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).

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.

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.

The influence of acupuncture on salivary flow rates in healthy subjects.

This study investigated the influence of acupuncture stimulation on the salivary secretion of eight healthy subjects. The salivary flow of each subject was measured before, during and after every acupuncture session. The unstimulated, chewing-stimulated and citric acid-stimulated flows were investigated, in combination with manual and electrically stimulated acupuncture. The results showed a significant increase of the unstimulated salivary flow both during and after the manual acupuncture stimulation as compared to baseline levels. There was no effect on the unstimulated salivary flow with electro-acupuncture. The stimulated salivary flow was not affected by manual acupuncture, while the electrically stimulated acupuncture led to a significant decrease of the chewing-stimulated salivary flow. The improvement of the unstimulated salivary secretion in healthy subjects was in accordance with our previous findings in xerostomic patients. It is possible that the salivary secretion is influenced by the augmented release of neuropeptides caused by acupuncture. Some neuropeptides have been shown to affect salivary secretion as well as capillary blood flow.

Laser fluorescence quantification of remineralisation in situ of incipient enamel lesions: influence of fluoride supplements.

The aims of this study were to test the laser fluorescence method for quantification of remineralisation in situ of enamel with incipient lesions and to evaluate the enhancement of remineralisation by fluoride (F) supplements when a F dentifrice was used on a regular basis by healthy young subjects. Enamel samples were cut from extracted premolar teeth with the natural surface kept intact, and subjected to a pH-cycling system to produce subsurface demineralisation in vitro. The enamel blocks were then inserted into composite holders bonded to the buccal surfaces of both upper first molars of 12 panelists. Each panelist participated in 3 separate experiments in a randomised order; each lasted for 5 weeks with washout intervals of 2 weeks between experiments; experiment 1: F dentifrice (0.145% F as NaF) only; experiment 2: F dentrifice + F lozenges (0.25 mg F x 6/day); experiment 3: F dentifrice + F chewing-gum (0.25 mg F x 6/day). Fluorescence radiance was measured before, during, and after in vitro demineralisation, and once a week during the in situ experimental periods. The enamel samples were then sectioned and analysed with transverse microradiography (TMR). Anova and Pearson correlation coefficient were used for the statistical analysis. At the end of the 5-week in situ periods, fluorescence radiance had been regained to a level of 80-100% of the value before in vitro demineralisation, indicating remineralisation of the enamel samples. There were no differences in the fluorescence radiance gain between the 3 different F exposures. However, there was a statistically significant time trend (p < 0.001), and a highly significant linear dependence (p < 0.001) between the final measurements obtained with the laser fluorescence method (LAF) and the data obtained from TMR, r = 0.76. It was concluded that: (1) with the sensitive LAF method it was possible to register the small changes in the enamel week by week during in situ remineralisation: (2) when F dentrifice was used regularly, F supplements such as F lozenges or F chewing-gum did not significantly enhance the in situ remineralisation of incipient enamel lesions in healthy, young adults with normal salivary flow.

Acupuncture treatment of patients with radiation-induced xerostomia.

Xerostomia is a common and usually irreversible side effects in patients receiving radiation therapy (> 50 Gy) for head and neck cancer. Of 38 patients with radiation-induced xerostomia, 20 in the experimental group were treated with classical acupuncture and 18 patients in the control group received superficial acupuncture as placebo. Within both groups the patients showed significantly increased salivary flow rates after the acupuncture treatment. In the experimental group 68% and in the control group 50% of the patients had increased salivary flow rates at the end of the observation period. Among those patients who had had all their salivary glands irradiated, 50% in both groups showed increased salivary flow rates (> 20%) by the end of the observation period of 1 year. The study indicates that among the patients who had increased salivary flow rates already after the first 12 acupuncture sessions, the majority had high probability of continual improvement after the completion of acupuncture treatment. The improved salivary flow rates usually persisted during the observation year. The changes observed in the control group were somewhat smaller and appeared after a longer latency phase. Significant differences for salivary flow rates could be observed only within each group, and there were no statistically significant differences between the groups. There were no differences in the improvement of salivary flow rates between those patients who were irradiated within a year before the acupuncture treatment and those who had received radiation therapy several years earlier. The results indicate that acupuncture might be a useful method for the treatment of radiation-induced xerostomia, and that superficial acupuncture should preferably not be used as placebo acupuncture.

Effects of fluoride-supplemented sucrose on experimental dental caries and dental plaque pH.

