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Horizontal Ridge Augmentation Utilizing
a Composite Graft of Demineralized
Freeze-Dried Allograft, Mineralized
CorticalCancellousChips,anda
BiologicallyDegradableThermoplastic
CarrierCombinedWithaResorbable
Membrane:ARetrospectiveEvaluationof
73ConsecutivelyTreatedCasesFrom
PrivatePractices
Nicholas Toscano, DDS, MS1*
Danny Holtzclaw, DDS, MS2
Ziv Mazor, DMD3
Paul Rosen, DMD, MS4
Robert Horowitz, DDS5
Michael Toffler, DDS6
Ridge deficiency is an unfortunate obstacle in the field of implant dentistry. Many techniques
are available to rebuild the deficient ridge. Some of these techniques are associated with
significant morbidity and often require a second surgical site. With the advent of guided
bone regeneration (GBR), one may now graft the deficient ridge with decreased morbidity
and without a second surgical site. The purpose of this retrospective consecutive case series
from 5 private practices is to report on the outcomes of a composite material of
demineralized freeze-dried allograft, mineralized cortical cancellous chips, and a biologically
degradable thermoplastic carrier (Regenaform RT) when combined with a resorbable
membrane for GBR of lateral ridge defects in human patients. The specific aim was to quantify
clinical results through direct measurement. Data were obtained from 73 consecutively treated
lateral ridge augmentations performed on 67 partial and/or completely edentate patients.
Clinical data (presurgical ridge width, ridge width at implant placement, and bone density at
implant placement) were obtained retrospectively from 5 private practices via an exhaustive
retrospective chart review, which was pooled and averaged for analysis. The average gain in
horizontal ridge width was 3.5 mm (range, 3–6 mm). The density of the bone was noted to be
type 2 to 3, with type 3 being the predominant finding. This retrospective case series from 5
clinical private practices suggests that the use of a composite material of demineralized freeze-
dried allograft, mineralized cortical cancellous chips, and a biologically degradable
thermoplastic carrier, when covered by a resorbable collagen membrane for GBR, is an
effective means of horizontal ridge augmentation.
Key Words: ridge augmentation, bone graft, particulate graft, dental implant
INTRODUCTION
Advances in surgical and im-
plant technology have enabled
dentists to meet the treatment
needs of an esthetically de-
manding patient population.
1
Historically, Albrektsson’s criteria have
served as the benchmark by which dental
implant success has been measured.2 Al-
though these criteria have remained the
gold standard, with a strict focus on
osseointegration and function, they do not
address contemporary concerns such as
esthetics or restorability secondary to im-
plant positioning. For example, implants may
be suboptimally placed because of anatomic
limitations, developmental defects, pathol-
ogy, bone resorption, and long-standing
ridge deficiencies, which when restored
may satisfy all of Albrektsson’s criteria for
success. Yet the implant may be a failure, as
seen in an undesirable esthetic outcome.
Implant malpositioning has been an
unfortunate complication of our profession.
The consequence of this can be off-axial
loading, which may result in biomechanical
problems, loosening, and/or fracturing of the
cover screw, implant, or implant collar.3,4
Implant malpositioning can adversely affect
clinical and prosthetic outcomes by creating
a suboptimal emergence profile, fracture of
the restoration, poor screw-hole positioning,
occlusal discrepancies, and compromised
esthetics and phonetics.
An ideal volume of bone is essential for
proper implant placement in the buccal/
palatal, apical/coronal, or mesial/distal di-
mension. Studies have demonstrated that
bone resorption will occur secondary to
tooth extraction5–12 (Figure 1). This tends
to occur over a 12 month period, most
notably in the first 4 months following
extraction5–11 and, depending upon location,
may range up to 5–7 mm buccolingually.8–12
In addition, 2–4 mm of vertical height loss
frequently accompanies the horizontal loss
and usually is seen when multiple adjacent
extraction sites are combined.8–12 To combat
this dimensional loss of bone volume, ridge
preservation techniques have been used to
maintain the alveolar ridge secondary to
tooth extraction.5,12–15 However, even with
current techniques, postextraction resorp-
tion may occur, mandating surgical manage-
ment of the ridge deficiency.12
Ridge splitting and expansion tech-
niques concurrent with bone grafting have
been well documented for treating hori-
zontal deficiencies. Included in these cate-
gories are ridge splitting and expansion,16,17
guided bone regeneration (GBR),18–21 dis-
traction osteogenesis,22 and block graft-
ing.23–28 The purpose of this retrospective
consecutive case series from 5 private
practices is to report on the outcomes of
a composite material of demineralized
freeze-dried allograft, mineralized cortical
cancellous chips, and a biologically degrad-
able thermoplastic carrier (Regenaform RT,
Exactech Dental Biologics, Gainesville, Fla)
when combined with a resorbable mem-
brane for GBR of lateral ridge defects in
human patients. The specific aim was to
quantify the clinical results through direct
measurement.
MATERIALS AND METHODS
Clinical data (presurgical ridge width, ridge
width at implant placement, and bone
density at implant placement) were obtained
retrospectively from 5 private practices via
an exhaustive retrospective chart review,
which was pooled and averaged for analysis.
A total of 73 consecutively treated lateral
ridge augmentations were performed on 67
partial and/or completely edentate patients
with a composite material of demineralized
freeze-dried allograft, mineralized cortical
cancellous chips, and a biologically degrad-
able thermoplastic carrier (Regenaform RT)
that was covered by a resorbable collagen
membrane (Ossix, Oropharma Inc, Langhorne,
Pa). All patients were free of systemic disease
that might compromise the results, such as
uncontrolled diabetes or thyroid disease,
osteopenia or osteoporosis, and blood dys-
crasias such as anemia, and all were smokers
of less than 1 pack of cigarettes per day. A
total of 43 augmentations were performed in
the maxilla and 40 in the mandible. Three
patients underwent bilateral grafts of the
mandible. Patients were treated under local
anesthesia using 2% lidocaine with 1:100 000
epinephrine or articaine 4% with 1:100 000
epinephrine. A beveled crestal incision was
made slightly to the palate or lingual of the
treatment site and was extended at least 1
tooth beyond in both mesial and distal
directions. After elevation of full-thickness
flaps, measurements were made near the
crest of the ridge using a UNC-15 probe to
record the preaugmentation ridge width.
Measurements were rounded up to the
nearest millimeter at pretreatment and at
posttreatment. The bone defect was decorti-
cated using a #4 round bur through the
cortical plate to enhance revascularization of
the site. The membrane (Ossix, Orapharma,
Inc, Warminster, Pa) was soaked in sterile
water or sterile saline, according to the
manufacturer’s instructions, and was trimmed
to fit the site. Further periosteal release was
performed to allow for tension-free closure of
the flap over the membrane and graft. The
thermoplastic composite graft was mixed
according to the manufacturer’s instructions
and was molded to fit the ridge defect. The
graft was covered with the pretrimmed
resorbable collagen membrane, and tension-
free closure was provided utilizing a combi-
nation of horizontal and vertical mattress
sutures (Figures 2 through 6). Patients were
placed on postoperative Motrin 800 mg 3 to 4
times daily for up to 10 days to provide both
anti-inflammatory and analgesic benefits, as
well as amoxicillin 500 mg 3 times a day or
875 mg 2 times daily for 10 days. Patients
were also instructed to use 0.12% chlorhex-
idine rinse, starting on the day after surgery,
twice daily for the first 2 weeks when the
sutures were removed, and for up to 4 weeks
if the membrane became exposed. Pa-
tients were subsequently seen at 1 month,
3 months, and 6 months after the implants
had been placed.
All cases were allowed to heal for a
minimum of 6 months before implants were
placed. At this time, a second measurement
was made following the elevation of a full-
thickness flap. Again, a UNC-15 probe was
used to record ridge width postaugmenta-
tion. This was done close to where the first
measurement was made. All clinicians noted
RESULTS
average gain in horizontal ridge width was
3.5 mm (range, 3–6 mm). The density of the
bone was noted to be type 2 to 3, with type
3 being the predominant finding. All im-
plants were successfully placed and ulti-
mately restored after an average 4 months of
healing (Figures 7 through 12).
Average presurgical ridge width was 4 mm,
and it was noted that maxillary sites tended
to have more advanced ridge defects then
mandibular sites. At stage I implant place-
ment, ridge width postaugmentation was
recorded at an average of 7.5 mm. The
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DISCUSSION
The use of autogenous iliac crest block grafts
has been associated with higher rates of
Toscano et al
FIGURES 7–12. FIGURE 7. Nonrestorable tooth #7 with endodontic lesion noted. FIGURE 8. A large defect is
seen postremoval of tooth and lesion. FIGURE 9. Defect is grafted before membrane placement. FIGURE 10.
Six months postgraft with implant placed. FIGURE 11. #7 showing nonrestorable of implant placed in
grafted bone. FIGURE 12. Implant restored 8 months postgrafting.
Journal of Oral Implantology
471
Horizontal Ridge Augmentation Utilizing a Composite Graft
postoperative sequelae and morbidity,29
often requiring patient hospitalization. Al-
though iliac crest bone may present certain
advantages, such as the ability to obtain a
larger volume of graft material that would
include osteogenic material, its value has to
be questioned in light of excellent results
obtained with other graft materials and
techniques, and the significant costs and
morbidities associated with its procure-
ment.30 Autogenous block grafts from the
mandibular symphysis or ramus may be more
advantageous in that they can be procured
through an in-office, outpatient procedure.
Furthermore, intraoral autogenous grafts
have a lower rate of resorption and better
revascularization vs iliac crest grafts.31,32
Ramus and symphysial grafts have their own
sets of reported postoperative complications
such as pain, infection, edema, chin ptosis,
incision dehiscence, paresthesia, anesthesia,
and neurosensory changes.25,27,28,33,34
When GBR is compared with block grafting
techniques for ridge augmentation, little
difference is seen in the horizontal bone gain
that can be achieved. Studies by Buser have
demonstrated that using ramus and symphy-
sis blocks yielded an average ridge width gain
of 3.53 mm (range, 1–7.5 mm).35–38 More
recently, Schwartz-Arad demonstrated that
the mean ridge width increase in more than
60 onlay grafts from the symphysis and ramus
was 3.8 mm, and a mean success rate of 87.5%
was defined as sufficient bone for implant
placement.30 Additionally, Triplett (1993) re-
ported success rates for onlay grafts at 93%.36
When this is compared with the GBR literature,
bone volume gains between techniques
appear similar. Buser showed that GBR
procedures produced a horizontal ridge width
gain of 1.5–5.5 mm.18 Studies by Feulle using
GBR techniques demonstrated a mean ridge
width gain of 3.2 mm (range, 2.2–4.2 mm).43
Success rates for GBR techniques have been
similar to those of block grafts, with studies by
Tolman, Zitmann, and Nevins reporting in-
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Vol. XXXVI/No. Six/2010
creases of 81% to 97%.39–41 A meta-analysis by
Tolman concluded that in most areas, the
success of GBR was similar to that of block
grafts, with only a slight advantage favoring
block grafting in the mandibular arch.39 A
systematic review by Aghaloo and Moy
reported findings of statistically significant
reduced implant survival rates at sites grafted
with autogenous bone block, compared with
other regenerative techniques.35 Their meta-
analysis found an implant survival rate of
74.4% for iliac crest grafts, as compared with
95.5% for GBR.
Block grafts from intraoral or extraoral
sources have the advantage of allowing
reentry slightly sooner for implant place-
ment. Pikos suggested that block grafts can
be reentered at 3–4 months in the mandible
and at 4–5 months in the maxilla.42 However,
the disadvantages of utilizing a second
surgical site, along with the increased
morbidity associated with the graft harvest,
make GBR an attractive technique for aug-
mentation of alveolar defects in preparation
for dental implant placement.
In the current study, grafting with com-
posite material of demineralized freeze-dried
allograft, mineralized cortical cancellous chips,
and a biologically degradable thermoplastic
carrier (Regenaform RT), when combined with
a resorbable membrane for GBR, resulted in
average horizontal ridge augmentation of
3.5 mm. This compares favorably with Buser’s
study of ramus and symphysial block grafts,
resulting in an average of 3.53 mm of ridge
width.37 The handling characteristic of the
composite graft, its combined osteoinductive
and osteoconductive nature, and the benefits
of avoiding a second surgical site make it
preferable over autogenous grafting tech-
niques.
CONCLUSION
This retrospective case series from 5 clinical
private practices suggests that the use of
Toscano et al
FIGURES 13–15. FIGURE 13. Deficient mandibular ridge with temporary implants placed. FIGURE 14. Ridge
grafted with tenting screws before membrane placement. FIGURE 15. Implants placed 6 months
postgrafting.
composite material of demineralized freeze-
dried allograft, mineralized cortical cancel-
lous chips, and a biologically degradable
thermoplastic carrier, when covered by a
resorbable collagen membrane for GBR, is
an effective means of achieving horizontal
ridge augmentation (Figures 13 through
15). An average of 3.5 mm of horizontal
ridge width was achieved via this technique.
Additional prospective and randomized
controlled clinical trials are needed to
determine the efficacy of this technique
and to compare it with others currently
used.
