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Biomedical subjects

H van Waes

Publications and source records attributed to H van Waes.

15 recordsLinked to original sources
PubMed1997

Three-dimensional measurement of enamel loss caused by bonding and debonding of orthodontic brackets.

A mechanical computerized three-dimensional scanner with a resolution of 1 micron was used to assess loss of enamel caused by orthodontic bonding and debonding. A total of 2646 measurements was performed on six human premolars. The results showed an average loss of enamel of 7.4 microns. The range was between 1 and 52 microns, which may account for discrepancies with earlier studies that measured only a few points per tooth surface.

Acid Etching, Dental↗
PubMed1993

[The dental filling therapy of carious deciduous molars: materials and methods. A review].

There is little consensus as to which restorative material or techniques are best suited to restore primary teeth. Techniques developed for the permanent dentition can seldom be applied to the primary teeth because of morphological differences and lack of cooperation by the children. The morphological properties of primary molars are discussed in this paper in relation to their therapeutic consequences. In addition to general guidelines for dental therapy in children, current restorative materials and techniques are compared regarding their suitability for the primary dentition. Finally the goals for the development of an ideal restorative material are formulated.

Child↗
PubMedDate not supplied

Elective mutism: effect of dental treatment with N2/O2-inhalation sedation: review and report of case.

Elective mutism in children is characterized by a marked, emotionally determined selectivity in speaking, such that the child demonstrates his or her language competence in some situations but fails to speak in other situations. An eight-year-old boy with elective mutism had to undergo restorative dental treatment. It was chosen to use relative analgesia to perform this treatment. The sedation with oxygen and nitrous oxide resulted in complete symptom remission as long as the sedation lasted.

Anesthesia, Dental↗
PubMedDate not supplied

Mild dental findings associated with severe osteogenesis imperfecta due to a point mutation in the alpha 2(I) collagen gene demonstrate different expression of the genetic defect in bone and teeth.

Serial intraoral photographs, radiographs, and ground sections from an extracted upper permanent canine served to characterize dental abnormalities in a 15-year-old girl suffering from severe (type III) osteogenesis imperfecta (OI) due to a point mutation that substituted glycine 688 of the alpha 2(I) chain of collagen I by serine. Dental records showed that all deciduous teeth exhibited clinical and radiographic characteristics of dentinogenesis imperfecta (DI), whereas permanent teeth including the removed canine appeared normal, although pulp chambers contained unusually large denticles. Despite the unconspicuous clinical appearance of the canine, histologic sections revealed small, canal-like, hypomineralized hard tissue patches that lacked a regular tubular structure and occupied a narrow band of the bulk of normal circumpulpal dentin at about the level of the cemento-enamel junction. The finding that a mutation in the gene for the alpha 2(I) collagen chain with serious consequences in bone has only minor effects in teeth would suggest that odontoblasts, unlike osteoblasts, can largely compensate for this particular genetic defect, possibly by excluding the abnormal alpha 2(I) chains and forming alpha 1(I) homotrimeric collagen I. The discrepant consequences in deciduous as opposed to permanent teeth and the specific localization of the dentinal abnormalities in permanent teeth lead us to speculate that the exclusion of defective alpha 2(I) chains could depend on the developmental stage and/or the rate of extracellular matrix formation.

Adolescent↗