital in orthodontic treatment timing and planning. Gingival crevicular fluid (GCF) contains abundant proteins from different sources and has been proven to be an ideal source of biomarkers. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) is an advanced technique that can detect low-molecular-weight peptides with high sensitivity and resolution. The aim of this research was to identify novel candidate biomarkers in GCF to help the diagnosis of pubertal growth peak by MALDI-TOF/MS. Results showed that the peak intensities of six peptides were significantly different between two groups: 1660.2 Da, 1783.0 Da, 2912.5 Da, 4178.6 Da, 5064.9 Da, and 6108.9 Da and are considered to be potential candidate biomarkers to identify pubertal growth peak. Further studies are needed to identify sequence information of these candidate biomarkers.

Biomarker levels in gingival crevicular fluid of subjects with different periodontal conditions: A cross-sectional study

OBJECTIVE

To compare five biomarker levels in gingival crevicular fluid (GCF) in different tooth-sites of subjects with healthy periodontium, aggressive periodontitis and severe chronic periodontitis, and to evaluate the value of these biomarker levels for diagnosis of the type and activity of periodontitis.

MATERIALS AND METHODS

Prior to therapy, GCF samples were collected using filter paper strip at different tooth-sites of 10 subjects with healthy periodontium (H), 15 with severe chronic periodontitis (CP) and 15 with aggressive periodontitis (AgP). The strips were weighed and the periodontal clinical parameters were recorded. Levels of interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and alkaline phosphatase (ALP) in GCF were assessed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The volumes of the GCF samples obtained in CP and AgP subjects were significantly higher than those from subjects with healthy periodontium (P<0.05). Levels of IL-6, TNF-α, CRP and ALP were significantly higher in the untreated disease sites in the CP and AgP groups compared to those in control sites in the H group, while IL-10 levels were lower in the CP and AgP groups than those in the control sites in the H group. However, the levels of all five biomarker levels showed significant correlation with the clinical parameters.

CONCLUSION

The measurement of five biomarker levels in GCF may facilitate overall screening of periodontitis patients in epidemiological studies and allow estimation of periodontitis activity.

Biomarkers associated with periimplant diseases

PURPOSE

Recently, implantology has shifted its focus from implant placement to periimplant disease early detection, prevention, and treatment. The purpose of this article was to review the current understanding of the biomarkers associated with periimplant diseases.

MATERIALS AND METHODS

A search of PubMed was conducted up to August 2013 with keywords "peri-implantitis" and "biomarkers." Selected articles addressed the relationship between biomarkers and periimplant mucositis or peri-implantitis.

RESULTS

Biomarkers have been shown to possess potential in detecting periimplant diseases. For example, interleukin (IL)-1β levels were shown to be a good marker to detect periimplant mucositis lesions before they progress to peri-implantitis. Matrix metalloproteinase (MMP)-8 levels in periimplant sulcus fluid may be useful for monitoring the progression of periimplant disease. Osteoprotegerin (OPG) and receptor activator of NFκB ligand (RANKL) were found to be significantly higher in peri-implantitis sites compared with healthy implant sites.

CONCLUSION

Biomarkers such as IL-1β, MMP-8, OPG, RANKL, and others have shown promising outcomes in differentiating from periimplant disease to health. However, because of varying results, additional evidence is needed to validate the links reported.

Estimation and Comparison of Salivary Calcium, Phosphorous, Alkaline Phosphatase and pH Levels in Periodontal Health and Disease: A Cross-sectional Biochemical Study

INTRODUCTION

In oral diagnostics there is a great challenge to determine biomarkers for screening and evaluating the disease activity. Biomarkers can also serve as a useful tool to measure the efficacy of the therapy.

AIM

To evaluate and compare the levels of salivary calcium, phosphorous, alkaline phosphatase and pH levels in periodontally healthy subjects and patients with gingivitis and periodontitis.

MATERIALS AND METHODS

The present study consisted of 150 subjects aged between 20-45 years who were divided into three groups; periodontally healthy, gingivitis and chronic periodontitis. Prior to the clinical examination the demographic details, relevant information of the subject, gingival index, plaque index, Oral Hygiene Index (OHI) and pH were recorded. Biochemical assay of saliva i.e., inorganic calcium, phosphorous and alkaline phosphatase were estimated by colorimetric method. ANOVA and Tukey's test were applied for statistical analysis.

RESULTS

The mean levels of biomarkers studied were; inorganic calcium (12.55μg/dl), phosphorous (14.50μg/dl), alkaline phosphatase (49.62μg/dl) and pH (11.65). There was a gradual increase in these levels as the condition progressed from health to gingivitis or periodontitis which was statistically significant at p<0.001.

CONCLUSION

Based on these results, it can be concluded that, the biomarkers like salivary calcium, phosphorous, alkaline phosphatase and pH can be considered for evaluating the diagnosis and prognosis of periodontal tissues in disease and health.

Correlation of alkaline phosphatase activity to clinical parameters of inflammation in smokers suffering from chronic periodontitis

CONTEXT

Current clinical periodontal diagnostic techniques emphasize the assessment of clinical and radiographic signs of periodontal diseases which can provide a measure of history of disease. Hence, new methodologies for early identification and determination of periodontal disease activity need to be explored which will eventually result in expedited treatment.

AIM

To evaluate the correlation of alkaline phosphatase (ALP) activity in gingival crevicular fluid (GCF) to clinical parameters of periodontal inflammation in smokers with chronic periodontitis.

