Bone graft varieties, studies on efficacy and techniques

1. Bone grafts and periodontal
regeneration
MICHAEAL. BRUNSVOLD& JAMES T.
MELLONIG
Periodontol 2000 Vol. 1. 2013, 80-91

2. • Periodontal bone grafting in the past has been controversial
and unpredictable
• Strong proponents of bone grafting argue that the majority of
healing studies show better success using grafting materials
than open flap debridement in managing severe osseous
defects.
• Others argue that the amount of bone regeneration possible
with current techniques is too limited and unpredictable to be
useful

3. Aim and objective
• This review attempts to clarify the role of bone grafting in the
present era of regeneration.
• The information discussed includes a definition of terms,
objectives of bone grafting, types of bone grafts, surgical
procedure and bone banking

4. Definition
• Periodontal regeneration- Periodontal regeneration is defined
as the process by which the architecture and function of the
periodontium is completely restored
• Repair- Defined as re-establishment of continuity without full
restoration of architecture and function.

5. Objectives of bone grafts
• The objectives of periodontal bone grafts are:
1)Probing depth reduction,
• 2) Clinical attachment gain,
• 3) Bone fill of the osseous defect and
• 4) Regeneration of new bone, cementum and periodontal
ligament

6. • Animal studies are of value to indicate the potential of graft
materials to produce favourable results.
• The results must be viewed with caution, however, and should
not be directly applied to humans.
• Animal studies compare graft and non graft procedures in
artificially created defects (Table 1).
• The majority of these reports indicate a superior result
obtained following the placement of a graft.
• Non graft control sites were never found to be superior to
grafted sites

7. • Human histologic analysis is the gold standard for determining
the true potential of any graft material to regenerate the
periodontium
• A critical step in these trials is documentation on the root
surface of where bacterial contamination occurred prior to
treatment.
• Many techniques have been suggested for documentation but
the most scientifically valid proof of regeneration of an
attachment apparatus is a notch placed in the most apical level
of calculus on the root surface (Dragoo MR et al 1983)

8. Evidence of new bone formation
• Bowers et al. studied this question by comparing the healing of
intraosseous defects with and without placement of decalcified freeze-dried
bone allografts in human periodontal defects.
• These defects were submerged by complete coverage with soft tissue flaps.
• Periodontal regeneration in 30 grafted and 19 non grafted defects was
measured using the most apical level of calculus on the root surface as a
reference marker.
• Results indicated that regeneration was possible with and without bone
grafts in the submerged environment.
• In grafted sites, however, more new attachment apparatus was found than
in nongrafted sites.
• Also, the frequency of regeneration was increased in grafted versus non
grafted sites.
• Their findings strongly suggest that bone grafts do have an inductive effect
on the periodontium.

9. • Egelberg et al has stated that there is little indication that bone
grafts induce new bone formation or stimulate connective
tissue attachment to teeth

10. Types of bone grafts
• Autografts
• Autogenous bone grafts are taken from one part of a patient’s body and
transferred to another.
• Several types of autogenous periodontal bone grafts include cortical bone
chips, osseous coagulum, bone blend, extraction socket bone and extraoral
cancellous bone with marrow
• The basis for current periodontal bone grafting procedures can be traced to
Nabers & O’Leary in 1965.
They used cortical bone shavings removed by hand chisels from within the
surgical site.
Using this material, they reported coronal increases in bone
• height.
• The intraosseous defects so treated were not felt to be amenable to other
forms of treatment.
• Long-term documented success of 6 cases was subsequently reported

11. • Osseous coagulum is obtained by using rotary instruments on
intraoral bone in the surgical site and then mixing the particles
of bone with the patient’s blood .
• The use of this material is based on the rationale that the small
particle size is predictably resorbed and replaced by host bone.
• The mineralized fragments are also thought to induce bone
formation.
• Osseous coagulum procedures have disadvantages,
• which include aspiration problems, an unknown quantity of
collected bone fragments and limitations concerning the
quantity of bone that can be obtained.
• The bone blend technique was designed to overcome some of
these problems.

12. • Bone blend is cortical or cancellous intraoral bone that is
obtained with a trephine, chisel or rongeur.
• It is placed in an amalgam capsule and triturated into particle
size in the range of 100 to 200 pm
• A mean fill of 73% was reported in a study of 25 defects
(Froum SI). In a comparison study, the bone blend grafts
produced 2.98 mm in bone fill compared with 0.66 mm when
open flap debridement was used (Froum SI)
• Bone from other sources in the oral cavity has been used
successfully for periodontal osseous grafts such as maxillary
tuberosity, extraction sockets, tori etc. (Soehren SE et al. 1979)

13. • Autogenous grafts of iliac cancellous bone and marrow offer
the greatest potential for induction of new bone in the
periodontium (Sottosanti et al. 1975)

14. Allografts
• Allografts are grafts transferred between genetically dissimilar
members of the same species.
• Three types of bone allografts are being used in periodontics.
• Demineralized freeze-dried bone is used most often.
• Non demineralized freeze-dried bone and
• Frozen iliac cancellous bone is used less frequently.
• Demineralized freeze-dried bone induces host mesenchymal
cells to differentiate into osteoblasts

15. • The use of DFDBA in human periodontal defects was
first reported by Librin et al. Three sites responded
with 4-10 mm of new bone.
• In another study, a mean of 2.4 mm of bone fill was
measured in 27 intraosseous defects using cortical
DFDBA

16. • Direct comparison of DFDBA and freeze-dried bone allograft
in 11 paired sites showed no statistical difference in probing
depth reduction, clinical attachment gain or bone fill
(Rummelhardt J et a.1989)
Other factors may influence the choice of using mineralized or
demineralized bone.
• Both types of bone are processed with multiple
• immersions in absolute ethanol.
• Decalcification involves the added immersion in 0.6 N HCI .
• Both of these processes are thought to inactivate the human
immunodeficiency virus
• In summary, there currently is not an ideal periodontal bone
graft material. All have limitations.

17. Surgical procedure
• The various factors related to the surgical technique of bone
grafting are hard to evaluate scientifically and, therefore, most
recommendations are based on clinical observations
• Root debridement is an extremely important step in bone-
grafting procedures.
• A combination of ultrasonic and hand instruments is
commonly used to insure that all hard and soft deposits plus
altered cementum are completely removed from the root
surface.

18. • Surface alterations can als be done to enhance periodontal
regeneration.
• These alterations include demineralization with citric acid and
tetracycline and the use of attachment proteins and growth
factors.
• There is encouraging evidence that at least some of these
agents may greatly increase the predictability of bone grafts.
• Guided tissue regeneration using membranes also holds
promise for increasing the success of bone grafting.

19. Conclusion
• Periodontal bone grafts have the potential to completely
regenerate the periodontium destroyed by periodontal disease.
• Complete regeneration, however,is unpredictable at present
• Recent developments related to bone grafting may greatly
enhance their predictability in the future.
• These include improved methods for root detoxification, a
better understanding of wound healing, application of the
principles of guided tissue regeneration, and use of growth
factors