Sensory stimulation (acupuncture) increases the release of vasoactive intestinal polypeptide in the saliva of xerostomia sufferers.

We have shown in earlier studies that xerostomia can be treated successfully with acupuncture. We also found that acupuncture stimulation can increase the concentration of neuropeptides in the saliva of healthy subjects. In this study, the concentration of the neuropeptide vasoactive intestinal polypeptide (VIP) was measured in the saliva of xerostomic patients in connection with acupuncture treatment (AP). Patients suffering from xerostomia caused by irradiation treatment, Sjögren's syndrome and other systemic disorders had been treated with acupuncture. Some of these patients showed an increase of their salivary flow rates after the AP was completed. Seventeen patients out of 65 were chosen due to their ability to produce enough saliva for the radio immunoassay (RIA) analyses to be conducted prior to the start of AP. VIP-like immunoreactivity (VIP-LI) was measured in the chewing stimulated saliva of these patients before and after the whole AP (24 sessions of 30 min each). The results showed that there was a significant increase of the concentration of VIP after the AP as compared to the measurements made before the start of the treatment (p<0.05). We concluded that the increase of neuropeptide VIP might be one of the mechanisms behind the positive effect of acupuncture on the salivary flow rates of the xerostomic patients.

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.

Fluoride concentrations in rat and human tooth pulps and their possible interference with phosphatase activities.

Alkaline and acid phosphatases (p-ases), fluoride (F), and calcium (Ca) were analyzed in the pulps of rat incisors and young human pre-molars. P-ase activities were about ten times higher in the rat than in the human pulps; in the latter, high p-ase activity appeared to be connected with rapid mineralization. Average total F was 3-4 ng/mg in both rat and human pulp, while Ca showed values several times higher, although greatly varying, in human than in rat pulps. Ionized F was two to three times higher in ultrafiltrates from rat and human pulps than in the blood plasma of the species; in the rat, the F content of the ultrafiltrates increased only three to four times when plasma F was experimentally elevated over 100 times. In vitro, rat pulp alk. p-ase activity was slightly inhibited only in the range above 100 mM NaF, while acid p-ase showed weak inhibition in the region from 0.15-0.25 mM and 40-60% inhibition in the range from 10-100 mM NaF. In vivo, no effect on pulp p-ases was found, even from sublethal NaF doses.

Environmental and physiological factors affecting dental fluorosis.

In addition to differences in fluoride intake and possibly to calcium deficiency or malnutrition, there are several factors which may account for individual differences in the occurrence of dental fluorosis. Disorders in acid-base balance affect the renal handling of fluoride such that, in acidosis, the excretion rate is diminished and, in alkalosis, the excretion rate is enhanced. Thus, any factor that can decrease urinary pH would be expected to increase the likelihood of dental fluorosis and vice versa. Results from studies with both rats and dogs have shown that acid-base disturbances per se, especially acidosis, adversely affect the mineralization of enamel in a manner that resembles fluorosis. It has been found that the retention and tissue levels of fluoride are increased by residence at high altitude. It has also been found that, in the absence of fluoride exposure, residence at high altitude per se can have a profound disruptive effect on amelogenesis which could be confused with fluorosis. The effects of diseases which lead to increases in urinary flow rate and water intake on the likelihood of the occurrence of dental fluorosis are also discussed.

A review of quantitative methods for studies of mineral content of intra-oral caries lesions.

Modern prospective caries studies require the measurement of small changes in tooth mineral content. Quantitative measurements of changes in mineral content in a single caries lesion is desirable. Quantitative methods can be either destructive or non-destructive. The latter type permits longitudinal studies to be conducted. Various methods available for the analysis of lesion parameters are reviewed. The basic principle of each method is summarized, and its characteristics are discussed. For each method, the correlation between the measured parameter and mineral loss, the useful range of mineral loss, the discrimination threshold, and the repeatability, are presented. Where such quantities were not available in the original papers, they were calculated from literature data. A comprehensive table of specifications of all methods is given.

Neuropeptides in the saliva of healthy subjects.

Five neuropeptides: Substance P (SP), Neurokinin A (NKA), Calcitonin Gene-Related Peptide (CGRP), Neuropeptide Y (NPY) and Vasoactive Intestinal Polypeptide (VIP), were measured in the saliva of eight subjects. The saliva was collected using different stimulation techniques: whole resting saliva, whole paraffin stimulated saliva, whole citric acid stimulated saliva and parotid saliva of different secretion rates -0.25 mL/min, 0.50 mL/min and 1.00 mL/min, also stimulated by citric acid. The neuropeptides were analysed by radioimmunoassay. The results showed that the concentration of all neuropeptides decreased significantly, two- to four-fold (CGRP up to 16-fold) in whole saliva, when the salivary secretion rates increased six- to eight-fold due to stimulation. However, the amounts of all neuropeptides released over time into the whole saliva increased two- to five-fold (ten-fold for CGRP) as the volumes of saliva increased due to chewing-stimulation as compared to resting saliva or citric acid stimulated saliva. There was also more CGRP in the resting saliva than in the citric acid stimulated saliva. The concentration of CGRP in the parotid saliva decreased three- to ten-fold when the salivary flow increased, whereas the concentration of NKA increased three- to four-fold and that of NPY almost two-fold under the same conditions. The concentrations of SP and VIP did not change in the different flows of parotid saliva. The release of all neuropeptides in the parotid saliva over time showed significant increases (3-14-fold) when the secretion rates increased except CGRP, which showed no changes at all. We concluded that neuropeptides are continuously released into the saliva. Their amounts increase with stimulation, but they are diluted by the increased volume of saliva, and they are also affected by the mode of stimulation-muscular activity leads to a greater release than citric acid stimulation. As the neuropeptides play an important role in the control of salivary secretory mechanisms, their normal occurrence and release are of fundamental importance for the understanding of the function of the salivary glands.