MATERIALS AND METHODS

Study population included 15 smoker male patients in the age group of 35-55 years suffering from moderate generalized chronic periodontitis with history of smoking present. Following parameters were evaluated at baseline, 1 month and 3 months after scaling and root planing: plaque index, bleeding index, probing pocket depth (PD), relative attachment level (RAL), and GCF ALP activity.

STATISTICAL ANALYSIS USED

Independent variables for measurements over time were analyzed by using Wilcoxon signed rank test.

RESULTS

A statistically significant reduction in all the clinical parameters and GCF ALP activity was observed from baseline to 1 month and 3 months. A correlation was observed between change in GCF ALP activity and PD reduction as well as gain in RAL at 3 months.

CONCLUSION

The present study emphasizes that total ALP activity could be used as a marker for periodontal disease activity in smokers. Estimation of changes in the levels of this enzyme has a potential to aid in the detection of progression of periodontal disease and monitoring the response to periodontal therapy.

Gingival crevicular fluid alkaline phosphate activity during the retention phase of maxillary expansion in prepubertal subjects: A split-mouth longitudinal study

INTRODUCTION

The aim of this study was to monitor the alveolar bone formation at the tension sites of teeth supporting the appliances for rapid maxillary expansion (RME) during the retention phase according to the local gingival crevicular fluid (GCF) alkaline phosphatase (ALP) activity.

METHODS

This split-mouth prospective study included 23 prepubertal subjects (15 girls, 8 boys; mean age, 9.0 ± 1.4 years) who had a constricted maxillary arch and were undergoing RME. Periodontal parameters, including probing depth, were recorded at 3 and 6 months after RME. Furthermore, the GCF ALP activity was measured at the tension sites of the supporting test teeth (TT) and at the antagonist control teeth (CT) sites.

RESULTS

Periodontal parameters were generally similar between the TT and CT sites during the study, with the exception that probing depth underwent a slight increase at the TT sites. At baseline, the GCF ALP activity was similar between the TT and CT sites; however, at both 3 and 6 months, significantly greater enzymatic activity was seen at the TT sites. The overall probing depth changes were not significantly correlated with the corresponding GCF ALP activity changes for either the TT or the CT sites.

CONCLUSIONS

Alveolar bone formation at the tension sites would last up to 6 months of retention after RME. These results warrant more comprehensive studies to assess whether the GCF ALP activity has potential as a diagnostic tool for bone formation during the retention phase of RME.

Relationship between Salivary Alkaline Phosphatase Enzyme Activity and The Concentrations of Salivary Calcium and Phosphate Ions

Although salivary alkaline phosphatase (ALP) can balance deand remineralization processes of enamel, there is no evidence regarding its effects on the concentrations of calcium and phosphate in saliva. The present study aims to determine the relationship between salivary ALP activity and the concentrations of calcium and phosphate in saliva. In this cross-sectional study, we evaluated salivary markers in 120 males, ages 19 to 44 years. All participants provided 5 mL of unstimulated whole saliva and the level of enzyme activity as well as calcium and phosphate concentrations were measured using a colorimetric method. Data were gathered and analyzed by statistical package for social sciences (SPSS) 13.00 using Pearson correlation test. A p value of <0.05 was considered statistically significant. The mean age of participants in the present study was 32.95 ± 8.09 years. The mean pH of saliva was 6.65 ± 0.62. Salivary parameters included average ALP activity (5.04 ± 1.866 U/dL), calcium (4.77 ± 0.877 mg/dL) and phosphate (10.38 ± 2.301 mg/dL). Pearson correlation test showed no significant relationship between ALP activity and calcium and phosphate concentrations in saliva (p>0.05). According to the results of the present study, there was no significant relation between salivary ALP activity and calcium and phosphate concentrations in saliva. However, further research is highly recommended.

Mass spectrometric analysis of gingival crevicular fluid biomarkers can predict periodontal disease progression

BACKGROUND AND OBJECTIVE

Gingival crevicular fluid has been suggested as a possible source of biomarkers for periodontal disease progression. This paper describes a technique for the analysis of gingival crevicular fluid from individual sites using mass spectrometry. It explores the novel use of mass spectrometry to examine the relationship between the relative amounts of proteins and peptides in gingival crevicular fluid and their relationship with clinical indices and periodontal attachment loss in periodontal maintenance patients. The aim of this paper was to assess whether the mass spectrometric analysis of gingival crevicular fluid may allow for the site-specific prediction of periodontal disease progression.

MATERIAL AND METHODS

Forty-one periodontal maintenance subjects were followed over 12 mo, with clinical measurements taken at baseline and every 3 mo thereafter. Gingival crevicular fluid was collected from subjects at each visit and was analysed using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Samples were classified based upon pocket depth, modified gingival index (MGI), plaque index and attachment loss, and were analysed within these groups. A genetic algorithm was used to create a model based on pattern analysis to predict sites undergoing attachment loss.

RESULTS

Three hundred and eighty-five gingival crevicular fluid samples were analysed. Twenty-five sites under observation in 14 patients exhibited attachment loss of > 2 mm over the 12-mo period. The clinical indices pocket depth, MGI, plaque levels and bleeding on probing served as poor discriminators of gingival crevicular fluid mass spectra. Models generated from the gingival crevicular fluid mass spectra could predict attachment loss at a site with a high specificity (97% recognition capability and 67% cross-validation).

CONCLUSIONS

Gingival crevicular fluid mass spectra could be used to predict sites with attachment loss. The use of algorithm-generated models based on gingival crevicular fluid mass spectra may provide utility in the diagnosis of periodontal disease.