Sucrose, 5% and 10% (w/v), supplemented with between 0 and 5 ppm fluoride (F), was tested for its influence in vitro on plaque-induced experimental in vitro enamel caries and plaque pH. Plaque growth on bovine enamel was initiated from saliva inocula and sustained in a multiple plaque growth system for up to 31 days by means of a basal medium with periodic applications of sucrose or sucrose supplemented with F. Change in enamel mineralization was assessed, before and after plaque growth, by microhardness testing and microradiography; pH was monitored with microelectrodes. It was found that enamel demineralization was inversely related to the F concentration in the range 2 to 5 ppm, for both 5% and 10% sucrose. Plaque pH responses were unaffected by the F supplements.

Effects on demineralization of enamel by fluoridated sucrose: a pilot study in an in situ caries model.

Blocks of human enamel, placed in removable partial dentures, were allowed to acquire natural plaque for seven days and were exposed extra-orally to a cariogenic challenge by repeated periods in a fluoride-sucrose solution. As a control, enamel blocks were exposed extra-orally to a sucrose solution. After two weeks of cariogenic challenge, the blocks were examined for mineral loss by quantitative microradiography on thin sections of the enamel. The results from six subjects showed that no significant effect on demineralization could be detected by the addition of fluoride corresponding to fluoride/sugar content of 1 mg/kg, 5 mg/kg, or 10 mg/kg (dry weight). One subject did not develop lesions at all, either with fluoride-sucrose or with sucrose exposure alone.

Acupuncture treatment of xerostomia caused by irradiation of the head and neck region: case reports.

Salivary flow rates were monitored in two patients, treated with acupuncture for post-radiotherapy xerostomia. The flow rates improved after acupuncture and the effect persisted during the 2-year observation period.

Effects on local blood flux of acupuncture stimulation used to treat xerostomia in patients suffering from Sjögren's syndrome.

Twenty-one patients with Sjögren's syndrome were given four different kinds of acupuncture stimulation, at acupuncture points previously used to treat xerostomia. The local blood flux in the skin overlying the parotid gland was measured with laser Doppler flowmetry before, during and after the acupuncture stimulation. The results showed that the local blood flux increased significantly during and after both manual acupuncture and low-frequency (2 Hz) electro-acupuncture as compared with superficial acupuncture. These results indicate that acupuncture induced an increase in the local blood flux which was more pronounced for those patients who had previously reacted with increased salivary flow to acupuncture.

The effect of acupuncture on salivary flow rates in patients with xerostomia.

Of 21 patients with severe xerostomia, 11 were treated with acupuncture and 10 patients received placebo acupuncture. Those patients who received acupuncture treatment showed increased salivary flow rates during and after the acupuncture treatment. The improved salivary values persisted during the observation year, whereas the patients who received placebo acupuncture showed some improvement of salivary flow rates only during the actual treatment. The results of the present study indicate that acupuncture may be a useful adjunct for the stimulation of salivary flow in some patients with xerostomia.

Enamel and dentin fluoride levels and fluorosis following single fluoride doses: a nuclear microprobe study.

Female rats were given single intraperitoneal doses of fluoride (F) (0, 4, 7, or 14 mg F/kg body weight). Plasma F levels returned to predose values within 24 h. Incisors from animals killed 35 or 70 days after the F doses had been given were analyzed for mineralization defects by microradiography, and for F and P concentrations by nuclear microprobe. At 35 days, all F-injected rats had enamel fluorosis. At 70 days, by which time the incisors would have been renewed nearly twice, fluorosis was still evident in the 14 mg/kg body weight group. The enamel and dentin F concentrations at each time point were proportional to the administered F doses that had been given weeks earlier. The F concentrations at 35 days were similar to those found at 70 days. The results support the hypothesis that, following pulse loading, F can be mobilized from the bone adjacent to the enamel organ and result in local F concentrations sufficiently large to adversely affect amelogenesis.

Effects of acid-base status and fluoride on the composition of the mineral in developing enamel and dentine in the dog.

Developing molar teeth of the dog were sectioned, embedded in copper containing polymethyl methacrylate, polished and their Ca/P and Ca/Na molar ratios investigated with the electron microprobe. The teeth were obtained at 30 days from 9 pups fed regimes of different acid-base status with or without fluoride supplementation from birth to sacrifice at 30 days. No clear trends in their Ca/P or Ca/Na ratios with variation in the diet were observed. However, evaluation of the Ca/P ratio of the enamel as a function of depth revealed that this ratio was 0.80 +/- 0.15 at the mineralization front. This suggests that in enamel brushite rather than octacalcium phosphate is the precursor phase of the mineral.