Subgingival plaque microbiota in Saudi Arabians after use of miswak chewing stick and toothbrush.

BACKGROUND: The chewing stick, the miswak, is used in many developing countries as the traditional means for oral hygiene. It is prepared from the roots, twigs and stem of Salvadora persica or other alternative local plants. OBJECTIVES: To compare the effects of the chewing stick miswak (from S. persica) and toothbrush on subgingival plaque microflora among Saudi Arabian individuals. Further, to investigate whether components extracted from S. persica may interfere with the subgingival plaque micro-organisms. MATERIAL AND METHODS: Fifteen healthy Saudi Arabian male volunteers aged 21-36 years were included in a single-blind, randomized cross-over study. The participants were taught how to use each device properly. Plaque sampling for DNA test was performed at the baseline, 1 week after professional tooth cleaning, and after 3 weeks of either miswak or toothbrush use. Identification and quantification of microbial species were performed by the checkerboard method, using whole genomic, digoxigenin-labelled DNA probes. Inhibition zones around miswak were examined on agar plates with Actinobacillus actinomycetemcomitans and the leukotoxicity of this bacterium was analyzed in a bioassay with macrophages+/-extracts of miswak. RESULTS: Miswak and toothbrushing had a similar influence on the levels of the subgingival microbiota. However, A. actinomycetemcomitans was significantly more reduced by miswak (p<0.05) than by toothbrushing. These results were supported by our in vitro results which, indicated that extracts from S. persica might interfere with the growth and leukotoxicity of A. actinomycetemcomitans. CONCLUSIONS: In contrast to toothbrush use, miswak use significantly reduced the amount of A. actinomycetemcomitans in the subgingival plaque.

Light-induced fluorescence studies on dehydration of incipient enamel lesions.

Changes in the hydration state of enamel affect its optical qualities, such as light scattering and fluorescence. In this study, the rate of fluorescence loss was measured when incipient enamel lesions with different de-remineralization history were left to dehydrate. Four groups of lesions were studied. In groups A, B and C, the lesions were prepared in vitro in an acid-gel system. Group A was kept as control, and groups B and C were remineralized (4 weeks) without and with 1 ppm F in solution, respectively. Group D consisted of natural incipient lesions. Enamel fluorescence was measured for all lesions immediately after removal from water and subsequently at short intervals for 30 min. The change in fluorescence with dehydration varied between the groups. In lesions from groups A and B, it followed a double exponential decrease, while in lesions from groups C and D, it followed a mono-exponential decrease. In all groups, the fluorescence of sound surfaces declined mono-exponentially. The 'fractional fluorescence difference', defined as (L(sound) - L(carious) )/L(sound), became constant after periods of dehydration of about 5, 5, 20 and 5 min for groups A to D, respectively. The observation of the change of fluorescence with dehydration should be taken into consideration when planning studies that use fluorescence as an assessment method. However, it might also be used to gain insight into the properties for fluid transport inside the various lesions, relevant to de-remineralization or fluoride treatments.

Quantitative light-induced fluorescence (QLF): a method for assessment of incipient caries lesions.

OBJECTIVES: To review the literature on validation and application of the quantitative light-induced fluorescence (QLF) method for quantitative assessment of early enamel lesions in vivo and in vitro. METHODS: QLF uses light with wavelengths around 405 nm to excite yellow fluorescence at wavelengths above 520 nm. Its diagnostic capacity is based on the mechanism that the intensity of natural fluorescence of a tooth is decreased by scattering due to a caries lesion. The equipment, the data processing and the interaction between equipment and operator are described. RESULTS: The method has been validated by many authors; the results are presented and compared. For artificial lesions, the validation line is curved. For larger mineral losses, the curve is linear with a slope of 10% fluorescence loss corresponding with a mineral loss of 0.15 kg x m(-2). For lesions caused by natural caries, it is tentatively concluded that fluorescence loss is linear to mineral loss with a slope similar to that of artificial lesions. Reliability and reproducibility have been tested in vivo and show interexaminer values of the interclass correlation coefficient, r, of 0.93

Application of quantitative light-induced fluorescence to monitor incipient lesions in caries-active children. A comparative study of remineralisation by fluoride varnish and professional cleaning.