Gingival crevicular fluid alkaline phosphatase as a potential diagnostic marker of periodontal disease

BACKGROUND

Alkaline phosphatase (ALP) enzyme is involved in the destruction of the human periodontium. The present study was conducted to determine the presence and levels of ALP activity in gingival crevicular fluid (GCF) in periodontal health, gingivitis, and chronic periodontitis.

MATERIALS AND METHODS

GCF samples were collected from 45 sites which were divided into three equal groups of healthy samples and gingivitis and chronic periodontitis samples. Various clinical parameters were evaluated and the levels of ALP were estimated using a semi-autoanalyzer. Analysis of variance was employed to compare the ALP levels in different groups. Pearson's correlation coefficient was utilized to find the correlation between ALP levels and various clinical parameters.

RESULTS

Difference in the mean ALP levels between healthy and gingivitis groups was found to be nonsignificant (P>0.05) and that between the chronic periodontitis group and healthy as well as gingivitis groups was found to be highly significant (P<0.001). Significant correlations existed between ALP levels and gingival index, probing depths, as well as clinical attachment levels.

CONCLUSION

The finding of the present study confirms the relationship between ALP level and periodontal disease, thus indicating that GCF ALP levels can be used as potential biochemical markers for the detection and progression of periodontal disease.

Induction of cytokines, MMP9, TIMPs, RANKL and OPG during orthodontic tooth movement

This controlled longitudinal intervention study investigated changes in cytokines and biomarkers of bone and tissue metabolism within gingival crevicular fluid (GCF) from patients undergoing orthodontic treatment. GCF was collected on Periopaper™ strips (Oraflow Inc., USA) from 20 volunteers at baseline, before tooth extraction and appliance placement and then at intervals during orthodontic treatment. Samples were taken 10 weeks following first appliance placement: at four hours; 7 days; and 42 days after application of distalising forces to maxillary canine teeth. Cytokines (GM-CSF, interferon-gamma, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10 and TNFalpha), tissue biomarkers (MMP-9, TIMP-1 & 2) and bone metabolism indicators (RANKL and OPG) were measured in GCF using multiplex assays. Tension sites adjacent to canines showed significant increases in IL-1beta, IL-8, TNFalpha, MMP-9 and TIMPs 1 and 2 across all time points following force application, while compression sites exhibited increases in IL-1beta and IL-8 after 4 hours, MMP-9 after 7 and 42 days and RANKL after 42 days. These data demonstrate that high levels of pro-inflammatory cytokines and biomarkers of tissue and bone metabolism in GCF are associated with orthodontic force application. Elevated levels were evident at 4 hours but continued for periods of up to 6 weeks. The data suggest that GCF biomarker analysis may help optimise orthodontic forces for individual patients.

Repeatability of gingival crevicular fluid collection and quantification, as determined through its alkaline phosphatase activity: implications for diagnostic use

BACKGROUND AND OBJECTIVE

In spite of four decades of studies on gingival crevicular fluid, no data have been reported on the repeatability of gingival crevicular fluid collection and the subsequent quantification procedures. The present study reports, for the first time, on the repeatability and method error of gingival crevicular fluid collection and quantification, as determined through its alkaline phosphatase (ALP) activity. Diagnostic considerations are then explored.

MATERIAL AND METHODS

Twenty-seven healthy subjects (17 women and 10 men; mean age ± SD, 21.2 ± 4.8 years) with optimal periodontal status were enrolled according to a blind prospective design. The gingival crevicular fluid was collected at baseline, and after 1 d, 1 wk and 3 mo. At each clinical session, two consecutive rounds of gingival crevicular fluid collection were made from each of the four maxillary incisors, allowing the recovery of resting and flow gingival crevicular fluid. The total ALP activities were determined spectrophotometrically, and repeatability and method errors for the resting, flow and overall (resting + flow) gingival crevicular fluid ALP activities were calculated, relative to the corresponding baseline levels.

RESULTS

No significant differences were seen over time, although the flow gingival crevicular fluid ALP activity was generally lower than that for the resting gingival crevicular fluid. The method errors ranged from 40 to 58%, with the flow and overall gingival crevicular fluid activities showing the highest and lowest errors, respectively.

CONCLUSION

Reliable use of the gingival crevicular fluid ALP collection and quantification, both in research and diagnosis on an individual basis, should take into account relevant errors, and variations are to be considered as true only above relevant thresholds.

Mapping biological to clinical phenotypes during the development (21 days) and resolution (21 days) of experimental gingivitis

AIM

To characterize and map temporal changes in the biological and clinical phenotype during a 21-day experimental gingivitis study.

MATERIALS AND METHODS

Experimental gingivitis was induced over 21 days in healthy human volunteers (n = 56), after which normal brushing was resumed (resolution phase). Gingival and plaque indices were assessed. Gingival crevicular fluid was collected from four paired test and contra-lateral control sites in each volunteer during induction (Days 0, 7, 14 and 21) and resolution (Days 28 and 42) of experimental gingivitis. Fluid volumes were measured and a single analyte was quantified from each site-specific, 30s sample. Data were evaluated by analysis of repeated measurements and paired sample tests.

RESULTS

Clinical indices and gingival crevicular fluid volumes at test sites increased from Day 0, peaking at Day 21 (test/control differences all p < 0.0001) and decreased back to control levels by Day 28. Levels of four inflammatory markers showed similar patterns, with significant differences between test and control apparent at Day 7 (substance P, cathepsin G, interleukin-1β, elastase: all p < 0.03) and peaking at Day 21 (all p < 0.002). Levels of α-1-antitrypsin showed no pattern.

