THE ANGIOGENIC RESPONSE OF HUMAN DENTAL PULP TO ORTHODONTIC FORCE APPLICATION

Student thesis: Doctoral ThesisDoctor of Philosophy

Abstract

In order to characterise the angiogenic response of human dental pulps to orthodontic force application, transcriptomic and proteomic changes were investigated relative to three early time-points of routine clinical treatment in contralateral pairs of treated and control teeth. It was hypothesised that varied intensities of hypoxic exposure (intermittent, repeated intermittent and chronic) would result in distinct angiogenic responses within untreated pulp tissues. It was further hypothesised that angiogenic responses of pulps exposed to early time-points of orthodontic treatment would correlate with those of tissues exposed to varied hypoxic intensities; and changes would be associated with known stages of clinical treatment, namely: initial, lag, acceleration and linear phases of orthodontic tooth movement.

Prior to performing all experimentation, methodologies for handling of rare clinical samples were established. Protocols for sample storage, homogenisation, RNAtotal isolation, quantification, purification and amplification were optimised; a normalising factor created from the mean expression of reference genes RPL13A and UBC was found to be most appropriate for RT-qPCR analysis of human dental pulps under these experimental conditions.
Orthodontic force application resulted in a potential angiogenic or putative inflammatory response at all treatment time-points; and altered gene expression associated with hypoxia is evident in pulps following 2 weeks of force application. The response to each defined hypoxic intensity was unique; and the associated angiogenic response correlated with the duration of hypoxic exposure. Reoxygenation following hypoxia was linked to the putative inflammatory response of pulps during orthodontic treatment.
Results showed that the experimental potential of a single clinical sample can be amplified significantly, dependent upon the selection of specific experimental protocols; thus eliminating the need for pooling samples or using cell lines which are far removed from true physiological conditions. Both angiogenesis and hypoxia appear to have a significant role in response of human dental pulps to routine orthodontic treatment.
Date of Award2017
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorKathryn Derringer (Supervisor) & Gordon Proctor (Supervisor)

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