10 1016@j Joen 2019 10 009
10 1016@j Joen 2019 10 009
10 1016@j Joen 2019 10 009
Necrotic Pulp/Apical
Periodontitis: A Case Series
ABSTRACT
SIGNIFICANCE
The current American Association of Endodontists clinical considerations for a regenerative
endodontic procedure state that a regenerative procedure is suitable for immature permanent A modified apexification
teeth with necrotic pulp when the pulp space is not needed for a post/core in the final procedure provides immature
restoration. Therefore, many immature permanent teeth with necrotic pulp that have permanent teeth with necrotic
sustained a substantial loss of coronal tooth structure either from caries or trauma are treated pulp/apical periodontitis
by apexification or mineral trioxide aggregate/Biodentine (Septodent, Lancaster, PA) apical requiring a post/core for a final
barrier techniques in which no further root maturation would occur. This case series presents restoration the potential of
10 immature permanent teeth with necrotic pulp in which a post/core was likely required in the continued apical root
future for adequate coronal restoration because of loss of substantial coronal tooth structure development, which is an
and a modified apexification procedure was used. All 10 cases after the modified apexification advantage over current apical
procedure showed no clinical symptoms/signs and showed radiographic evidence of healed/ barrier techniques.
healing of periapical lesion after a 2-year review. Eight cases showed increased thickness of
the apical root canal walls, increased apical root length, and apical closure. The overall
percentage change in root length was 7.52%, in root width at the apical one third it was
18.89%, and in radiographic root area it was 15.04% at the 24- to 72-month follow-up period.
This modified apexification procedure allows for the tooth to be restored with a post/core if
required for the final restoration in the future as well as continued root development. (J Endod
2019;-:1–8.)
KEY WORDS:
Apexification; apical barrier techniques; modified apexification procedure; post restoration;
regenerative endodontic procedure
Apexification is a method to induce a calcified barrier in a root with an open apex or the continued apical
development of an incompletely formed root in teeth with necrotic pulps1. The purpose of apexification is
to create an apical calcified tissue barrier at the open apex of immature permanent teeth with necrotic
pulp to facilitate root canal filling and also prevent extrusion of root canal filling into the periapical tissues.
The materials used to create an apical calcified tissue barrier can be calcium hydroxide, mineral trioxide From the *Department of Endodontics,
New York University College of Dentistry,
aggregate (MTA), and Biodentine (Septodent, Lancaster, PA)2–4. Calcium hydroxide apexification usually
New York, New York; and †School of
takes an extended period of time such as months for an apical calcified tissue barrier to form. Additionally, Dentistry, The University of Queensland,
calcium hydroxide has a poor sealing ability and poor setting. Compared with calcium hydroxide, MTA Brisbane, Australia
and Biodentine have an excellent sealing ability and take a shorter time to set. Therefore, MTA and Address requests for reprints to Dr Louis
Biodentine can serve as an apical barrier, and clinicians do not have to wait for an apical hard tissue M. Lin, Department of Endodontics, New
barrier to form. Consequently, MTA and Biodentine apical plugs have been used more often than calcium York University College of Dentistry, 345
hydroxide apexification in recent years. East 24th Street, New York, NY 10010.
E-mail address: lml7@nyu.edu
A regenerative endodontic procedure has the potential to promote thickening of the canal walls 0099-2399/$ - see front matter
and/or continued root development of immature permanent teeth with necrotic pulp/apical periodontitis5.
Copyright © 2019 American Association
The “AAE Clinical Considerations for a Regenerative Procedure”6 list under the “case consideration of Endodontists.
