Journal of Biomaterials Applications

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Journal of Biomaterials Applications
http://jba.sagepub.com/content/early/2011/01/28/0885328210396946
The online version of this article can be found at:
DOI: 10.1177/0885328210396946
J Biomater Appl published online 22 February 2011
Ferreira Junior
Etiene Andrade Munhoz, Augusto Bodanezi, Tania Mary Cestari, Rumio Taga, Paulo Sergio Perri de Carvalho and Osny
Long-term rabbits bone response to titanium implants in the presence of inorganic bovine-derived graft
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Article
Long-term rabbits bone response
to titanium implants in the presence
of inorganic bovine-derived graft
Etiene Andrade Munhoz1, Augusto Bodanezi2,
Tania Mary Cestari3, Rumio Taga3, Paulo Sergio Perri de
Carvalho1 and Osny Ferreira Junior1
Abstract
This study evaluated bone responses to titanium implants in the presence of an inorganic graft material. The bilateral
mandible incisors of 24 rabbits were surgically extracted and one of the exposed sockets, chosen at random, was filled
with an inorganic xenogenic bone graft (Gen-ox ), whereas the remaining socket was left to heal naturally and served as
a control. After 60 days, titanium implants were inserted in the specific areas, and on days 0, 30, 60, and 180 after the
implant insertions, six animals of each group were killed. Digital periapical radiography of implant region was obtained
and vertical bone height (VBH) and bone density (BD) were evaluated by digital analysis system. In the undecalcified
tissue cuts, bone-to-implant contact (BIC) and bone area (BA) within the limits of the implant threads were evaluated and
compared statistically by means of two-way ANOVA and Tukey’s test ( <0.05). No significant differences were detected
in VBH and BA, either between groups or between different experimental intervals. The BD was significantly higher in
the experimental group than in the control group in all the intervals tested, but there were no significant differences by
interval. The BIC was statistically lower in the control group on day 0; however, a significant increase was observed on
days 60 and 180 ( <0.05). The use of an inorganic xenograft prior to insertion of a titanium implant did not interfere
with the course of osseointegration.
Keywords
inorganic xenograft, titanium implants, osseointegration
Introduction
The maintenance of height, thickness, and quality of
bone in order to provide an adequate implant placement
and prosthetic rehabilitation1 is a constant challenge
after surgical procedures that involve hard tissue
removal. To address this problem, filling of the bone
defect with a graft has been recommended.2–6
Autologous bone is undoubtedly the best graft material
for this purpose due to the biocompatibility;3 however,
its scarcity and significant post-procedural
morbidity makes its use limited and difficult. For
these reasons, it is important to find alternative graft
substitutes that present satisfactory characteristics of
biocompatibility, osseointegration, and availability as
well as inductive and conductive properties.
In this context, the inorganic version of bovine
xenografts has demonstrated remarkable
osteoconductive properties.4,5 These include the
hydroxyapatite mineral content, a porous architecture
that allows for a trabecular network to be formed,
biomechanical properties similar to that of human
cancellous bone5 and the absence of immunological
and inflammatory responses that are elicited.4
Journal of Biomaterials Applications
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DOI: 10.1177/0885328210396946
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1Department of Stomatology and Oral Surgery, School of Dentistry,
University of Sa˜o Paulo, Bauru, Brazil.
2Department of Conservative Dentistry, School of Dentistry, Federal
University of Rio Grande do Sul, Porto Alegre, Brazil.
3Department of Oral Biology, School of Dentistry, University of Sa˜o
Paulo, Bauru, Brazil.
Corresponding author:
Etiene Andrade Munhoz, Department of Stomatology and Oral Surgery,
School of Dentistry, University of Sa˜o Paulo, Al. Dr. Ota´vio Pinheiro
Brisolla 9-75, 17012-901, Bauru, Sa˜o Paulo, Brazil
Email: etiamfob@yahoo.com
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When a titanium implant is inserted in a grafted
area, a bone-like response, in the form of high quality
osseointegration, is expected to occur.7 It is known that
xenograft materials can establish desirable connective
tissues and cancellous bone interactions during the first
stages after implant insertion; however, this configuration
may be unfavorable at later periods when implant
stability must be acquired.8,9
The microscopic responses of medullary bone to
biomaterials and titanium implants had been reported
separately and in a few short-term investigations.