ABBREVIATION
GBR: guided bone regeneration
REFERENCES
1. Buser D, Martin W, Belser UC. Optimizing
esthetics for implant restorations in the anterior
maxilla: anatomic and surgical considerations. Int J Oral
Maxillofac Implant. 2004;19(suppl):43–61.
2. Albrektsson T, Zarb G, Worthington P, et al. The
long-term efficacy of currently used dental implants: a
review and proposed criteria of success. Int J Oral
Maxillofac Implant. 1986;1:11–25.
3. Rangert B, Jemt T, Jorneus L. Forces and
moments on Branemark implants. Int J Oral Maxillofac
Implant. 1989;4:241–247.
4. Khraisat A, Abu-Hammad O, Dar-Odeh N,
et al. Abutment screw loosening and bending resis-
tance of external hexagon implant system after lateral
cycle loading. Clin Implant Dent Relat Res. 2004;6:157–
164.
5. Nevins M, Camelo M, De Paoli S, et al. A study of
the fate of the buccal wall of extraction sockets of teeth
with prominent roots. Int J Periodontics Restorative
Dent. 2006;26:19–29.
6. Cardaropoli G, Araujo M, Lindhe J. Dynamics of
bone tissue formation in tooth extraction sites: an
experimental study in dogs. J Clin Periodontol. 2003;30:
809–818.
7. Araujo MG, Lindhe J. Dimensional ridge alter-
ations following tooth extraction: an experimental
study in the dog. J Clin Periodontol. 2005;32:212–218.
8. Johnson K. A study of the dimensional changes
occurring in the maxilla after tooth extraction. Part 1:
normal healing. Aust Dent J. 1963;8:428–434.
9. Johnson K. A study of the dimensional changes
occurring in the maxilla after tooth extraction. Aust
Dent J. 1969;14:241–244.
10. Schropp L, Wenzel A, Kostopoulos L, et al. Bone
healing and soft tissue contour changes following
single-tooth extraction: a clinical and radiographic 12-
month prospective study. Int J Periodontics Restorative
Dent. 2003;23:313–323.
Journal of Oral Implantology
473
Horizontal Ridge Augmentation Utilizing a Composite Graft
11. Lam RV. Contour changes of the alveolar pro-
cesses following extraction. J Prosthet Dent. 1960;10:25–32.
12. Iasella JM, Greenwell H, Miller RI, et al. Ridge
preservation with freeze-dried bone allograft and a
collagen membrane compared to extraction alone for
implant site development: a clinical and histologic
study in humans. J Periodontol. 2003;74:990–999.
13. Fiorellini JP, Howell TH, Cochran D, et al.
Randomized study evaluating recombinant human
bone morphogenetic protein-2 for extraction socket
augmentation. J Periodontol. 2005;76:605–613.
14. Sclar AG. Preserving alveolar ridge anatomy
following tooth removal in conjunction with immediate
implant placement: the Bio-Col technique. Atlas Oral
Maxillofac Surg Clin North Am. 1999;7:39–59.
15. Sclar AG. Strategies for management of single-
tooth extraction sites in aesthetic implant therapy.
[published erratum appears in: J Oral Maxillofac Surg.
2005;63:158.] J Oral Maxillofac Surg. 2004;62(9 suppl 2):
90–105.
16. Duncan JM, Westwood RM. Ridge widening for
the thin maxilla: a clinical report. Int J Oral Maxillofac
Implants. 1997;12:224–227.
17. Scipioni A, Brushi G, Calesini G. The edentulous
ridge expansion technique: a five-year study. Int J
Periodontics Restorative Dent. 1994;14:451–459.
18. Buser D, Dula K, Belser U, Hirt HP, Berthold H.
Localized ridge augmentation using GBR, I. Surgical
procedures in the maxilla. Int J Periodontics Restorative
Dent. 1993;13:29–45.
19. Mellonig JT, Nevins M. Guided bone regener-
ation of bone defects associated with implants: an
evidence-based outcome assessment. Int J Periodontics
Restorative Dent. 1995;15:168–185.
20. Zitzmann N, Naef R, Scharer P. Resorbable versus
nonresorbable membranes in combination with Bio-Oss
for guided bone regeneration. Published erratum ap-
pears in: Int J Oral Maxillofac Implants. 1997;12:844–852.
21. Simion M, Jovanovic SA, Tinti C, Benfenati SP.
Long-term evaluation of osseointegrated implants
inserted at the time or after vertical ridge augmenta-
tion: a retrospective study on 123 implants with 1–
5 year follow-up. Clin Oral Implants Res. 2001;12:35–45.
