摘要:

Abstract —Giant tubules (GT) in the axiomesiodistal plane of the incisal dentin of 21 unerupted permanent incisors of 1/2—2‐yr‐old calves were studied by scanning electron microscopy, light microscopy and contact microradiography. A technique is described by which the incisal dentin was split along the axiomesiodistal plane exposing the GT lumina longitudinally for SEM study. The luminal organic content was carefully removed mechanically or chemically. The GT originated 50–250 μm underneath the incisal dentino‐enamel junction and converged pulpally, terminating in the incisal edge of the pulp. A confluence of adjacent tubules towards the pulp was seen. Each GT had a relatively constant diameter along its length, in the range of 10–50 μm. The dentinal tubules circumvented the GT origins and pursued a straight course pulpally, parallell to the characteristic wall zone surrounding each GT. Very few dentinal tubules entered the GT lumen at any level. The luminal lining along the larger part of the GT consisted of collagen fibrils forming a criss‐cross pattern, while the most pulpal part was lined by a smooth organic sheath. The GT walls at any transversal level within one tooth had a lower mineral content than the circnmpulpal dentin between them. It was concluded that the GT formation is not caused by crowding of

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01766.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —Stannous fluoride but not stannous chloride has shown a caries inhibiting effect in animal studies. The effect of aqueous solutions of stannous fluoride and stannous chloride on dental enamel surfaces was investigated by scanning electron microscope and analytical electron microprobe. Some large globules and a continuous layer of small globules were observed after stannous fluoride treatment. The large globules were soluble in both water and alkali, whereas the small ones were only soluble in alkali. Both fluoride and tin were found to be present on the enamel surfaces by the electron microprobe after stannous fluoride treatment. The fluoride could not be detected after immersion in distilled water whereas alkali treatment removed the tin. The large fluoride‐containing globules may consist of calcium fluoride as this substance is known to be slightly soluble in water and soluble in alkali. Stannous chloride treatment gave a layer of small tin‐containing globules with properties similar to the layer formed on enamel treated with stannous fluoride. It is therefore suggested that the tin‐containing layer is not associated with caries protection whereas calcium fluoride‐like deposition on the enamel probably is a factor in the caries inhibition caused by stannous

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01767.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —Oral implantation of streptomycin resistant S. mutans was enhanced when chlorhexidine mouthrinses were applied before implantation. The difference in recovery of implanted bacteria between implantations with and without prior chlorhexidine mouthrinses was significant 9 days (P<0.05), 15 days (P<0.05) and 28 days (P<0.01) after implantation. After 28 days implanted bacteria were no longer detected in any of the 20 test subjects when chlorhexidine was not used prior to implantation, but persisted in 11 subjects when chlorhexidine was use

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01768.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —Attachment and spreading of phagocytes on a mineralized tissue surface is crucial for their proper resorptive function. In other studies, attachment and spreading have been shown to be highly dependent on the nature and composition of the surface. In the present study, peritoneal macrophages were cultured on infected and non‐infected mineralized and non‐mineralized dental tissues, which were examined with scanning electron microscopy at different observation periods. Although some cells had attached to non‐infected predentin, only a few showed signs of spreading, even after long incubation times. This contrasted with the behavior of macrophages cultivated on enamel, mineralized dentin and infected predentin. Most of these cells showed spreading and the characteristics of active, phagocytosing cells. The reluctance of macrophages to spread on non‐infected predentin was suggested to be due to the non‐mineralized nature of this tissue, although an influence of endogenous resorption inhibitors cannot

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01769.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —All visible plaque was professionally removed from teeth of 40 children who were highly infected with S. mutans and lactobacilli. Shortly before and after the removal of plaque the concentrations of those bacteria were assessed in saliva stimulated by chewing. S. mutans and lactobacilli correlated well at baseline but not after plaque elimination, e.g. more than 80% of childrenwhowere heavily infected with S. mutans could be identified by a lactobacillus test at baseline. After the elimination of plaque, the mean concentration of S. mutans dropped by 64% but lactobacilli remained unchanged. The results indicate that oral hygiene measures taken by the patient prior to sampling of saliva may mask the true concentration of salivary S. mutans and complicate the identification of high caries risk patient