3–6,10–16 In an opposite way, Ferreira et al.10
showed recently new bone formation on sinus lift
augmentation on humans 3 years after grafting and
socket’s implant insertion.
To achieve specific evidences on responses of
combined procedures, this prospective study aimed to
evaluate the influence of an inorganic xenograft filled
on rabbit’s mandible sockets on the maintenance of
alveolar vertical bone height, bone density, and the
osseointegration course following the insertion of
titanium implants.
Materials and methods
Surgical procedures
Twenty-four adult laboratory male rabbits
(Oryctolagus cuniculus), 6 months-old, weighing
between 3 and 4 kg were used for this study. All experiments
were carried out in accordance with the
European Communities Council Directive of
November 24, 1986 (86/609/EEC) regarding the care
and use of animals for experimental procedures, and
were approved by the Institutional Review Board of
Bauru Dental School, University of Sa˜o Paulo.
During the experiment the animals were put in individual
cages with specific breed and water ad libitum.
Each animal was anesthetized (ketamine hydrochloride
50 mg/kg and xylazine hydrochloride 5 mg/kg) and
underwent routine oral disinfection procedures, which
included tongue cleaning, irrigation, and rinsing with
chlorhexidine before the surgical extraction of both
bilateral lower incisors. Due to the incisive anatomy,
one 4 mm-diameter defect distally, communicating
with each alveolar socket was performed.
Next, one of the sockets, chosen at random, was
completely filled with a bovine derived cancellous inorganic
bone graft in particles of 0.5–0.75mm with slow
resorption rate (Gen-ox , BAUMER SA, Mogi Mirim,
SP, Brazil), whereas the remaining socket became filled
with blood before being closed by continuous suture.
Post-operatory medication consisted in intramuscular
injection of analgesic (ketoprofen 1 mg/kg) for 3 days
and antibiotic (tetraciclin 25 mg/kg) at the procedure
day and after 7 days.
Sixty days after the first procedures, the rabbits were
prepared for surgical insertion of 3.75 8.5mm
machined surface titanium implants (Conexa˜o
Implantes, Aruja´ , SP, Brazil) at the previously exposed
areas of the mandible (right and left sides). This size
was chosen due to the limited vertical and horizontal
rabbit’s mandible bone thickness. Under abundantly
cooled sterile saline irrigation, a guide drill was first
used to mark the implant locations. The sites were
then sequentially enlarged to 2 and 3mm in diameter
with spiral drills and were finally tapped. Post-implants
radiographs were performed to verify the implant position
(Figure 1).
After implantation, on days 0, 30, 60, and 180, six
animals of each group were killed by overdose of anesthetics
and intra-cardiac injection of potassium chloride.
The respective mandibles were immediately
removed and split in half at the mental symphysis
before being fixed in 10% neutral buffered
formaldehyde.
Radiographic evaluation
Each hemi-mandible was positioned on the sensor of
the periapical radiographic digital system (Digora,
Soredex Orion Corporation, Helsinki, Finland) using
the paralleling technique with RINN XCP positioner
(Dentsply, Elgin, Illinois, USA) and exposed to X-rays
(X-707, Yoshida Dental MFC Co. Ltd, Tokyo, Japan,
set at 70 kVp, 7 mA) with a focus–film distance of 40 cm
in a parallel direction for 0.09 s.
The evaluation of the radiographic images was
performed using Digora software (Orion Co. Soredex,
Helsinki, Finland) (Figure 2).
Figure 1. Post-implant radiograph showing adequate implant
position.
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The mean distance from the alveolar bone crest to
the implant platform (vertical bone height) was
obtained from the mesial and distal implant sides,
whereas the mean radiographic bone density (pixel
value) was measured in four areas adjacent to the
implant (two mesial and two distal).
