Distribution of fluoride in saliva and plaque fluid after a 0.048 mol/L NaF rinse

An ultramicro method has recently been described for measurement of plaque-fluid fluoride concentration (Vogel et al., 1990a). This method was used: (1) for exploration of the variation in fluoride concentration of plaque fluid collected from the same buccal tooth sites following a 0.048 mol/L NaF (0.2%) rinse, and (2) for examination of the distribution of fluoride in plaque fluid and saliva within one hour after this rinse. Results indicated an average coefficient of variation (CV) of 31% for plaque-fluid fluoride in triplicate samples recovered simultaneously from the buccal-proximal region of two teeth after the rinse. This was similar to the CV found for plaque-fluid fluoride from the same sites after separate administrations of the rinse. A strong linear correlation was found between salivary and plaque-fluid fluoride at 30 and 60 min after rinse administration, showing that plaque-fluid fluoride is influenced by the concentration of salivary fluoride after administration of this rinse. Plaque-fluid fluoride concentrations were higher than that in saliva at baseline, 30, and 60 min. Very large inter-site and intersubject variations in plaque-fluid distribution were observed, with the central incisors showing the slowest clearance. These variations suggest that an examination of plaque-fluid fluoride from specific tooth regions may be essential for understanding the effects of fluoride on the site-specificity of caries.

Effect of fluoride amalgams on artificial recurrent enamel and root caries

The present study examined the effect of F-containing amalgams on recurrent caries in vitro. Four amalgams were tested: A - Conventional amalgam; B - Amalgam A with 1% SnF2; C - Non-gamma-2 amalgam; D - Amalgam C with 1% SnF2. Twenty fillings from each amalgam were placed at the cementoenamel junction in sound extracted human teeth. The teeth were covered with varnish except for a 2-mm-wide zone around the fillings and immersed in separate vials containing dialyzed 15% gelatin gel, pH 4.2, for 17 days. Longitudinal sections through the created enamel and root lesions were examined using polarized light microscopy with distilled water as imbibition medium. Lesion depth was measured adjacent to the fillings and at the midpoint of the lesions. In the amalgam D group, 14 enamel lesions and 15 root lesions showed no demineralization in the area closest to the fillings, and mean lesion depth was significantly smaller than adjacent to the F-free amalgams in enamel as well as in root surfaces. In the root lesions, protection was most evident in amalgam D. At the midpoint of the lesions, depths were not statistically different between groups A-D. This study suggests that fluoride amalgams have anticaries properties sufficient to inhibit recurrent caries.

Previous injuries and persisting symptoms in female soccer players

One hundred and fifty players in a female senior soccer division, starting up a new season, were examined for past injuries and persisting symptoms. An incidence of 0.18 injury/player/year was found, which is not significantly different from previously reported injury rates for male soccer. Sprains to the lower extremity and shin-splints were the most common previous injuries. Forty-three percent of the players had some kind of persistent symptom as a result of a past injury. Symptoms from previous ankle and knee sprains and from overuse injuries were the most common. Players who had sustained an ankle joint injury were more prone to have persistent symptoms (p less than 0.05) if they had persistent mechanical instability. Compared to previous retrospective studies on men's soccer, the women showed a higher rate of previous patellar dislocations. These injuries often caused persistent symptoms. The women showed fewer serious knee injuries. This might depend on a real difference in incidence or is just a reflection of female players ceasing to play soccer after a severe knee injury.

Association of selected bacteria with the lesions of root surface caries

Plaque from the root surfaces of 165 subjects (mean age 65.5 years, 22-26 teeth/subject) was analysed for specific bacteria. Five subject groups were defined: A (DMFS 16.4), B (DMFS 55.9), C1 (DMFS 55.6), C2 (DMFS 57.0) and C3 (DMFS 48.1). Groups C1 and C2 had unrestored root surface lesions; Group A, B and C3 were free of unrestored root caries and differed in their coronal caries experience. Streptococcus mutans was isolated more frequently from the root lesions in Groups C1 and C2 than from intact root surfaces in Group A. Streptococcus oralis, Streptococcus mitis 1 and Streptococcus sanguis were isolated more frequently from Group A. The percentage contribution that S. mutans made to plaque from lesions in Groups C1 and C2 was higher than that from plaque in Group A and Actinomyces viscosus serovar 2 contributed more to plaque in Group C1 than in samples from Group A. The percentage counts of Lactobacillus in plaque from lesions in Groups C1 and C2 were higher than those from intact roots in Groups A, B, and C3. Subjects were also grouped on the presence of Lactobacillus and S. mutans in plaque samples. Samples with both organisms (n = 17) showed significantly higher isolation frequencies of specific strains of S. mitis 1 and also A. viscosus serovar 2 compared with samples of plaque containing S. mutans or Lactobacillus. Actinomyces naeslundii serovar 1 was not isolated from samples containing both S. mutans and Lactobacillus. The results confirm an association of S. mutans and Lactobacillus with root surface lesions and suggest a relationship between lesions and A. viscosus serovar 2.

