Biomedical subjects

E M Bronkhorst

Publications and source records attributed to E M Bronkhorst.

9 recordsLinked to original sources

PubMed1992

Effects of digital grey-scale modification on the diagnosis of small approximal carious lesions.

The aim of this study was to evaluate the accuracy of approximal caries diagnosis from digitized radiographs and digitally modified radiographic images, compared with conventional radiography. Twenty bitewing radiographs were digitized and from the digitized radiographs mirror-images were produced, resulting in 40 digital images. The caries progress at three approximal surfaces was graded by 12 dentists from conventional radiographs, digital unmodified images and digitally modified images. The image modifications were derived from the cumulative probability of grey values in the original digital image using one of five probability distributions: uniform, exponential, Rayleigh, hyperbolic cube root and hyperbolic logarithmic. Interobserver agreement was substantial. The unmodified digital images produced sensitivities comparable to radiographs but their specificities were lower. When the diagnostic task was to discriminate between 'caries' and 'no caries', the exponential, hyperbolic cube root and hyperbolic logarithmic modifications and radiographs performed equally well. With the decision cut off between 'dentinal caries' and 'no dentinal caries', the sensitivity of the hyperbolic logarithmic type of modification was statistically significantly superior to that of radiographs, but this modification was also associated with a statistically significant reduction of specificity. It is concluded that in particular the hyperbolic logarithmic modification can be an alternative to conventional radiography in incipient approximal caries diagnosis and restorative decision making.

Color↗

PubMed1992

Performance of some diagnostic systems in examinations for small occlusal carious lesions.

The objective of this study was to compare the performance in occlusal caries diagnosis of various available diagnostic systems when applied to the same teeth. The sample investigated consisted of 13 children for whom 4 premolar and 19 molar teeth were judged to require a sealant. The indication was based on the criteria 'fissure discoloration', 'enamel decalcification' and 'absence of dentinal decay'. For predefined locations within these occlusal fissures a diagnosis was obtained by the following diagnostic systems: clinical examination, examination on fiber-optic transillumination (FOTI), fissure discoloration, electrical resistance measurement, radiographic examination and ratings of fissure morphology. Tooth material was removed until no (more) carious enamel or dentin was left. Two dentists then jointly decided on the status of decay for each of the defined locations within the fissure. These ratings served as the 'gold standard' diagnoses. The electrical resistance measurement with a sensitivity of 0.96 and a specificity of 0.71 was the only diagnostic tool with acceptable performance. Radiographic diagnosis was characterized by a moderate sensitivity and specificity. All other diagnostic systems had either very low sensitivities or very low specificities, or both. The positive predictive value of FOTI examination and the negative predictive value of the electrical resistance measurements were very high, irrespective of the prevalence of occlusal dentinal decay.

Adolescent↗

PubMed1991

Approximal caries diagnosis using fiber-optic transillumination: a mathematical adjustment to improve validity.

Several studies were conducted recently to evaluate the use of Fiber-Optic Trans-Illumination (FOTI) in the diagnosis of approximal carious lesions. All these studies utilized radiographic readings to validate the FOTI diagnoses. Other investigations studied the value of radiographic readings using more solid validating techniques, which made it possible to judge the true state of decay, such as histology, cavity preparation and microradiography. In this study, data from both types of studies were used to estimate the validity of FOTI diagnosis of approximal caries relative to the true status of decay through correction for radiographic misclassification. The results indicate that particularly the sensitivity of FOTI diagnosis has yet to be determined.

Dental Caries↗

PubMed1991

Health through oral health; guidelines for planning and monitoring for oral health care: a critical comment on the WHO model.

Recently a joint working group of WHO/FDI published guidelines for planning and monitoring oral health care. In the report a model for calculations of future need for dental manpower was introduced as an effective planning tool. An analysis of whether the WHO model is appropriate to calculate the future need for manpower planning was carried out. It appears that the model has serious methodological shortcomings. The model expects the user to know the future oral care needs concerning preventive, special group, surgical, orthodontic, and periodontal care. In calculating future needs for restorative and prosthetic care, the model restricts itself to looking back in time and roughly calculating what has happened in the past, assuming this will happen again.

Adolescent↗

PubMed1989

[Oral health perspective in children and adolescents].

Members of a panel gave their opinions on future developments affecting the prevalence for caries and gingivitis among the Dutch youth (0-34). For the younger age groups a small increase of the dmf-t count was expected by the members of the panel, which was in line with the results of a simulation model. For the oldest group the model showed a smaller decrease for the DMF-T count then the panel members forecasted.

Adolescent↗

PubMed1989

[Oral health in 35-55-year old people].

Changes in treatment planning and improved dental materials can probably cause a further improvement of the oral health in 35-55-year old people. Expectations concerning new developments in this field and the quantitative results of a computer simulation model, based on a corresponding scenario, were compared. The results suggest a minor decrease of missing teeth per person and the percentages edentulous people in the age group 35 years and over. An additional effect of the scenario is a considerable saving in total expenses for dental health care.

Adult↗

PubMed1989

[Changes from aging].

Expectations concerning the future of the oral health of the Dutch elderly and the quantitative results of a computer simulation model are put together. On an individual level no major changes in the oral health of the elderly dentates are to be expected. The ageing of the population and the decrease of the percentage of edentulous patients will result in a strong increase of the number of elderly people who need regular dental care. Due to the increasing age at which people become edentulous, no increase of treatment related to atrophic edentulous jaws is to be expected. On the other hand the introduction of new treatments, like the use of oral implants, might result in an increase of treatments of this kind.

Aged↗

PubMed1989

[An attempt to decrease periodontal diseases. A scenario-experiment].

The prevalence of periodontal diseases in the Dutch population is high. Is the employment of a great number of dental hygienists in the future the answer to this problem? With the aid of a computer model of the Dutch dental health care system this question was analysed. Forecasting for the year 2015 showed no considerable decrease of the prevalence of periodontal diseases, despite the employment of 2000 dental hygienists from 1990 on. Time and financial limitations in periodontal treatments were the main reasons for this rather disappointing result.

Dental Hygienists↗

PubMed1989

[Implications from an increase in wealth for the dental health care].

After a theoretical introduction concerning the relation between wealth and dental health, the consequences as deducted from a scenario which implies a yearly increase of income for the whole population of 1.5% are presented. The main results are a strong income-dependency for the implications of an increase in income for the utilization of dental care. People from the lower socio-economical classes are expected to show increase in the amount of care consumed, while people from the higher socio-economical classes are expected to show a need for more expensive and more preventive treatment. The improvement of the oral health situation due to an increase of wealth is not expected to be significant.

Dental Care↗