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Biomedical subjects

H Almqvist

Publications and source records attributed to H Almqvist.

10 recordsLinked to original sources
PubMed2003

Non-invasive management of superficial root caries lesions in disabled and infirm patients.

UNLABELLED: In disabled and infirm patients with limited, if any, capacity for independent oral self-care, it is difficult to control progression of root caries lesions. OBJECTIVE: To evaluate the effect of non-restorative cariostatic treatment on progression of active superficial root caries lesions (n = 56). DESIGN: Pilot study. SETTING: Department of Cariology, Institute of Odontology, Karolinska Institutet, Huddinge. SUBJECTS: 15 physically-dependent patients. INTERVENTION: The patients were allotted to one of the following groups. Group 1, professional tooth cleaning and application of tap water flavoured with eucalyptus oil; Group 2, professional tooth cleaning and application of Cervitec, (1% chlorhexidine in thymol-containing varnish), Group 3, professional tooth cleaning and application of Cervitec and Fluor Protector (varnish containing 0.1% fluoride). Every three months for 18 months, each subject received the treatment twice within a 10-day interval. MEASUREMENTS: The status of the 56 root caries lesions was evaluated every six months using a root caries index based on visual and tactile criteria. The examiners were blind to which treatment group the patients belonged. RESULTS: In most subjects (14 out of 15), progression of root caries lesions was arrested. No statistically significant differences could be demonstrated between the three treatment groups. However, regardless of treatment regimen, there was a statistically significant difference between the greater number of subjects exhibiting no progression of root caries lesions and those with lesion progression, at 6 (p = 0.022), 12 (p = 0.006) and 18 months (p < 0.001). CONCLUSION: This pilot study suggests that in disabled and infirm patients regular professional tooth cleaning with a fluoride containing paste, with or without supplementary varnishing with chlorhexidine-thymol and/or fluoride can prevent further progression of existing superficial root caries lesions.

Aged↗
PubMed2000

Effect of eyelid botulinum toxin injection on lacrimal drainage.

PURPOSE: To determine the effect of eyelid botulinum toxin injection on the lacrimal drainage and to assess the use of botulinum toxin in dry eye conditions. METHODS: Prospectively, three test groups were examined and one lacrimal system investigated in each person in each group. Botulinum toxin A (3.75 IU) was injected into the medial part of 13 lower eyelids of 13 normal test subjects and the medial part of nine lower eyelids in nine patients with dry eyes. A dose of 2.5 IU was injected into the medial part of 10 lower eyelids and the medial part of 10 upper eyelids of 10 patients with dry eyes. The drop test was used to determine the lacrimal drainage capacity and the blink output, before and after the injection. The subjective effect of the botulinum toxin injection on eye comfort was investigated. RESULTS: Three weeks after lower eyelid botulinum toxin injection, the mean blink output was reduced to 64% (1.19 of 1.87; P <.001) and 70% (0.94 of 1.35; P <.001) of the baseline values in the groups of normal subjects and patients, respectively. After injection in both the upper and lower eyelid, the mean blink output was reduced to 38% (0.54 of 1.41; P <.001) of the baseline value. The patients with dry eyes reported an improved eye comfort in six of nine cases after injection in the lower eyelid and in seven of 10 cases after injection in both the upper and lower eyelid. Adverse effects included one case of increased discomfort for 3 weeks after injection. CONCLUSION: Injection of botulinum toxin into the medial part of the eyelids decreased the lacrimal drainage, suggesting a new way to treat dry eye conditions. Further studies are required to assess the clinical value of this treatment.

Adult↗
PubMed1993

Influence of constant fluoride levels in solution on root hard tissue de- and remineralization measured by 125I absorptiometry.

To study the effect of fluoride on de- and remineralization of root hard tissue, an automatic pH-cycling caries model, simulating Stephan curves, was used for 21 days. From each of 13 unexposed human roots, four cementum/dentin blocks were prepared. Four experiments were carried out: one block from each tooth as subjected to pH cycling without and with fluoride at the concentrations of 0.02 ppm (1.0 mumol/l), 0.20 ppm (10.5 mumol/l) and 2.00 ppm (105.3 mumol/l) in the de- and remineralizing solutions, respectively. Mineral change in the specimens was monitored by 125I absorptiometry. When no fluoride was added to the solutions the change in transmission (delta T) increased continuously over 21 days, indicating loss of mineral. In the 0.02-ppm F experiment, there was a marked decrease in delta T, but almost no change in the 0.20-ppm F experiment. pH cycling with 2.00 ppm F in the solutions resulted in a gain of mineral in or most likely on the surface of the cementum/dentin blocks, indicated by a continuously decreasing delta T. The fluoride level in the solution significantly influenced the change in the mineral content of the specimens. Microradiographs of the sectioned blocks showed radiodense surface zones, varying degrees of subsurface demineralization and signs of remineralization or mineral deposition.

Absorptiometry, Photon↗
PubMed1993

Effect of intermittent delivery of fluoride to solution on root hard-tissue de- and remineralization measured by 125I absorptiometry.