Fluoride: an adjuvant for mucosal and systemic immunity

Fluoride, the agent responsible for reduction of dental caries worldwide, and a recognized proliferative agent, is a potent adjuvant when given intragastrically to rats. Intragastric fluoride causes increases in the size and cellularity of the Peyer's patches and mesenteric lymph nodes as well as the number of plasma cells secreting IgG and IgA antibodies to ovalbumin given in their drinking water. Rats ingesting NaF and fed OA showed a significant increase in surface immunoglobulin expression on lymphocytes from the Peyer's patches and mesenteric lymph nodes. The frequency of CD4+ T cells in these lymphoid tissues was elevated while that of CD8+ T cells was significantly decreased. In separate experiments, rats parenterally immunized with myelin basic protein (MBP) and fed NaF twice weekly, had significantly elevated serum IgG antibody activity to MBP compared to similarly immunized rats not receiving NaF. The supplemental fluoride prescribed for infants and especially that which is inadvertently ingested by children and adults given fluoride gels, is within the concentration range of that which produced the effects we observed in rats. The adjuvant effect we describe thus has relevance for fluoride therapy worldwide.

The incidence of ankle sprains in soccer

This study investigated the relationship between exposure time and ankle sprains in soccer. Forty-one teams (639 players) from four male senior soccer divisions at different levels of skill (divisions I-VI) were followed prospectively for 1 year. The exposure to soccer and the number of injuries per player were higher in higher divisions, but the injury incidence, percentage of ankle injuries and incidence of ankle injuries were the same at different levels of skill. Of all injuries 17 to 20% were ankle sprains and the incidence varied between 1.7 to 2.0 ankle injuries per 1,000 hours of exposure. Since players with previous ankle problems run an increased risk of reinjury we suggest that these players receive preventive advice.

Humoral immunity in root caries in an elderly population. 2

Saliva specimens stored for 18 months at -20 degrees C with or without glycerol and the anti-protease benzamidine-HCl, lost all antibody activity for S. mutans. IgA activity in processed whole saliva decreased significantly after one week when stored either at 4 degrees C or -20 degrees C with or without glycerol, although it was stable in parotid saliva for at least 40 days. Loss of activity prior to processing was significant in the first 24 h, and the addition of 50% glycerol and storage at -70 degrees after processing, prevented loss of antibody activity in both whole and parotid saliva. Diurnal variations in IgA, lactoferrin and the IgA secretion rate were insignificant in parotid saliva but showed some fluctuations in whole saliva. Albumin and lactoferrin levels exhibited the greatest fluctuation in whole saliva specimens although IgA and IgA antibody levels were still more characteristic of the patient than the time of sampling. Monthly variations in IgA, IgA antibody activity and other parameters were least in parotid saliva and e.g., values for parameters that were high in patients samples on the first month, remained high during the 4-month study period. Statistical analyses showed a high correlation between values obtained for most of the 15 parameters that were measured in parotid and whole saliva specimens collected from greater than 20 patients during 2 successive visits. Whole saliva values for albumin, lactoferrin and albumin levels in parotid saliva, were most variable but differences were not significant. Hence, patients with very low or very high values, even in whole saliva, can be identified within the population on the basis of specimens collected at a single time.

Normal course of events amongst Swedish soccer players: an 8-year follow-up study

In this study 180 male soccer players entered into a prospective study of injuries in 1980. They were examined again in 1988. The aim of the present study was to evaluate the course of events during their active period. The study was carried out using a questionnaire. The importance of major injuries was evaluated. Hospital records were scrutinized and 179 of 180 (99 per cent) were included in the evaluation.

The gene for insulin-like growth factor-binding protein-1 is localized to human chromosomal region 7p14-p12

Insulin-like growth factors (IGF) I and II are bound to high-affinity binding proteins in the blood circulation and other body fluids. These IGF-binding proteins are expressed at different concentrations in different tissues and are thought to regulate the activity of IGF I and II. Cloned cDNA for IGF-binding protein-1 (IGFBP1) has been used to verify the location of its gene to human chromosome 7 by Southern blotting to DNA from a human-mouse hybrid cell line. Further, by in situ hybridization the gene was regionally localized to 7p14-p12, and a Mendelian-inherited two-allele BglII restriction enzyme length polymorphism was identified, with the most frequent allele occurring in 53% of the chromosomes.

