Osseous Autografts II: Histological Responses to Osseous Coagulum-Bone Blend Grafts

“Osseous Autografts II: Histological Responses to Osseous Coagulum-Bone Blend Grafts” – The Journal of Periodontology – 11/1975

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Osseous Autografts
II. Histological Responses to Osseous
Coagulum-Bone Blend Grafts
by
S. J. FROUM
R. THALER
I. W. SCOPP
S. S. STAHL
THE CURRENT INVESTIGATION is a continuation of a
previously reported study which dealt with the responses
of intraosseous defects to a variety of therapeutic
procedures.1 In the initial report we reviewed clinical and
histological literature pertinent to the subject and also
described clinical responses to the placement of either
osseous coagulum-bone blend or autogenous iliac marrow
and cancellous bone grafts into human periodontal
defects. Our results concurred with those of Hiatt and
Schallhorn2 which suggested that similar levels of osseous
regeneration apparently took place regardless of
graft material used.
In order to further study the behavior of osseous
coagulum-bone blend grafts in human infrabony defects,
three cases will be presented in which histologic findings
of block sections were obtained from the graft site 6 to 13
weeks postsurgery.
MATERIALS AND METHODS
All patients in this investigation were referred for
periodontal therapy to the Periodontal Section of the
Dental Service at the Veterans Administration Hospital
in New York City. Although they were in excellent
health at the time of the study, each suffered from severe
periodontitis. Three patients were selected with infrabony
defects on anterior teeth scheduled for extraction. These
teeth were adjacent to teeth which were to be retained,
but which also had infrabony defects requiring osseous
surgery. Each patient signed an informed consent form.
Initial periodontal therapy was similar in all patients.
It consisted of oral hygiene instruction, scaling, occlusal
adjustment, root planning and curretage under local
anesthesia. An oral hygiene index was utilized, and only
when the index approached zero was surgery performed.
During initial therapy two sets of study models were
constructed. The pre-surgical and post-surgical measurements
of pocket depths and osseous recontouring were
described in detail in our previous publication.1

Periodontics Section. Dental Service, New York Veterans Administration
Hospital and the Department of Periodontics, New York
University College of Dentistry at the Brookdale Dental Center, New
York. N. Y.

Prior to block section, radiographs were taken and soft
tissue measurements were recorded. At this time, osseous
measurements were made through intact tissue using the
stent as a fixed reference point. The accuracy of the latter
technique has been described.3
Block sections were removed following the technique
described by Dragoo and Sullivan.4 Healing and prosthetic
replacement of the extracted teeth occurred without
complication in all three cases. The clinical aspects of
the three cases will now be described in detail.

Case 1
Pertinent Medical History. A 64-year-old male presented
for periodontal therapy. The patient’s medical
history revealed that the patient suffered from a herniated
disc during the Second World War. A laminectomy
was performed soon afterward. The patient also
revealed a history of hepatitis in I960. He had a lipoma
removed in 1972 but was currently in good health.
Pertinent Periodontal History.  The mandibular central
incisors and left lateral incisor had such severe periodontal
involvement that these teeth were recommended for
extraction. The left canine (which was to be retained) had
an infrabony defect on its mesial aspect. To reduce the
mobility of the left central incisor (Class II). an intracoronal
wire was used to fabricate a splint between the
central and left lateral incisors.
Periodontal measurements on the left central incisor
(tooth #24) were recorded prior to and during osseous
coagulum-bone blend implant surgery. The initial pocket
depth on the mesial of this tooth was 7.2 mm. An inverse
bevel full thickness flap was reflected revealing a two wall
infrabony defect with an osseous depth which measured
5.9 mm using the stent as a fixed reference point (Fig. I).
The defect was debrided, root accretions were removed,
and the defect was irrigated and overfilled with osseous
coagulum-bone blend. The flap was then coapted and
sutured to insure maximum soft tissue coverage. A
periodontal dressing was applied and the patient was put
on antibiotic coverage for one week. Thirteen weeks
postoperatively immediately prior to block section,
measurements were again recorded. Pocket depth now
measured 3.9 mm. Clinical crestal bone sounding, utilizing
the stent, revealed an apparent osseous fill of 3.4 mm.
The healing after block section was uneventful.
Case II
Pertinent Medical History. A 40-year-old male presented
for periodontal therapy who had been treated at
the NYVAH one year earlier for a bilateral mandibular
fracture. He also revealed a history of syphilis in 1970.
The patient was currently in excellent health.
Pertinent Periodontal History. In order to replace the
maxillary left lateral incisor and because of the severe
overbite and flaring of the remaining incisors, these teeth
were scheduled for extraction. The distal aspect of one of
these teeth (tooth #7) as well as the mesial of tooth #11,
which was to be retained, had infrabony defects. Periodontal
measurements on tooth #7 were recorded prior to
and during osseous coagulum-bone blend implant surgery.