section” that a regenerative endodontic procedure is indicated when the “pulp space is not needed for https://doi.org/10.1016/
post/core final restoration.” Therefore, if the coronal tooth structure of the immature permanent teeth with j.joen.2019.10.009
Increased
thickness Increased
Types of of the apical apical Years of
Case Periapical Periapical apical plug root canal root Apical final
number Tooth Age Etiology Symptoms lesion healing materials walls length closure review
1 9 9 Trauma Asymptomatic Yes Yes MTA Yes Yes Yes 4
2 8 10 Trauma Asymptomatic Yes Yes MTA Yes Yes Yes 2
3 9 10 Trauma Draining sinus Yes Yes MTA Yes Yes Yes 2
tract
4 31 12 Caries Pain on biting Yes Yes MTA Yes Yes Yes 4
5 18 13 Caries Pain on chewing, Yes Yes Biodentine Yes Yes Yes 2
draining sinus
tract
6 8 10 Trauma Asymptomatic Yes Yes MTA Yes No Yes 2
7 7 28 Dens Pain on biting Yes Yes MTA No No No 3
invaginatus
8 10 18 Trauma Asymptomatic Yes Yes MTA No Yes No 3
9 29 12 Caries Asymptomatic Yes Yes MTA Yes Yes Yes 3
and dens
evaginatus
10 8 7 Trauma Asymptomatic Yes Yes MTA Yes Yes Yes 4
irrigated with copious amounts of 3% sodium thickness of ProRoot MTA (Dentsply, Johnson The radiographic outcome was
hypochlorite. The canal was dried and dressed City, TN) or Biodentine was then prepared assessed. The preoperative and postoperative
with calcium hydroxide. The access cavity was according to the manufacturer’s instructions, images were saved in a JPEG format and
closed with a cotton pellet and Intermediate carried into the canal with the MAP system transferred to ImageJ software (version 1.41;
Restorative Material (Dentsply Sirona, (Produitis Dentaies SA, Vevey, Switzerland), National Institutes of Health, Bethesda, MD)
Charlotte, NC) for 2 weeks. and carefully condensed into the canal coronal with the TurboReg plug-in (Lausanne, VD,
At the second visit if the tooth was to the collagen matrix with measured hand Switzerland) for root length, dentin thickness,
asymptomatic, the access cavity was pluggers. Radiography was performed to check and radiographic root area (RRA)
reopened, and the calcium hydroxide was the placement of the MTA/Biodentine plug. The measurement. The images were calibrated,
removed with copious amounts of sodium rest of the coronal canal space was backfilled and the root length, dentin thickness, and RRA
hypochlorite irrigation. The canal was dried with with warm gutta-percha using a vertical from both the preoperative and reevaluation
paper points without EDTA irrigation and also compaction technique. The access cavity was images were measured, which were
no induction of intracanal bleeding from the restored with composite resin (Figs. 2–4). If the performed according to the procedure
periapical tissues. A biocompatible resorbable tooth was symptomatic, another round of described by Bose et al17, Jeeruphan et al18,
collagen matrix (Collagen Matrix, Inc, Oakland, chemomechanical debridement and calcium and Flake et al19.
NJ) of 3-mm thickness was prepared and hydroxide dressing of the canal was performed The “straight-line” tool was used to
placed into the apical canal approximately 1–2 until the tooth became asymptomatic before measure the root length and dentin thickness.
mm short of the apex using appropriate completion of the modified apexification A straight line from the cementoenamel
Buchanan hand plungers (SybronEndo, procedure. The treated teeth were reviewed junction to the radiographic apex of the tooth
Orange, CA) to prevent extrusion of MTA/ at 3, 6, and 12 months; 2 years; and up to 4 was measured as a root length. The dentin
Biodentine into the periapical tissues. A 3-mm years. thickness was obtained as the difference
between the root width and the pulpal space at
the level of the apical one third on preoperative
TABLE 2 - Radiographic Outcome and reevaluated radiographic images (below
the MTA or Biodentine apical plug).
Case Tooth Root length (%) Root width (%) Radiographic Root Area (%) The “polygon” tool was used to outline
the entire radiographic root area starting from
1 9 6.02 35.94 20.55
2 8 3.1 19.55 10.5 the mesial to the distal cementoenamel
3 9 3.38 25.73 16.20 junction and peripherally by the periodontal
4 31 8.96 22.58 11.30 ligament space. The RRA measurement was
5 18 8.08 10.94 8.98 calculated by subtracting the pulp space area
6 8 0.61 17.70 14.62 from the entire root area in each radiograph.
7 7 0.70 0.46 0.74 All radiographic measurements were
8 10 10.41 0.62 9.08 collected. The radiographic root length,
9 29 24.21 20.17 30.73 dentin wall thickness, and root area were
10 8 9.78 35.21 27.69
reported as a percentage change in root
Average 7.53 18.89 15.04
length, a percentage change in dentin
thickness, and a percentage change in root no clinical symptoms/signs and showed 15.04% at the 24- to 72-month follow-up
area, respectively. radiographic evidence of healed periapical period (Table 2).
pathology. Eight cases showed increased
RESULTS thickness of the apical canal walls, increased
FIGURE 3 – (A ) A preoperative periapical radiograph of tooth #9. The tooth had a complicated crown fracture and has an open apex and a periapical lesion. Clinically, the tooth was
diagnosed with necrotic pulp and asymptomatic apical periodontitis. (B ) A postoperative periapical radiograph after the modified apexification procedure. (C ) A periapical radiograph of
the 2-year follow-up showing resolution of the periapical lesion and apical closure.