Fluoride pharmacokinetics: its implications in the fluoride treatment of osteoporosis

This report reviews some aspects of fluoride pharmacokinetics in relation to the treatment of osteoporosis. The bioavailability of conventional plain NaF tablets has been shown to be close to 100, for sustained-release NaF tablets close to 90%, and for enteric-coated NaF tablets 65%. The simultaneous intake of food and/or calcium tablets reduces the bioavailability by 30 to 40%. Fluoride renal clearance is influenced by both urinary pH and flow and the clinical consequences of this is discussed. Studies on plasma kinetics of fluoride during chronic fluoride intake suggests that a plasma sample taken at mid-dosage intervals will give reproducible "mean steady-state" levels. It is suggested that improvements of the clinical benefit of fluoride therapy in osteoporosis might be achieved if the dosage regimen were based on the pharmacokinetic properties of the fluoride preparation used as well as plasma fluoride monitoring.

Pharmacokinetics of fluoride in man and its clinical relevance

A large number of parameters will influence and mediate the activity and the pharmacological response of dental fluoride products after systemic or topical treatment. This report reviews some aspects of the pharmacokinetics of fluoride in man, fluoride bio-availability, plasma kinetics, and kinetics of fluoride in saliva and plaque fluid. Pharmacokinetic studies in growing dogs show that 90% of a single injected fluoride dose is retained shortly after birth, but at maturity it decreases to about 50%. The degree of fluoride accumulating in calcifying tissues seems to be strongly related to age. The bio-availability of fluoride from swallowed fluoride toothpaste is shown to be decreased if the toothpaste is ingested close to a meal. Several studies show that fluoride exerts its cariostatic effects through the liquid phase surrounding the enamel. The importance of fluoride in the fluid environment of the teeth and the kinetics of fluoride in saliva are discussed. Clinical studies using different slow-release fluoride systems indicate that they are promising cariostatic agents--in particular intra-oral slow-release devices and lozenges. A new micro-analytical method to study the kinetics of fluoride in plaque fluid collected from single tooth sites has been developed. Preliminary studies show that the clearance of fluoride from plaque fluid is slowest in the upper incisor region, followed by the molar region, and faster in the lower incisor region. A site-by-site study of the concentration of fluoride in plaque fluid after topical fluoride administration could be extremely beneficial in optimization of the methods and recommended safety regimens for fluoride therapy.

Fluoride analysis in nanoliter- and microliter-size fluid samples

A variety of techniques is described for measuring fluoride in volumes of from 0.005 to 5 microL, including: (1) micropipette procedures for transference and dilution of samples, (2) construction of miniature and micro fluoride-selective electrodes, and (3) methods for adapting standard electrodes for micro- and semi-micro volumes. These described techniques have a number of advantages, including speed of analysis, high accuracy, and adaptability to many types of fluid samples. Recent studies involving use of these procedures include the analysis of fluoride in: (1) plaque fluid samples from single sites before and after topical fluoride administration, (2) tooth mineral samples recovered by acid-etch or microdrill biopsy of enamel, and (3) fluid recovered from the interior of the tooth during simulation of the caries process.

Studies of human gastric mucosa after application of 0.42% fluoride gel

Dental prophylaxis with APF gels (1.23%) may cause gastric distress as a side-effect. This gastric irritation is probably due to a direct toxic effect of fluoride (F), swallowed in conjunction with the treatment, on the gastric mucosa. The aim of the present study was to investigate whether--and to what extent--a dental treatment with 3 g of a 0.42%-F gel could affect the gastric mucosa due to inadvertent swallowing of the gel. Ten subjects underwent a control gastroscopy, and two weeks later, a second gastroscopy was performed two h after a F gel treatment. During the gastroscopy, the mucosa was examined and the injuries graded according to an arbitrary scale. Four biopsies of the antral and corpus regions of the stomach were taken and evaluated histologically. The mean (+/- SD) amount of F retained after the application was 5.1 +/- 2.1 mg, i.e., 40% of the applied amount of F. Petechiae and erosions were found in the mucosa in seven of the ten patients. The histopathological evaluation revealed changes in nine of ten patients, with the surface epithelium as the most affected component of the mucosa. The present study clearly shows that a treatment with a F gel of rather low F concentration may result in injuries to the gastric mucosa. The importance of current recommended guidelines so that the amount of F swallowed during a gel application can be minimized is emphasized. From a toxicological standpoint, the use of a low-F gel instead of a 1.23%-F gel in small children is recommended for avoidance of adverse gastric effects.

