Periodontitis is associated with altered plasma fatty acids and cardiovascular risk markers.

BACKGROUND AND AIMS: In periodontitis it has been found that some perturbation exists in lipid biomarkers, such as increased serum total cholesterol and low-density lipoprotein cholesterol. Nevertheless, the relationship between fatty acids and periodontitis has been demonstrated only in a few studies and remains controversial. The aim of this investigation was to explore the effects of periodontitis on a cluster of traditional and novel cardiovascular risk factors such as plasma-lipids profile, types of plasma fatty acids, adhesion molecules and systemic inflammatory markers. METHODS AND RESULTS: At a university dental school, 56 patients all over 35 years old were enrolled and invited to participate in the study. Total plasma fatty acids, saturated, n-6 polyunsaturated and monounsaturated fatty acids, peroxidability index, soluble VCAM, TNF-alpha, cholesterol, triacylglycerols, and VLDL-c were significantly higher in the periodontitis group compared to the non-periodontitis group. CONCLUSIONS: This close association found between plasma triacylglycerols, LDL-c, saturated fatty acids, polyunsaturated fatty acids, total amount of fatty acids and coenzyme Q(10) with some periodontal data such as periodontal probing depth, recession of the gingival margin and clinical attachment level (Pearson correlation between 0.3 and 0.6), leads to the conclusion that there is an inter-relationship between periodontitis, plasma fatty acids profile and the increase in metabolic risk factors for cardiovascular diseases.

Metabolic syndrome and periodontitis: is oxidative stress a common link?

A review of pathological mechanisms that can explain the relationship between periodontitis and cardiovascular disease (CVD) is necessary to improve the management of both conditions. Metabolic syndrome is a combination of obesity, hypertension, impaired glucose tolerance or diabetes, hyperinsulinemia, and dyslipidemia. All these have been examined in recent years in terms of their relationship to periodontitis. Reviewed data indicate an association between some of them (body mass index, high-density lipoprotein-cholesterol [HDL-C], triglycerides, high blood pressure, among others) and periodontitis. Oxidative stress may act as a potential common link to explain relationships between each component of metabolic syndrome and periodontitis. Both conditions show increased serum levels of products derived from oxidative damage, with a pro-inflammatory state likely influencing each other bidirectionally. Adipocytokines might modulate the oxidant/anti-oxidant balance in this relationship.

Nifedipine and cyclosporin affect fibroblast calcium and gingiva.

It has been stated that cyclosporin and nifedipine produce gingival overgrowth. However, the specific pathogenic mechanism remains uncertain. We used an experimental rat model to test the hypothesis that changes in collagen metabolism and numbers of gingival blood vessels are not mediated by intracellular calcium concentration (ratiometric Fura-2 AM measurement) in gingival fibroblasts. In the cyclosporin group, both width (364.2 +/- 67.5 mum) and microvessel density (number of vessels/mm(2), stained with anti-CD34 antibody) (41.6 +/- 5.1) of gingiva were statistically different when compared with those in the control group (width = 184.3 +/- 35.2 mum, microvessel density = 19.6 +/- 2.4). The nifedipine group showed the highest content of collagen (proportion of total stroma occupied by collagen, stained with Picro-Mallory) (nifedipine group = 66.3 +/- 9.4, cyclosporin group = 55.2 +/- 7.9, control group = 30.1 +/- 10.2). Freshly cultured fibroblasts from the cyclosporin group exhibited higher ratiometric values of fluorescence than did both the control and nifedipine groups (p = 0.03). Our results support the hypothesis that changes in gingival collagen metabolism are not mediated by calcium intracellular oscillations.

The effects of a supervised toothbrushing programme on the caries increment of primary school children, initially aged 5-6 years.

