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Notes: Abstract. The current study aimed to apply a novel enhanced chemiluminescence assay in the analysis of gingival crevicular fluid (GCF) alkaline phosphatase (ALP) levels from patients with untreated adult periodontitis. 3666 sites in 25 patients were monitored prior to and after attachment loss was detected with a Florida disc probe. Parameters assessed were, relative attachment level, probing pocket depth, occurrence of bleeding on probing (single episode), GCF volume (μl), total ALP levels (μIU/30 s sample time) and ALP concentration (IU/l). After recruiting patients to the study, all measures were taken at baseline and 3 months later, prior to the institution of non-surgical periodontal therapy at active sites. Thresholds for determining attachment loss were calculated using a modification of the tolerance method. The mesio-buccal sites of all teeth had GCF samples collected. The size of individual patient thresholds used to define whether attachment loss had occurred, was dependent upon the discomfort felt by that patient during electronic probing, with a positive correlation existing between discomfort on probing (10 cm visual analogue scale) and threshold size (R=0.52, p〈0.049). A total of 274 sites (7.5%) experienced attachment loss of which 39 sites had GCF samples available for analysis. Total ALP levels were significantly higher at baseline for sites that progressed to attachment loss than paired controls (p〈0.003), but all other parameters showed no differences (p〉0.1). There were significant increases in total ALP levels and GCF volumes for active sites between baseline and 3 month measures (p〈0.01), but not for control sites or test site ALP concentration (p〉0.8). The diagnostic accuracy for GCFALP as a predictor of future attachment loss (threshold 900 μIU/30 s) was 64%, with +ve and −ve predictive values of 62% and 68%. When a threshold of 1300 μIU/30 s was selected for ALP as a marker of recent or currently active disease, diagnostic accuracy and +ve/−ve predictive values were 77% and 77%/76%, respectively. These results indicate that total GCF ALP levels may serve as a predictor of future or current disease activity.

Notes: Abstract. Using a recently developed chemiluminescent assay enabling alkaline phosphatase (ALP) quantification in nanolitre volumes of gingival crevicular fluid (GCF), we have investigated GCF ALP levels in health and in the presence of gingivitis. In gingival health, there was a site-specific pattern of ALP concentration with higher enzyme concentrations around the upper and lower anterior teeth. Furthermore, clinically normal sites that had been subjected to different levels of plaque control produced significantly different ALP levels, (p 〈 0.03). This indicates that biochemical components of GCF may be used to measure sub-clinical inflammatory status. The ratio of GCF to serum ALP varied from 6:1 to 11:1, suggesting that a major source of the enzyme is through local production. The main cross-sectional study of 30 patients with gingivitis (276 sites) demonstrated that total GCF ALP levels, collected over a 30-s sampling time were higher for a gingival index of 1 than of 0 (p 〈 0.014). There was no significant relationship between total GCF ALP and plaque levels of the enzyme, and analysis of plaque within the study group demonstrated very low levels of ALP, indicating that the enzyme is likely to be largely derived from the periodontal tissues. The ratio of GCF ALP levels to those of saliva within individuals was 530:1, thereby eliminating saliva contamination as a risk, when total GCF ALP is being measured.

Notes: Abstract Hypophosphatasia is rare enzymopathy that normally presents within the first few years of life and often has profound effects upon the periodontiurn. It is a heritable disorder characterised by defective mineralisation of the skeletal and dental structures of the body and a deficiency in the liver/bone/kidney (L/ B/K) isoenzyme of alkaline phosphatase (ALP), There has been a tremendous advance in our knowledge of this condition over the last decade due to the advent of highly specific DNA probes and novel microanalytical techniques. This paper aims to review current literature about hypophosphatasia with special reference to the dental aspects of the condition and to shed light upon the controversial area of its mode of genetic: inheritance. It is concluded that hypophosphatasia may result from the existence of 2 defective alleles, which alone or in combination may cause the condition, One allele is expressed in an autosomal dominant manner producing milder phenotypic characteristics, whilst the other is expressed in an autosomal recessive manner producing the more severe clinical form that often results in neonatal death. The milder phenotypes may go undiagnosed and the consequence of this in genetic counselling terms is extremely important.

Notes: Background: The involvement of reactive oxygen species (ROS) in periodontal pathology is unclear but will be modulated by in vivo antioxidant defence systems. The aim of this cross-sectional study was to determine both local (saliva and gingival crevicular fluid (GCF) and peripheral (plasma and serum) antioxidant capacity in periodontal health and disease.Materials and Methods: Twenty non-smoking volunteers with chronic periodontitis were sampled together with twenty age- and sex-matched, non-smoking controls. After overnight fasting, saliva (whole unstimulated and stimulated) and blood were collected. Total antioxidant capacity (TAOC) was determined using a previously reported enhanced chemiluminescence method.Results: GCF antioxidant concentration was significantly lower (p〈0.001) in periodontitis subjects compared to healthy controls. Although mean levels of peripheral and salivary TAOC were also lower in periodontitis the difference was only significant for plasma (p〈0.05). Healthy subjects' GCF antioxidant concentration was significantly greater than paired serum or plasma (p〈0.001). Data stratified for gender did not alter the findings and a male bias was revealed in all clinical samples except GCF.Conclusions: These findings suggest that the antioxidant capacity of GCF is both qualitatively and quantitatively distinct from that of saliva, plasma and serum. Whether changes in the GCF compartment in periodontitis reflect predisposition to or the results of ROS-mediated damage remains unclear. Reduced plasma total antioxidant defence could result from low-grade systemic inflammation induced by the host response to periodontal bacteria, or may be an innate feature of periodontitis patients.

Notes: Background: C1-esterase inhibitor (C1eIn) is an important modulator of complement activation via the classical pathway. Deficiencies or dysfunction involving this inhibitor underlie the condition of angioneurotic oedema.〈section xml:id="abs1-2"〉〈title type="main"〉Aim: The purpose of this report is to describe a female patient who presented at the age of 24 years with an apparently aggressive form of periodontitis and severe oedema, localised to the free gingival tissues. After 21 years of repeated surgical reduction of the gingiva, a diagnosis of C1eIn dysfunction was made.〈section xml:id="abs1-3"〉〈title type="main"〉Methods: Exhaustive serological investigations were performed along with histopathology.〈section xml:id="abs1-4"〉〈title type="main"〉Results: All investigations were unremarkable, until the function of the C1eIn molecule was investigated. These demonstrated a functional activity of only 29% and a raised C1q at 157 mg/l. Subsequent repeated investigation with careful specimen handling demonstrated undetectable levels of C1eIn and normal C1q. A diagnosis of C1eIn dysfunction was made, although at present it is unclear whether this represents an unusual variant of hereditary dysfunctional C1eIn deficiency. The patient was managed by various means, including steriodal and non-steroidal drugs, the latter forming part of her maintenance regime.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions: To our knowledge, this is the first case of angio-oedema localised to the free gingiva. The role of stress in the acute exacerbations of oedema and bone loss is discussed along with the diagnostic pitfalls associated with this case.

Notes: Abstract The sonic sealer operates at frequencies of 2 to 6 kHz and is powered by pressurised air from the dental unit. Variables likely to affect how these instruments perform include the air pressure input and load applied by the operator. Other variables include the brand of sealer used and the clinical technique of the operator. The aim of this study was to investigate differences in instrument performance within a dental teaching hospital. Light microscopy was used to measure the displacement amplitudes in air of 32 Sonic sealers which were in regular clinical use in three departments (Periodontal Unit, Restorative Unit and School of Hygiene). During operation, the air pressure was kept at a constant 2.8 kg cm−2and measurements were made on each instrument with three scaling tips (universal, sickle and periodontal). The periodontal scaling tip exhibited the greatest vibration although this was not significant (p〉0.1). There was a significant difference in performance between the different clinical environments where the sealers were used (P〈0.01). 4 new sonic scaling instruments made by different manufacturers were selected for displacement amplitude measurements. One brand of sonic sealer demonstrated a significantly greater displacement amplitude in comparative measurements between instruments (P〈0.01). This study demonstrated differences in the oscillation of sonic sealers which should be recognised by clinicians when using these instruments, since they may influence clinical performance.

