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O Fejerskov

Publications and source records attributed to O Fejerskov.

At least 55 records · Page 3Linked to original sources
PubMed1993

Validity of CPITN's assumptions of hierarchical occurrence of periodontal conditions in a Kenyan population aged 15-65 years.

In order to study the validity of the hierarchical principle of the CPITN we used data originating in a cross-sectional study of periodontal disease in a random sample comprising 1131 Kenyans aged 15-65 yr to determine, for each tooth present in each individual, the absence or presence of gingival bleeding, of dental calculus, of a pocket of 4-5 mm or a pocket of 6+ mm, such that each tooth had a separate recording for bleeding, calculus, pocket 4-5 mm and pocket 6+ mm. According to the hierarchical principle of CPITN a tooth with pockets as the most severe finding is assumed positive also for calculus and bleeding, and a tooth with calculus as the most severe finding is assumed positive also for bleeding. Our analysis showed that calculus as the most severe finding of a tooth overestimates the occurrence of bleeding by up to 18%, depending on age of the individuals and the set of teeth examined. Pockets as the most severe finding in a tooth overestimates the occurrence of bleeding by up to 13%, and overestimates calculus by up to 54%, most pronounced in the younger age groups. The effect of these overestimations on prevalence and severity estimates was the most pronounced for the severity measures, particularly regarding the severity of bleeding, whereas prevalence estimates remained relatively unaffected. Undoubtedly, this result should be seen in the light of a very high prevalence and severity of both bleeding and calculus in this population.

Adolescent↗
PubMed1993

Influence of CPITN partial recordings on estimates of prevalence and severity of various periodontal conditions in adults.

This study compares the results of a full mouth examination with the results of examining only the CPITN selection of 10 index teeth 17/16, 11, 26/27, 47/46, 31 and 36/37 for estimates of prevalence and severity of the conditions assessed with the CPITN, i.e. gingival bleeding, dental calculus, pockets 4-5 mm deep and pockets 6+ mm deep. The mean number of sextants recorded with bleeding or with calculus was generally overestimated when examinations were based on the CPITN selection of index teeth, whereas the mean number of sextants with pockets, whether moderate or deep, were generally underestimated. Similarly, the prevalence of pockets, whether moderate or deep, was underestimated in virtually all age groups while the prevalence of calculus was overestimated in all age groups and the prevalence of bleeding was overestimated among persons below 30 yr of age. We conclude that the partial recording approach of the CPITN methodology is reasonably well suited for identifying persons who are relatively healthy according to the hierarchy of the CPITN parameters. There is, however, a considerable risk that persons presenting with the more severe conditions, i.e. pockets, will be overlooked if only partial recordings are performed.

Adolescent↗
PubMed1993

Accuracy and precision in vitro of Beetrode microelectrodes used for intraoral pH measurements.

The accuracy and precision of 12 different microelectrodes were assessed through a series of pH recordings of buffer solutions with known pH values. Some electrodes were quite accurate, yielding an average deviation of recordings from true values of about 0.05 pH units, while other electrodes yielded average deviations of up to 0.20 pH units. The precision of the electrodes also varied between electrodes. While all recordings were within 0.15 pH units from the true values for some electrodes, other electrodes showed a marked dispersion with less than 25% of the recordings being within 0.15 pH units from true values. For some electrodes accuracy depended on true pH values, while no such dependency was noted with respect to the precision of the electrodes tested. Both accuracy and precision may be impaired when pH recordings are made on solutions with pH values outside the pH range encompassed by the calibration buffers. Our results demonstrate that the accuracy and precision of these microelectrodes cannot be considered fixed and known parameters. Electrodes should therefore be checked prior to clinical use, and electrodes with low accuracy and precision should be excluded from further use.

Buffers↗
PubMed1993

A critical review of the relative anticaries efficacy of sodium fluoride and sodium monofluorophosphate dentifrices.