Histological and morphometrical assessment
The specimens were dehydrated using an ascending
series of ethanol, embedded in glycolmethacrylate
(Technovit 7200 s, Heraeus Kulzer GmbH, Wehrheim,
Germany) and polymerized. Undecalcified sections of
200–300 mm were obtained in the long axis of the
implants (longitudinal), perpendicular to their threads
using Exakt Cutting-Grinding System (EXAKT
Apparatus GmbH, Norderstedt, Germany). On regular
pauses, each implant platform was measured with a
digital caliper and when the maximum diameter of
the titanium screw was confirmed (3.75 mm) at one
side, the other was successively ground to a thickness
between 70 and 100 mm, so that tissue assessment halfway
implant buccal and lingual edge could be
performed. Since de greatest part each embedded specimen
had to be grinded, just a single section could be
obtained from each specimen. Afterwards, the sections
were stained with toluidine blue 1%. Microscopically it
can be observed in all sections soft tissue of the oral
mucosa, connective tissue, and mature bone around the
threads and also biomaterial particles in experimental
group. The mature bone evidences major trabeculae
with Harversian canals and filling cones, characteristics
of bone turnover (Figures 3 and 4).
A single blind examiner performed the histometric
analysis using an image analysis system consisting of a
Zeiss Axioskop 2 microscope, Sony CCDIRIS- RGB
camera (Sony Corporation, Tokyo, Japan) and
Kontron KS-300 software (Kontron Elektronik
GmbH, Image Analysis Division, Echinf, Munich,
Germany) connected to an IBM computer, using 10
and 40 objectives.
One section representative of the implant
mid-portion was used. Due to the semi-circle format
of the rabbit’s socket, only the apical portion of the
titanium implant had certain contacted the xenograft
despite the defect performed, so the three apical titanium
threads at both sides (mesial and distal) were
selected as interest area. The digital images of three
apical titanium threads adjacent to the mesial and
distal sides of implant were obtained and the percentage
of bone-to-implant contact (BIC) defined as the
length of bone surface border in direct contact with
the implant perimeter, as well as the percentage of
bone area (BA) within the limits of the implant threads
were evaluated.
The resulting mean value of these measurements was
then used for statistical calculations.
Statistical analysis
The method of Kolmogorov and Smirnov was
used to confirm that the data were sampled from
Figure 2. Radiographic image measured on Digora Software.
Munhoz et al. 3
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a Gaussian distribution. After, the data were analyzed
with a misted two-factor analysis of variance
(ANOVA) for comparisons among time intervals and
individual comparisons between groups were executed
by means of paired t-test both adjusted to the 95%
confidence interval. Statistical analyses were performed
with SPSS software v.18 0 for windows (SPSS,
Chicago, IL, USA)
Results
Radiographic analysis
The crest to implant distances in the experimental and
control groups were not statistically different in the
intervals studied. In paired t-test there was a statistical
difference in radiographic density between the experimental
and control groups in all the time intervals, the
experimental group being higher (p¼0.0004 at day 0,
p¼0.0030 at 30 days, p¼0.0151 at 60 days, and
p¼0.0002 at 180 days).
When the time intervals were compared, the radiographic
crest to bone distances and bone density were
not statistically different (Table 1).
Histological and morphometric findings
The medullar space was occupied by bone marrow
tissue. All implants in the two groups appeared to be
osseointegrated, that is showed no soft-tissue encapsulation.
No major morphologic differences were seen
among the three groups in the cortical bone and
marrow tissues. Both endosteal and periosteal bone
proliferation was noted in all groups. The bone
Figure 3. Representative histological view of wound healing around implant in the control and experimental groups at days 0, 30, 60,
and 180. Direct bone to implant contact with some connective tissue and the presence of the biomaterial is shown. (TB stain, original
magnification 10).
Figure 4. Representative histological view of socket healing in
the experimental group. Direct interaction of the biomaterial and
bone with the presence of osteoblasts (!) and filling cones can
be observed. (TB stain, original magnification 40).
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apposition was evaluated observing bone trabeculae
volume and the presence of filling cones.
In the control group at all periods the mature bone
marrow was in direct contact with the implant and
some connective tissue, while in the experimental
group the biomaterial (inorganic bovine graft) was in
contact with the adjacent bone and eventually with the
implant, and there was some adjacent connective tissue
(Figure 3). In all time intervals, the biomaterial had
direct interaction with the adjacent bone without
fibrous encapsulation (Figure 4).
