Discussion
In this case of a 75-year-old patient, pulp vital testing, measurement
of periodontal pocket depth, and CBCT provided an accurate diagnosis of
a cemental tear with severe periodontitis at #25, and a sinus tract at
the labial gingiva was found to be caused by periodontal inflammation
due to the cemental tear, but without endodontic disease. In addition,
the patient had healthy periodontal tissue. These findings can support
that cemental tear is one of the causes of periodontal abscess in
non-periodontitis patients (14, 15).
According to the new classification that consists of Class (0 to 6),
Stage (A, B, C, and D), and treatment decision-making and selection for
cemental tears (2), this case was classified as Class 3/Stage C, and the
regeneration approach with rhFGF-2, which can effectively regenerate
periodontal tissue in patients who suffer from periodontal disease
(16-18), was applied. Bacteria invade the concealed site of the
fractured fragments of a cemental tear and scattered cemental fragments
within the granulomatous tissues to colonize, proliferate, and survive
(13). A dental operating microscope is essential to improve access to
the operative field and to facilitate complete removal of torn cemental
fragments and granulation tissue during the operation (2). Therefore, in
this case, a surgical approach was adopted using a dental operating
microscope.
In this case, the labial bone defect was regenerated to the position of
the crest of lingual bone, showing successful clinical and radiographic
outcomes. In our previous case of a cemental tear with root-canal
perforation into the labial site, chronic apical periodontitis, a severe
loss of labial bone, and a proximal bone defect at the middle third of
the root in #25, significant PD reduction, CAL gain, and proximal bone
regeneration were obtained after perforation repair, root canal
treatment, and periodontal treatment including periodontal regeneration
therapy, although bone regeneration at the labial site was not observed
(13). The tooth-root states differed between our previous report (13)
and the present report in periodontal regeneration therapy, as follows.
In the previous case, #25 had an obturated root canal, perforation
repair, and a large wedge-shaped defect at the labial site, and #25 in
the present report had vital pulp, no perforation repair, and a thin
dentin defect, unlike the wedge-shaped defect, implying endodontic
treatment, perforation repair, and the size (area and depth) of the
root-dentin defect might have caused the worse prognosis of the labial
bone regeneration in the previous case. Clinical research is necessary
so that the classification of the
size (area and depth) of a root-dentin defect, healthy vital pulp or
non-vital pulp, and the presence or absence of perforation repair may be
considered in the treatment strategy for periodontal destruction with a
cemental tear in addition to the classification of class and stage (2).