While there is broad consensus in the research community that fluoride dentifrices provide important anticaries benefits, debate still remains as to the most efficient form of fluoride used in toothpastes. Recently, the authors of this paper collaborated as part of a scientific advisory group whose objective was to comprehensively review all clinical information available comparing the anticaries efficacy of the two agents most widely used in fluoridated toothpastes, sodium fluoride (NaF) and sodium monofluorophosphate (SMFP). This review included a detailed analysis of each published study pertinent to the question, a comprehensive meta-analysis of all available clinical findings, and an epidemiological assessment of how anticaries benefits of dentifrices may be anticipated to propagate with time. Overall, the use of meta-analysis of head-to-head clinical comparisons between the two fluoride-active systems was found to be the most valid means for comparing the relative efficacy of NaF and SMFP dentifrices. Results of this analysis demonstrated that NaF was significantly more effective than SMFP in preventing caries (p < 0.01). While the numerical difference in efficacy between NaF and SMFP measured between 5 and 10% (total DMFS) over a 2- to 3-year clinical period, this could be expected, on theoretical grounds, to propagate to substantially larger differences (e.g. 10-20%) over 10-20 years. Hence, the difference in efficacy between these two actives was judged to be clinically important as well as statistically significant. Based upon these findings the authors recommend that NaF be used as the active system in fluoridated dentifrices whenever practically feasible. However, the authors caution that this recommendation pertains to the formulation of NaF in highly compatible abrasive systems, which must be demonstrated by critical evaluation of ionic fluoride within formulations for stability, availability and bioavailability. One additional recommendation emanating from this review is that important improvements must be made in the design, execution and reporting of future caries clinical trials in order to bring these important methods up to scientifically acceptable standards.

Adolescent↗
PubMed1993

Root caries in Scandinavia in the 1980's and future trends to be expected in dental caries experience in adults.

The large variety of diagnostic criteria used adds some uncertainty to comparisons of recent clinical and epidemiological data on root caries in Scandinavia. Nevertheless, it is apparent that the prevalence of frank carious cavities on the root among 60(+)-year-olds is about 30-40%. When inactive and recurrent lesions and fillings are included, the prevalence is almost 100% in 60(+)-year-olds. At this age, the mean number of root surface fillings is about 7, and the mean number of active caries lesions ranges from 0.9 to 3.4. The degree of gingival recession does not appear to be a direct measure of root caries risk in a population. When the number of teeth at risk is accounted for, the age-dependent increase in prevalence of root caries is very weak. Therefore, comparisons of root caries prevalence between populations are meaningful only when information on number of teeth present and teeth at risk is also available. Recent studies from various parts of the world have demonstrated that caries is ubiquitous in all populations and that caries progression continues throughout life. The impact of this on trends in prevalence and incidence of dental caries in adults is discussed in the light of what is known about the natural history of dental caries.

Adolescent↗
PubMed1993

Expression of the endothelial leukocyte adhesion molecule-1 (ELAM-1) on endothelial cells in experimental gingivitis in humans.

In inflammatory conditions, mediators such as interleukin-1 (IL-1) are released by resident tissue cells as well as by infiltrating inflammatory cells. IL-1 activates endothelial cells causing them to express an adhesion molecule called endothelial leukocyte adhesion molecule-1 (ELAM-1). IL-1 is produced by macrophages, but can also be produced by activated keratinocytes. Here we present data from a study of experimentally induced gingivitis, showing the expression of ELAM-1 on endothelial cells even in tissue with little or only minor signs of clinical or histological inflammation. These results indicate that ELAM-1 is found on endothelial cells of the gingiva early in the course of experimental gingivitis, before overt clinical or histological evidence of inflammation is apparent.

Cell Adhesion↗
PubMed1993

Six-year progression of destructive periodontal disease in 2 subgroups of elderly Chinese.

Two groups of elderly chinese were selected from a large epidemiological sample on the basis of a low ("best" group) or a high ("worst" group) number of sites with attachment loss levels > or = 6 mm and/or pocket depth > or = 4 mm and at least 16 teeth present. Six years later the patients were clinically reexamined and the subgingival microflora was assessed. This paper presents the clinical characteristics of destructive periodontal disease progression among the two subgroups. The "best" group lost an average of 1.8 teeth, contrasting the average loss of 5.3 teeth among the "worst" group. Virtually all teeth lost among the "worst" group had a baseline attachment loss level > or = 4 mm, in contrast to 48% among the "best" group. While dental caries could be identified as a cause of tooth loss in both groups, the excess tooth loss among the "worst" group seems attributable to periodontal destruction. The average of 1.21 mm attachment/site lost among the "best" group was not statistically significantly different from the 1.36 mm/site lost among the "worst" group during the 6 years. Individual mean losses of attachment ranged from a gain of 0.03 mm to a loss of 3.19 mm. An attachment loss > or = 2 mm at a site was highly positively associated with a high initial attachment loss level (> or = 4 mm) at that site among the "best" group, whereas a highly negative association was seen among the "worst" group.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1992