The results are summarized in Table 2. In two-way
ANOVA test there was no significant difference in the
BIC through the intervals (p¼0.1196) in the experimental
group, but in the control group there were
differences between days 0 and 60 (p¼0.0013) and
days 0 and 180 (p¼0.0039). At paired t-test the experimental
group showed significantly higher values of
BIC on day 0 compared to the control group
(p¼0.0117) and there was no difference in the other
periods (p¼0.2370 at 30 days, p¼0.6414 at 60 days,
and p¼0.7353 at 180 days).
In two-way ANOVA test the differences in BA
throughout the intervals were not statistically significant
for the control and experimental groups
(p¼0.2556). There were no significant differences in
BA detected between the control and experimental
groups in paired t-test (p¼0.1132 on day 0,
p¼0.1329 at 30 days, p¼0.9659 at 60 days, and
p¼0.2111 at 180 days).
Discussion
For clinical diagnosis, radiographic analysis is the only
objective method available for implant/graft interaction
assessment, and the ideal methods of biomechanical
and microscopy analysis are nearly unfeasible.
The criteria normally adopted to determine implant
success through radiographic analysis are the absence
of continuous radiolucency around the implant14 and
the extent of vertical bone loss, which should not
exceed 0.9mm to 1.6mm during the first year and
0.2mm in the subsequent years.13,14
When the vertical bone loss index of the control
specimens were summed throughout the tested intervals,
the total level of loss was higher than the standard
established, but similar to that presented by Hatley
et al.15 for bone regression in rabbit tibias.
The absence of significant differences in the crest to
bone distance between the experimental and control
groups, during the whole period of the experiment,
suggested that the xenograft did not promote vertical
alterations in bone height after the insertion of titanium
implants. Although this method of measurement is
routinely used as a parameter for bone healing assessment
executed after tooth extraction, periodontal treatment
and implant insertion,8,14,15–19 in this study VBH
results of the experimental group might not be relevant
for this purpose because the grafted area around the
implant was too tiny and thus not adequately plausible
for assumptions. The small buccolingual thickness of
Table 1. Data from the radiographic analysis of vertical bone height and bone density.
Periods
Vertical bone height (mm) Bone density (pixel value)
Control Experimental Control Experimental
Initial (day 0) 0.2625 0.27 0.6958 0.73 162.49 3.59a 182.78 7.79a
30 days 1.3833 2.27 1.4375 0.95 163.69 14.71b 187.07 5.18b
60 days 0.225 0.21 0.9041 1.08 160.14 17.50c 184.41 4.68c
180 days 1.016 1.79 1.5708 1.91 144.13 5.67d 181.66 10.66d
a,b,c,dStatistically significant (p 0.05).
Table 2. Data form the histomorphometrical analysis of bone implant contact (BIC) and bone mass (BM).
BIC (%) BM (%)
Periods Control Experimental Control Experimental
Initial (day 0) 36.32 11.25abc 70.31 23.02c 39.19 11.31 64.58 27.76
30 days 58.18 18.95 70.91 13.08 43.72 12.37 53.63 12.37
60 days 73.75 16.10a 69.98 21.68 54.94 18.27 55.43 18.27
180 days 69.43 9.42b 65.46 19.54 62.97 21.20 50.62 21.20
a,b,cStatistically significant (p 0.05).
Munhoz et al. 5
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rabbit’s mandible limits the creation of wider experimental
bone defects, thus even the thinnest implant
screws available provide a restricted space for graft
particles around the coronal and middle portion of
the titanium implants.
Moreover, some variation in the radiographic
distance of bone crest-to-implant shoulder (VBH) has
probably occurred since the adoption of more efficient
measures for correcting the unavoidable radiographic
distortion of the implant inserted into bone was not
feasible.