Notes: This paper aims to review the role of free radical-induced tissue damage and antioxidant defence mechanisms in inflammatory diseases that involve pathogenic processes similar to the periodontal diseases. There is a clearly defined and substantial role for free radicals or reactive oxygen species (ROS) in periodontitis. but little research has been performed in this area. This paper reviews the considerable data available relating ROS activity and antioxidant deference to inflammatory diseases and attempts to draw parallels with periodontitis. in an effort to stimulate more periodontal research in this important area. The recent discovery of the transcription factor nuclear factor κB (NF-κB) is reviewed and several potential pathways for cytokine-induced periodontal tissue damage, mediated by NF-κB, are discussed. Emphasis is placed on cytokines that have been studied in periodontitis. principally TNF-α IL-I, IL-6. IL-8 and β-interferon. The link between cellular production of such important mediators of inflammation and the antioxidant (AO) thiols. cysteine and reduced glutathione (GSH), is discussed and it is hypothesised that NF-κB antagonists may offer important therapeutic benefits.

Notes: Hypophosphatasia is an inherited disorder characterized by defective mineralization of the skeletal and dental structures of the body and deficient liver/bone/kidney alkaline phosphatase (L/B/K ALP) activity. There has been a tremendous advance in our knowledge of this condition over the last decade due to the advent of highly specific DNA probes and novel microanalytic techniques. The purpose of this paper is threefold: to review the dental aspects of current literature about this rare condition; to present a case (and family study) that was diagnosed in a 5-yr-old boy from 0.14 μl of gingival crevicular fluid, using a new ultrasensitive chemiluminescent assay for the enzyme alkaline phosphatase; and to provide strong evidence for an autosomal dominant mode of inheritance.

Notes: This paper reports the detailed calibration of the new Periotron 8000® with different fluids and uses the method of least squares to derive polynomial regression equations up to the 6th order, to investigate the most accurate descriptor of the resulting calibration lines. The use of a 4th order polynomial regression equation (recommended by the manufacturer) provided better coefficients of determination (R2: 0.999) and root mean square errors (RMSE = 1.6) than either linear regression (R2: 0.986, RMSE = 10.9) or quadratic models (R2: 0.998, RMSE = 3.2). Data derived using the manufacturer's MLCONVERT software program lacked accuracy and incurred large errors for volumes 〉 0.5 μl. Calibrations performed on one day could be used with accuracy to derive volumes 〉0.1 μl collected on subsequent days, when using the same machine (s.d. for residuals plot=2.49 Periotron units), but this was not the case for different machines (s.d. = 9.57 Periotron units). Varying serum protein concentration by up to 500% had a negligible effect on calculated volumes above 0.1 μl. We conclude that the Periotron 8000® is at least as reliable a machine as the Periotron 6000®, and that the calibration lines for both machines are best described using 4th order polynomial regression equations and “look-up” tables, rather than quadratic (Periotron 6000®) or the manufacturer's software (Periotron 8000®). Serum seems to be an acceptable GCF substitute for calibrations, which can be performed 1 day, and used on subsequent days for a given machine and for volumes above 0.1 μl.

Notes: The search for markers of periodontal disease activity and progression has accelerated over the last decade, in an effort to replace existing subjective clinical measures of periodontal health status. Research is being aimed at establishing more objective and quantitative methodology, capable of rapid diagnosis prior to the appearance of clinical signs of destructive disease. Such tests need to be sensitive enough to evaluate individual periodontal sites in health as well as disease states. We report the development of a new chemiluminescent assay for the enzyme alkaline phosphatase, that is capable of quantifying the enzyme in sub-microliter volumes of gingival crevicular fluid and serum. The technique will measure alkaline phosphatase (ALP) whilst immobilised on paper strips, without the need for an elution stage. It is simple, versatile and amenable to chair-side use. We discuss in detail the assay procedure and have examined levels of ALP in 11 adult volunteers with clinically healthy periodontal tissues. The mean ALP concentration was 2135 IU/L for GCF and 183 IU/L for serum, a 12-fold difference. There also appeared to be an “oral pattern” of enzyme distribution in healthy periodontal sites, with levels being higher in the anterior region of the mouth and highest in the lower anterior region.