Putative periodontopathogens in "diseased" and "non-diseased" persons exhibiting poor oral hygiene.

The aim of the study was to assess the occurrence of some putative periodonto-pathogens in "test" and "control" sites in "diseased" and "non-diseased" persons, respectively, from an adult rural Kenyan population exhibiting poor oral hygiene and widespread loss of attachment (LA). 14 persons (less than 35 years) were assigned to a "diseased" category on the basis of at least 4 sites with LA greater than or equal to 4 mm; at least 5 mm LA and a pocket greater than or equal to 4 mm interproximally in a lower incisor ("test" site): and less than 2 mm LA and no pocket greater than or equal to 4 mm distal to a lower canine or mesial to a lower first premolar ("control" site). Age-matched "non-diseased" persons were identified on the basis of no sites with LA greater than 2 mm and no pockets greater than or equal to 4 mm associated with LA. Paperpoint samples from test and control sites as well as a scraping sample from the dorsum of tongue were examined for presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides intermedius, B. melaninogenicus group, Capnocytophaga, Selenomonas spp., and Wolinella recta. P. gingivalis was found in 79% of test sites and 36% of control sites in "diseased" persons, and in 18% and 35% of test and control sites, respectively, in "non-diseased" persons. "No other bacterial group discriminated significantly between test and control sites or between diseased and non-diseased subjects. The surprisingly high occurrence of P. gingivalis in non-diseased subjects, both subgingivally and on tongue, indicates that deep periodontal pockets are not prerequisite ecological environments for P. gingivalis establishment.

Adult↗
PubMed1992

Use of palladium touch microelectrodes under field conditions for in vivo assessment of dental plaque pH in children.

The aim of this study was to assess the applicability of palladium touch microelectrodes, connected to battery-run pH meters, for in vivo plaque pH measurements in children. The pH was assessed in 20 7-year-old and in 19 14-year-old caries-active and caries-inactive rural Kenyan children. The resting pH was measured at non-carious interproximal and occlusal sites and in open dentine cavities. Independent repeated measurements were performed at given sites at intervals of 15 s and 5 min and on different days. The resting plaque pH varied widely among the children, and there was no significant difference between caries-active and caries-inactive groups. The most striking feature was the considerable erratic fluctuations of pH at a given site with time, both in resting and in sucrose-challenged plaque. These fluctuations were sensitively recorded by palladium touch microelectrodes. After a sucrose rinse, not all sites in the same mouth behaved in a similar fashion, and thus the classical 'Stephan curve' was not always apparent. In conclusion, the palladium touch microelectrodes are highly applicable for plaque pH measurements in children, even under extreme field conditions.

Adolescent↗
PubMed1992

Validity of diagnosis of questionable caries lesions in occlusal surfaces of extracted third molars.

This study was to evaluate the accuracy of visual inspection, conventional radiography, and digital radiographic methods for the detection of occlusal carious lesions in third molars from a present-day adolescent population. Seventy-eight third molars, considered clinically to be without occlusal cavities, were extracted from young soldiers. Before extraction, an intra-oral radiograph was obtained. After extraction, the teeth were examined visually as per the criteria: 0 = no caries, 1 = chalky/stained fissure indicative of enamel caries, 2 = chalky and dark-stained fissure considered indicative of a dentinal lesion, and 3 = as per criterion 2, but with small surface defects (microcavities). The radiographs were digitised, and image enhancement with contrast stretch and a filtering procedure was performed, respectively. The three types of radiographic image were assessed as per the criteria: 1 = no caries/caries confined to enamel, 2 = caries involving the outermost dentine, and 3 = deep dentinal caries extending half-way or more to the pulp. Ground sections (500-600 microns in thickness) served as validation for lesion depth. The digital radiographic method with contrast stretch performed overall best of the four methods (greater than 70% detection rate) while visual inspection (53% detection rate) performed better than conventional radiography (48% detection rate). When results from visual inspection and conventional radiography were combined, an increase in the detection rate of 11% was obtained with a 7% increase in false-positive scorings. When digitally contrast-manipulated radiographs were combined with visual inspection, a gain of 33% was obtained with an 11% increase in false positives.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Effect of sugarcane chewing on plaque pH in rural Kenyan children.

