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Biomedical subjects

B Angmar-Månsson

Publications and source records attributed to B Angmar-Månsson.

At least 37 records · Page 2Linked to original sources
PubMed1997

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.

Adult↗
PubMed1997

Quantification of formation and remineralization of artificial enamel lesions with a new portable fluorescence device.

Quantitative laser fluorescence has been reported as a useful method for the non-destructive in vitro and in vivo diagnosis of early enamel caries. A portable system for intraoral use has been developed with a new light source and filter system replacing the laser light to facilitate clinical application. This new device was validated with microradiographic and chemical analyses for assessment of mineral changes in enamel during lesion formation and remineralization in vitro and compared with the laser light equipment. A significant correlation was found between fluorescence changes and mineral loss: r = 0.79 (laser system) and r = 0.84 (portable lamp system). The correlation between the two fluorescence methods was r = 0.93. The portable fluorescence device seemed to be a promising new tool for reproducible and sensitive assessment of the severity of incipient enamel lesions.

Animals↗
PubMed1997

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.

Acupuncture Therapy↗
PubMed1996

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.

Acupuncture Therapy↗
PubMed1996

Mineral loss in incipient caries lesions quantified with laser fluorescence and longitudinal microradiography. A methodologic study.

The laser fluorescence method (LAF) was validated with longitudinal microradiography (LMR) for assessment of mineral loss in incipient caries lesions in human enamel. Fluorescence radiance scans and LMR recordings were made of 36 enamel slabs with incipient lesions. Original sound values for fluorescence radiance and enamel amount (kg.m-2) at the lesion site were reconstructed by a computer algorithm. Changes in fluorescence radiance and amount of enamel in each measuring point were calculated. The reconstruction method was tested on 20 sound enamel surfaces. The differences between measured and reconstructed values were -0.13 +/- 0.17% with LAF and 0.002 +/- 0.005 kg.m-2 with LMR. The repeatability of the caries quantification was tested by measuring one lesion 20 times. The fluorescence loss in this lesion was 18.2 +/- 1.0%. The enamel loss was 0.09 +/- 0.02 kg.m-2. The correlation between measurements with the two methods was r = 0.73. The non-destructive laser fluorescence method was concluded to be a sensitive and valid method for quantification of mineral loss in enamel caries lesions.

Adolescent↗
PubMed1995

A new method for in vivo quantification of changes in initial enamel caries with laser fluorescence.

A new method for the in vivo assessment of changes in initial enamel caries lesions was developed and tested. A CCD camera equipped with a high-pass filter (lambda > 520 nm) collects the fluorescence image of carious teeth, illuminated intraorally with diffuse laser light (lambda = 488 nm). Incipient lesions show a loss in fluorescence to be expressed as a percentage of fluorescence radiance of sound tissue. A PC program (Inspektor, model QLF 1.0) is used for display, storage, and subsequent analysis of images. To enable the calculation of fluorescence loss, the fluorescence of sound tissue at the lesion site is reconstructed from the radiances of sound tissue bordering the lesion. This method was tested on 19 visually sound buccal surfaces in vivo. The differences between actual and reconstructed radiance was -1.6 +/- (SD) 1.1%, over areas varying between 8 and 14 mm2. The repeatability of the caries quantification was tested by measuring one arrested initial caries lesion 25 times in vivo. The lesion area was 0.56 +/- 0.20 mm2, and the loss of fluorescence was 17.6 +/- 0.7%, corresponding to a lesion depth of 17 +/- 2 microns. The new quantitative method was applied for the testing of an in vivo caries model using plaque-accumulating brackets on premolars scheduled for extraction. Videoimages were recorded in vivo before bracketing and 0, 2, 3, and 5 weeks after debracketing. Clear changes between the different time points were recorded for both lesion size and mineral content.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

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.

Acidosis↗
PubMed1995

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.

Analysis of Variance↗
PubMed1994

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.

Amelogenesis Imperfecta↗
PubMed1994

Strategies for improving the assessment of dental fluorosis: focus on optical techniques.