CONCLUSIONS

Levels of substance P, cathepsin G, interleukin-1β and neutrophil elastase act as objective biomarkers of gingival inflammation induction and resolution that typically precede phenotypical changes.

Effects of periodontal therapy on GCF cytokines in generalized aggressive periodontitis subjects

AIM

To examine changes in levels of gingival crevicular fluid (GCF) cytokines, after periodontal therapy of generalized aggressive periodontitis (GAgP).

MATERIALS AND METHODS

Twenty-five periodontally healthy and 24 GAgP subjects had periodontal clinical parameters measured and gingival crevicular fluid (GCF) samples collected from up to 14 sites/subject. GCF samples were analysed using multiplex bead immunoassay for: GM-CSF, IFN-γ, IL-10, IL-1β, IL-2, IL-6 and TNF-α. Aggressive periodontitis subjects were randomly assigned to either scaling and root planing (SRP) alone or SRP plus systemic amoxicillin (500 mg) and metronidazole (400 mg) 3 times a day for 14 days. Clinical parameters and GCF cytokines were re-measured 6 months after treatment. Differences over time were analysed using the Wilcoxon test and between groups using the Mann-Whitney test.

RESULTS

Significant reductions in GCF GM-CSF, IL-1β and the ratio IL-1β/IL-10 and increases in GCF IL-6 were detected after therapy. The mean change in GCF cytokines did not differ significantly between groups.

CONCLUSIONS

Periodontal therapy improved GCF cytokine profiles by lowering IL-1β and increasing IL-10 levels. The reduction in GCF GM-CSF after therapy implicates this cytokine in the pathogenesis of GAgP. There was no difference between therapies in changes of GCF cytokines.

Host-derived diagnostic markers related to soft tissue destruction and bone degradation in periodontitis

BACKGROUND

A major challenge in clinical periodontics is to find a reliable molecular marker of periodontal tissue destruction with high sensitivity, specificity and utility.

OBJECTIVES

The aim of this systematic review is to evaluate available literature on 'the utility of molecular markers of soft and hard periodontal tissue destruction'.

MATERIALS AND METHODS

Based on the focused question, 'What is the utility of molecular markers of soft and hard periodontal tissue destruction', an electronic and manual search was conducted for human studies presenting clinical data for the potential of molecular markers of tissue destruction in biofluids; gingival crevicular fluid (GCF), saliva, and serum.

RESULTS

Papers fulfilling the inclusion criteria were selected. All relevant data from the selected papers were extracted and recorded in separate tables for molecules in GCF, saliva, and serum.

CONCLUSION

Within the defined limits of the Problem/Population, Intervention, Comparison, Outcome, the present analysis reveals that (a) no single or combination of markers exists that can disclose periodontal tissue destruction adequately; (b) while the most fruitful source of biomarkers for periodontal destruction appears to be in molecules tightly related to bone and soft tissue destruction, this remains to be objectively demonstrated. Currently, clinical measurements are still the most reliable.

What do 'omic technologies have to offer periodontal clinical practice in the future?

BACKGROUND AND OBJECTIVE

Periodontal diseases are the most common chronic inflammatory diseases of humans and a major cause of tooth loss. Inflammatory periodontitis is also a complex multifactorial disease involving many cell types, cell products and interactions. It is associated with a dysregulated inflammatory response, which fails to resolve, and which also fails to re-establish a beneficial periodontal microbiota. There is a rich history of biomarker research within the field of periodontology, but exemplary improvements in analytical platform technologies offer exciting opportunities for discovery. These include the 'omic technologies, such as genomics, transcriptomics, proteomics and metabolomics, which provide information on global scales that can match the complexity of the disease. This narrative review focuses on the recent advances made in in vivo human periodontal research by use of 'omic technologies.

MATERIAL AND METHODS

The Medline database was searched to identify articles currently available on 'omic technologies with regard to periodontal research.

RESULTS

One hundred and sixty-one articles focusing on biomarkers of and 'omic advances in periodontal research were analysed for their contributions to the understanding of periodontal diseases.

CONCLUSION

The data generated by the use of 'omic technologies have huge potential to inform paradigm shifts in our understanding of periodontal diseases, but data management, analysis and interpretation require a thoughtful and systematic bioinformatics approach, to ensure meaningful conclusions can be made.

Proteomic analysis of a noninvasive human model of acute inflammation and its resolution: the twenty-one day gingivitis model

The 21-day experimental gingivitis model, an established noninvasive model of inflammation in response to increasing bacterial accumulation in humans, is designed to enable the study of both the induction and resolution of inflammation. Here, we have analyzed gingival crevicular fluid, an oral fluid comprising a serum transudate and tissue exudates, by LC-MS/MS using Fourier transform ion cyclotron resonance mass spectrometry and iTRAQ isobaric mass tags, to establish meta-proteomic profiles of inflammation-induced changes in proteins in healthy young volunteers. Across the course of experimentally induced gingivitis, we identified 16 bacterial and 186 human proteins. Although abundances of the bacterial proteins identified did not vary temporally, Fusobacterium outer membrane proteins were detected. Fusobacterium species have previously been associated with periodontal health or disease. The human proteins identified spanned a wide range of compartments (both extracellular and intracellular) and functions, including serum proteins, proteins displaying antibacterial properties, and proteins with functions associated with cellular transcription, DNA binding, the cytoskeleton, cell adhesion, and cilia. PolySNAP3 clustering software was used in a multilayered analytical approach. Clusters of proteins that associated with changes to the clinical parameters included neuronal and synapse associated proteins.