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01770.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —Earlier studies have shown that a single high dose of fluoride induces subameloblastic cysts separated by morphologically unaltered ameloblasts in the developing rat molar. In the present investigation, the ultrastnucture of both the ameloblasts forming the cystic wall, and the cells within the cystic lumina were studied by means of transmission electron microscopy. It was shown that 24 h after fluoride injection the ameloblasts of the cystic wall showed various degrees of cytopiasmic and nuclear alterations. Some cells displayed signs of necrosis as indicated by condensation of the chromatin. The cytopiasmic changes varied from altered organelle morphology to fragmentation and almost complete shedding of the whole cytoplasm. In the ameloblasts of the cystic wall secretory products accumulated intracellularly, in distended rough endoplasmatic reticulum, in vesicles of the Golgi region and extracellularly between ameioblasts as well as between cells in the stratum intermedium, indicating an altered matrix secretion. Electron lucent material, cell and cell fragments were found in the cystic lumina, the two latter apparently originating from the ameloblastic layer. The degenerative changes seemed to follow the normal pattern of cell degeneratio

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01771.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —Oral health, the amount of salivary Streptococcus mutans and lactobacilli, and the flow rate, pH and buffer capacity of paraffin‐stimulated whole saliva were analyzed in 35 adult diabetic patients and their age‐ and sex‐matched non‐diabetic, clinically healthy controls. All patients had insulin‐dependent diabetes (IDDM) with a mean (± SD) duration of 14.0 ± 9.1 yr. The prevalence of dental caries was as high in the diabetic group as in the controls but the past caries experience was remarkably lower in those individuals whose diabetes had started at a very early age (= 7 yr). In agreement with the clinical data, the salivary levels of cariogenic microorganisms were of the same order of magnitude in both study groups. However, the relative proportion of S. mutans from the total cultivable aerobic microflora was significantly higher (P<0.01) in diabetics compared to the controls. The other studied salivary parameters did not differ between the groups. Remarkable individual differences were observed in the correlation between glucose levels of blood and whole saliva among diabetics. In spite of the noncariogenic dietary habits, the adult diabetic patients seem to be at least as susceptible to dental caries as non‐diabetics, probably due to the leakage of glucose from blood into

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01772.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —A multifactorial grading system was used for histologic classification and grading of malignancy in 89 patients with squamous cell carcinoma in the floor of the mouth. All patients had been treated with surgery alone and only those patients were included in the study who at the initial diagnosis had no clinically suspected regional lymph node or distant metastatic involvement. There was a statistically significant correlation between the mean total malignancy scoring, on the one hand, and clinical staging, frequency of recurrences, and death from the first primary oral carcinoma, on the othe

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01773.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —Thirty referred patients and 15 control subjects were investigated with reference to the occurrence of bimetallic corrosion in the oral cavity. No differences between patients and controls could be found regarding the registered charge transfer between dissimilar short‐circuited dental metallic restorations and/or appliances. However, a relatively large number of periodontal and mucous membrane affections, carious lesions and stomatognathic and/or temporomandibular joint disturbances were found within the patient gr

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01774.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract —A study was conducted to determine differences in flexure strength between unrepaired and repaired dental composite bars. Four groups, each consisting of 10 samples, were investigated. Group A consisted of unrepaired samples, while groups B‐D consisted of samples which had been cut to lengths of 17.5 mm and repaired to a total length of 35.0 mm. The cut surfaces of these samples were washed with water (group B), treated with phosphoric acid, water and bonding agent (group C), or treated with a silane‐toluene solution (group D) before new material was added. The samples were stored in distilled water at 37°C, and after 3 and 6 months the flexure strength of samples from each group was determined by “four‐point” bending. The results showed that repaired composites were weaker than unrepaired samples. The mean strength of the silane‐toluene treated group was superior in strength to that of the other two groups. This group was also least affected by exposure to water. Of the other two groups, specimens treated with the acid etch technique were superior in strength to t

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01775.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY