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Notes: summary  Dentine hypersensitivity is recognized as a pain arising from fluid movement within dentine tubules that are open to the oral environment. Blocking the tubules is considered to be the principal aim of treatment, and the accurate assessment of tubule occlusion is the primary goal of many in vitro studies. This assessment usually comprises either measuring tubule permeability or scanning electron microscope examination of the dentine surface. Several scanning microscopy studies have claimed to quantify tubule occlusion, but are descriptive, qualitative or semi-quantitative evaluations. The present study was undertaken to assess the use of digital image analysis in quantifying the effectiveness of a selected desensitizing agent from micrographs of control and treated dentine surfaces. Using a dentine disc model, an accurate methodology was sought to investigate the occluding potential of Butler Protect (J.O. Butler, Chicago, IL, USA). Subjective examination of the images indicated there was little difference after a single application, but considerable effect after 20 applications. Quantitative digital analysis of a test image, demonstrated reproducibility between two examiners when used in fully- and semi-automated mode. After a single application of Butler Protect, multilevel statistical modelling demonstrated decreases in tubule area and maximum, minimum and mean diameter measurements (P 〈 0·001), whereas single level analysis showed increases in area and maximum and mean diameters. Multiple application of Butler Protect demonstrated even greater decreases in all parameters (P 〈 0·001). This quantitative methodology was reproducible between examiners and, when combined with good controls and multilevel statistical modelling, was able to discriminate a single application of desensitizing agent.

Notes: Recent studies have attempted to determine the prevalence of dentine hypersensitivity (DH) in both hospital and general practice. Results indicate that DH prevalence is higher in patients referred for specialist treatment than in general practice. The aim of this study was to determine perception and prevalence of DH in general practice. Completed questionnaires from 277 patients (115 males, 162 females, mean age 41·7 years [SD 14·36]) were collected. Self-reported DH prevalence (52%) was observed between the third and fourth decades, peaking in the third and in good agreement with that previously published (45·2%), and significantly more females complained of DH than males (SND=2·24, 95% CI 0·01734–0·2661). Cold was perceived as the most common cause of DH, in agreement with other studies. Only 12·6% of patients reported periodontal surgery compared to 15·5% previously. Of those who received hygiene therapy (67·9%) only 15·5% reported DH following treatment which mainly did not last ≥5 days. Most patients with DH did not perceive the condition as severe and did not seek treatment (75·1%). Only 23·3% used a desensitizing dentifrice. The results indicated that self-reporting of DH is lower than reported in a dental hospital population and was not perceived as a major dental problem by most patients in a general dental practice population.

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: 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: 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: Previous studies have reported on dentine sensitivity (DS) prevalence in hospital and general practice populations. Results from these studies indicate that perception and prevalence of DS vary depending on the population. The study aimed to determine any major differences in the perception and prevalence of DS in subjects in a military training establishment. Questionnaires from 228 subjects [188 completed by males, 39 completed by females, with one person not indicating their gender of mean age 24·0 years (s.d. 7·16)] were collected and analysed using the Statistical Package for the Social Sciences (SPSS). Fifty percent of the subjects (n=114) claimed to have DS. Yet approximately 30% of the subjects (29·8%, n=68) perceived the condition as a slight problem and approximately 40% of the subjects (40·8%, n=93) claimed it was an occasional problem and approximately 50% (49·1%, n=112) did not seek treatment. Seventeen subjects (7·5%) used a desensitizing paste during periods of discomfort. No clear pattern emerged with regard to seasonal variation in DS although 5·7% (n=13) subjects considered DS to be more of a problem in winter. Only 7·9% (n=18) reported any previous periodontal surgery, consistent with previous studies (12·6 and 15·5%). Of those who received regular scaling (27·2%, n=62), only 23 (10·1%) reported any discomfort following treatment, which did not last ≥5 days. The results indicate that self-reporting of DS was similar to previous reports, although it is of fundamental importance that such studies should be supplemented with a thorough clinical examination to determine more reliable prevalence data.

Notes: summary The dentine disc has been extensively used as a model for assessing potential desensitizing agents in vitro by scanning electron microscopy (SEM). Although the disc provides a readily available and reproducible test substrate, this paper addresses the problems associated with this model such as the natural variation in the dentine tubules and the resulting differences in surface morphology. At the ultrastructural level the surface of a single etched disc exhibits variations in the size, density, orientation and extent of etching of the cut dentine tubules. In the present study a precise control procedure was designed which allowed greater correlation between test and control surfaces. Two adjacent areas of the same disc were used, one as the test surface, the other the control. Two proprietary desensitizers were examined using this methodology. This study has shown that the dentine disc is a good, reliable model for in vitro screening and testing of potential desensitizing agents, providing such controls are applied.

Notes: In-office products containing oxalates have been claimed to be clinically effective in reducing dentine sensitivity, although there has been limited supporting clinical data. The rationale for their use appears to be based on their potential to act as occluding and/or nerve desensitizing agents. Four commercially available oxalate-containing products were applied to etched dentine discs and the extent of tubule occlusion was observed by scanning electron microscopy. Tenure Quick (aluminium oxalate), Sensodyne Sealant (ferric oxalate) and MS Coat (oxalic acid) covered the dentine surface and occluded the tubules. However, Butler Protect (potassium oxalate) did not cover the surface to any great extent but provided some occlusion. The presence of oxalates after application to glass slides and dentine discs was examined using thin film X-ray diffraction. From samples on glass, only potassium oxalate could be clearly identified (JCPDS 14-0845). No oxalate was detected on dentine discs in either thin film geometry or standard theta two theta mode. We have demonstrated that professionally applied in-office products containing oxalate are capable of covering the dentine surface and/or occluding the tubules to varying degrees. However, X-ray diffraction analysis was unable to confirm the oxalate profile for all products as described in the available commercial 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.