Fluid exudates from inflamed bone-anchored hearing aids demonstrate elevated levels of cytokines and biomarkers of tissue and bone metabolism

OBJECTIVE

The purpose of the current study was to determine the presence of biomarkers of tissue and bone metabolism and 10 cytokines within the fluid exudate from around bone anchored hearing aids (BAHAs), with a view to understanding the mechanisms of peri-BAHA inflammation.

STUDY DESIGN

Fluid exudate from around BAHAs was collected from volunteers (n = 10) with inflammation and controls (n = 10) without inflammation around the BAHA.

SETTING

Studies of periodontitis and dental peri-implantitis have demonstrated that fluid exudate, arising from the hard tissue-soft tissue junction, is increased during disease; this fluid contains biomarkers of tissue metabolism, bone metabolism and inflammation.

PATIENTS

Volunteers were recruited from the Queen Elizabeth Hospital, Birmingham, UK and New Cross Hospital, Wolverhampton, UK.

INTERVENTIONS

This was an observational study and no interventions were carried out as part of the study.

MAIN OUTCOME MEASURE

Biomarkers of tissue metabolism (MMP9, TIMP1 and 2), bone metabolism (RANKL and OPG) and cytokines (GM-CSF, interferon (IFN)-*, IL-1A, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10 and TNF>) were measured in the fluid samples by Luminex multianalyte assay.

RESULTS

Volumes of fluid exudate were significantly higher (p < 0.05) at sites of inflammation than from un-inflamed tissues surrounding BAHAs. IL-1*, IL-6, IL-8, TNF*, MMP9, TIMP1 and 2 were found in both inflamed and un-inflamed samples and levels were significantly higher in samples from inflamed sites. RANKL, IFN*, IL-2, IL-4, and GM-CSF were detected only at inflamed sites whereas OPG, IL-5 and IL-10 were not detected in any samples.

CONCLUSION

These data demonstrate that peri-BAHA tissues showing clinical signs of inflammation are associated with increased fluid exudate, which contains elevated levels of key biomarkers of inflammation and a biomarker profile that is consistent with increased tissue and bone remodeling around BAHAs.

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.

The relationship between periodontal status and alkaline phosphatase levels in gingival crevicular fluid in men with hypergonadotropic hypogonadism

PURPOSE

The aim of this preliminary study was to determine the possible relationship between alkaline phosphatase (ALP) levels in the gingival crevicular fluid (GCF) and periodontal disease in men with hypergonadotropic hypogonadism (HH).

MATERIALS AND METHODS

A total of 41 patients were divided into four groups. 9 with HH and periodontitis (P/HH), 11 with HH and gingivitis (G/HH), 12 with systemically healthy and periodontally healthy (H/C) and 9 with systemically healthy and periodontitis (P/C). The clinical evaluation of patients was based on the following parameters; the plaque index (PI), gingival index (GI), probing depths (PD) and attachment level (AL). The levels of ALP in the GCF were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

No significant difference could be detected in the mean clinical parameter data between the P/HH and P/C groups (p > 0.05). The periodontitis patients in both groups (P/C and P/HH) had higher mean probing depths than the H/C and G/HH patients (p < 0.001). The concentrations and total amounts of ALP in the GCF were significantly higher in both periodontitis groups compared to healthy and gingivitis groups (p < 0.01). The serum ALP levels were significantly higher in the P/HH group when compared to the other groups (p < 0.001).

CONCLUSION

The findings of this study suggested that HH could be implicated as a contributing factor to the progress of periodontal disease.

Gingival crevicular fluid alkaline phosphatase levels in postmenopausal women: effects of phase I periodontal treatment

BACKGROUND

The aim of this study was to determine how estrogen status may possibly influence gingival crevicular fluid (GCF) alkaline phosphatase (ALP) levels in estrogen-deficient (ED) and -sufficient (ES) postmenopausal women at baseline (BL) and 1 year after periodontal phase I treatment (AT).

METHODS

Thirty-six postmenopausal women on estrogen supplements (mean serum estradiol levels >30 pg/ml; estrogen sufficient) and 37 postmenopausal women not on estrogen supplements (mean serum estradiol levels <30 pg/ml; ED) were divided into two subgroups as chronic periodontitis and clinically healthy controls after clinical and radiographic examination. The ES group consisted of 19 control (ES/C) and 17 chronic periodontitis (ES/P) patients, and the ED group consisted of 20 control (ED/C) and 17 chronic periodontitis (ED/P) patients. Plaque (PI) and gingival (GI) indices, bleeding on probing (BOP), probing depths (PD), clinical attachment loss (CAL) scores, and GCF samples were recorded at BL and AT. The levels of ALP in the GCF were measured photometrically. The paired samples Student t and Wilcoxon tests were used to compare the ALP levels and clinical parameters between BL and AT. The correlation among the ALP and clinical parameters was analyzed using the Pearson correlation.

RESULTS

The mean of all clinical parameters (PI, GI, BOP, PD, and CAL) was significantly (P <0.05) higher in periodontitis groups (ES/P and ED/P) than controls (ES/C and ED/C). Periodontitis groups (ES/P and ED/P) demonstrated significantly increased GCF volumes and GCF ALP levels (P <0.05) compared to controls (ES/C and ED/C). There were no significant differences in the concentrations of ALP between periodontitis and control groups (P >0.05). The BL GCF ALP total levels of the ED/P group were significantly higher than the ES/P group (P <0.05). The BL and AT serum ALP levels of the ED/P group were not significantly but were numerically higher than the ES/P group. One year after periodontal treatment, the GCF volume, GCF ALP total, and concentrations decreased significantly in both periodontitis groups (P <0.05). However, the GCF ALP levels were still numerically higher in the ED/P group. A positive statistical correlation was found between total ALP levels and PD (r = 0.621; P <0.05).

