Case report
A 75-year-old woman with osteoporosis visited Nippon Kokan Fukuyama
Hospital with a chief complaint of a gingival abscess and swelling
around #9. Her gingiva in all areas of the mouth except #9 and #25
was healthy (Figure 1A) and she had good oral hygiene (plaque control
record: 13.8%). Her #9 was found to have received trauma two years
earlier and to have a vertical root fracture. Therefore, #9 was
extracted with her informed consent. In contrast, the patient had no
subjective symptoms related to #25. A sinus tract was observed on the
labial side of the gingiva around #25 (Figure 1A); #25 responded
positively to thermal and electric pulp vital tests by
PULPER® (GC, Tokyo, Japan) and
Digitest® (Parkell, Farmingdale, NY, USA). Pocket
probing depth (PPD) on #25 was 3 mm in all areas except the labial
center, whose PPD was 9 mm. Probing of the labial center resulted in
bleeding. Clinical attachment loss at #25 of the labial center was 16
mm; #25 was inclined labially and showed tooth attrition (Figure 1B). A
gutta-percha point (size 40/02; GC Dental Industrial Corp., Tokyo,
Japan) was used to trace the periodontal pocket of the labial center
(Figure 1B). Radiography showed that the tip of the gutta-percha point
inserted into the sinus tract reached the mesial site at one-fourth of
the root length from the root apex of #25 (Figure 1C). Radiolucent
areas were not observed around the tip of the inserted gutta-percha
point (Figure 1C). Dental
radiographs in the orthoradial projection and the eccentric projection
of #25 showed no radiopaque fragments at the root (Figure 1D). The
patient’s oral hygiene was good, and her gingiva and bone levels in all
areas of the mouth except #25 were healthy, suggesting that #25 should
be classified as a periodontal abscess in a non-periodontitis patient
(14, 15).
Cone-beam computed tomography (CBCT) images (3DX Multi-Image Micro CT
FPD8; J Morita, Tokyo, Japan) of #25 showed an extensive bone defect on
the labial aspect and narrow-range defects on the mesial and distal
aspects at the buccal side (Figure 2A and B). Three-dimensional
reconstruction of CBCT images showed narrow shallow vertical bone
defects from the existing marginal bone in the three sites (Figure 2C).
Radiopaque thin fragments, which were completely and incompletely
detached from the root surface,
were observed at the distal-labial and mesial-labial aspects of the root
(Figure 2A and B). This was diagnosed as a case of cemental tear
accompanied by severe periodontitis. According to the new
three-dimensional classification of cemental tears (2), this case was
classified as Class 3 (clinically inaccessible, infrabony and/or
dehiscence, no apical involvement)/Stage C (cemental tear and the
associated bony defect involves 3 surfaces of the root). The clinical
symptoms and the results of the examinations suggested that
whileendodontic treatment was not necessary, periodontal treatment
(surgical removal of cemental fragments and granulomatous tissue, biopsy
of removed tissues, and periodontal regenerative therapy with rhFGF-2)
was. Informed consent was obtained from the patient after explanation of
the risks, benefits, and costs of the proposed treatments.
Occlusal adjustment was conducted at the anterior tooth to improve
occlusal function after extraction of #9. After scaling and root
planing had been carried out, the periodontal pocket (PPD of the labial
center: 9 mm) remained, although the swelling, abscess, and sinus tract
had disappeared (Figure 3A). Under disinfection with povidone iodine and
local anesthetic administration with Xylocaine®(DENTSPLY-Sankin Co., Tochigi, Japan) in the right mandibular region, a
full-thickness mucoperiosteal flap with a single-flap approach to the
labial access was raised (Figure 3B). After granulomatous tissue was
partially removed (Figure 3C), cemental fragments on the root were
stained with methylene blue dye (MORIMURA DENTAL Co., Tokyo, Japan)
(Figure 3D). After the removal of cemental fragments and the remaining
granulomatous tissue with hand curettes under the dental operating
microscope, the range of the bone defect was found on the proximal and
labial aspects (Figure 3E and F). Subsequently, root planing was
conducted. A thin dentin defect that did not extend to the wedge-shaped
defect occurred on the labial-site root. For this, rhFGF-2 (Kaken
Pharmaceutical Co., Tokyo, Japan) was applied into the bone defect
(Figure 3G). The flap was then repositioned without tension and sutured
with 7-0 nylon (Mani, Tochigi, Japan) (Figure 3H). During surgery, the
cemental fragments (Figure 3I) and granulomatous tissues (Figure 3J)
were collected for biopsy.
Histopathological examination of the removed cemental fragment with
hematoxylin and eosin (HE) staining showed the acellular cementum
(Figure 4A and B). A thin layer of fibrous connective tissue
representing the periodontal ligament was attached to the cemental
fragment (Figure 4B). Gram-positive bacteria (Figure 4C) and periodic
acid-Schiff (PAS)-positive bacteria (Figure 4D) were observed on the
cemental fragment. Small, scattered cemental fragments existed within
the removed granulomatous tissue (Figure 5A and B). Gram-positive
bacteria (Figure 5C) and PAS-positive bacteria (Figure 5D) were observed
on the small, scattered cemental tears within the granulomatous tissue.
Two years after the surgery, no abnormal findings were seen
radiographically (Figure 6A), and clinically healthy soft tissues were
observed without severe gingival recession (Figure 6B). PPD of all sites
was 2 mm. #25 had no bleeding on probing and no tooth mobility. The
clinical attachment level of the labial center was improved from 16 mm
to 9 mm (attachment gain: 7 mm). CBCT 2 years after the surgery showed
reconstruction of the labial bone wall (Figure 7A, B and C) and proximal
bone walls (Figure 7B). In particular, the regenerated labial bone had a
similar height to the lingual bone (Figure 7A).