Children in the London Boroughs of Kensington, Chelsea and Westminster have one of the highest levels of caries in England and Wales. In 1997/98, the mean dmft for 5-year-old children was 2.83 with only 45.9% of the children being caries free. The aim of this study was to determine whether teacher-supervised toothbrushing, once a day, at school, during term time, with commercial toothpaste containing 1,450 ppm fluoride, could reduce dental caries in primary school children when compared with children from the same community who did not receive this intervention. A total of 517 children (mean age 5.63 years) were recruited for the study. Class teachers were trained individually by the same dental hygienist in an appropriate toothbrushing technique for young children. Children in the intervention group brushed once a day at school. All examinations were by visual assessment only. All teeth present were assessed using the BASCD criteria. For children in the intervention group, the overall caries increment (2.60) was significantly less (10.9%; p < 0.001) than for children in the non-intervention group (2.92). Among different tooth surfaces, the difference in caries increment between the intervention group (0.78) and the non-intervention group (1.03) was greatest for the proximal surfaces (21.4%; p < 0.01). In conclusion, this study suggests that a programme of daily teacher-supervised toothbrushing with fluoride toothpaste can be effectively targeted into socially deprived communities and a significant reduction in dental caries can thereby be achieved especially among caries-susceptible children.

Clinical evaluation of ferric oxalate in relieving dentine hypersensitivity.

Previous in vitro permeability and scanning electron microscopic (SEM) studies have demonstrated the effectiveness of the oxalate ion in dentine permeability reduction and effective tubule occlusion. The aim of this randomized double-blind, split mouth 4-week clinical study, therefore was to determine whether a 1-min application of ferric oxalate (Sensodyne Sealant) on exposed root dentine was effective in reducing dentine hypersensitivity (DH). Thirteen subjects [8F:5M, mean age 46.2 (s.d. 4.15) years] completed the study. The subjective response was evaluated by tactile, thermal and evaporative methods of assessment. Data were collected at baseline and post-application at +5 min and 4 weeks. Analysis was based on paired t-test (P=0.05) and Wilcoxon-Mann-Whitney tests. No statistically significant differences were noted between ferric oxalate and placebo preparations at +5 min and 4 weeks for any of the test stimuli. There was, however, a clear trend towards immediate reduction (+5 min) in DH reverting back to baseline values at 4 weeks with the exception of the Biomat Thermal Probe mean values, which maintained the reductions in DH compared with placebo. The results of the present study demonstrated that a 1-min application of ferric oxalate is both rapid and effective in reducing DH although its long-term effectiveness still needs to be determined.

A survey of dental hygienist numbers in Canada, the European Economic area, Japan and the United States of America in 1998.

OBJECTIVE: The aims of this study were to establish how many dental hygienists were licensed to practice in Canada, Japan, USA and the 18 member states of the European Economic Area (EEA) and to compare these with the populations and numbers of dentists practising in the countries concerned. METHOD: Data for the overall populations, numbers of 'active' dentists, of dental hygienists and of employed dental hygienists in the member states of the EEA in 1998 were taken from the responses to a Council of European Chief Dental Officers survey carried out in 2000/2001. Data for these variables for Canada, Japan and the USA in 1998 were accessed from published reports. The ratios of population: active dentist; population: dental hygienist; and active dentist: dental hygienist were calculated and compared. RESULTS: The overall populations and total number of active dentists in the 18 EEA member states and Canada plus Japan plus the USA were broadly similar in 1998 (EEA overall population 381 million with 245169 active dentists: Canada/Japan/USA overall population 421 million with 253825 active dentists). However, there were only 13295 dental hygienists in the EEA as opposed to a total of 215435 in Canada, Japan and the USA. In terms of population:dental hygienist and active dentist: dental hygienist ratios the UK was found to have proportionally far fewer dental hygienists than Canada, Japan, USA or the four Nordic members of the EEA. CONCLUSION: The survey revealed that relative to overall populations and numbers of dentists, there are far fewer dental hygienists in the EEA than in Canada, Japan and the USA and that scope for the UK to import dental hygienists from other EEA member states is probably very limited.

Keratinocyte growth factor receptor is up-regulated in cyclosporin A-induced gingival hyperplasia.

Keratinocyte growth factor stimulates the growth and activity of epithelial cells via the keratinocyte growth factor receptor. We have recently shown that the growth factor is markedly elevated in cyclosporin A-induced gingival hyperplasia tissue in vivo, but the effects of cyclosporin A on the receptor are not yet known. The present study was therefore carried out to determine whether expression of the keratinocyte growth factor receptor is up-regulated in gingival hyperplasia compared with normal gingiva. Using immunohistochemistry and the reverse-transcribed polymerase chain-reaction, we obtained results which showed that receptor antigen and gene transcript levels were both elevated in gingival hyperplasia tissue. In addition, flow cytometry and the reverse-transcribed polymerase chain-reaction showed that the receptor and mRNA were also higher in gingival epithelial cells following incubation with cyclosporin A in vitro. These findings suggest that the keratinocyte growth factor-receptor pathway of mesenchymal-epithelial interaction could play an important part in the molecular pathogenesis of gingival hyperplasia.

Development of an in vitro microassay for glucose quantification in submicrolitre volumes of biological fluid.

Glucose quantification in serum or plasma is traditionally based on a colourimetric enzymatic assay using commercially available assay kits. Sample volumes of blood or serum are usually in the range of a few microlitres to a few millilitres. However, for biological fluids such as gingival crevicular fluid (GCF), which can only be sampled in submicrolitre volumes, such assays have proven unsuitable. The aim of this study was to develop a reliable and reproducible assay for quantifying glucose in submicrolitre samples of GCF. The assay involved modification of a commercially available kit for glucose quantification. Test solutions of (i) serum and (ii) serum with added glucose at known concentrations (range 50-400 mg/dl) were prepared to simulate GCF and GCF enriched with glucose, respectively. Submicrolitre volumes (range 0.2 microl to 0.8 microl) of the test solutions were added to the reagent solution (200 microl) using a Hamilton syringe. The reaction was performed under standard conditions of time and temperature. The colour change was assayed spectrophotometrically at 492 nm. The results showed that this microassay is sufficiently sensitive to detect 50 mg/dl glucose in 0.2 microl of sample and indicate that the accuracy and sensitivity of this assay make it suitable for glucose quantification in submicrolitre volumes of GCF, particularly relevant to investigations of the relationship between diabetes mellitus and chronic inflammatory periodontal disease. In vivo evaluation of this novel microassay was performed using GCF samples taken from periodontally healthy and chronic periodontitis patients. Using non-parametric analysis, the results showed that the assay detected statistically significant differences in glucose concentrations between the two patient groups (p < 0.05). Higher glucose levels were detected at the periodontally diseased sites. For each patient, the GCF-glucose: blood-glucose ratio was calculated. The results show that this ratio was higher in the periodontitis group (1: 2) when compared to the healthy group (1: 9). In conclusion, the results of this investigation have shown that this microassay can quantify glucose in GCF and that GCF-glucose levels are higher at periodontitis sites.

The antioxidant capacity of saliva.

BACKGROUND/AIMS: Saliva, a heterogeneous fluid comprising proteins, glycoproteins, electrolytes, small organic molecules and compounds transported from the blood, constantly bathes the teeth and oral mucosa. It acts as a cleansing solution, an ion reservoir, a lubricant and a buffer. In addition to its other host-protective properties, saliva could constitute a first line of defence against free radical-mediated oxidative stress, since the process of mastication and digestion of ingested foods promotes a variety of reactions, including lipid peroxidation. Moreover, during gingival inflammation, gingival crevicular fluid flow increases the change of saliva composition with products from the inflammatory response; this, in turn, could have some rôle in controlling and/or modulating oxidative damages in the oral cavity. This is the reason why the antioxidant capacity of saliva has led to increasing interest, and the development of techniques suitable for saliva antioxidant evaluation. MATERIALS AND METHODS: Here, we review the current peer-reviewed literature concerning the nature and characteristics of free radicals, reactive oxygen species, oxidants, pro-oxidants and antioxidants in saliva, especially pro-oxidant and antioxidant features, as well as current methods for assessing the antioxidant capacity of saliva. RESULTS AND CONCLUSIONS: In the last decade, several methods have been developed for assaying the antioxidant activity of saliva, indicating an increasing interest of researchers and clinicians. Unfortunately, systematic studies of saliva are still lacking, even in healthy populations.

The effects of a novel Bioglass dentifrice on dentine sensitivity: a scanning electron microscopy investigation.