Diurnal fluoride concentration in whole saliva in children living in a high- and a low-fluoride area

Salivary fluoride concentrations were investigated in 12-year-old children living in areas with low (0.1 ppm) or high (1.2 ppm) fluoride concentration in the drinking water. Unstimulated whole saliva was collected from 27 children from the respective areas every 2nd hour for 46 h except during sleep. The mean salivary fluoride concentration was 0.32 +/- 0.013 mumol/l (n = 419) in the low-fluoride (LF) area and 0.87 +/- 0.047 mumol/l (n = 401) in the high-fluoride (HF) area. No significant rhythm could be found for the diurnal variations in the mean or individual salivary fluoride concentrations. However, in the HF area the individual salivary fluoride concentrations fluctuated widely and randomly.

Three-dimensional measurement of rearfoot motion during running

Excessive ranges of motion during running have been speculated to be connected to injuries to the lower extremities. Movement of the foot and lower leg has commonly been studied with two-dimensional techniques. However, differences in the alignment of the longitudinal axis of the foot with the camera axis will produce measurement errors for projected angles of the lower extremities. A three-dimensional approach would not have this limitation. The purpose of this study is to present a three-dimensional model for calculation of angles between lower leg and foot, lower leg and ground, and foot and ground, and to compare results from treadmill running derived from this model with results derived from a two-dimensional model for different alignment angles between foot axis and camera axis. A two camera Selspot system was used to obtain three-dimensional information on motion of the studied segments. It was found that several two-dimensional variables measured from a posterior view are very sensitive to the alignment angle between the foot and the camera axis. Some variables change as much as 1 degrees for every 2 degrees of change of the alignment angle. The large influence of rotations other than the measured one in two-dimensional measurements makes advisable the use of a three-dimensional model when studying motion between foot and lower leg during running.

Fluoride intake in early infancy

Current regulations concerning nutrient content of infant formulas do not specify either a lower or an upper limit for fluoride content. There would appear to be no need to specify a lower limit. An upper limit of 0.06 mg per 100 kcal is achievable and is recommended. Intake of fluoride by the infant will be influenced more by the water used as a diluent than by the concentrated liquid or powder used in formula preparation.

Reconstruction of the anterior cruciate ligament in athletes, using a fascia lata graft: a review with preliminary results of a new concept

This paper describes a new concept for the intra-articular reconstruction of the anterior cruciate ligament in competitive athletes. The concept includes careful selection of patients, the use of fascia lata as a graft, an operative technique which includes notchplasty and isometric placement of the graft, as well as aggressive rehabilitation according to Wolff's law. The majority of the patients were able to return to their preinjury activity level in their sport without major complications such as rerupture. A longer follow-up period is needed, however, to evaluate the long-term results of the concept.

Surface-related injuries in soccer

The review of the effects of artificial turf and natural grass on surface-related traumatic injuries in soccer suggests that surfaces with artificial turf produce more abrasion injuries than surfaces with natural grass. Most authors report no significant difference in injury frequencies for the number of traumatic injuries. However, some authors report fewer traumatic injuries on artificial turf, especially after a period of adaptation on the artificial turf. A difference in injury pattern and injury mechanism when playing on different types of surfaces has been suggested, as well as an increased injury risk for frequent alternating between different playing surfaces. The relationship between knee and ankle injuries and the fixation of the foot to the ground is not yet evaluated in soccer. In American football, the severity and incidence of knee and ankle injuries were reported to be significantly lower when using shoes with lower friction properties. However, in American football severe injuries typically occur in collision situations often independent of the surface. Soccer is characterised by sprinting, stopping, cutting and pivoting situations, where shoe-surface relations are essential and frictional resistance must be within an optimal range. Future research should address this compromise between performance and protection.

Binding of type-I and type-II collagens to Staphylococcus aureus strains isolated from patients with toxic shock syndrome compared to other staphylococcal infections

Toxic shock syndrome toxin-1 (TSST-1) producing strains of Staphylococcus aureus isolated from 18 patients with toxic shock syndrome (TSS) and from 56 patients with other diagnoses were compared for capacity to interact with various serum and connective tissue proteins. TSS associated isolates showed significantly stronger binding of Type-I collagen (Cn-I) and Cn-II than non-TSS strains, in a particle agglutination assay (PAA) as well as in 125I labelled Cn uptake experiments. 125I Cn-IV binding, was similar between the two groups, whereas in PAA, a stronger interaction was observed for non-TSS than TSS associated strains. The median binding of 125I Cn to TSS-associated strains were 52.2 (Cn-I), 30.6 (Cn-II) and 20.0 (Cn-IV) compared to 20.0 (Cn-I), 14.4 (Cn-II) and 24.4 (Cn-IV) values of non-TSS strains. A saturation with 125I Cn-I and Cn-II binding was established for TSS (30 min) and non-TSS (15 min) strains. 125I Cn-IV binding reached a saturation in 10 min and 90 min with TSS and non-TSS strains respectively. Finally, the binding profiles of TSS associated and non-TSS strains to fibronectin, fibrinogen, laminin and IgG did not differ in both PAA and radioisotope assays. In scanning electron microscopy, cells of TSS associated strains bound to the reprecipitated native Cn-I fibrils. In contrast, most cells of non-TSS strains were localized to the distal end or were trapped between the Cn fibrils.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on fluoride concentrations in human submandibular/sublingual saliva and their relation to flow rate and plasma fluoride levels

Submandibular/sublingual saliva and blood were collected from five subjects after ingestion of 1 mg fluoride as NaF. An individual collection device, made from a silicone impression material, was used to collect the saliva in 10-minute samples, before and during 2 hr after the fluoride intake. In two separate experiments on each individual, submandibular/sublingual saliva was collected continuously at different flow rates: without stimulation and with gustatory stimulation. Blood was also collected at intervals throughout the experiments. The concentration of fluoride in the submandibular/sublingual saliva was less than that in the plasma but independent of salivary flow rate. The ratio between the saliva and plasma fluoride concentrations at the peak of the mean plasma fluoride concentrations was 0.55 +/- 0.13 and 0.69 +/- 0.11 in the experiments on unstimulated and stimulated salivary, flow rate, respectively. The total amount of the ingested fluoride dose that was excreted through the submandibular/sublingual glands during 130 min was highly correlated with the salivary flow rate. The fraction of the ingested fluoride dose excreted in 2 hr was 0.04 +/- 0.02% in the unstimulated saliva and 0.15 +/- 0.09% in the stimulated saliva.

Influence of flow rate, pH and plasma fluoride concentrations on fluoride concentration in human parotid saliva

In two separate studies the influence of some physiological factors on salivary fluoride excretion was investigated. In the first study, parotid saliva, at two predetermined flow rates, and capillary blood were sampled after ingestion of 1 mg fluoride. In the second study, parotid saliva was collected at five different flow rates, starting 1 h after ingestion of 5 mg fluoride. Capillary blood was sampled throughout the experiment. The first study showed that parotid saliva and plasma fluoride concentrations were closely correlated (r = 0.81). The mean parotid salivary and plasma fluoride concentration ratio (S/P ratio) +/- SD ranged from 0.29 +/- 0.11 to 0.65 +/- 0.15. The fractions of the ingested fluoride dose excreted from one parotid gland were 0.08 and 0.18% at flow rates of 0.25 +/- 0.02 and 0.49 +/- 0.06 ml/min, respectively. The second study showed that at the mean basal plasma fluoride concentration of 0.65 +/- 0.18 mumol/l the mean S/P ratio was 0.55 +/- 0.24. At a plasma fluoride concentration ranging from 3.5 to 11.6 mumol/l the S/P ratio was 0.73 +/- 0.15. Thus the S/P ratio was influenced by the plasma fluoride concentration, but not by variations in parotid salivary flow rate or pH.

Studies on fluoride excretion in human whole saliva and its relation to flow rate and plasma fluoride levels

Five volunteers participated in two separate experiments where whole saliva was collected without stimulation or with stimulation by chewing on paraffin wax. The saliva was collected continuously for 120 min after ingestion of 1 mg fluoride as NaF. Blood was collected at intervals throughout the experiments. The results showed that the concentration of fluoride in whole saliva mirrored the fluoride concentration in plasma, but at a lower level. Variations in salivary flow rate (0.34 +/- 0.15 ml/min for unstimulated and 1.06 +/- 0.28 ml/min for stimulated) did not affect the salivary fluoride concentration. The amount of fluoride excreted into stimulated whole saliva was significantly correlated with the salivary flow rate, with a correlation coefficient of 0.98. The fraction of the ingested fluoride dose recovered in whole saliva within 2 h was 0.05 +/- 0.02 and 0.18 +/- 0.09% for the unstimulated and the stimulated whole saliva, respectively.