FIGURE 1. Clinical appearance of osseous crater at time of
initial surgery. Probe placed into osseous defect. Case I.

The preoperative pocket depth of the distal of tooth
#7 and 8.1 mm. An inverse bevel full thickness flap was
reflected revealing a one wall hemiseptum with an
osseous depth which measured 4.3 mm using the stent
(Figs. 2A and 2B). The defect was debrided, root
accretions were removed, the defect was irrigated and
overfilled with osseous coagulum-bone blend. The flap
was then coapted and sutured to insure maximum soft
tissue coverage. A periodontal dressing was applied and
the patient was put on antibiotic coverage for one week.
Six weeks postoperatively, immediately prior to block
section, measurements were again recorded. Pocket
depth now measured 4.0 mm. Clinical crestal sounding,
using the stent, revealed an apparent osseous fill of 2.6
mm. The healing after block section was uneventful.
Case III
Pertinent Medical History. A 53-year-old male revealed
a history of treatment for depression in 1971.
Presently, the patient was in excellent physical and
mental health.

FIGURE 2. A. Clinical appearance of osseous crater at time of initial surgery. Case II: B. Probe in position at osseous crater of Case II at time of initial surgery.

FIGURE 3. A. Overview of a mesio-distal cut section of the graft site. Case I. mesial of tooth #24. Tooth and tissue removed 13 weeks after graft had been placed. Hematoxylineosin stain. Magnification 10 x. B. Higher magnification of arrowed area shown in Figure 3A .  Note new cementum formation at graft site and osteogenesis at alveolar seams. Magnification 25 x C. Further magnification of seen cementum seen in Figure 3B. Note the relative lack of cellularity in the cementum and the presence of lamellae. Magnification 64 x.

Figure 4.A. Parallel orientation of  periodontal ligament fibers between bone and cementum seen in Fig, 3A.  Also note osseous remodelling at the wall. Magnification  64 x B. New bone formation at alveolar wall {arrow) from section shown in Figure 3A. C. New cementum forming on dentin from section shown in Figure 3 A. Magnification 64 x. D. Osseous remodelling at crater wall from section shown in Figure 3A. Magnification 64 x ,

Pertinent Periodontal History. The mandibular centrals
and left lateral incisor were diagnosed for extraction.
The distal of the right central incisor (tooth #25)
and mesial of the left canine (tooth #22), which was to be
retained, had infrabony defects. Prior to initial therapy
an intracoronal splint was constructed on teeth #23 to 25
because of the severe mobility of tooth #25. Prior to and
during osseous implant surgery, periodontal measurements
were recorded on tooth #25. The preoperative
pocket depth on the distal of this tooth was 8.0 mm. An
inverse bevel full thickness flap was reflected. Root
accretions were removed and the defect was debrided. It
was classified as a combination one wall hemiseptum
with two walls at its base. The osseous depth of the defect
measured 3.4 mm using the stent. The defect was
overfilled with osseous coagulum-bone blend. The flap
was coapted and sutured to insure maximum soft tissue
coverage. A periodontal dressing was applied and the
patient was put on antibiotic coverage for one week.
Nine weeks postoperatively, immediately prior to
block section, measurements were again recorded.
Pocket depth was now 2.2 mm. Clinical crestal sounding
revealed an apparent osseous fill of 2.4 mm. Healing
after block section was uneventful.