In 5 rural Kenyan children, the effect of sugarcane chewing on plaque pH was compared with the effect of a mouthrinse with 10% sucrose at various intraoral sites. They all had poor oral hygiene and at least two carious cavities in occlusal surfaces of molars. pH measurements were conducted under field conditions using paladium touch microelectrodes connected to a battery-operated pH meter. There was a marked difference in pH response of non-carious approximal sites between maxilla and mandible, with the lowest values in the maxilla. However, the pH recovery following the instantaneous drop occurred in parallel even if most pH values had not returned to baseline values 30 min after the sucrose rinse. Following the sugarcane chewing, the pH fall was less pronounced on all sites, and within 5-10 min the values had returned to resting pH and even exceeded this. In carious cavities, a similar pattern was observed, although the acidity in these sites was more pronounced, also reflected in a lower resting mean pH. The main conclusion from this study is that sugarcane chewing yields a less pronounced pH drop and a quicker pH recovery in dental plaque than is seen following a mouthrinse with 10% sucrose. This difference probably results from stimulation of salivary flow associated with the chewing.

Adolescent↗
PubMed1992

Fluoride concentrations in unerupted fluorotic human enamel.

Unerupted fluorotic human enamel was obtained from teeth surgically removed from patients with dental fluorosis. Fluoride was measured in samples produced by serial acid etching from the surface to the interior of blocks of buccal and lingual enamel. The severity of fluorosis, according to the TF index, was determined from the macroscopic and microradiographic appearance of the specimens. The shape of the fluoride profiles was not affected by the degree of severity of fluorosis, but the fluoride concentrations increased with increasing severity of lesions. Fluoride concentrations were similar to those previously recorded in erupted fluorotic enamel and were not related to the length of time the teeth had been present in the jaws. It was concluded that the fluoride content of erupted fluorotic enamel represents fluoride acquired during tooth formation and that further uptake prior to eruption may be negligible.

Acid Etching, Dental↗
PubMed1992

The effect of sucrose on plaque pH in the primary and permanent dentition of caries-inactive and -active Kenyan children.

The hypothesis that the Stephan pH responses of dental plaque would be different in caries-active and -inactive individuals was tested in 20 seven-year-old and 19 14-year-old Kenyan children. In each age group, half the children had greater than or equal to 2 dentin cavities; the other half had no such lesions. With a palladium-touch microelectrode, interdental plaque pH was monitored between m1/m2 in each quadrant in the primary dentition and in the four molar/premolar regions in the permanent dentition. pH was also monitored in caries cavities in the occlusal surfaces of lower first molars and on the tongue. pH was measured before and up to 60 min after the children rinsed with 10 mL of 10% sucrose. Caries status of the individual was unrelated to plaque pH in comparable non-carious sites in both of the age groups. The pH minimum in the maxilla was about 0.5 pH units lower than that in the mandible. Active occlusal caries lesions had a resting pH value of about 5.5, about 1 pH unit lower than that of sound surfaces. The pH dropped to about 4.5 in caries lesions and recovered slowly. In sound occlusal sites, a pH drop to about 6.0 was followed by a relatively rapid return to the resting value. Thus, when the mean values were considered, the classic Stephan curve response was evident. However, when the pH changes at single sites were considered at various time intervals, a substantial, erratic fluctuation was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

A random effects model for some epidemiological features of dental caries.