odontoblast and produce root dentin24. HERS also occur to the arrested root in the modified endodontic procedures of immature
cells can also signal stem cells in the dental apexification procedure of immature permanent teeth with necrotic pulp/apical
follicle to differentiate into cementoblasts and permanent teeth with pulp necrosis/apical periodontitis7.
produce cementum through epithelial- periodontitis. In the present case series, Vigorous induction of periapical
mesenchymal interaction23. In addition, HERS continued apical root development (thickening bleeding into the apical canal space as a
cells are capable of undergoing epithelial- of the apical canal walls, increased root length, scaffold might physically damage the HERS
mesenchymal transition into and apical closure) appeared to occur and prevent root growth31. In the modified
cementoblasts21,23. Therefore, HERS cells are frequently with the modified apexification apexification procedure, only the apical 4–5
responsible for an increase in thickness of the procedure, probably because the potential of mm of the canal space is empty after
canal walls, length of the root, and apical revascularization/revitalization is related to the chemomechanical debridement. Therefore,
closure. If the HERS is damaged by persistent length of the root and the size of the apical induction of periapical bleeding into the apical
apical periodontitis or physical irritation during foramen9,10 and the preservation of the HERS canal as a scaffold might not be necessary.
the induction of periapical bleeding, continued cells. However, chemomechanical debridement
root development could be halted. Wound healing is a continuum and was used in the modified apexification
In immature permanent teeth with sequela of inflammation. It is the host’s procedure to help disrupt and disinfect
necrotic pulp/apical periodontitis, the programmed response to injury to eliminate intracanal bacterial biofilm. Because all 10
development of the root is usually arrested. irritants, and the response begins the moment cases had complete periapical healing, our
When infection/inflammation involves the the tissue is insulted27,28. Wound healing is to infection control measurement of the infected
pulpal-periapical tissue complex, recapitulate the event of embryonic tissue root canals using chemomechanical
proinflammatory cytokines, such as interleukin morphogenesis29,30 and is a very complex debridement and calcium hydroxide
1 and tumor necrosis factor alpha, released biological process, which requires spatial and intracanal medication was effective.
from immunoinflammatory cells are capable of temporal orchestration of cells, matrix, and In the current apexification procedure
inhibiting biological functions of the apical bioactive growth factors, cytokines, and (ie, an MTA/Biodentine apical plug of immature
papilla cells and the HERS cells25,26, thus chemokines. During wound healing of the permanent teeth with necrotic pulp/apical
resulting in the arrest of physiological root injured tissue, the wound will be filled with periodontitis), continued root development
development. Therefore, to rescue arrested granulation tissue, regardless of the size of the might occur but further maturation usually
root development of immature permanent wound as a part of programmed wound does not. In a study using a similar quantitative
teeth with necrotic pulp/apical periodontitis, healing processes27,28. Eventually, the wound analysis, Bose et al17reported minimal
infection/inflammation of the pulp-periapical will heal with tissue similar to or different from changes in root length and root canal width in
tissue complex must be controlled so that the the original tissue (regeneration or repair). In immature teeth treated with an MTA plug
apical papilla cells and the HERS cells can the modified apexification procedure, the apexification procedure. In the present case
resume their biological function. Regenerative apical canal space can be easily filled with series, 8 of 10 cases treated with the modified
endodontic procedures of immature granulation tissue from inflamed periapical apexification procedure of immature
permanent teeth with necrotic pulp/apical tissues even without induction of periapical permanent teeth with necrotic pulp/apical
periodontitis have shown if infection/ bleeding into the apical canal space if the periodontitis showed continued root
inflammation of the pulpal-periapical tissue apical foramen is large enough. The progenitor development. Two cases did not show
complex is controlled, the arrested root will cells from apical bone marrow, the periodontal continued root development, probably
have the potential to continue to develop5. ligament, and apical papilla can migrate and because of severe damage to the HERS cells.
Usually, healing of the arrested root of proliferate into the apical root canal space; The significance of continued root
immature permanent teeth with necrotic pulp/ differentiate into cementoblasts, osteoblasts, development in terms of increasing strength of
apical periodontitis after regenerative or odontoblasts; and produce cementumlike, the immature permanent tooth with necrotic
endodontic procedures is by repair and not bonelike, or dentinlike tissue, similar to the pulp in the present case series is not known
regeneration7. A similar biological event should tissues formed in the canals after regenerative and warrants further investigation.
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