The aim of this study was to apply the quantitative light-induced fluorescence (QLF) method in a randomised controlled study, comparing treatment with fluoride varnish and professional tooth cleaning for remineralisation of white spot lesions in caries-active adolescents. In the fluoride varnish group (n = 13; 32 lesions), professional tooth-cleaning was followed by application of fluoride varnish at the beginning of the study, after 1 wk, and then once every 6 wk for 6 months. The other group (n = 18; 30 lesions) underwent professional tooth-cleaning once every 6 wk for 6 months. Enamel fluorescence was measured at baseline and at each visit. In the fluoride varnish group there was a significant change over time (baseline: 6 months) for both lesion area: and average change in fluorescence (decreased lesion area and increased fluorescence radiance). The corresponding changes in the professional tooth-cleaning group were not significant. There was a significant difference in average change in fluorescence between the two test groups. For lesion area, there was no significant difference, but a tendency towards a difference between the test groups. It was concluded that (a) the QLF method is a sensitive method, suitable for longitudinal quantification of incipient caries lesions on smooth surfaces; and (b) that repeated fluoride applications had a favourable effect on the remineralisation of white spot lesions as measured after 6 months.

How to measure the effects of fluoride treatments in clinical trials? Assessment: modern versus traditional methods.

In recent years there has been a pronounced change in the epidemiology and disease pattern of dental caries. In the current context, traditional methods of caries assessment, discriminating lesions at cavitation, are clinically inappropriate, and obsolete for research requiring detection of a very early phase of mineral loss. Modern prospective caries studies require sensitive methods permitting the measurement of small changes in tooth mineral content, and objective, quantitative measurements of such changes are now possible in a single caries lesion. For longitudinal studies there are noninvasive methods for assessment of new lesions as well as quantitative changes (progression or regression) in existing lesions. Among as yet unresolved issues are improved methods to assess the current activity of a lesion, methods for detection and quantification of secondary caries and root caries, calibration of methodologies between different research institutes, and methods capable of assessment of the whole continuum in the development of a caries lesion, from initial loss of mineral to cavitation.

Validation of DIAGNOdent for quantification of smooth-surface caries: an in vitro study.

The aims were 1) to validate a laser-based device, KaVo DIAGNOdent, for quantification of caries lesions on smooth surfaces, using histopathologic and microradiographic analyses as the gold standard, and 2) to test inter- and intra-observer agreements. We also investigated the influence on DIAGNOdent readings of the storage medium used for extracted teeth. Two observers measured independently the tooth surfaces of 40 extracted premolars that had been stored in thymol-saturated saline. After subsequent storage in neutral-buffered formalin for 14 days they were re-measured. The teeth were then sectioned for histopathologic and microradiographic analysis. The Spearman rank correlation coefficients between lesion depth and DIAGNOdent readings were 0.78-0.83 and 0.85 for teeth stored in thymol-saturated saline and formalin, respectively. Inter- and intra-observer agreements were 0.94 and 0.95 when the teeth were stored in thymol-saturated saline. The DIAGNOdent reading was almost 1.5 times higher for teeth stored in formalin than for those stored in thymol saline. The Spearman rank correlation coefficient between mineral loss in enamel (deltaZ) and DIAGNOdent readings ranged from 0.64 to 0.68. It was concluded that DIAGNOdent may be helpful for assessing smooth-surface caries, but the cut-off points need to be assessed under clinical conditions. The increase in fluorescence associated with storage of teeth in formalin warrants further investigation.

Tuned-aperture computed tomography for detection of occlusal caries.

OBJECTIVES: To evaluate the use of tuned-aperture computed tomography (TACT) for the detection of primary occlusal caries. MATERIALS AND METHODS: The material comprised 76 extracted posterior teeth, 51 with caries. Radiographs were recorded both with the Sens-A-Ray (Regam Medical Systems Int. AB, Sundsvall, Sweden) digital radiographic system and with Kodak EktaSpeed Plus film (Eastman-Kodak Co., Rochester NY, USA) employing an Orthopantomograph OP 100 (Instrumentarium Imaging, Tuusula, Finland) and a Prostyle Intra (Planmeca, Helsinki, Finland) dental unit respectively. The Sens-A-Ray radiographs were used to construct TACT slices and TACT iterative slices. The teeth were subsequently sectioned in 300 microm thick slices. Microradiographs were exposed and analysed with respect to the true presence of lesions. Seven observers subjectively evaluated the radiographs and ROC analyses performed. Conventional radiographs were compared with TACT images by means of the area under the ROC curves, Az. Paired t-test was used to compare Az values. Interobserver agreement was evaluated using the Kendall coefficient and the Friedman Anova. RESULTS: TACT radiographs were significantly better than conventional radiographs for diagnosing all types of occlusal caries combined (P(TACT) (slices)=0.02. P(TACT) (iterative slices)=0.01). However, neither TACT system was significantly better than film for enamel and dentinal caries separately. Observer agreement was moderate. However, observers demonstrated significant systematic differences in their readings (P<0.001). CONCLUSION: TACT may be a feasible method for diagnosing primary occlusal caries.

Comparison of QLF and DIAGNOdent for quantification of smooth surface caries.

The aim was to compare the detection and quantification of smooth surface caries by KaVo DIAGNOdent and quantitative laser/light-induced fluorescence (QLF) using a laser and a lamp as two different light sources. On 40 premolar teeth extracted from adolescents, 71 non-cavitated approximal surfaces were assessed. For QLF, both mean and maximum fluorescence losses were registered. To provide a gold standard for verification, the teeth were then sectioned and lesion depth, stratified on a five-point scale, was determined by histopathology and microradiography. The correlation between the gold standard and the two methods was assessed by Spearman's rank correlation coefficient. The sensitivity and specificity of the methods for detection of smooth surface caries at D(3) level were also assessed. For lesion depth, correlation with the gold standard was similar for QLF and DIAGNOdent: about 0.85. With respect to dentinal caries detection, sensitivity for DIAGNOdent was 0.75 and specificity 0.96, with a cut-off point of 9. The corresponding values for QLF were 0.94 and 1, with a cut-off value of 20% of fluorescence loss. Spearman's rank correlation coefficients for enamel mineral loss and QLF and DIAGNOdent, respectively, were 0.76 and 0.67. It was concluded that for quantification of smooth surface caries, the methods are of equal merit, but for scientific purposes, QLF offers the advantage of closer correlation with changes in mineral content.

Characterization and validation of diagnostic methods.

Diagnosis is defined as the determination of disease, but not as the determination of the signs and symptoms thereof. The use of modern diagnostic methodology in the clinic is hampered by cost considerations and by the still widespread belief that, e.g. caries lesions and periodontal breakdown are irreversible processes that need to be detected and treated invasively as early as possible, their measurement thus being irrelevant. Modern instrumental and quantitative methods allow early detection and introduction of noninvasive preventive measures to control the development of the disease. Such methods are also very beneficial in clinical research as they may describe the speed of progress or regress of disease. In epidemiology, such methods reduce the classical problem of calibration of observers. Repeatability, reproducibility, accuracy and validity are defined as method-characterizing quantities, for which examples are given. To express the validity of quantitative methods compared with a quantitative gold standard, the use of scatter plots and correlation and regression methods is suggested. Validation of a dichotomous method with a dichotomous gold standard in terms of sensitivity and specificity is discussed. To validate a quantitative method with a dichotomous gold standard, the receiver operating characteristic curve is suggested, with the requirement that the cutoff value should be determined in relation to the use of the method. However, preferably a quantitative method should not be reduced to a dichotomous one by using a cutoff value, but instead all available information should be used by the diagnostician. It is argued that the use of a secondary standard instead of the accepted gold standard usually leads to inadequate results, even when the validity of the secondary standard is known. Finally, it is argued that the choice of a gold standard is a matter of reasoning and weighing of arguments and not of following a prescribed procedure.

Effect of acid-etching on remineralization of enamel white spot lesions.

This in vitro study aimed at investigating whether full remineralization would occur in white spot lesions when the surface porosity was increased by acid-etching. The effect of fluoride was also investigated. Enamel blocks with in vitro produced white spot lesions were used. Group A was exposed to a remineralizing solution only. In group B, the lesions were etched with 35% phosphoric acid for 30 s, then treated as in group A. Group C was treated as group A + daily treatment with a fluoride toothpaste slurry (1,000 ppm) for 5 min. Group D was treated as group B + the daily fluoride treatment of group C. The remineralization was measured weekly with Quantitative Light-induced Fluorescence during the experimental period. After 10 weeks of remineralization, mineral profiles were assessed with transverse microradiography. The enamel fluorescence was partly regained. There were significant differences in the lesion depth, mineral content at the surface layer, and integrated mineral loss between the groups. Addition of fluoride accelerated the remineralization only in the beginning; in later stages the process leveled out and even reached a plateau in all the groups. It was concluded that full remineralization was not achieved by etching, by the addition of fluoride, nor by the combination of both treatments in this in vitro study.