CONCLUSION

These data suggest that the presence of ALP in GCF is not simply a reflection of the local inflammation state and that a patient's estrogen status may possibly influence local ALP levels in GCF.

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.

Disease progression: identification of high-risk groups and individuals for periodontitis

AIMS

While the role of bacteria in the initiation of periodontitis is primary, a range of host-related factors influence the onset, clinical presentation and rate of progression of disease. The objectives of this review are (1) to present evidence for individual predictive factors associated with a patient's susceptibility to progression of periodontitis and (2) to describe the use of prognostic models aimed at identifying high-risk groups and individuals in a clinical setting.

METHODS

Relevant publications in the English language were identified after Medline and PubMed database searches. Because of a paucity of longitudinal studies investigating factors including clinical, demographic, environmental, behavioural, psychosocial, genetic, systemic and microbiologic parameters to identify individuals at risk for disease progression, some association studies were also included in this review.

FINDINGS AND CONCLUSIONS

Cigarette smoking is a strong predictor of progressive periodontitis, the effect of which is dose related. High levels of specific bacteria have been predictive of progressive periodontitis in some studies but not all. Diabetics with poor glycaemic control have an increased risk for progression of periodontitis. The evidence for the effect of a number of putative factors including interleukin-1 genotype, osteoporosis and psychosocial factors is inconclusive and requires further investigation in prospective longitudinal studies. Specific and sensitive diagnostic tests for the identification of individuals susceptible to disease progression are not yet a reality. While factors assessed independently may not be valuable in predicting risk of future attachment loss, the combination of factors in a multifactorial model may be useful in identifying individuals at risk for disease progression. A number of multifactorial models for risk assessment, at a subject level have been developed but require validation in prospective longitudinal studies.

Ability of Examiners to Estimate the Pain Experienced by Patients From Probing During Initial Periodontal Examination

BACKGROUND

The aims of the present study were to identify the level of pain experienced by patients from probing during periodontal examination, and to determine to what extent the examining periodontist and the dental assistant could estimate the degree of pain experienced by the patients.

METHODS

For each of three periodontists, 20 patients referred for periodontal diagnosis and treatment were selected. The periodontist carried out his examination, which included probing at six sites per tooth. Following probing, the patients rated the pain using a visual analog scale (VAS). The periodontist and the dental assistant who helped out during the examination independently rated the pain level they perceived that each patient experienced, also using a VAS.

RESULTS

Most patients showed low pain responses to probing. However, using an arbitrary threshold of VAS > or =40 mm to indicate significant pain, some patients had a painful experience. Differences were observed between the pain levels expressed by the three groups of patients. While two of the three periodontists were able to appraise the pain experienced by their patients, the third was not.

CONCLUSIONS

It seems important that the periodontist at the first encounter with the patient should be sensitive to the discomfort the examination may entail. This may influence the patients' decision to accept the required treatment, and may also affect the patients' attitude to and co-operation with the subsequent treatment.

Mechanisms of action of environmental factors--tobacco smoking

AIM

To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis.

MAIN FINDINGS

Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers. Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity.

CONCLUSION

Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment.

Crevicular fluid levels of TGFβ1 in drug-induced gingival overgrowth

OBJECTIVE

To determine if local, gingival crevicular fluid (GCF) levels of TGFbeta1 were altered in drug-induced gingival overgrowth.

PATIENTS AND METHODS

GCF samples were collected on Periopaper strips from 45 renal transplant recipients who had been medicated with cyclosporin or cyclosporin in combination with other putative overgrowth-inducing drugs for a minimum of 6 months. Twenty-two subjects had gingival overgrowth while the other 23 patients showed no signs of gingival changes and constituted the medicated control group. Non-medicated controls consisted 20 periodontally healthy individuals who had never taken overgrowth-inducing drugs. GCF levels of TGFbeta1 and alkaline phosphatase, a marker of inflammation, were determined by enhanced chemiluminescence ELISA and enzyme activity assays, respectively.

RESULTS

TGFbeta1 levels in GCF from overgrowth and non-overgrowth sites in overgrowth sufferers did not differ. However, there were significant differences in median concentration (P = 0.001) and GCF levels of TGFbeta1 per sample (P = 0.05) between study groups with overgrowth patients having higher amounts per sample and lower concentrations than medicated and healthy controls. Median levels of alkaline phosphatase per GCF sample differed between site (P = 0.01) with higher levels present at overgrowth sites. Despite this, the concentration of enzyme in GCF did not differ between site or patient group.

CONCLUSIONS

GCF TGFbeta1 detected in overgrowth patients could reflect a higher level of gingival inflammation because of difficulties in plaque control consequent on the development of overgrowth. However, the higher local levels of total TGFbeta1 in overgrowth patients could indicate that it is a risk factor for developing gingival overgrowth.

Advances in periodontal disease markers

A computer-assisted medline search was conducted to find the relevant articles concerning the periodontal disease markers in gingival crevicular fluid (GCF) and saliva published during the 10-year period from 1993 to July 2003. This review suggests that certain diagnostic uses of saliva and GCF show promise. Although both fluids have been used to evaluate the risk for an individual to develop periodontal disease and to monitor of the host response to periodontal therapy, GCF has the chance of being closely approximated to the periodontal tissues where periodontal disease begins. The enzymes contributed to extracellular matrix (ECM) molecules and non-ECM molecules degradation and markers for polymorphonuclear leukocytes (PMN) activity and influx into the gingival tissue seem to provide valuable information regarding the periodontal disease diagnosis and prognosis. There is also an increasing evidence implicating reactive oxygen species and nitric oxide pathway in the pathogenesis of periodontal diseases. Although promising results have been achieved with the assays evaluating the markers in assessment of periodontal disease status, up to now, none of these tests are used routinely. Further, one commercially available genetic test has been reported to have the potential to be used to predict the periodontal disease, but there are controversial reports on this genetic susceptibility test.