HISTOLOGIC OBSERVATIONS
At the outset, it must be stated that histologic evidence
based on three specimens only indicates possible rather
than probable histologic responses. And it is within these
limitations that the repair phenomena observed in our
specimens must be evaluated. For clarity, responses will
be divided by anatomical sites, i.e., histologic activities at

FIGURE 5. Spicules being exfoliated in specimen removed 6
weeks after graft had been placed. Case II. distal of tooth #7.
Mesio-distal section.  Hematoxylin-eosin stain. Magnification
10 x.

the (I) alveolar walls. (2) bony implants. (3) periodontal
ligaments, and (4) cementum. Since all three specimens
showed similar responses, overall histologic trends will be
reported.
Alveolar Walls. In our specimens, osteogenesis was the
most frequent response seen at the osseous seams. In
other areas, osteoblasts lined the seams, but osteoid was
not visible. Although evidence of resorption-apposition
remodeling was present along all walls, our material
obviously could not indicate whether or not this remodeling
occurred pre- or post-surgical therapy. However,
osteoclastic activity and appearance or resorption bays
were relatively limited (Fig. 3A-3C, 4A-4D).
Bony Implants. Bony implants were seen in all specimens.
In some sections, spicules were being exfoliated
(Fig. 5). Yet, despite this exfoliation, spicules within the
defects showed evidence of osteogenesis and osteoclasis.
But again, the predominant impression was that most
spicules observed within the defects were either lined by
osleoblasts or demonstrated both osteoid and an osteoblast
lining at their borders. Resorption appeared limited.
Some of the spicules contained osteocytes within
their lacunar spaces, while others appeared empty. The
latter observation may reflect loss of vitality of the
spicule, or be due to the plane of section. In other
spicules, osteocytes were present in some portions of the
specimen, but not in others (Figs, 6A 6C). Furthermore,
it seemed that larger spicules were more apt to contain
empty lacunar spaces and demonstrate peripheral resorption
than smaller spicules.
Periodontal Ligament. The periodontal ligament appeared
exceedingly cellular. Connective tissue lined the
osseous walls and the spicules. In some areas, the
periodontal ligament was functionally oriented with
fibers bundles apparently inserting at either the osseous
walls or the borders of the spicules at one end and at the

FIGURE 6. A. Spicules in area of graft from specimen shown in Figure 5. Sole evidence osteogenesis (arrow) and osteoclasis at the borders of the spicules. Magnification 64 x . B. Spicule in area of graft from specimen shown in Figure 5.  Note active connective tissue surrounding spicule, some osteoblasts lining spicule and variations in lacunar content. Magnification 64 x. C. Spicule demonstrating empty lacunae and osteogenic activity in graft site.Case I. Magnification 64 x.

newly formed cementum at the opposing root surface
(Fig. 7). In other areas, the orientations of the ligament
appeared to run parallel to the root surface (Fig. 4A).
Root Surface. The root surfaces facing the implants

FIGURE 7. Functionally oriented periodontal fibers between
spicule and new cementum [arrow) Irani specimen shown in
Figure 5.   Magnification 64 x .

showed evidence of cemental resorption extending into
dentin in some areas, but not in others. Again, our
present material does not allow for conjecture as to the
time when these resorptive processes occurred, However,
it was striking to note significant amounts of “new”
cementum which was present at the root surfaces in the
area of implants. This cementum was essentially acellular,
slightly lamellated and had formed on old cementum
as well as on dentin (Figs. 3C and 8A). Furthermore,
some cemental apposition was also present at root
surfaces of teeth immediately adjacent to the teeth
surrounded by the osseous defect. However, this cemental
apposition was significantly less than that seen
at the tooth wall facing the implant (Fig. 8B). Cementoblasts
appeared to be lining the new cementum
and collagen insertion or parallel collagen fill was noted
along these root surfaces.

COMMENT
To the best of our knowledge, this is the first histologic
evidence of the response of the periodontium to the
“bone blend” type of osseous coagulum. In general, the
periodontal response appeared similar to what has been
described with other autogenous bone grafts in previously
published observations. 2, 4, 5, 6, 7
For example, osteogenesis has been reported in experimental
and human histologic material as early as two
weeks after surgery5, 6 and was found to be significantly
active for at least two months after implantation.4
Cementogenesis has been reported to take place within a
similar time span.4, 5
Smaller si/e bone particles have been described to

FIGURE 8. A. New cementum formed on old cementum in area of graft from specimen shown in Figure 5. Magnification 64 x B.
New cementum forming on mesial root of tooth #6. Case II. This tooth was adjacent to tooth #7 where the major osseous deflect was located. Note the lesser amount of new cementum. Magnification 64 x.