Fluoride content in khat (Catha edulis) chewing leaves.

Khat (qat) leaves are chewed for their psychostimulative effects; there is an unconfirmed suggestion that they contain a high concentration of fluoride (F). Khat samples from Yemen were suspended in deionized water, spun, and the supernatants exposed to a chelator that decomplexes F, which was assayed with an F(-)-electrode coupled to an ion analyser. F released into whole saliva after chewing khat for 15 min and from khat suspended in stimulated whole saliva for 1.5 h in vitro was measured also. Total F in dried khat leaves and their ash was assayed by the acid-hexamethyldisiloxane microdiffusion method. All methods demonstrated negligible amounts of F in or from khat leaves (<0.02 microg F/ml leached into water or saliva; 0.06 microg F/ml in saliva after chewing; 0.93 microg total F/g in dried leaf, 2.07 microg total F/g in ash).

Occlusal caries detection with KaVo DIAGNOdent and radiography: an in vitro comparison.

A new laser fluorescence method, KaVo DIAGNOdent, was tested with respect to reproducibility and validity and compared with radiography regarding accuracy in the detection of occlusal caries. Seventy-six extracted premolar and molar teeth were measured twice with DIAGNOdent under both wet and dry conditions, at an interval of 2 weeks. Conventional film radiographs were exposed. Microradiographic analysis of sections of the teeth served as the gold standard. Intra-class correlation coefficient and Pearson's correlation coefficient were used to assess the reproducibility and the validity of the method, respectively. The influence of time and varying humidities on DIAGNOdent readings were analysed by two-way repeated measure ANOVA. ROC curves were plotted for DIAGNOdent readings and radiographic registration of caries by 6 observers, and the areas under the curves were compared using Student's t test. Under both wet and dry conditions, the reproducibility of the DIAGNOdent method was excellent: R = 0.97 and 0.96, respectively. The diagnostic accuracy of DIAGNOdent was significantly better than that of radiography (p< or =0.001). In this in vitro study of detection of occlusal caries, the diagnostic performance of the DIAGNOdent method was superior to that of radiography.

Oral status of 81 subjects with eating disorders.

The aim was to explore possible correlations between the oral status of patients undergoing treatment at a special outpatient psychiatric clinic for eating disorders and such variables as psychiatric diagnosis and duration of illness, oral hygiene habits, salivary function, and dietary habits. Healthy volunteers of a similar age were recruited for comparison. The material comprised 100 consecutive referrals, of whom 79 were women and 2 were men (age range 17 to 47, median 25 yr) participated. The eating disorders were diagnosed according to the American Psychiatric Association's DSM III-R criteria. The clinical and radiographic examinations were supplemented by standardized intraoral photographs, study models and salivary analysis. The decayed, missing, filled surfaces (DMFS) index was 15.3+/-10.9, a significantly higher caries frequency than for the reference group. More than half the subjects had erosive tooth wear involving the dentine, and about one-third had very low unstimulated salivary flow rates and very high counts of mutans streptococci and lactobacilli. Erosive tooth wear was significantly correlated to the number of years of binge-eating. Compared to age-matched individuals, subjects with diagnosed eating disorders are more susceptible to both dental caries and erosion. They should be encouraged to adopt appropriately tailored preventive programmes and to have regular dental check-ups.

Developments in caries diagnosis and their relationship to treatment decisions and quality of care. ORCA Saturday Afternoon Symposium 1997.

This symposium report evaluates the achievements made in caries diagnostic research since the previous symposium held in 1992. The symposium aimed at presenting the state of the art of caries diagnostic methods, on presenting the links between caries diagnosis and subsequent treatment decisions and their effect on the treatment outcomes, particularly the quality of dental care. The variation among dentists in diagnosing (small) caries lesions and in treatment decision making is considerable. This has been explained by the imperfection of caries decision making tests, but also by making incorrect treatment decisions due to incorrect or partial understanding of diagnostic test parameters. Meta-analyses into the performance of caries diagnostic tests revealed that the available quantitative methods are very promising. It was concluded that these methods had high correlations with lesion depth. They were considered suitable to monitor small changes in lesions. Many obstacles have been experienced in attempting to transfer the outcomes of diagnostic research into clinical practice and it was concluded that caries diagnosis researchers should co-operate with manufacturers to introducing valid new diagnostic tools to the market. Main research priorities for the coming 10 years are to conduct cost-effectiveness and cost-utility studies of caries diagnostic tools, to continue to review the performances of diagnostic tests, to transfer diagnostic knowledge and experience to the general practitioners particularly by constructing evidence-based clinical guide-lines, to study the relationship between diagnosis and treatment decision, and to assess the effect of diagnostic and treatment decisions on the outcome of care.