Radiographic density is positively correlated with
bone mineral deposition, and for this reason its assessment
may be used to estimate the extent of healing in
the bone adjacent to the implant.12,15,20 The difference
in radiographic bone density between groups after 180
days was already described in a clinical prospective
study using a third molar socket model.19 Possibly the
radiopacity provided by the mineral content of remaining
graft particles could explain this result. Similar findings
were described by Zitzman et al.,6 when an
analogue cancellous bovine bone-derived graft
(BioOssTM) was applied in humans and by Oltramari
et al.21 using a socket’s model in minipigs. The authors
also suggested that the inorganic part of the xenograft
particles may be resorbed after long periods; however in
this investigation, this hypothesis could not be
disproved.
Due to the semi-circle format of the rabbit’s socket,
only the apical portion of the titanium implant had
certain contacted the xenograft despite the defect
performed. Therefore, the degree of bone implant
contact was measured in both mesial and distal surfaces
of the last three threads of the screw (interest area); this
is a reliable procedure that is supported by other
investigations.13,22–28
The degree of bone-implant contact observed in this
study was comparable to the ones presented in other
studies using similar xenograft materials7,25 or higher
than that described by De Vicente et al.,23 Rahmani
et al.24 and Schwarz et al.26 The absence of significant
differences between groups when the bone-implant
contact mean values were assessed on days 30, 60,
and 180 of the experiment and the similarity to the
results of other investigations7,23–26 could indicate
that the presence of a bovine-derived inorganic graft
at the implant insertion area did not impair, at any
time, the titanium osseointegration.
The unexpected lower BIC observed in the
nongrafted controls at day 0 may be due to the characteristics
of rabbit’s osseous tissue, in other words the
expressive content of bone marrow, scanty bony trabeculae,
and the tiny cortical.29 Thus, during implant insertion
probably the inherent lower stiffness of this
structure resulted in cortical fragmentation in a way
that almost no contact of bone trabeculae to titanium
implant occurred. The fact that the experimental group
has a significantly higher BIC value at time 0 is an
important finding for the primary fixation of the
system and it can be explained by the presence of the
biomaterial that served as conductor to precocious
bone deposition at experimental sites and improved
the bone resistance.
Since bone healing went on through 180 days, no
difference in BIC was observed between groups at this
interval possibly because the inherent increase in bone
trabeculae quantity surrounding the implant in the
control group responded for this equivalence.
Our BA after 180 days results were equivalent to the
results presented by De Vicente et al.23 who used a
similar graft material (BioOssTM) in the mandibles of
dogs. However, the general BA detected in the xenograft
group was higher than that observed by Schwartz
et al.,26 who used an analogue material (BioOssTM).
Although both products were bovine derived cancellous
inorganic bone grafts and presented similar chemical
and physical properties,30 fortuitous differences in
manufacturing procedure and formula should be
taken into account.
Given the absence of significant modifications in the
BA, BIC, and BD of the experimental group from 30 to
180 days, it could be suggested that the microscopic
response of medullar mandible bone of rabbits to the
titanium implant is established in the first 30 days.
Since it is the first study to use inorganic bovine graft
associated to titanium implants at rabbit’s mandible
site, periods of 30, 60, and 180 days were performed
because there is not literature data to preview in
how much time there was osseointegration on this
grafted area.
From the initial sample of 28 animals, four presented
infection at the implantation possibly by contamination
or surgical technique error, as described by Montes
et al.31 Although those animals were discarded, the
factors may have had some influence on measured
pieces/data obtained thus being responsible for an
increase in variance (Tables 1 and 2) and the lack of
statistical difference between groups.
Clinicians should know that inorganic bovine xenograft
following tooth extraction may be a practical and
viable option to avoid an unnatural appearance of the
final crown resulting from irregular ridge anatomy after
bone remodeling. Apart from maintaining alveolar
bone architecture or providing bone gain, observed in
recent follow-up researches,10,32,33 grafting with inorganic
xenograft seems not interfere with implant
osseointegration. It should be clear; however, that the
procedures tested in combination may not be applicable
to humans and before this occurs, more specific studies
are necessary.
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Conclusion
Under the conditions of this prospective study, it can be
concluded that the use of an inorganic xenograft prior
to a titanium implant insertion did not interfere with
the course of osseointegration of titanium implants in
rabbit’s mandible.