We describe a random effects model for caries lesion development and progression based on considering the effects of the pH fluctuations over time in microbial dental plaque as a Wiener process with a single absorptive barrier. The model predicts that the period of greatest risk to developing caries occurs shortly after eruption, but thereafter the longer a surface survives without developing a lesion, the less likely will it be that a lesion will subsequently develop. The model is able to anticipate why the effect of water fluoridation on caries prevalence is most pronounced when caries is diagnosed at cavity level. This model offers one way in which the variability which characterizes the complex ecosystem associated with dental caries may be considered a subject of interest for enhancing our understanding of its pathogenesis and epidemiology.

Absorption↗
PubMed1991

Detection of occlusal caries without cavitation by visual inspection, film radiographs, xeroradiographs, and digitized radiographs.

The study compared visual inspection, conventional film radiographs, xeroradiographs, and digitized radiographs for the detection of caries in occlusal surfaces without cavitation. 166 extracted premolars and permanent molars without macroscopic cavitation were included. Eight observers assessed five grades of occlusal caries by visual inspection and by the three imaging techniques. Histologic sections (700-1,000 microns) served as validating criterion for the presence and depth of carious lesions, 82 teeth being found carious (27 with deep dentinal involvement) and 84 being scored as sound. Approximately 20% of the dentinal carious lesions were detected by visual inspection and 40% by conventional film radiography (both with a minimal number of false-positive observations). By xero- and digital radiography, an increasing number of false-positive scorings was seen. By digital radiography the true-positive detection rate was similarly increased to 60%. The predictive values of a positive test were, on average, 0.85 for visual inspection, 0.89 for film, 0.78 for xero-, and 0.82 for digital radiography and for a negative test 0.56, 0.61, 0.61, and 0.69, respectively. However, digital radiography was able to detect over 70% of deep dentinal lesions in contrast to 45% by the other two imaging methods, without an increase in false-positive diagnoses of truly caries free teeth, compared with the other techniques.

Bicuspid↗
PubMed1991

Active and inactive root surface caries lesions in a selected group of 60- to 80-year-old Danes.

In 90, 60- to 80-year-old patients with teeth retained in both jaws (mean 20.4 +/- 4.3), a total of 1,092 root surface lesions were recorded. Of these 156 were diagnosed as active caries lesions, whereas 509 were considered inactive, and 427 were filled. About 60% of the elderly had one or more active lesions and 79% had fillings. Seventy percent had more than 8 filled or carious (active or inactive) surfaces. The percentage of carious and filled root surfaces in relation to surfaces at risk demonstrated that the buccal surfaces of lower molars and premolars and upper canines were the most severely affected (RCI = 70%) with fillings predominating on easily accessible surfaces. A constant relationship between active and inactive lesions was found on all other surfaces but third molars and upper incisors. The data suggest that active and inactive root caries lesions must be diagnosed as separate entities if the dynamic nature of root surface caries is to be explored in epidemiological studies and clinical trials.

Aged↗
PubMed1991

A quantitative analysis of mineral loss and shrinkage of in vitro demineralized human root surfaces.

Demineralization of dentin specimens proceeds at a faster rate than that of enamel. Although this is generally accepted, a quantification of the rate of formation of root lesions is hampered by the shrinkage of the lesions when these are dried prior to microradiographic analysis. This leads to a significant underestimation of the lesion depth and total mineral loss. The aim of this paper was to quantitate the rate of mineral loss during root lesion formation in vitro and to determine the shrinkage of root specimens as a result of drying. Unerupted roots of human teeth were subjected to a demineralizing system of 0.1 mol/L lactate buffer (pH = 4.8) with 0.2 mmol/L methanehydroxydiphosphonate during four, 11, 22, and 44 days. The root lesions were assessed by quantitative microradiography. The demineralizing solutions were analyzed to determine the amounts of root tissue dissolved. A comparison of these two sets of data showed that, with the demineralizing system used, root lesions may shrink up to 62%. Fixation of the specimens in fixative did not affect this shrinkage. Chemical analysis showed that mineral loss proceeded linearly with time. From the data-sets of this study, a model was developed to compensate for the shrinkage in the dentin specimens. In this way, it was possible to calculate the lesion depth at four demineralization times as being 130, 220, 320, and 530 microns, respectively. These values were in agreement with a microscopic determination of the lesion depth.

Decalcification Technique↗