摘要:

Abstract –Parathyroid hormone (PTH) plays an important role in regulating calcium in serum. It is also known to affect bone and dentin formation. The purpose of this investigation was to evaluate enamel formation in normal rats receiving added PTH. It is in two parts: a pilot study where a known method was tested, followed by the main study where the rats were given different doses of PTH. The enamel was examined in both studies and in the main study the ameloblasts were also investigated. Contradictory results were seen. In the pilot study, severe enamel aberrations occurred, while no divergence from normal amelogenesis was noted in the main study. A factor causing the disparate results was the use of a hard tissue marker (oxytetracycline) in the pilot study. It can be concluded that injections of PTH in doses that affect bone and dentin did not cause any changes in normal enamel formatio

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01869.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –Deposition of alkali‐soluble fluoride on enamel in the presence and absence of an acquired pellicle was studied in vitro during a single topical application of a 2% sodium fluoride solution at neutral pH. Five experimental groups of repeated measures design were established. The amount of alkali‐soluble fluoride formed on enamel (i.e., calcium fluoride) was measured by chemical assessments and by SEM. The results showed that there were no differences among the groups demonstrating the incapacity of pellicle to interfere with deposition of alkali‐soluble fluoride on enamel. The fluoride ions are thus able to reach the enamel in spite of the presence of the p

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01870.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –An epidemiologic study on the prevalence and distribution of dental caries in 16‐and 18‐yr‐olds was carried out in 1987 in the county of Vasterbotten, northern Sweden. The subjects had participated in the Public Dental Health Service, including prophylactic programs, since early childhood. The results showed the mean DFS‐value to be 5.7 for the 16‐yr‐olds and 8.1 for the 18‐yr‐olds. The DFT and DFS‐values were higher in the urban than in the rural areas for both age groups, mainly due to more occlusal surfaces being filled in the urban area. Earlier studies have shown a higher prevalence of caries in rural compared to urban areas, explained by a lower socioeconomic level in the rural areas. Although the socioeconomic differences between urban and rural areas persist, the difference in caries prevalence seems to have been eradicated. Both age groups included small subgroups with a high number of DF‐surfaces, requiring individualize

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01871.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The present study investigated whether the incidence or prevalence of filled teeth/ approximal surfaces at one age could be predictive for the incidence in another period or for the prevalence at the age of 18. The study was conducted in 12–18‐yr‐olds in Norway. Regression analysis showed that the best prognosis for subsequent incidence of filled teeth/approximal surfaces could be made at the age of 15. By using regression analysis or discriminant analysis it was possible at the age of 15 to predict with high accuracy those who would acquire more fillings than the median at the age of 18. Discriminant analysis with one predictor variable is suggested for clinical use. The variable that discriminated best between above and below median number of new fillings in the period 15 18 yr was untreated lesions in the inner half of the enamel in the approximal surfaces of premolars and molars at the age of 15. From the use of simple prediction tools, it was concluded that individuals at the age of 15 with a low prevalence of filled teeth/filled approximal surfaces and without untreated approximal lesions would be subjected to a low incidence of new fillings until the ag

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01872.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The effect of several oral hygiene products on an adhesion‐based assay for salivary mutans streptococci (Dentocult‐SM Strip Mutans) was studied in three women. The mutans streptococci levels were recorded for up to 24 h after a 1‐min rinse with the product. The chlorhexidine (0.05%) and stanno‐amine fluoride solutions (corresponding 0.025% F) interfered selectively with the adhesion‐based assay. No such effect was observed for a polyvidoneiodine solution (10 μg/ml) or two toothpastes containing either sodium lauryl sulfate or amine fluorides. The results indicate that antimicrobial agents showing retention in the oral cavity may interfere for several hours after their use with adhesion‐based assays of salivary mutan