The effect of intermittent fluoride levels on root hard-tissue de- and remineralization was studied once daily for 21 days in a pH-cycling caries model with simulated fluoride clearance curves. Four root hard-tissue blocks, from each of 12 human teeth, were cut out parallel to the cementum surface. During a daily 15-hour period, the blocks were subjected 12 times to pH changes similar to those which occur in plaque after a carbohydrate intake. The fluoride was delivered immediately before a daily nine-hour remineralization period. Four experiments were independently carried out: One block from each tooth was subjected to pH-cycling without and with fluoride delivery, simulating a rinse with 0.025, 0.2, and 1.0% sodium fluoride (NaF), respectively. The mineral change in the blocks was monitored by 125I absorptiometry and expressed as the change in transmission (delta T). The surface between the data points (delta T values) and the x axis (time points) was used as a summary measure, i.e., the area under the curve (AUC). When no fluoride was delivered, the delta T increased over 21 days, indicating loss of mineral. The AUC was, on average, 5.85 +/- 0.68 (mean +/- S.E.) %.day. In the 0.025% NaF-rinse experiment, there was a marked reduction in mineral loss, indicated by an average AUC of 1.66 +/- 0.59%.day. In both the 0.2 and 1.0% NaF-rinse experiments, a decrease in delta T, indicating gain of mineral, was observed from day 2. Negative delta T values occurred after 7 and 3 days, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1990

Automatic pH-cycling caries model applied on root hard tissue.

The development of a caries lesion is a dynamic process that includes frequently alternating periods of de- and remineralization, a process for which no in vitro models currently exists. The aim of this study was to develop a model which could repeatedly generate identical pH versus time curves over extended periods of time. To test the model demineralization studies on cementum/dentin were performed. Cementum/dentin blocks were repeatedly subjected to de- and remineralizing solutions delivered by a computerized pump system connected to a pH-meter and a recorder. pH versus time curves similar to those produced in plaque after carbohydrate intake were generated 18 times during 15 h followed by a remineralizing period of 9 h every day for 16 days. The intra-day and inter-day variation of the pH-cycling model were found to be low. The mineral change of the blocks was followed by 125I absorptiometry and the transmission through the blocks during the experimental period increased in average by 1.4 +/- (SE) 0.18%. Microradiographic analysis of the transversal sections of the blocks confirmed the development of lesions resembling root caries.

Absorptiometry, Photon↗
PubMed1990

Root hard-tissue demineralization rate measured by 125I absorptiometry: comparison with lesion-depth measurements.

The aim of the present study was to compare demineralization of root hard tissue, monitored by 125I absorptiometry, with lesion-depth measurements under polarized light microscopy. The intact roots of ten human molars, which had not been exposed to the oral environment, were divided into 39 cementum/dentin blocks and exposed to a buffer solution of pH 4.5 containing 2.2 mmol/L calcium and inorganic phosphate. After demineralization for 3.5, 7, 14, and 21 days, transmission measurements by 125I absorptiometry were performed, and one block from each tooth was taken out of the solution for lesion-depth measurement. The results showed a high degree of correlation (r = 0.952) between lesion depth and change in transmission, with a more rapid increase initially in both variables. A linear relationship with the square root of time was found. Conversion of transmission data to lesion-depth data was possible when this caries model system was used on cementum dentin blocks.

Absorptiometry, Photon↗
PubMed1988

Gingival and mucosal reactions after intensive chlorhexidine gel treatment with or without oral hygiene measures.

The aim of this study was to elucidate whether soft tissue reactions during chlorhexidine (CHX) treatment might be associated with meticulous oral hygiene measures. A commercially available 1% chlorhexidine digluconate gel (Hibitane Dental Gel) was applied in a custom tray for the mandibular arch, 10 min daily, for 14 days. A split mouth approach was used to allow evaluation of the effect of oral hygiene measures with toothbrush, toothpaste, and dental floss on one side of the arch. During the treatment period, 8 out of 12 subjects developed gingival and/or mucosal reactions appearing as white patches or ulcerations. Both the gingival reactions on the buccal marginal gingiva and the mucosal reactions near the margin of the custom tray occurred only when the gel treatment was combined with meticulous oral hygiene measures. The white patches, which could easily be detached, leaving ulcerated areas, consisted entirely of stratified squamous epithelium. The findings suggest that intensive treatment with chlorhexidine gel, in individually fitted custom trays, combined with meticulous oral hygiene measures may induce toxic effects on the surface layers of the gingiva and mucosa.

Chlorhexidine↗
PubMed1988

In vitro root caries progression measured by 125I absorptiometry: comparison with chemical analysis.

Radiation from a 125I source and a non-image-forming detector was used for non-destructive measurements of root caries progression. Blocks were cut parallel to the cementum surface of unexposed human roots. These blocks were then individually demineralized in under-saturated calcium phosphate solutions over an 84-hour period. In order for the in vitro root surface demineralization to be followed, the changes in transmission (delta T) through the blocks were measured, by 125I absorptiometry, eight times during the course of the experiment. Chemical analyses of the calcium output (delta Ca) from the blocks into the demineralizing solutions were also performed, and the rate of demineralization (Vdem) was calculated from these values. The precision of 125I absorptiometry was calculated from 176 duplicate transmission measurements, and the coefficient of variation was found to be 0.20%. The correlation coefficient between delta T and total delta Ca for each of 22 cementum/dentin blocks ranged between r = 0.934 and r = 0.998. The progression of root hard-tissue lesions observed by these two methods and by the calculated Vdem was found to be proportional to the square and cubic roots of time. The study shows that 125I absorptiometry can be used for continuous non-destructive measurements of root hard-tissue demineralization in vitro.

Calcium↗