Microhardness changes in dentine after neonatal capsaicin application.
OBJECTIVE
To determine if desensitization of the nociceptive innervation in the dental pulp has an effect on odontoblast function in the rat.


METHODS
Neonatal systemic application of capsaicin was used to selectively eliminate nociceptive innervation. 12 capsaicin-treated rats were intravitally perfused at 150 days of life with 4% formaldehyde and jaws were prepared for Vicker's microhardness (VMH) measurement. As a control, 12 rats were injected with vehicle on the 3rd day of life and intravital perfusion was carried out exactly as those used for the experimental group. Immunohistological labeling of CGRP was carried out in both groups to assure the efficiency of desensitization in the experimental group. The VMH was measured in the incisors of each animal for a quantitative analysis of dentine quality.


RESULTS
Vicker's microhardness was significantly higher in the control rats compared with the capsaicin-treated rats (P < 0.001).


CONCLUSIONS
Neonatal systemic application of capsaicin produces changes in the quality of dentine in the rat over time and therefore it is suggestive that selective elimination of the nociceptive innervation in pulpal tissue may effect odontoblast function.
Krage
T L
TL
Department of Operative and Preventive Dentistry and Endodontics, Heinrich-Heine University, Duesseldorf, Germany. krage@med.uni-duesseldorf.de
Stiefel
A
A
Stephan
B M
BM
Zimmer
S
S
Lambrichts
I
I
Raab
W H-M
WH
D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002211:Capsaicin / Q000494:pharmacology*; D003782:Dental Pulp / Q000294:innervation; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D006244:Hardness; D009475:Neurons, Afferent / Q000187:drug effects; D009619:Nociceptors / Q000187:drug effects; D009804:Odontoblasts / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D018712:Analgesics, Non-Narcotic; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin