Pulpal status of human primary teeth with physiological root resorption.
OBJECTIVE
The overall aim of this study was to determine whether any changes occur in the pulpal structure of human primary teeth in association with physiological root resorption.


METHODS
The experimental material comprised 64 sound primary molars, obtained from children requiring routine dental extractions under general anaesthesia. Pulp sections were processed for indirect immunofluorescence using combinations of: (i) protein gene product 9.5 (a general neuronal marker); (ii) leucocyte common antigen CD45 (a general immune cell marker); and (iii) Ulex europaeus I lectin (a marker of vascular endothelium). Image analysis was then used to determine the percentage area of staining for each label within both the pulp horn and mid-coronal region. Following measurement of the greatest degree of root resorption in each sample, teeth were subdivided into three groups: those with physiological resorption involving less than one-third, one-third to two-thirds, and more than two-thirds of their root length.


RESULTS
Wide variation was evident between different tooth samples with some resorbed teeth showing marked changes in pulpal histology. Decreased innervation density, increased immune cell accumulation, and increased vascularity were evident in some teeth with advanced root resorption. Analysis of pooled data, however, did not reveal any significant differences in mean percentage area of staining for any of these variables according to the three root resorption subgroups (P > 0.05, analysis of variance on transformed data).


CONCLUSIONS
This investigation has revealed some changes in pulpal status of human primary teeth with physiological root resorption. These were not, however, as profound as one may have anticipated. It is therefore speculated that teeth could retain the potential for sensation, healing, and repair until advanced stages of root resorption.
Monteiro
Joana
J
Department of Paediatric Dentistry, Leeds Dental Institute, Leeds, UK.
Day
Peter
P
Duggal
Monty
M
Morgan
Claire
C
Rodd
Helen
H
D015415:Biomarkers / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D003782:Dental Pulp / Q000098:blood supply / Q000294:innervation / Q000473:pathology*; D003804:Dentin / Q000294:innervation; D004730:Endothelium, Vascular / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017493:Leukocyte Common Antigens; D007962:Leukocytes / Q000473:pathology; D055806:Microvessels / Q000473:pathology; D008963:Molar / Q000473:pathology; D009412:Nerve Fibers / Q000473:pathology; D009804:Odontoblasts / Q000473:pathology; D009811:Odontometry; D037121:Plant Lectins / Q000032:analysis; D012391:Root Resorption / Q000473:pathology*; D014092:Tooth Root / Q000473:pathology; D014094:Tooth, Deciduous / Q000473:pathology*; D043222:Ubiquitin Thiolesterase / Q000032:analysis; D039762:Ulex
D015415:Biomarkers; D037121:Plant Lectins; C482860:UCHL1 protein, human; C036850:Ulex europaeus lectins; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human; D043222:Ubiquitin Thiolesterase