Puros White Paper r1.qxd - 3GO

ACLINICAL CASE SERIES
IN ORAL REHABILITATION
Clinical and Histological Analyses of Puros ®
Cancellous Chip Allografts in Humans
INTRODUCTION
Localized human periodontal defects and
generalized ridge atrophy can significantly
compromise esthetics and a patient's
ability to function. While prosthetic rehabilitation
alone can sometimes mitigate these
problems, bone grafting to reconstruct the
hard tissue anatomy will often be necessary
to achieve the desired results. Current treatment
standards also dictate that dental
implants be placed in relation to the anticipated
needs of the prosthetic restoration,
rather than according to the limitations of
available bone. 1 Development of sufficient
bone volume for implant placement can often
only be addressed through bone grafting.
Autogenous bone harvested at the time of
surgery is considered the "gold standard"
of bone graft materials because of its
availability, biological safety and ability to
form new bone through all three known
mechanisms of bone regeneration: osteogenesis,
osteoinduction and osteoconduction. 2-3
Drawbacks to the exclusive use of autogenous
bone include increased operating time,
donor site morbidity, poor quality or quantity
of available bone, limitations in the sizes and
shapes of available grafts, and the potential
for intraoperative and postoperative complications.
4-6
Allogenic bone graft materials have been
widely used as alternatives to autogenous
bone for over four decades, and have
been shown to enhance the rate of bone formation
by serving as a scaffold across the
defect site for the regenerating bone (osteoconduction).
6-9 While alloplastic bone substitutes
have also been shown to effectively fill
periodontal bone defects, 5, 10-14 they reportedly
provide little or no new bone formation and
heal through connective tissue encapsulation
of the graft material.
5, 15
Puros (Zimmer Dental Inc., Carlsbad, CA)
is an allogenic, solvent-preserved, human
cancellous bone graft material. Voluntary tissue
donors were selected according to a stringent
protocol that included patient and family
interviews, review of medical, social, and
sexual histories, physical examinations,
autopsy findings (if performed) and laboratory
tests to rule out infectious or malignant
diseases. Tissues were aseptically harvested
24 hours postmortem by a tissue bank certified
by the American Association of Tissue
Banks (AATB), and held in approved storage
until preservation and sterilization processes
were performed.
Additional serological tests were performed
to rule out Hepatitis B/C antigens
and antibodies to HIV I/II. The donor
bone was subjected to the Tutoplast ® Process
(Tutogen Medical, Inc., Neunkirchen,
Germany), which included delipidization,

osmotic treatment, oxidative treatment, solvent
dehydration and sterilization through
limited-dose gamma radiation (17.8 GY). 16-17
Processing removes the fat, cells, antigens
and microbes, but retains the osteoconductive
properties of the material by preserving the
collagen, trabecular pattern and porosity of
the donor bone. This method of processing
has also been shown to inactivate the HIV
virus and the agent responsible for
Creutzfeldt-Jakob disease (CJD). 17-22
This two-part paper reports on the (1) clinical
and (2) histological results of Puros
allogenic bone graft material used in vivo.
Part 1:
Clinical Use of Puros Cancellous Chip Allograft in the
Treatment of Human Periodontal Defects
J. Daulton Keith, Jr., DDS, FICD
Private Practice in Periodontics, Charleston, South Carolina
CASE NO. 1: RESORBED LABIAL PLATE
A52-year-old female non-smoker presented
with a missing right maxillary lateral
incisor and severe atrophy of the labial plate
[Fig. 1]. Clinical evaluation revealed an alveolar
ridge 3 mm in width [Fig. 2]. A monocortical
bone graft was harvested from the
patient’s chin and secured in place with two
lag screws [Fig. 3]. Puros bone graft material
was mitered around the autogenous graft
[Fig. 4] and the entire site was covered with
BioMend ® (Zimmer Dental Inc., Carlsbad,
CA), a type-I collagen barrier membrane
[Fig. 5]. After 5 months of healing, adequate
bone fill was achieved and restorative procedures
were commenced [Fig. 6].
1 2
3 4
5 6
Case No. 1 Fig. 1: Preoperative ridge defect; Fig. 2: Periodontal
probe indicates 3 mm of ridge width; Fig. 3: Monocortical chin
graft in place; Fig. 4: Puros bone graft in place; Fig. 5: BioMend
membrane covers entire graft site; Fig. 6:Healed bone graft at 5 months.
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CASE NO. 2: EXTRACTION DEFECTS
A65-year-old female smoker presented
with severe osseous defects in the left
molar region [Fig. 7]. Prior to treatment, the
patient stopped smoking. The non-salvageable
teeth were extracted [Fig. 8] and the
osseous defects were packed with Puros allogenic
bone graft material [Fig. 9]. A
BioMend type I collagen barrier membrane
was placed over the graft material [Fig. 10]
and the soft tissues were sutured [Fig. 11].