Dentine sensitivity (DS) is a common condition which affects 8-35% of the population. Both In-Office and Over-the-Counter products have been used in treatment, usually occluding open dentine tubules on the exposed root surface. Currently there appears to be no ideal material which permanently occludes dentine tubules. Bioactive and biocompatible glasses are known to induce osteogenesis in physiological systems and may offer suitable materials for surface reactivity which could theoretically occlude tubules. A new dentifrice formulation containing a modified Bioglass material replacing part of the abrasive silica component was compared with original 45S6 bioactive glass. Dentine discs were treated with original Bioglass, three coded dentifrices containing 0, 2.5 and 7.5% Bioglass and two further selected dentifrice products. These specimens were prepared for scanning electron microscopy (SEM) and viewed in a Cambridge stereoscan 90B. The results demonstrated that original bioactive glass particles covered the dentine surface and/or occluded dentine tubules, although this original formulation was easily dislodged. Dentifrice with different ratios of added Bioglass was assessed to provide greater surface coverage and tubule occlusion than without Bioglass. It was concluded that the inclusion of bioactive glass particles in a suitably formulated vehicle may be an effective agent for the treatment of dentine sensitivity.

Dentists' perceptions of dentine hypersensitivity and knowledge of its treatment.

The aim of the present investigation was to determine by questionnaire, UK dentists' perception of Dentine Hypersensitivity (DH) and knowledge of its treatment. A total of 403 questionnaires were sent to a selected group of UK dentists who had either inquired about further postgraduate education or had attended a course at the Eastman Dental Institute/Hospital. A total of 181 of 403 dentists (44.9%) (118M; 36F, 17 no response, mean age 38.2 years [s.d. 8.97]) returned the questionnaire. About 92.8% (n=168) of responding dentists claimed to see patients with DH in their practice. According to the dentists' replies at least one of four of their patients suffered from the complaint. About 71.8% (n=130) of dentists reported that DH was a severe problem in at least 10% of their patients and that pain from DH lasted no more than 4 weeks. Most of responding dentists claimed to be asked about DH by their patients and stated that they offered advice or treatment to their patients. Nearly 87.3% (n=158) of responding dentists provided a wide range of treatment options/advice which included both in-office and over-the-counter (OTC) products. Popular responses included desensitizing pastes/gels, Topical F(-) varnishes and toothpastes/rinses/gels, advice on atraumatic tooth brushing, dentine bonding agents (DBA), glass-ionomer cements (GIC) and other unspecified restorations. Of the various in-office treatments Duraphat was the most cited choice of varnish/primer options. Sensodyne toothpaste was the most popular of the specified OTC products. Most dentists appeared to understand the aetiological features associated with DH and provided a wide range of factors including the effects of incorrect tooth brushing, dietary acids as well as the possible influence on non-dental topics such as stress. Most responding dentists believed that their advice on DH was generally effective although they did highlight that certain aspects on the condition were lacking such as appropriate scientific information including the prevention of DH and its treatment. The results from the present study highlight several discrepancies in the perception and knowledge of the treatment of DH between dentists and their patients. The results from this study are, however, reasonably consistent with those previously reported by Dutch investigators. The results from this study also highlighted a need for guidelines on the aetiology, prevention and treatment of DH for both dentists and their patients. The reported average frequency and duration of discomfort from DH by the responding dentists appeared to be consistent with the available literature.

Dentine hypersensitivity in subjects recruited for clinical trials: clinical evaluation, prevalence and intra-oral distribution.

Relatively few studies have reported on the frequency, distribution and severity of dentine hypersensitivity (DH) in subjects recruited for clinical trials of desensitizing agents. Potential subjects (n= 48 M, 81 F, mean age 35.1 years) for inclusion into such a study were screened to determine the extent of the problem. 117 subjects (41 M, 76 F) mean age 24.9 years were clinically examined. Evaluation by questionnaire indicated that the prevalence of DH was proportionately higher in the 20-29.9 years (34.9%), and 30-39.9 years groups (33.3%), respectively. Sensitivity to cold was the main presenting symptom. Tactile (probe) and cold air (dental air syringe) stimuli were used to clinically evaluate DH. Of the teeth eligible for evaluation 1561/3136 (49.8%) responded to either one or both of the test stimuli; 274/3136 (8.7%) responded to tactile only stimulation, 779/3136 (24.8%) to thermal only stimulation and 508/3136 (16.2%) to both tactile and thermal stimulation. Of those teeth responding to the stimuli, 477 (30.6%) were premolars, 437 (28%) incisors, 415 (26.8%) molars and 232 (14.9%) canines. The results agree with those of previously reported studies in that DH is most frequently observed on premolars and that proportionately more teeth are sensitive to evaporative than to tactile stimulation. Furthermore it would appear from the results of the study that tactile is less effective than thermal/evaporative stimulation in the evaluation of DH.