Pain Experienced by Patients During Periodontal Maintenance

BACKGROUND

The aims of this study were to determine: 1) the degree of pain experienced by patients during probing and debridement; 2) whether the treating hygienists could estimate the degree of pain experienced by the patients; and 3) whether the patients' pain responses could be predicted by factors such as the patients' age, gender, number of residual periodontal lesions, and answers to a questionnaire on dental anxiety.

METHODS

Prior to periodontal maintenance procedures, two groups of 20 adult patients to be treated by two hygienists completed an anxiety questionnaire. Subsequently, measurements of probing depths were performed, followed by pain ratings by each patient using a visual analog scale (VAS). The hygienists also completed a VAS, estimating the pain level they perceived their patient to have experienced. The same protocol was repeated for instrumentation (debridement).

RESULTS

Most patients showed low pain responses to both probing and instrumentation. However, using an arbitrary threshold of VAS > or = 40 mm, 20% to 33% of the patients had a significant pain experience. The hygienists were quite accurate in their relative estimates of their patients' pain experiences. Regression analyses disclosed that significant portions of the pain responses could be predicted by the patients' answers to one of the dental anxiety questions.

CONCLUSIONS

Recognition of patients who are likely to experience significant pain during periodontal treatment may be facilitated by the use of one question on dental anxiety. During treatment, the ability to gauge and respond to patients' pain experiences would seem to be an important component of a therapist's clinical skills.

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.

Levels of TGFbeta1 in gingival crevicular fluid during a 21-day experimental model of gingivitis

OBJECTIVE

TGFbeta1 is a multifunctional growth factor with both pro- and anti-inflammatory properties. This study aimed to determine levels of TGFbeta1 in gingival crevicular fluid (GCF), serum and plasma in the early stages of gingival inflammation.

DESIGN

A 21-day experimental model of gingivitis employing a split mouth design with a soft vinyl splint used to cover test teeth during brushing.

SUBJECTS

Ten healthy volunteers (mean age 21 years; five males and five females).

METHODS

GCF and blood (with and without EDTA) was collected on days 0, 7, 14 and 21. GCF volumes were measured on a precalibrated Periotron 8000TM. Clinical indices of gingival inflammation and plaque levels were obtained after GCF sampling. Normal brushing resumed after GCF collection on day 21 and final samples were collected on day 35. TGFbeta1 and alkaline phosphatase (ALP) levels were determined using enhanced chemiluminescent methods.

RESULTS

Clinical indices and GCF volumes increased at test sites during the 21-day test period. Concentrations of TGFbeta1 and ALP in GCF (test and control), serum and plasma did not change throughout the study (P > 0.3). However, total amounts of TGFbeta1 (pg sample-1) and ALP (mu IU sample-1) in GCF increased at test sites and were significantly higher than baseline values at days 7, 14 and 21 (P < 0.04). Control sites showed no variation in TGFbeta1 or ALP levels throughout the study period (P > 0.35). All parameters at test sites returned to control levels at day 35 (P > 0.3).

CONCLUSION

The data indicate that GCF TGFbeta1 levels increase early in plaque-induced inflammation. Whether the biological consequence of this site-specific increase is pro- or anti-inflammatory in nature remains to be elucidated.

Mediators of periodontal osseous destruction and remodeling: principles and implications for diagnosis and therapy

Osteoclastic bone resorption is a prominent feature of periodontal disease. Bone resorption via osteoclasts and bone formation via osteoblasts are coupled, and their dysregulation is associated with numerous diseases of the skeletal system. Recent developments in the area of mediators of osteoclastic differentiation have expanded our knowledge of the process of resorption and set the stage for new diagnostic and therapeutic modalities to treat situations of localized bone loss as in periodontal disease. This review describes the current state of knowledge of osteoclast differentiation and activity, mediators, and biochemical markers of bone resorption and their use and potential use in clinical periodontics. Finally, therapeutic strategies based on knowledge gained in the treatment of metabolic bone diseases and in periodontal clinical trials are discussed, and the potential for future strategies is proposed relative to their biologic basis. The intent is to update the field of periodontics on the current state of pathophysiology of the osteoclastic lesion and outline diagnostic and therapeutic strategies with a rational basis in the underlying biology.

Alkaline phosphatase activity in gingival crevicular fluid during human orthodontic tooth movement

Bone remodeling that occurs during orthodontic tooth movement is a biologic process involving an acute inflammatory response in periodontal tissues. A sequence characterized by periods of activation, resorption, reversal, and formation has been recently described as occurring in both tension and compression tooth sites during orthodontic tooth movement. We used a longitudinal design to investigate alkaline phosphatase (ALP) activity in gingival crevicular fluid (GCF) to assess whether it can serve as a diagnostic aid in orthodontics. Sixteen patients (mean age, 15.5 years) participated in the study. The maxillary first molars under treatment served as the test teeth (TT) in each patient; in particular, 1 first molar was to be retracted and hence was considered the distalized molar (DM), whereas the contralateral molar (CM) was included in the fixed orthodontic appliance but was not subjected to the distal forces. The DM antagonist first molar (AM), free from any orthodontic appliance, was used as the baseline control. The GCF around the experimental teeth was harvested from mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. The clinical gingival condition was evaluated at the baseline and at the end of the experimental term. ALP activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total ALP activity (mUnits/sample). GCF ALP activity was significantly elevated in the DMs and the CMs as compared with the AMs at 1, 2, 3, and 4 weeks; conversely, in the AMs, GCF ALP activity remained at baseline levels throughout the experiment. Moreover, the enzyme activity in the DMs was significantly greater than in the CMs. In the DMs, a significantly greater ALP activity was observed in sites of tension compared with sites of compression. This difference was not seen with the CMs, in which the enzyme activity increased to the same extent in tension and compression sites. These results suggest that ALP activity in GCF reflects the biologic activity in the periodontium during orthodontic movement and therefore should be further investigated as a diagnostic tool for monitoring orthodontic tooth movement in clinical practice.