induce more bone formation than larger pieces5 which
concurs with our observations. Along this line, it should
be remembered that functional remodeling probably
continues at an implant site, albeit at a slower pace, for
many months or years after surgery as a response to
continuous function,2, 7, 8 but the most active phase appears
to take place within two to three months after
placement of the graft.
A point of special interest was the variations in
orientation of periodontal ligament fibers which were
seen both within the same specimen as well as between
specimens. These observations must be coupled with the
report by Ellegaard and associates6 who in experimental
studies of graft healing stated: “even after 24 weeks very
few areas showed well defined bundles of collagenous
fibers attached to the new cementum. Usually, the fibers
of the periodontal ligament were oriented parallel to the
root surface. However, fibers oriented parallel to the root
surface could also be seen further apically where no
surgery had been done.” On the other hand, in an
eight-month postsurgery human specimen, Dragoo and
Sullivan4 reported a “fairly mature, functionally oriented
periodontal ligament.” Our observations support the
thesis that fibers early in the repair process orient either
functionally or parallel to the root. The reason for this
variation in orientation is not known. Since histology
obviously cannot trace a continuous process in the same
specimen, it relies on sequential specimens for disclosure
of a continuous process. At this time, human graft
specimens are limited in number. Thus, it may well be
true that initially parallel oriented fibers adapt a more
functional orientation with time. On the other hand,
parallel orientation may occur in the early phases of
healing as a result of as yet unknown factors in the
repairing milieu and remain in that orientation. Further
study of this phenomenon is obviously needed, since it
may be of clinical significance.
Finally, our present findings demonstrate an apparent
enhancement of cementogenesis at the site of implant
similar to that reported by Dragoo and Sullivan.4 Since
We did not use iliac bone graft, it appears that not only
“undifferenliated cells” may enhance cementogenesis,
but also tissues transplanted in a “bone blend.”

SUMMARY
Three human intraosseous lesions were treated using
osseous coagulum-bone blend as graft material. These
sites were surgically removed 6 to 13 weeks after
treatment and the blocks prepared for histologic analysis.
Periodontal remodeling at the site of grafting was
noted in all specimens. This remodeling involved the
osseous walls, periodontal ligament, cementum and graft
spicules. Both osteoclastic and osteoblastic activities
were seen at the borders of the spicules. Exfoliation of
spicules was particularly frequent in the six-week specimen.
Nevertheless, regeneration of both bone and cementum
was actively taking place even in this early specimen
and was still evident in the older specimens.
Of particular interest was the apparent marked increase
in cementogenesis at the graft sites and the
variations in parallel or functional orientation of the
periodontal ligament in these areas. Significant functional
orientation of segments of the periodontal ligament
were seen in the early specimens, but not in the
latter one. The reason for such variations in ligament
pattern is not known at this time.

REFERENCES
1. Froum, S.J.. Thaler, R.. Scopp. I. W.. and Stahl. S. S.:
Osseous Autografts I. Clinical responses to bone blend or hip
marrow grafts. J Periodontol 46:515, 1975.
2. Hiatt, W. H.. and Schallhorn. R G.: Intaoral transplants
of cancellous bone and marrow in periodontal lesions. J
Periodontol 44: 194, 1973.
3. Schallhorn, R. G.. Hiatt, VV. H., and Boyce, W.: Iliac
transplants in periodontal therapy. J Periodontol 41: 566. 1970.
4. Dragoo, M. R.. and Sullivan. H. C: A clinical and
histological evaluation of autogenous iliac bone grafts in
humans: Part 1. Wound healing 2 to 8 months. J Periodontol
44: 599. 1973.
5. Rivault, A. F., Toto, P. D. Levy, S.. and Gargiulo, A.
W.: Autogenous bone grafts: Osseous coagulum and osseous
retrograde procedures in primates. J Periodontal 42: 787. 1971.
6. Ellegaard, B.. Karring, T., Lislgarten, M.. and Loe, H.:
New attachment after treatment of interradicular lesions. J
Periodontol 44: 209, 1973.
7. Ross, S. E.. and Cohen, D. W.: The fate of an osseous
tissue autograft. Periodontics 6: 145. 1968.
8. Nabers, C. L.. Reed, O. M.. and Hamner, III. J. E.:
Gross and histologic evaluation of an autogenous bone graft 57
months post-operatively. J Periodontol 43: 702, 1972.