Utilisation of locally delivered doxycycline in non-surgical treatment of chronic periodontitis. A comparative multi-centre trial of 2 treatment approaches.

AIM: In the present 6-month multicentre trial, the outcome of 2 different approaches to non-surgical treatment of chronic periodontitis, both involving the use of a locally delivered controlled-release doxycycline, was evaluated. MATERIAL AND METHODS: 105 adult patients with moderately advanced chronic periodontitis from 3 centres participated in the trial. Each patient had to present with at least 8 periodontal sites in 2 jaw quadrants with a probing pocket depth (PPD) of > or =5 mm and bleeding following pocket probing (BoP), out of which at least 2 sites had to be > or =7 mm and a further 2 sites > or =6 mm. Following a baseline examination, including assessments of plaque, PPD, clinical attachment level (CAL) and BoP, careful instruction in oral hygiene was given. The patients were then randomly assigned to one of two treatment groups: scaling/root planing (SRP) with local analgesia or debridement (supra- and subgingival ultrasonic instrumentation without analgesia). The "SRP" group received a single episode of full-mouth supra-/subgingival scaling and root planing under local analgesia. In addition, at a 3-month recall visit, a full-mouth supra-/subgingival debridement using ultrasonic instrumentation was provided. This was followed by subgingival application of an 8.5% w/w doxycycline polymer at sites with a remaining PPD of > or =5 mm. The patients of the "debridement" group were initially subjected to a 45-minute full-mouth debridement with the use of an ultrasonic instrument and without administration of local analgesia, and followed by application of doxycycline in sites with a PPD of > or =5 mm. At month 3, sites with a remaining PPD of > or =5 mm were subjected to scaling and root planing. Clinical re-examinations were performed at 3 and 6 months. RESULTS: At 3 months, the proportion of sites showing PPD of < or =4 mm was significantly higher in the "debridement" group than in the "SRP" group (58% versus 50%; p<0.05). The CAL gain at 3 months amounted to 0.8 mm in the "debridement" group and 0.5 mm in the "SRP" group (p=0.064). The proportion of sites demonstrating a clinically significant CAL gain (> or =2 mm) was higher in the "debridement" group than in the "SRP" group (38% versus 30%; p<0.05). At the 6-month examination, no statistically significant differences in PPD or CAL were found between the two treatment groups. BoP was significantly lower for the "debridement" group than for the "SRP" group (p<0.001) both at 3- and 6 months. The mean total treatment time (baseline and 3-month) for the "SRP" patients was 3:11 h, compared to 2:00 h for the patients in the "debridement" group (p<0.001). CONCLUSION: The results indicate that simplified subgingival instrumentation combined with local application of doxycycline in deep periodontal sites can be considered as a justified approach for non-surgical treatment of chronic periodontitis.

Capnocytophaga granulosa and Capnocytophaga haemolytica: novel species in subgingival plaque.

BACKGROUND: The oral cavity accommodates one of the most diverse microfloras in the human body. Knowledge of this microflora, and of the periodontal microflora in particular, proves crucial towards an understanding of the bacterial-host interactions which lead to the development of infectious inflammatory periodontal diseases. Capnocytophaga species have been implicated as putative periodontal pathogens. To date, only 3 members of this genus (C. gingivalis, C. ochracea and C. sputigena) have been isolated from subgingival plaque. AIM: This communication reports the isolation of 2 recently-speciated strains, namely C. granulosa and C. haemolytica, from subgingival plaque collected from adult periodontitis patients. MATERIAL AND METHODS: Subgingival plaque was collected from 29 patients with chronic adult periodontitis. Plaque samples were inoculated onto fastidious anaerobe agar and incubated anaerobically for 5 days. Routine identification of clinical isolates was performed by 16S rRNA PCR-RFLP analysis, using Cfo I as restriction enzyme and corroborated by 16S rRNA gene sequencing. RESULTS: 16 of 29 patients (55%) tested positive for either C. granulosa and or C. haemolytica. A total of 70 isolates (63 C. granulosa and 7 C. haemolytica) were cultivated from subgingival plaque. 15 (51%) patients tested positive for C. granulosa, and 3 (10%) patients tested positive for C. haemolytica. CONCLUSION: This is the 1st report which recounts the presence of C. granulosa and C. haemolytica in subgingival plaque. Further research is required to establish the relative proportions of these species subgingivally in health and disease.

