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Notes: 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.〈section xml:id="abs1-2"〉〈title type="main"〉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.

Notes: 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.

Notes: Background, aims: Conventional treatment of chronic periodontitis involves mechanical debridement of periodontal pockets. Recently, subgingival antimicrobials have been used adjunctively following such debridement. This 2-centre study compared the clinical effects of subgingival scaling (SRP) with SRP plus subgingival application of 25% metronidazole gel, Elyzol® (SRP+gel), in patients with chronic adult periodontitis.Method: Voluntary informed written consent was obtained from 45 subjects at the Eastman (mean age 46, range 34–63) and 43 subjects at RAF Halton (mean age 47, range 34–71) who participated in this blind, randomised split-mouth design study. All had at least 2 sites in each quadrant with probing pocket depth (PPD) 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE27012910:ges" location="ges.gif"/〉5 mm. PPD, bleeding on probing (BOP), and clinical probing attachment levels (CAL) measured using a stent, were recorded at baseline and at 1, 3, 6 and 9 months post-therapy. After subgingival scaling of all quadrants, 2 quadrants were randomly selected to be treated with metronidazole gel.Results: A paired t-test on baseline values showed no bias between groups. Both treatments effectively reduced the signs of periodontitis. At each follow-up visit, reduction in PPD, CAL and BOP after the combined treatment was greater than for SRP alone. Paired t-tests showed that the improvement in the SRP+gel group was statistically significantly better (p〈0.001) than for SRP alone (mean 0.5±0.6 mm. 95% CI 0.4–0.6 mm.) Similarly, the % of sites which improved to a final pocket depth of 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE27012910:les" location="les.gif"/〉3 mm and the % of sites which improved over the 9 months of the study by as much as ≥2 mm were greater for SRP+gel than for SRP alone.Conclusions: At the end of the study, the mean reductions for PPD were 1.0 mm (SRP) compared to 1.5 mm (SRP+gel), and for CAL they were 0.4 mm (SRP) compared to 0.8 mm (SRP+gel), with mean difference for CAL between treatments of 0.4±0.6 mm (95% confidence intervals of 0.3–0.6 mm). The combination therapy of SRP+gel was superior to the conventional treatment of SRP alone, and these differences were maintained for 9 months.

Notes: summary  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.

Notes: 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.

Notes: 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.

Notes: 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.

Notes: 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 ≤2% of Korean patients claimed to have used a desensitizing dentifrice. Pain from DH was reported as low grade (slight, occasional) occurring over 5 years in both populations. Cold appeared to be the most reported stimulus in the two populations. Less periodontal surgery had been undertaken in these two populations (12·6% U.K. and 7·1% Korean) compared with those referred to a teaching hospital periodontal department (34·5%). This compared favourably with previous findings in the general dental population (15·5%). Discomfort following hygiene therapy did not appear to last ≥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.

Notes: In this letter we report the application of barium–strontium–titanate (BST) thin film oxides as the dielectric layer in radio-frequency-microelectromechanical system (rf-MEMS) capacitive switches. BST thin films deposited at ambient temperature by off-axis sputtering have been employed for application in rf-MEMS switches. Their dielectric properties have been characterized in the frequency range from 1 to 20 GHz both on magnesium oxide and on gold metal films. Switches have been fabricated which demonstrate promising on-state capacitance and good dielectric breakdown properties. Dielectric breakdown in excess of 400 kV/cm has been measured on switches cycled in excess of 2000 times during testing. © 2002 American Institute of Physics.

Notes: 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 µl to 0.8 µl) of the test solutions were added to the reagent solution (200 µl) 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 µl 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.