Morfhological Changes In Dental Pulp After The Teeth

Romanian Journal of Morphology and Embryology 2005, 46(2):131–136

Morphological changes in dental pulp
after the teeth preparation procedure
ANCA VIŢALARIU1), IRINA-DRAGA CĂRUNTU2)
1)

Department of Oral Rehabilitation, Faculty of Dentistry, “Gr. T. Popa” University of Medicine and Pharmacy, Iassy
2)
Department of Oral Biology, Faculty of Dentistry, “Gr. T. Popa” University of Medicineand Pharmacy, Iassy

Abstract

The aim of this study was to evaluate the immediate changes in the pulp-dentin complex that result from crown preparation, and their
correlation with the thickness of remaining dentin and the preparation technique (with or without water spray cooling). Thirty upper intact
premolars scheduled for extraction for orthodontic reasons were high speed prepared,extracted immediately after preparation and divided
in 5 groups. The analysis of the pulp morphology demonstrated that there are several differences according with the preparation technique.
The most severe changes appear after the profound preparation without water-cooling, the odontoblastic layer being extremely affected.
Also, vascular reactions and inflammatory infiltrate (in the absence ofbacteria) were present. Our study revealed that the histologic
changes in the pulp and dentin following complete crown preparation occur anyway and they are considered difficult to avoid, even if an
adequate technique of preparation is used.
Keywords: dental pulp, odontoblast, histologic changes, full crown preparation.

Introduction
The dentin and the dental pulp are considered as a
biologicentity named dentin-pulp complex, with very
tight-related elements, a common mesenchymal origin,
a conjugated evolution, as well as permanent
interactions. For all these reasons, some authors
refer the dentin-pulp complex as a histo-physiologic
entity [1, 2].
Pulp reactions to the tooth preparation techniques
are still a major concern in restorative dentistry [3, 4].
The term “stressedpulp” used in the literature means
a bad prognosis from the beginning, because, previous
to the prosthesis, caries, old restorations, occlusal
trauma, abrasion or periodontal disease already
exhausted the pulp adaptability. For such a tooth, any
additional trauma, even a small one, can cause a
degenerative process in the pulp [5].
According to many longitudinal investigations, there
is a highrate of vital teeth exhibiting typical signs of
pulp complications, while there is a significantly
increased frequency of endodontic treatments following
dental preparation and crowns cementation [6-8].
Displacement of odontoblastic nuclei following the
teeth preparation is a phenomenon taken into account
when high-speed dental engines were introduced in the
late 1950s [9, 10].
Thephenomenon was described initially as
“aspiration” of the odontoblastic nuclei into the dentinal
tubules [9, 10], but the term “displacement of
odontoblasts” [3, 11] has come into common use
because it does not suggest any certain mechanism for
its occurrence.
It was demonstrated that the pulp reactivity includes
also immediate vascular responses, resulted from the
grinding of dentin [12-14].
Thereactivity of the dental pulp is reported in
almost all stages of the prosthetic treatment [15-20], the
pulp response being influenced by many factors: the

thickness of remaining dentin, the frictional heat and
vibrations generated by high speed burs during crown
preparation, the excessive drying of dentine, the effects
of local anesthesia and of the astringent and hemostatic
substancesused for the temporary enlargement of the
gingival sulcus, the impression and cementation
materials.
The first step, the ablation of the dental hard tissues,
is a non-biological process by its own destructive
nature. Thus, in order to restrict the destructive effect, a
minimal removal of dental substance is performed, with
the aim to preserve the pulp vitality. There is few data in
the...