Amine and tin fluoride inhibition of Streptococcus sanguis adhesion under continuous flow.

This study evaluated the ability of topically applied amine fluoride (AmF) and AmF-tin fluoride to inhibit the adhesion of Streptococcus sanguis within a parallel plate flow cell system. One of three AmF compounds and two tin fluoride preparations significantly reduced the net bacterial adhesion to conditioned glass over a 1-h period. Tin(IV) fluoride inhibited S. sanguis adhesion to the greatest extent, and this was shown to be dependent on the formation of the conditioning film prior to agent application.

Comparison of dentine hypersensitivity in selected occidental and oriental populations.

Epidemiological data on dentine hypersensitivity (DH) prevalence are limited. Few studies have compared prevalence between populations. The aim of this investigation, therefore, was to compare the perception and prevalence of DH in two distinct non-periodontal practice populations, one U.K. and one Korean. Completed questionnaires from 557 patients (230 males and 327 females, comprising 115 males and 162 females, mean age 41.7 years (s.d.=14.36), U.K. and 115 males and 165 females, mean age 29.7 years (s.d.=11.86), Korean) were collected. Analysis was by frequency distribution and cross-tabulation (Statistical Package for the Social Sciences (SPSS)). DH prevalence was similar and at levels comparable with those reported previously. Prevalence was higher in the third and fourth decades in both populations. Although there were no differences between U.K. or Korean males and U.K. or Korean females, there was a significant difference between gender reporting of DH, with more females complaining of DH than males (standard normal deviation (SND)=4.3, 95% confidence interval (CI)=0.1134-0.2736). DH appeared to be regarded by patients as not severe in most cases, so treatment was not generally sought. Of those who claimed to have sought treatment, a significant number had received restorative treatment. Of those patients, only 23.3% of U.K. and or=7 days in either population. The results indicated that there were no significant differences between U.K.- and Korean-based populations in their perception of DH, with the exception that more females complained of sensitivity than males in both groups. Overall, DH was not considered a major dental problem by most patients in either of the populations.

An assessment of the quality of referral letters sent to a specialist periodontist during a nine month period.

There have been concerns about the quality of referral letters received by specialist periodontists. This retrospective study aimed to assess the quality of all referral letters received over a nine month period, by a specialist periodontist working in a publicly financed community clinic, and to compare the results with those obtained from a study which assessed referral letters received by the periodontal department of a London teaching hospital during the same period. After the assessors had trained for intra- and inter-examiner reproducibility, the letters were assessed using the Categorisation System for Periodontal Referral Quality (CSPRQ) (Snoad et al., 1999). The year and country of qualification (UK or non-UK), and possession or otherwise of postgraduate qualifications for each of the referring dentists was ascertained from the UK Dentists Register. The results from this study and those from the hospital study were statistically tested using the Chi-squared test. Before the studies commenced the assessors achieved 100% inter-examiner reproducibility when applying the CSPRQ. A total of 114 letters was received, six of which were excluded. Of the remaining 108, 38 were categorised as of an acceptable standard. There were differences in the performance of dentists from different age groups in that 56% of letters from those qualified from 10-20 years, 29% of those from dentists qualified < 10 years and 27% of those qualified > 20 years were of an acceptable standard. The results were broadly similar to those of the hospital study except that there was a statistically significant difference (P< 0.05) between the quality of referrals from dentists qualified between 10 and 20 years and those with non-UK primary qualifications. It was concluded that the overall quality of referral letters assessed in this study was poor and that the CSPRQ provided a highly reproducible technique for assessing the quality of periodontal referral letters.