Acknowledgments
The authors disclose any conflicts of interest. Baumer SA and
Conexa˜o Sistema de Pro´ teses Ltda kindly donated the inorganic
bovine bone and implant screws used, respectively. The
authors wish to thank FAPESP process 06/1545-7 for providing
funds for this research and to American Journal Experts
for English editing service.
References
1. Camargo PM, Lekovic V, Weinlaender M, et al.
Influence of bioactive glass on changes in alveolar process
dimensions after exodontia. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod 2000; 90: 581–586.
2. Carmagnola D, Adriaens P and Berglundh T. Healing of
human extraction sockets filled with Bio-Oss. Clin Oral
Impl Res 2003; 14: 137–143.
3. Artzi Z, Tal H and Dayan D. Porous bovine bone mineral
in healing of human extraction sockets: 2.
Histochemical observations at 9 months. J Periodontol
2001; 72: 152–159.
4. Benke D, Olah A and Mohler H. Protein-chemical analysis
of Bio-Oss bone substitute and evidence on its carbonate
content. Biomaterials 2001; 22: 1005–1012.
5. Piattelli M, Favero GA, Scarano A, Orsini G and Piattelli
A. Bone reactions to anorganic bovine bone (Bio-Oss)
used in sinus augmentation procedures: a histologic
long-term report of 20 cases in humans. Int J Oral
Maxillofac Implants 1999; 14: 835–840.
6. Zitzmann NU, Scharer P, Marinello CP, Schupbach P
and Berglundh T. Alveolar ridge augmentation with
Bio-Oss: A histological study in humans. Int J Period
Rest Dent 2001; 21: 289–295.
7. You TM, Choi BH, Li J, et al. The effect of platelet-rich
plasma on bone healing around implants placed in bone
defects treated with Bio-Oss: a pilot study in the dog
tibia. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod 2007; 103: e8–e12.
8. Meijndert L, Raghoebar GM, Meijer HJA and Vissink A.
Clinical and radiographic characteristics of single tooth
replacements preceded by local ridge augmentation: a
prospective randomized-clinical trial. Clin Oral Impl Res
2008; 19: 1295–1303.
9. Meijndert L, Raghoebar GM, Schupbach P, Meijer HJA
and Vissink A. Bone quality at the implant site after
reconstruction of a local defect of the maxillary anterior
ridge with chin bone or deproteinised cancellous bovine
bone. Int J Oral Maxillofac Surg 2005; 34: 877–884.
10. Ferreira CE, Novaes AB, Haraszthy VI, Bittencourt M,
Martinelli CB and Luczyszyn SM. A clinical study of 406
sinus augmentations with 100% anorganic bovine bone.
J Periodontol 2009; 80: 1920–1927.
11. Buser D, Weber HP and Lang NP. Tissue integration of
non-submerged implant 1-year results of a prospective
study with 100 ITI hollow-cylinder and hollowscrew
implants. Clin Oral Implan Res 1990; 1: 33–40.
12. Bragger U. Radiographic parameters for the evaluation
of peri-implant tissues. Periodontology 2000; 4: 87–97.
13. Albrektsson T, Zarb G, Worthington P and Eriksson
AR. The long-term efficacy of currently used dental
implants: a review and proposed criteria of success. Int
J Oral Maxillofac Implants 1986; 1: 11–25.
14. Albrektsson T and Isidor F. Consensus report of
session IV. In: Lang NP, Karring T (eds) Proceedings
of the 1st European Workshop on Periodontology.
London: Quintessence Publishing Co. Ltd, 1994,
pp.365–369.
15. Hatley CL, Cameron SM, Cuenin MF, Parker MH,
Thompson SH and Harvey SB. The effect of dental
implant spacing on peri-implant bone using the rabbit
(Oryctolagus cuniculus) tibia model. J Prosth 2001; 10:
154–159.
16. Choi CR, Yu HS, Kim CH, et al. Bone cell responses of
titanium blasted with bioactive glass particles. J Biomater
App 2010; 25: 99–117.
17. Blanes RJ, Bernard JP, Blanes ZM and Belser UC. A
10-year prospective study of ITI dental implants placed
in the posterior region. I: Clinical and radiographic
results. Clin Oral Impl Res 2007; 18: 699–706.