Sensory stimulation (acupuncture) increases the release of calcitonin gene-related peptide in the saliva of xerostomia sufferers.

Over the last decade, several patients afflicted with xerostomia have been treated with acupuncture. Their salivary flow rates increased significantly and the improvement lasted during a long observation period. We also found that the release of several neuropeptides in the saliva of healthy subjects can be increased by acupuncture stimulation. The concentration of vasoactive intestinal polypeptide increased significantly in the saliva of xerostomic patients after acupuncture treatment. The release of the neuropeptide calcitonin gene-related peptide (CGRP) was investigated in the saliva of xerostomic patients in order to elucidate further the mechanisms of the effect of sensory stimulation (acupuncture) on the salivary secretion. CGRP-like immunoreactivity was measured with radioimmunoassay (RIA) before and after a double series of acupuncture treatment, in stimulated saliva of 14 patients who suffered from xerostomia. The results showed that the concentration of CGRP increased significantly (P<0.001) in the saliva of these patients after the end of acupuncture treatment as compared to base-line levels. Taking into consideration the influence of CGRP on the salivary flow, as well as its trophic effect, we concluded that the increased release of CGRP could be one of the factors that affect positively the salivary flow rates of xerostomic patients who were treated with acupuncture.

The influence of sensory stimulation (acupuncture) on the release of neuropeptides in the saliva of healthy subjects.

In recent studies we have shown that xerostomia (dry mouth) can be treated successfully with sensory stimulation (acupuncture). The increase of saliva secretion lasted often for at least one year. Some neuropeptides have been found to influence the secretion of saliva. The aim of this study was to investigate the mechanisms behind the effect of acupuncture on salivary secretion by measuring the release of neuropeptides in saliva under the influence of sensory stimulation. VIP-like immunoreactivity (VIP-LI), NPY-LI, SP-LI, CGRP-LI and NKA-LI were analysed in the saliva of eight healthy subjects. Manual acupuncture and acupuncture with low-frequency electrical stimulation (2 Hz) were used. The saliva was collected during 20 minutes before the start of acupuncture stimulation, then during 20 minutes while the needles were in situ and then for another 20 minutes after the needles were removed. Four different saliva sampling techniques were used: whole resting saliva, whole saliva stimulated by paraffin-chewing, whole saliva stimulated by citric acid (1%), and parotid saliva, also stimulated with citric acid (1%). The results showed significant increases in the release of CGRP, NPY and VIP both during and after acupuncture stimulation, especially in connection with electro-acupuncture. SP showed only few increases, mainly in connection with electro-acupuncture, whereas NKA generally was unaffected by the acupuncture stimulation. The sensory stimulation-induced increase in the release of CGRP, NPY and VIP in the saliva could be an indication of their role in the improvement of salivary flow rates in xerostomic patients who had been treated with acupuncture.

A longitudinal laser fluorescence study of white spot lesions in orthodontic patients.

Orthodontic treatment with fixed appliances increases the caries risk in young persons. The aim of this study was to apply a new caries diagnostic method, quantitative laser fluorescence, for longitudinal in vivo quantification of changes in incipient enamel lesions related to fixed orthodontic appliances. Seven young patients with active caries lesions disclosed at removal of the orthodontic brackets and bands were enrolled in the study. Caries preventive measures were intensified, including dietary advice, oral hygiene instructions, and the regular use of a fluoride dentifrice. The caries lesions were monitored with the quantitative laser fluorescence method after removal of the brackets and once a month thereafter. For each lesion, three quantities were measured: lesion area (mm2), mean fluorescence loss (%) over the lesion, and maximum loss of fluorescence (%) in the lesion. During a 1-year follow-up period, the areas of the lesions decreased and the enamel fluorescence lost was partly regained indicating that a remineralization process had occurred. It was concluded that quantitative laser fluorescence seems suitable for in vivo monitoring of mineral changes in incipient enamel lesions, and useful for the evaluation of preventive measures in caries prone persons, such as orthodontic patients.