22. Urbani G, Lombardo G, Santi E, et al. Distraction
osteogenesis to achieve mandibular vertical bone
regeneration: a case report. Int J Periodontics Restorative
Dent. 1999;19:321–331.
23. Proussaefs P, Lozsada J. The use of intraorally
harvested autogenous block grafts for vertical alveolar
ridge augmentation: a human study. Int J Periodontics
Restorative Dent. 2005;25:351–363.
24. Triplett R, Schow S. Autologous bone grafts
and endosseous implants: complementary techniques.
J Oral Maxillofac Surg. 1996;54:486–494.
25. Misch CM. Comparison of intraoral donor sites
for onlay grafting prior to implant placement. Int J Oral
Maxillofac Implants. 1997;12:767–776.
26. Lyford RH, Mills MP, Knapp CI, Scheyer ET,
Mellonig JT. Clinical evaluation of freeze-dried block
allografts for alveolar ridge augmentation: a case series.
Int J Periodontics Restorative Dent. 2003;23:417–425.
27. Pikos MA. Block autografts for localized ridge
augmentation: part I. The posterior maxilla. Implant
Dent. 1999;8:279–285.
28. Boyne PJ, James RA. Grafting of the maxillary
sinus floor with autogenous marrow and bone. J Oral
Surg. 1980;38:613–616.
29. Rudman RA. Prospective evaluation of morbid-
ity associated with iliac crest harvest for alveolar cleft
grafting. J Oral Maxillofac Surg. 1997;55:2219–2223.
30. Schwartz-Arad D, Levin L, Sigal L. Surgical
success of intraoral autogenous block onlay grafting
for alveolar ridge augmentation. Implant Dent. 2005;14:
131–138.
31. Smith JD, Abramsson M. Membranous vs.
endochrondrial bone autografts. Arch Otolaryngol.
1974;99:203–205
32. Bruchardt H. The biology of bone graft repair.
Clin Orthop Relat Res. 1983;174:28–42.
33. Raghoebar GM, Louwerverse C, Kalk WW, et al.
Morbidity of chin bone harvesting. Clin Implant Dent
Relat Res. 2001;12:503–507.
34. Clavero J, Lundgren S. Ramus or chin grafts for
maxillary sinus inlay and local onlay augmentation:
comparison of donor site morbidity and complications.
Clin Implant Dent Relat Res. 2003;5:154–160.
35. Aghaloo TL, Moy PK. Which hard tissue
augmentation techniques are the most successful in
furnishing bony support for implant placement. [pub-
lished erratum appears in: Int J Oral Maxillofac Implants.
2008;23:56.] Int J Oral Maxillofac Implant. 2007;22(suppl):
49–70.
36. Triplett R, Schow S. Autologous bone grafts
and endosseous implants: complementary techniques.
J Oral Maxillofac Surg. 1996;54:486–494.
37. Buser D, Dula A, Hirt HP, Schenk RK. Lateral
ridge augmentation using autografts and barrier
membranes: a clinical study with 40 partially edentu-
lous patients. J Oral Maxillofac Surg. 1996;54:420–432.
38. Schwartz-Arad D, Levin L, Sigal L. Surgical
success of intraoral autogenous block onlay bone
grafting for alveolar ridge augmentation. Implant Dent.
2005;14:131–138.
39. Tolman D. Reconstructive procedures with en-
dosseous implants in grafted bone: a review of literature.
Int J Oral Maxillofac Implants. 1995;10:275–294.
40. Nevins M, Mellonig JT, Clem DS, Reiser GM, Buser
DA. Implants in regenerated bone: long-term survival. Int
J Periodontics Restorative Dent. 1998;18:34–45.
41. Zitzmann NU, Naef R, Scharer P. Resorbable
versus nonresorbable membranes in combination with
Bio-Oss for guided bone regeneration. Int J Oral
Maxillofac Implants. 1997;12:844–852.
42. Pikos MA. Mandibular block autografts for
alveolar ridge augmentation. Atlas Oral Maxillofacial
Surg Clin N Am. 2005;13:91–107.
43. Feuille F, Knapp CI, Brunsvold MA, Mellonig JT.
Clinical and histologic evaluation of bone-replacement
grafts in the treatment of localized alveolar ridge
defects. Part 1: mineralized freeze-dried bone allograft.
Int J Periodontics Restorative Dent. 2003;23:29–35.
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