In its milder forms, enamel fluorosis is characterized clinically by diffuse opacities. The appearance is due to optical properties of a subsurface or surface porous layer with lower mineral content. These areas usually have texture and color similar to those of initial caries lesions but generally another shape and location. Therefore, several optical methods, previously used to diagnose initial caries lesions, were applied to fluoride-induced opacities on extracted premolars and on incisors of four subjects in vivo. These methods included light-scattering measurements, white light illumination, violet light illumination, ultraviolet illumination, and laser fluorescence. Video images were captured with a charge-coupled-device (CCD) camera, digitized, and computer-processed. It is concluded that the light-scattering monitor can be used for the determination of the local porosity of fluorotic enamel and that the laser fluorescence method might be developed into a method applicable for the assessment of the severity of enamel fluorosis.

Fluorescence↗
PubMed1993

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.

Acupuncture Therapy↗
PubMed1993

Advances in methods for diagnosing coronal caries--a review.

Diagnostic methods for coronal caries in common use include visual inspection, tactile examination with a probe, bite-wing radiography, and often fiber-optic-transillumination (FOTI). Early diagnosis enables small lesions to be identified so that remineralization of lesions by preventive measures can be attempted; in clinical research, it may shorten the time for clinical trials. Quantitative methods may potentially decrease interexaminer variations and facilitate the determination of small progressions or regressions. This review discusses recent advances in the development of such methods, i.e., endoscopic methods, FOTI, light-scattering, laser fluorescence, ultraviolet illumination, penetration of dyes, iodide penetration, electrical resistance, ultrasonic imaging, and improved radiographic imaging techniques. Diagnosis of occlusal surfaces gains from the use of the electrical resistance method (preferable when the emphasis is on finding lesions) or radiography (when the emphasis is on identifying sound surfaces). Digitized radiography with simple contrast enhancement gives some further improvement. Quantitative methods are not yet proven to be good enough to measure small changes. Quantitative methods are not yet proven to be good enough to measure small changes. For occlusal surfaces, the electrical resistance method may be, but this has to be confirmed. For approximal surfaces, digitized radiography and fluorescent dye penetration have to be tested for clinical feasibility. It is concluded that there are many methods in development, but all require clinical testing, and many still need development before clinical use.

Dental Caries↗
PubMed1992

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.

Acupuncture Points↗
PubMed1992

Comparison of laser fluorescence and longitudinal microradiography for quantitative assessment of in vitro enamel caries.

A new quantitative, non-destructive method using laser-induced fluorescence (LAF) was compared with longitudinal microradiography (LMR) for assessment of mineral changes in enamel slices using an in vitro caries model. Ten enamel slices, cut longitudinally from sound natural smooth surfaces of human teeth, were exposed to de- and remineralization in a pH-cycling model. The enamel slices were subjected to LAF and LMR measurements before and at 2, 4, 7, and 9 days of demineralization. For LAF, the average fluorescence radiance decreased during the demineralization period with 11% by day 2 and 49% by day 9. For LMR, the corresponding average loss of mineral content changed with 0.01 and 0.10 kg.m-2 over the same time period. The mineral losses in each individual enamel slice measured with the two techniques were strongly correlated, r = 0.97. The Spearman rank correlation coefficient for all LAF and LMR demineralization results was 0.86. The precision (coefficient of variation) for LAF was 3.1%, corresponding to 0.005 kg.m-2, and the repeatability error for LMR was 0.02 kg.m-2, indicating a lower discrimination threshold for LAF compared to LMR. It was concluded that the new, sensitive, non-destructive LAF method provides possibilities for further improvement in the quantification of initial caries lesions in natural smooth enamel surfaces for use in in vitro studies. Furthermore, it offers potential in in situ caries studies as well as a tool in the diagnosis of early enamel caries in vivo.

Contrast Media↗
PubMed1991

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.

Animals↗
PubMed1991

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.

Animals↗