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01873.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –In this study 17 strains ofPorphyromonas gingivalis, both reference and clinical isolates, were investigated for their in vitro interaction with human polymorphonuclear leukocytes, hydrophobicity, density, and virulence in a mouse model. The results of the phagocytosis, hydrophobicity, and density experiments showed thatP. gingivalisstrains could be divided into two distinct groups. One group of strains were readily attached and phagocytosed when exposed to the leukocytes. These bacteria were hydrophobic and had a higher buoyant density than the other group, which were poorly phagocytosed, had a low buoyant density, and were hydrophilic. This latter group also exhibited an extracellular meshwork resembling a glycocalyx when examined by electron microscopy. There were also significant differences between strains in the mouse pathogenicity model. Two strains caused an invasive, spreading infection compared with the other 15 strains which produced small, localized abscesses. There was no clear correlation between the results of the phagocytosis assay and the virulence of the bacteria when injected subcutaneously in mice. Resistance to phagocytosis may be important for survival of these bacteria, but it does not in itself imply the ability to cause damage to the hos

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01874.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –In order to find out if it is possible to prevent caries and gingivitis by periodical use of chlorhexidine‐fluoride mouthrinses with or without strontium, and to find out what effects they have on salivary mutans streptococci and lactobacilli counts, a total of 243 schoolchildren aged 11 yr with high DMFS scores were randomly divided into four groups. One group (C) served as a basic control. Subjects in the second group (GXF) rinsed their mouths twice a day every third week with a rinsing solution containing 0.05% chlorhexidine gluconate and 0.04% NaF. In the third group (CXFS) the rinsing solution contained 500 ppm Sr during the first and second year and 15 ppm during the last 6 months, in addition to chlorhexidine and fluoride. In the fourth group (CX) the solution contained only 0.05% chlorhexidine gluconate. All the rinsing solutions had pH 5.8 buffered with succinic acid‐NaOH buffer. After 2 yr and 9 months, the mean DMFS (SD) increments in the C, GXF, GXFS, and GX groups were 3.8 (5.7), 2.5 (3.2), 3.5 (4.8), and 3.4 (5.5), respectively. The percentage of subjects with bleeding gingival units had decreased from initial to final values as follows: C, 81–38; GXF, 88–42; GXFS, 89–56; GX, 89–37. The number of lactobacilli and mutans streptococci in saliva remained virtually unchanged throughout the study. For caries increment and gingival bleeding, the differences between groups were not statistically significant. The chlorhexidine‐fluoride combination tended to prevent caries, but the effect on gingival bleeding and salivary counts of mutans streptococci and lactobacilli

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01875.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The effect of immediate permanent root‐filling and immediate intracanal calcium hydroxide treatment on experimentally contaminated and necrotized periodontal membranes (PDM) in avulsed and subsequently replanted monkey teeth was studied. Almost the entire root surface in the non‐endodontically treated control teeth were covered with inflammatory resorp‐tion, A significant shift towards ankylosis not associated with root resorption (>80% of the total root surface area) was noted following calcium hydroxide treatment. About two thirds of the root surfaces from the teeth with permanent root fillings showed surface resorptions or ankylosis preceded by root resorption. The root surface area which would have been covered by inffammatory resorption, unless endodontic treatment had been implemented, were instead predominantly covered by either surface resorption (permanent root filling) or ankylosis (calcium hydroxide treatment), Ankylosis compared with surface resorption may in the long term lead to progressive loss of root substance due to replacement resorption. It was concluded that calcium hydroxide may be an excellent initial intracanal treatment in teeth with healthy PDM, but care should be taken not to risk unnecessary development of ankylosis by prolonged treatment of teeth with compromi

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01876.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The effect of delayed intracanal calcium hydroxide treatment on experimentally induced extensive inflammatory root resorption in monkeys was studied. A significant shift from inflammatory resorption to ankylosis was noted following calcium hydroxide treatment. Furthermore, calcium hydroxide treatment appeared to change the pattern of ankylosis over time, although the total ankylotic area remained the same. Ankylosisprecededby root resorption (replacement resorption) increased, while ankylosisnot associated withroot resorption decreased. It was concluded that intracanal calcium hydroxide treatment of teeth with compromised PDM may cause unnecessary replacement resorption if left in the root canal for a long time or changed repeatedl

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01877.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract –The purpose of the study was to examine if Bio‐Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio‐Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles of rats. Light microscopic evaluation revealed no osteoinduction or osteoconduction in connection with sintered or unsintered Bio‐Oss. A foreign body reaction was observed around bot

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1991.tb01878.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY