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At least 127 records · Page 7Linked to original sources
PubMed1991

[The effect of plaque fluid on demineralization of enamel powder].

The aim of this study was to explore any substance in dental plaque which might affect the demineralization of enamel. Plaque fluid was prepared by centrifugation of pooled plaque from 56 young adults without periodontal diseases. Enamel was separated from healthy teeth of adolescents and crushed into powder. The enamel powder was treated separately by plaque fluid and synthetic plaque fluid (as a control, with similar calcium, fluoride content and pH as the natural). After this, the enamel powder was washed with PBS. Both the plaque fluid-treated and synthetic plaque fluid-treated enamel powder were demineralized by mixed organic acid (pH 4.5). The calcium content in both plaque fluids, PBS and organic acid after treatment with enamel powder was analysed by atomic absorption spectrophotometer. The results showed that there was no promoting effect in plaque fluid on demineralization of enamel, but, on the other hand, some protecting action was observed which might contribute to the presence of proteins in plaque fluid.

Adult↗
PubMed1990

[In vitro experiments on effect of soft drinks on dental enamel].

The composition and dental properties of eight different soft drinks, representing some of the most popular types used in the U.K., were examined. Demineralisation experiments were conducted on hydroxylapatite, the basic component of dental enamel, determining calcium dissolving by atomic absorption spectroscopy and phosphorus by UV/vis spectrophotometry. The titratable acid content of the drinks was found to give a better guide than their pH to their potential dental erosiveness. The sugars content, in their ready-to-drink form, varied from zero in a low-calorie product up to almost 14% in a black-currant drink, but using a technique with a relatively long contact time, and in the absence of intact dental plaque, the demineralising action on hydroxylapatite of the acids already in the drinks eclipsed the effects of the acid generated by oral micro-organisms from the sugars in the drinks. The pure citrus juices showed potentially the worst dental properties, followed by the orange and blackcurrant concentrates after dilution to their ready-to-drink form, with least demineralisation from the carbonated drinks, and a cola drink giving especially low figures.

Carbonated Beverages↗
PubMed1976

[Primary hyperparthyroidism. Analysis of 152 patients with special reference to acute life threatening complications (acute hyperparathyroidism)].

The findings of 152 patients with proven primary hyperparathyroidism are reportedmthe purpose of the analysis was to find difference between the various clinical manifestations of the disease. Furthermore the occurrence of acute hyperparathyroid crisis in our series as well as in the literature are described. 65.8% of the patients were females, 34.2% were males. The leading symptom in 98 patients (group I) were kidney stones and in 23 patients (group II) cystic bone disease. Both manifestations of the disease occurred in only 7 patients (group III) and no symptoms related to the kidneys or to the bones occurred in 24 patients (group IV). Because of the difference of the clinical manifestations the additional data were analyzed for each group separately and compared with each other. There was no difference in the mean serum calcium levels for all four groups, however, patients of group I were on the average younger, the duration of the disease was longer and the weight of the parathyroid adenoma was lower compared to the other three groups, Data are presented regarding calcium excretion, phosphate clearance and tubular reabsorption of phosphate for each group. At operation single or multiple adenoma formation was present in 133 patients, whereas diffuse hyperplasia was found in 17 and carcinoma in 2 other patients. 46 of the adenomas were found in an atypical anatomical localisation. This observation is responsible for the many unsuccessful or second explorations of the neck; The weight of the adenomas varied between 0.1 and 23.5 g. The most difficult diagnosis was that of diffuse hyperplasia. The sucess of the surgical intervention was usually established in over 80% of the cases within 24 to 48 hours after the operation with a significant fall of serum calcium. There ist still no definite explanation for the variability of the clinical manifestations of primary hyperparathyroidism. Parathyroid hormone determinations on larger numbers of patients are not yet published. The assumption, that different hormones or peptide fragments are reposible for the different action on bone and kidney is discussed; In our series of 152 patients acute hyperparathyroid crisis occurred eight times. Our findings are compared to the other well documented cases in the literature. Main symptoms were nausea, vomiting, abdominal pain and different states of cerebral dysfunction. Most of the patients had calcium levels over 16 mg/100 ml. Partial renal insufficiency with elevated blood urea and phosphate retention was found in over 50% of the cases. Overall mortality of all cases with acute parathyroid crisis is 52.5%. The pathogenesis of acute hyperparathyroidism and the implications of high calcium levels are discussed. According to our own experience hypercalcenia can be controlled with an intensive therapeutic program and emergency operation for acute parathyroid crisis is no longer necessary.

Acute Disease↗
PubMedDate not supplied

[De- and remineralization processes of the surface layer of the enamel in intact and pulp-extirpated teeth].

Clinico-laboratory investigation of 61 intact teeth and 61 teeth after pulp extraction was performed, including in vivo acid enamel biopsy and intravital staining with 2% methylene blue solution. The regularities were established governing Ca and P efflux from superficial enamel layer of intact and pulp-extracted teeth into the acid solution with respect to age, group of the tooth and pulp extraction terms. The pulp extraction factor was investigated with special reference to the tooth acid resistance and its remineralization rate.

Adolescent↗
PubMed1986

Hardness changes and mineral loss in enamel during the intra oral cariogenicity test in the presence of 0.125% EHDP with or without 0.1% F-.

The effects of a high EHDP concentration (0.125%) were measured under Intra Oral Cariogenicity Test (ICT) conditions in the presence or absence of F- (0.1%). EHDP as well as EHDP supplemented with F- inhibited the softening of enamel slabs to a similar extent as measured by microhardness. Measurements of the calcium and phosphate levels as a function of depth showed that the addition of F- to the EHDP solution further decreased mineral loss in the deeper layers. The results suggest that the inhibition of demineralization of the enamel by EHDP and F- is due to inhibition of acid production by microorganisms.

Calcium↗
PubMed1986

Comparison of the hardness change and mineral loss in enamel by dimethyl ammonium fluoride (alpha C12 DMEAHF) or NaF treatment under intra oral cariogenicity test conditions.

Changes in hardness as well as in Ca and P were determined in enamel slabs after treatment with 3% sucrose together with NaF or alpha C12 DMEAHF (both containing 0.006% F-) under Intra Oral Cariogenicity Test conditions. NaF treatment resulted in a hypermineralization of the surface of the enamel lesion suggesting formation of CaF2. Treatment with ammonium fluoride along with the same low F- concentration inhibits the caries process completely and seems to be a very promising anticaries agent.

Ammonium Compounds↗
PubMed1987

[Hyperfunctioning parathyroid carcinoma].

Two cases of parathyroid carcinoma with hyperparathyroidism, a relatively rare endocrine tumor are reported. It accounts for approximately 1-4% of all cases of primary hyperparathyroidism. Parathyroid crisis occurred for three times in one case. It is difficult to make an early diagnosis, frequently leading to misdiagnosis and wrong treatment. During operation iatrogenic implant or incomplete resection may occur, resulting in recurrence and repeated operations. It is important to differentiate from hypercalcemia caused by parathyroid adenoma. Neck mass, hypercalcemia usually above 14 mg%, severe decalcification and pathological fractures are characteristic. Fibrosis and inflammatory reaction of the tumor and metastases in the neck lymph nodes are commonly seen at operation. Histologically active tumor cell mitosis, capsular and vascular invasions usually exist. Local recurrences often occur after surgical treatment. If the surgeon can recognized the malignant change and give a curative resection in the initial operation, more gratifying results can be obtained.

Adult↗