Effective Human Pulpal Blood Flow Changes During Brief Intrusive Force Application and Continuous Orthodontic Force Application using Laser Doppler Flowmetry

Abstract

Aims: 1.To study the changes in human pulpal blood flow (PBF)during and after application of intrusive force for 4 minutes in right maxillary central using laser Doppler flowmeter.2.To evaluate the effect on human pulpal blood flow after application of continuous orthodontic intrusive force for 72 hrs in right maxillary central incisor using laser Doppler flowmeter. Material and methods: Brief intrusive force application: Eight subjects (men; mean age = 19.6 yrs) had an intrusive force applied to a maxillary central incisor through lever system. A cast chrome cobalt coping was fabricated to fit over the incisor and thus provided a reproducible point of force application. Each subject participated in six testing sessions (0 gm, 5 gm, 50 gm, 100 gm, 250 gm force application and local anesthetic application). During each session, PBF was measured by laser Doppler flowmeter, 4 mins baseline period, then 4 min force application and then continuously measures next 12 mins. The last session local anesthetic with vasoconstrictor (epinephrine 1:100,000) was administrated in place of the force application to determine the ability of this experimental paradigm to detect reductions in PBF. Continuous orthodontic force application: Seven subjects (men, mean age = 19.6 yrs) were selected and 2 OZ intrusive force applied to a maxillary central incisor using modified utility arch. PBF was measured before application of orthodontic force and after 72 hrs intrusive force application Results: There is no significant reduction in pulpal blood flow during and after the application of brief intrusive force for 4 mins. But there is definite amount of reduction in pulpal blood flow that occurs after application of 2 oz continuous orthodontic force for 3 days. Conclusion: The study result indicates that there is a definite alteration in pulpal blood flow following continuous force application. But pulp does not affected by brief intrusive force.

Evaluation of Tooth Surface Characteristics after Application of Intrusive Orthodontic Forces Using Scanning Electron Microscope: An In vivo Study

“…Furthermore, electric pulp testing is based on the stimulation of sensory nerves and relies on assessments and responses from patients. [10] Han et al [30] and Sadhasivam et al [31] reported a significant reduction in the pulpal blood flow when force duration was increased to few days.…”