Elastase, alpha2-macroglobulin and alkaline phosphatase in crevicular fluid from implants with and without periimplantitis

The aim of this investigation was to determine the presence of selected enzymes and enzyme inhibitors in crevicular fluid collected from implants with and without clinical, radiographic and microbiological signs of periimplantitis. Eleven implants with symptoms of periimplantitis in eight patients (four men and four women) were compared to eleven implants in seven subjects (one man and six women) without periimplantitis. Periimplant crevicular fluid (PICF) was collected at the mesial and distal sites of each implant. Alkaline phosphatase activity (ALP) was measured by using p-nitrophenyl-phosphate as substrate, elastase activity (EA) by the use of a low molecular weight fluorogenic substrate, and the inhibitor alpha2-macroglobulin (alpha2M) by ELISA. ALP, EA and alpha2M were detected in the majority of samples in both groups. In comparison to the clinically healthy implants, total amounts of each of these substances were significantly higher in PICF collected around implants with periimplantitis. The mean total amounts of EA, alpha2M and ALP in the healthy group were: EA: 1.8 ng, alpha2M: 3.1 ng, ALP: 24.1 U, and in the periimplantitis group EA: 23.1 ng, alpha2M: 25.2 ng and ALP: 142.3 U. In addition, all three mediators were correlated with the clinical parameters. The results confirm the similarity of the inflammatory response of tissues surrounding implants and natural teeth, and suggest that ALP and EA could be promising markers of bone loss around dental implants.

Pain experienced by patients during periodontal maintenance treatment

BACKGROUND

The aims of this study were to assess the degree of pain experienced by patients during probing and debridement and to determine whether the pain responses could be predicted by the patient's age, gender, percentage of sites > or = 4 mm deep, and responses to a questionnaire on dental anxiety.

METHODS

Prior to the maintenance procedures, 26 adult patients completed an anxiety questionnaire. Subsequently, measurements of probing depths were performed. The patients activated a tallying device at each probe entry that evoked pain (pain frequency). Pain levels for each quadrant were also assessed with a visual analog scale (VAS). Following probing, the same protocol was repeated during instrumentation (debridement).

RESULTS

Most patients showed low pain responses to both probing and instrumentation as evaluated by both methods of measurement. However, using arbitrary thresholds of pain frequency > or = 50% and VAS > or = 40 mm, approximately 15% of the patients had a painful experience. Stepwise multiple regression analyses disclosed that significant portions of the pain levels could be predicted by gender and the patients' answers to 2 of the dental anxiety questions.

CONCLUSIONS

Recognition of patients who are likely to experience pain during periodontal treatment can be facilitated by the use of 2 questions on dental anxiety and the VAS response to probing during examination.

Clinical, radiographic and biochemical assessment of IL-1/TNF-alpha antagonist inhibition of bone loss in experimental periodontitis

OBJECTIVES

To assess clinical, radiographic, and biochemical markers as diagnostic indicators of disease activity by comparing ligature-induced bone loss in the presence or absence of IL-1/TNF-alpha antagonist inhibition of bone loss in a primate model.

MATERIAL AND METHODS

6 animals with a naturally-occurring gingivitis were evaluated over a 6-week time period following the placement of silk ligatures and initiation of a soft diet. Three animals received intrapapillary injections of soluble receptors (blockers), capable of blocking the biologic activity for both IL-1 and TNF-alpha, and 3 animals received vehicle (control) injections. Injections were given 3X per week over the course of the study. Clinical assessments included a gingival index and quantification of gingival crevicular fluid (GCF) levels. Collected GCF samples were then used in the biochemical assessment of pyridinoline (PYD) and bone alkaline phosphatase (BAP). Radiographic assessment was made using computer-assisted subtraction radiography to measure both bone density (CADIA) values and linear changes in crestal bone height.

RESULTS

Significant (p<0.01) changes using both radiographic measures occurred between 2 and 4 weeks following initiation of disease in this model. The use of the blockers significantly (p<0.01) reduced the levels of radiographic bone loss by approximately 50% over that found in the control sites. Both biochemical markers showed the greatest increase during the first two weeks of the study with PYD levels increased 35-fold over baseline levels after 1 week. This difference in response was significantly (p<0.05) greater than the levels found in the non-ligated teeth or in the ligated teeth receiving blockers injections. BAP levels showed significant increases in ligated teeth compared to non-ligated teeth, but failed to show any significant differences between animals treated with vehicle and those treated with IL-1/TNF antagonists. In contrast to these radiographic and biochemical effects, there were no significant differences detected between animals treated with antagonists and the control group for any of the clinical measures.

CONCLUSIONS

The results of this study demonstrate that both subtraction radiography and PYD crevicular fluid levels can detect relative differences in periodontal disease progression, while BAP crevicular fluid levels cannot.