18. Kim DM, Badovinac RL, Lorenz RL, Fiorellini JP and
Weber HP. A 10-year prospective clinical and radiographic
study of one-stage dental implants. Clin Oral
Impl Res 2008; 19: 254–258.
19. MunhozEA, Ferreira Junior O, YaeduRYF and Granjeiro
JM. Radiographic assessment of impacted mandibular
third molar sockets filled with composite xenogenic bone
graft. Dentomaxillofacial Radiol 2006; 35: 371–375.
20. Dodds RA, York-Ely AM, Zhukauskas R, et al.
Biomechanical and radiographic comparison of demineralized
bone matrix, and a coralline hydroxyapatite in a
rabbit spinal fusion model. J Biomater Appl 2010; 25:
195–215.
21. Oltramari PV, Navarro Rde L, Henriques JF, et al.
Evaluation of bone height and bone density after tooth
extraction: an experimental study in minipigs. Oral Surg
Oral Med Oral Pathol Oral Radiol Endod 2007; 104:
e9–16.
22. Balatsouka D, Gotfredsen K, Lindh CH and Berglundh
T. The impact of nicotine on bone healing and osseointegration.
An experimental study in rabbits. Clin Oral Impl
Res 2005; 16: 268–276.
23. De Vicente JC, Recio O, Martı´n-Villa L, Junquera LM
and Lo´ pez-Arranz JS. Histomorphometric evaluation of
guided bone regeneration around implants with SLA surface:
an experimental study in beagle dogs. Int J Oral
Maxillofac Surg 2006; 35: 1047–1053.
24. Rahmani M, Shimada E, Rokni S, et al. Osteotome sinus
elevation and simultaneous placement of porous-surfaced
dental implants: a morphometric study in rabbits. Clin
Oral Impl Res 2005; 16: 692–699.
Munhoz et al. 7
Downloaded from jba.sagepub.com at UNIV DE SAO PAULO BIBLIOTECA on June 30, 2011
25. Therheyden H, Jepsen S, Mo¨ ller B, Tucker MM and
Rueger DC. Sinus floor augmentation with simultaneous
placement of dental implants using a combination
of deproteinized bone xenogenic and recombinant
human osteogenic protein-1. A histometric study in
miniature pigs. Clin Oral Implant Res 1999; 10:
510–521.
26. Schwarz F, Rothamel D, Herten M, et al.
Immunohistochemical characterization of guided bone
regeneration at a dehiscence-type defect using different
barrier membranes: an experimental study in dogs.
Clin Oral Impl Res 2008; 19: 402–415.
27. Nikolidakis D, Meijer GI, Oortgiesen DAW,
Walboomers XF and Jansen JA. The effect of a low
dose of transforming growth factor b1 (TGF-b1) on the
early bone-healing around oral implants inserted in trabecular
bone. Biomaterials 2009; 30: 94–99.
28. Veis AV, Trisi P, Papadimitriou S, et al. Osseointegration
of Osseotites and machined titanium implants in
autogenous bone graft. A histologic and histomorphometric
study in dogs. Clin Oral Impl Res 2004; 15: 54–61.
29. Cordioli G, Atiyeh F, Piattelli A and Majzoub Z. Healing
of transplanted composite bone grafts–implants: a pilot
animal study. Clin Oral Implan Res 2003; 14: 750–758.
30. Accorsi-Mendonc¸a T, Conz MB, Barros TC, de Sena LA,
Soares Gde A and Granjeiro JM. Physicochemical characterization
of two deproteinized bovine xenografts. Braz
Oral Res 2008; 22: 5–10.
31. Montes CC, Pereira FA, Thome´ G, et al. Failing factors
associated with osseointegrated dental implant loss.
Implant Dent 2007; 16: 404–412.
32. Arau´ jo M, Linder E, Wennstro¨m J and Lindhe J. The
influence of bio-oss collagen on healing of an extraction
socket: an experimental study in the dog. Int J Period
Rest Dent 2008; 28: 123–135.
33. Arau´ jo MG and Lindhe J. Ridge preservation with the
use of Bio-Osss collagen: a 6-month study in the dog. Clin
Oral Impl Res 2009; 20: 433–440.
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