After 7 months of healing, surgical reentry
revealed significant bone fill [Fig.
12]. There were no visible signs of the
resorbable barrier membrane. Following subsequent
grafting procedures in other locations,
the functional and esthetic needs of the
patient were fully restored.
7 8
9 10
11 12
Case No. 2 Fig. 7: Preoperative osseous defects; Fig. 8: Left
molar extraction sites; Fig. 9: Puros graft in place; Fig. 10:
BioMend barrier membrane covers the entire graft site; Fig. 11:
Surgical site sutured; Fig. 12: New bone formation after 7 months
of healing.
13 14
15 16
17 18
Case No. 3 Fig. 13: Preoperative radiograph; Fig. 14: Harvested
bone chips mixed with Puros; Fig. 15: Grafts in place; Fig. 16:
Biomend Extend membrane placed over graft; Fig. 17: Radiograph
of graft site; Fig. 18: New bone formation after healing.
CASE NO. 3: PNEUMATIZED SINUS
A62-year-old female presented with
severe alveolar ridge resorption and
pneumatization of the maxillary right sinus
[Fig. 13]. A monocortical bone graft was harvested
from the iliac crest, placed in the right
tuberosity area and secured in place with
screws. Autogenous bone chips were mixed
with Puros allogenic bone graft material and
packed into the remainder of the defect [Figs.
14-15]. BioMend Extend TM (Zimmer Dental
Inc., Carlsbad, CA) type I collagen membrane
was placed over the graft [Fig. 16], the
soft tissue flaps were approximated and
sutured [Fig. 17]. After five months of healing,
the BioMend Extend graft material had
completely resorbed and the new bone completely
filled the defect [Fig. 18].
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Part 2:
Histological Analysis of Puros Cancellous Chip Allograft
After 6 Months In Vivo
Ricardo Gapski, DDS, MS, 1 Rodrigo E.F. Neiva, DDS, 2 Tae-Ju Oh, DDS, 3
Hom-Lay Wang, DDS, MSD 4
1 Clinical Assistant Professor, Department of Periodontology, University of Missouri at Kansas City.
2 Clinical Assistant Professor, Department of Periodontics/Prevention/Geriatrics, University of Michigan
School of Dentistry.
3 Clinical Assistant Professor, Department of Periodontics/Prevention/Geriatrics, University of Michigan
School of Dentistry.
4 Professor, Department of Periodontics/Prevention/Geriatrics, University of Michigan School of Dentistry.
HISTOLOGY REPORTS
Abiopsy sample was obtained from a
human grafted tooth extraction socket 6
months after grafting with Puros cancellous
chip allograft material. The retrieved specimen
was dehydrated in ascending concentrations
of alcohol, embedded in specialized
resin (Technovit 7200 VLC, Kulzer,
Wehrheim, Germany) and processed to
obtain thin ground sections. Each section was
stained with 1% toluidine blue to improve
contrast for histomorphometric analysis with
backscattered electron image analysis.
Histological examination revealed that
graft turnover (resorption and replacement
by new bone) occurred rapidly with
Puros cancellous bone chips. Low-power
photomicrographs showed dense and thick
trabeculae that provided the core with good
integrity [Figs. 19a]. Cancellous bone was
not uniformly distributed throughout the
core, but most of the bone was quite mature,
and graft particles were so well integrated
that it was nearly impossible to differentiate
them from the new bone [Figs. 19b-c]. Highpower
photomicrographs [Figs. 19d] showed
that a lamellar pattern of mature bone had
formed of the surfaces and surrounded the
residual particles of Puros.
BIOPSY SPECIMENS FROM AN AUGMENTED HUMAN EXTRACTION SOCKET
Core 20x Occlusal 40x Apical 40x
Occlusal 100x
19a
19b
19c
Puros
New Bone
Fig. 19a: Entire biopsy core section 20x; Fig. 19b: Occlusal section of core enlarged 40x; Fig. 19c Apical section of
core enlarged 40x; Fig. 19d Occlusal section of core enlarged 100x.
19d
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DISCUSSION
After grafting, successful bone regeneration
requires a concurrent revascularization
and substitution of the graft material with host
bone without a significant loss of strength. 13
The pattern, rate and quality of new bone substitution
are determined, in part, on complex
reactions between the healing processes of the
biological host and the nature of the graft
material. 21
The Tutoplast Process retains the essential collagen
structure of the Puros donor bone.
Collagen is a key component in a wide variety of
human body tissues, including bone, skin, tendons,
cartilage and blood vessels. There are 21 known
collagens, and each serves a specific role. It comprises
approximately 90-95% of the organic component
of bone, 22-23 and is a fundamental building
block in the process of new bone formation.
The cases presented in this paper are clinically
important because the demonstrate the efficacy
of Puros allograft material in generating effective
new bone fill.
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