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.

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).

Oligodontia of the permanent dentition in two sisters with polycystic ovarian syndrome: case reports.

Oligodontia or severe hypodontia is a rare developmental dental anomaly commonly associated with syndromes and systemic abnormalities. This report presents two sister, aged 18 and 21, who collectively had 56 congenitally missing permanent teeth. Both patients exhibited pubertal hirsutism, menstrual disturbances, and enlarged ovaries with multicystic lesions defined ultrasonically. These features are consistent with the diagnosis of polycystic ovarian syndrome, a disease not previously linked to hypodontia. A genetic component of this condition is proposed. The significance of this entity is discussed and the importance of early diagnosis and treatment regimens are emphasized.

Relationship between oral symptoms, salivary function, smoking habits and general health in patients with complaints related to dental restorative materials.

Eighty consecutive patients, referred to the Department of Prosthetic Dentistry, Public Dental Service, Stockholm, for examination of complaints related to dental restorative materials or for supposed adverse effects from mercury released from dental amalgams were investigated. Clinical examination as well as battery of laboratory tests were performed. Statistical correlations were found between subjective and objective oral symptoms and lowered pH-values in stimulated saliva (p less than 0.001) as well as between objective oral symptoms only and lowered pH-values in stimulated saliva (p less than 0.001), which indicate salivary tests to be a useful tool when examining this type of patients.

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.

Fluorosis-like effects of acidosis, but not NH+4, on rat incisor enamel.

Previous studies have shown that chronic acidosis induced by NH4Cl is associated with disturbances in enamel mineralization that resemble severe fluorosis and increased fluoride concentrations in both soft and hard tissues. It has not been shown whether these effects are due to acidosis per se or exposure to high levels of NH+4. This 42-day study with rats fed a low-fluoride diet was done to identify the etiological factor. Two control groups received deionized water or water containing NaCl. Two groups received NH+4-containing compounds that did not produce acidosis (NH4HCO3 or HN4 acetate). Two other groups were rendered acidotic by exposure to NH4Cl in the drinking water (metabolic acidosis) or to an atmosphere containing 10% CO2 (respiratory acidosis). The femur epiphysial fluoride concentrations were elevated in the NH4Cl and NH4 acetate groups, and the magnesium concentrations were elevated in the groups exposed to NH+4 compounds and in the 10% CO2 group. Microradiographic analysis revealed severe disturbances in the mineralization pattern of incisor enamel in both acidotic groups, but normal enamel in the other groups. Enamel fluoride and magnesium concentrations were highest in the acidotic groups. The enamel fluoride concentrations were low (8-14 ppm) and not regarded as the cause of the defective mineralization. It was concluded that the effects on structure and composition of enamel were due to acidosis and not to exposure to high levels of NH+4.

Mineral distribution in the enamel of teeth with amelogenesis imperfecta as determined by quantitative microradiography.

The aim of the present investigation was to determine the mineral distribution in the enamel of teeth with amelogenesis imperfecta (AI) by quantitative microradiography. A further aim was to correlate the findings to clinical manifestations and inheritance patterns for AI. Included in the study were a total of 29 teeth with AI, 28 primary and one permanent, and seven unaffected teeth, five primary and two permanent. Quantitative microradiography was applied to sagittally ground sections, 70-90 microns, of the teeth. The mineral content of the enamel, expressed as percentage by volume, was lower in most of the teeth with AI than in the unaffected teeth. The largest range for the mineral distribution was found in the enamel of the variants clinically characterized by hypomineralization. These teeth showed a mineral distribution pattern that reflected an extremely low mineral content in the bulk of the enamel. In the AI teeth clinically characterized by hypoplasia, the mineral distribution pattern was similar to that of the unaffected teeth, although with larger local variations in mineral content. Apart from the teeth connected with X-linked inheritance, no differences were found among teeth with similar clinical variants connected with different inheritance patterns.

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.

Initial caries diagnosis in rat molars, using laser fluorescence.

Scoring of enamel caries in rat molars in ordinary light and in laser fluorescence was compared. Fifty rats were infected with Streptococcus mutans; 5 served as control rats, and the other 45 were fed a cariogenic diet for 15-20 days. With Keyes's system, the total enamel caries score for 35 of the test rats was 29.1 lesions per rat (l/r) in ordinary light and 39.6 l/r in laser fluorescence. The corresponding scores for fissure caries were 15.9 l/r and 21.6 l/r, respectively. Fissure caries scores of thin, longitudinal, central sections from the molars of the 10 remaining test rats were 18.0 l/r in ordinary light, 21.4 l/r in laser fluorescence, and 17.1 l/r in microradiographic analysis. In conclusion, the use of laser fluorescence improves scoring of early enamel carious lesions in rat molars, offering potential reductions in test time and/or sucrose load in animal caries research.