摘要:

Abstract –The Royal Dental College, Copenhagen, houses an extensive collection of human teeth which have been extracted in Denmark. The collection presently includes 203 permanent mandibular molars with a root complex containing a facially‐located supernumerary root. This macrostructure is named radix paramolaris (RP). By analyzing the large number of specimens available it was possible to establish uniform and precise criteria for the identification of RP on M1 inf, M2 inf, and M3 inf The analyses included both separate and non‐separate RP. The representation of the RP variants according to tooth type was mapped. Furthermore, the following clinically relevant variables with respect to RP were registered: degree of separation, divergence, apical bend, apical gracility, and fusion. Because of the nature of the material, the study was mostly qualitative and non‐metric. The results are aimed primarily at clinical dentists, dental morphologists, and dental anthropo

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01884.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –Based on serially cut 200‐μm‐thick sections from 21 human mandibular third molars, a quantitative characterization was made of the morphology in the mesial and distal interlobal groove. Two parameters were used: depth of interlobal groove and structure angle. The interlobal groove depth varied between 0.13 and 0.55, taken in relation to the maximum crown height. The structure angle varied between 2° and 170°. If the structure angle was ≤25°, the interlobal groove was classified as a fissure; if the angle was>25°, the interlobal groove was classified as a groove. Only in 18% of the sections did the interlobal groove manifest itself as a fissure. The study demonstrates that it was possible unambiguously to describe the two‐dimensional profile of interlobal grooves by groove depth and s

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01885.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –Stannous fluoride (SnF2) has been shown to be an effective caries preventive agent. After topical treatment of enamel surfaces, two reaction products have been demonstrated to precipitate on the surfaces, a larger type of globules, probably a calcium fluoride like product, and a smaller type of globules, probably a tin phosphate. The aim of the present study was to examine the amino acid composition and the formation of the acquired pellicle on SnF2‐treated enamel in vivo. The chemical composition was examined by amino acid analysis of pellicle material collected in vivo from SnF2‐treated enamel surfaces. Pellicle formation was examined by scanning electron microscopy on SnF2‐treated enamel fragments carried in the mouth for 2 h. The results showed that pellicle material was formed in abundant amounts and covered the globular surfaces following the SnF2treatment. The chemical analyses showed amino acid profiles with high content of acidic and neutral amino acids. The profiles were different from known amino acid profiles obtained from analyses of pellicle material collected from untreated enamel s

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01886.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –In an earlier study, we found that chronic treatment with β2‐adrenoceptor agonists in asthmatic subjects gave an impaired saliva secretion and a higher caries prevalence than in healthy controls. Twenty‐one of the asthmatics and their matched controls were examined 4 yr later in a follow‐up study. Samples of whole saliva stimulated by chewing and parotid saliva stimulated by citric acid were collected and dental caries was scored. In the asthmatic group the secretory rates of stimulated whole and parotid saliva decreased by 20% and 35%, respectively, compared to the control group. The number of lactobacilli increased. The asthmatic subjects had a decreased output per minute of total protein, amylase, hexosamine, salivary peroxidase, lysozymc, secretory IgA, a bacteria‐aggregating glycoprotein, potassium, and calcium in stimulated parotid saliva. Initial and manifest caries lesions as well as the number of DFS were significantly increased in the asthma group. We conclude that asthmatic patients treated with β2‐adrenoccptor agonists have an increased caries susceptibility due to an impaired saliva secretion caused by the use of β‐adr

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01887.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –Activity in temporalis and masseter muscles, and traits of facial morphology and occlusal stability were studied in 22 patients (19 women, 3 men; 15–45 yr of age) with anterior open bite and symptoms and signs of craniomandibular disorders. Facial morphology was assessed by profile radiographs, occlusal stability by tooth contacts, and craniomandibular function by clinical and radiological examination. Electromyographic activity was recorded by surface electrodes after primary treatment with a reflex‐releasing, stabilizing splint. Maximal voluntary contraction was reduced compared to reference values, particularly in subjects with muscular affection, but maximal activity increased significantly when biting on the splint. Maximal voluntary contraction was positively correlated to molar contact and negatively to anterior face height, mandibular inclination, vertical jaw relation and gonial angle. Relative loading of the muscles was markedly increased during resting posture. It was concluded that reduced occlusal stability and long‐face morphology were associated with weak elevator muscle activity with disposition overload and tenderness. The results also indicated that increase of occlusal stability might lead to increased muscle strength and possibly reduce risk of physical

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01888.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –Two types of fear desensitization, video training, and clinical rehearsals, were evaluated using psychometric tests, behavioral measures, and interviews for a group of 68 dental fear patients with high and low general trait anxiety. After treatment, a visual analogue scale (VAS) also tested the degree of perceived anxiety before going off to an unknown dentist. Results indicated no significant differences in dental fear reduction effects of the two types of desensitization. However, both treatments showed significant and meaningful effects when compared with a group of 75 dental fear patients on a waiting list who were also tested once at the beginning of the waiting period and again after 6 months. Only high general anxiety subjects resisted desensitization and failed standardized dental treatment tests. Exit interviews revealed that both groups named securing/accepting personnel, conversations about their fears and relaxation, in that order, as the most important factors in their dental fear reduction. Psychometric trust scores confirmed this. VAS scores showed a significant increase in fear level about the next dentist, also indicating trust as a major factor in reducing dental fear. Suggestions are made about which patient conditions can affect the choice of either of these training method

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01889.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –Acute and long‐standing adverse effects from dental materials used in the treatment of 13 325 patients in 15 820 appointments were recorded by 137 dentists. Twenty‐four suspected side effects were reported by the patients and 22 by the clinicians; 7 were classified as “probable” or “possible” acute reactions and 15 as long‐standing effects, 13 being “verified” and 2 “probable”. In another survey, 31 dentists representing a total of 387 years of practice recollected 113 patients with side effect

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01890.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The aim was to study the fluoride release 1) from 7 and 15‐month‐old glass ionomer specimens after treating them with fluoride; 2) from fresh compared with matured material; and 3) from specimens stored for 29 months in running water. Glass ionomer test specimens which had been in running water for first 7 then 15 months were treated with a 50 ppm fluoride solution after which the specimens were again exposed to running water for first 24 h and then 1 wk. The fluoride release was measured after each of the two periods of time. The fluoride treated specimens released more fluoride than the nontreated ones. This effect was not observed with composite resin specimens which were studied for comparison. Fluoride release from fresh glass ionomer specimens was observed to be 3–10 fold compared to specimens that had matured for 3 days. The release of fluoride from specimens that had been in running water for 29 months was measured and the results were compared with those of earlier measurements. It was found that the release reached a constant level for all tested glass ionomers during the seco

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01891.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The effect of area ratio, chloride concentration and brushing on amalgam in contact with gold was studied by measuring the amounts of elements released in the electrolyte. A type III gold alloy was stored for 4 months in contact with a conventional amalgam, area relations 6/1 and 6/3, in an electrolyte containing 85 mM NaCl with 10 mM phosphate buffer. A specimen with area relation 6/1 was also stored in a 10 mM NaCl solution with 10 mM phosphate buffer. The solutions were renewed each month and analyzed for Cu, Zn, Sn, Hg, and Ag in an atomic absorption spectrophotometer. Cross‐sections of the amalgams were studied in a scanning electron microscope. The tendency for Sn and Cu to be released from the amalgam was greater than for the other elements. The Sn‐release probably mainly originated from surface corrosion and Cu‐release from subsurface corrosion. A stronger galvanic influence enhanced only the release of Cu, and to a less extent Zn. The subsurface corrosion of the amalgam and increasing release of Cu was, in contrast to the other elements, largely dependent on a high chloride concentration in the electrolyte. Light brushing of the specimens had no effect on the amounts of elements r

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01892.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The amount of methacrylic acid produced by incubation of the dimethacrylate ester TEGDMA in human whole saliva was measured. The conversion rate of TEGDMA was determined in stimulated saliva from dental students and in unstimulated saliva from both dental students and patients. The differences in mean conversion rate measured in the three groups were not statistically significant (P=0.346). The mean conversion rate ± SD for all saliva samples was 4.54 ± 3.24 μmol MAA/L. h. The surface of BISGMA/TEGDMA‐polymer specimens treated with porcine liver esterase in activities equivalent to those found in human saliva exhibited a lower Wallace microhardness than the surface of untreated specimens. Polymer specimens incubated in human saliva exhibited a similar reduction in the microhardness. The results demonstrated that enzymes in human saliva are capable of softening the surface of dimethaerylate polymers presumably by inducing a hydrolysis of methacrylate ester bonds. The mechanical removal of a surface layer softened by hydrolases will expose a new surface layer to enzymatic attack. The enzymatic softening may thus contribute to the in vivo wear of composite restor

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01893.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY