| Histologic
Findings in Sinus Augmentation with Autogenous Bone Chips Versus
a Bovine Bone Substitute (*) |
|
 Purpose:
The aim of this study was to compare a bovine bone substitute
(Bio-Oss) to autogenous bone with respect to its value as a material
for sinus augmentation.
Materials
and Methods: In 10 beagle dogs 12 months of age, the 3 maxillary
premolars were extracted on both sides. Six weeks later, 2 cavities
of predefined size were produced in the region of the nasal cavity.
The antral window was 25 mm long and had a vertical extension of
7 mm. Two Frialit-2 implants (3x8 mm) were placed in each bone defect
(n = 20). Every implant was primarily stable because of fixation
in native bone. In each maxilla, 1 bone defect was filled with autogenous
bone harvested from the mandible and 1 was filled with Bio-Oss (material
selected at random). The animals were sacrificed at 90 and 180 days,
and histologic specimens were examined and the results subjected
to statistical analysis by the Wilcoxon test for paired observations.
Results:
No healing problems were observed. Histologically, after 90 days
the volume of the augmentation showed a reduction of 14.6 ±
4.4% within the Bio-Oss group and 3.8 ± 2.5% in the group
with autogenous bone. Bone-implant contact of 52.16 ± 13.15%
in the Bio-Oss group and 60.21 ± 11.46% in the autogenous
bone group was observed. At 180 days, the Bio-Oss group showed bony
ingrowth of the substitute, whereas in the autogenous group a differentiation
from original bone could no longer be made. The volume reduction
was 16.5 ± 8.67% in the Bio-Oss group and 39.8 ± 16.14%
in the autogenous group. Bone-implant contact of 63.43 ±
19.56% in the Bio-Oss group and 42.22 ± 12.80%
in the autogenous bone group was measured.
Discussion
and Conclusion: The results indicated that because of the nonresorptive
properties of the bone substitute Bio-Oss, regeneration of the defects
is achievable. It was demonstrated that the bone substitute seemed
to behave as a permanent implant. The volume of the area augmented
by autogenous bone decreased over the observation period.
| 
|
| Flow
chart of the experimental design.
|
| |
| Drawing
of sinus augmentation procedure.
|
| |
| A
site augmented with Bio-Oss. (Left) After elevation of the
sinus floor and implant placement; (right) after augmentation
with Bio-Oss.
|
| |
|
| Illustration
of the region of interest for the measurement of implant-bone
contact. |
Histologic specimen used for measurement of implant-bone contact
(red arrows indicate zones without contact; magnification
x 1.25). |
| 
|
|
| Histologic
specimen augmented with Bio-Oss at 180 days shows minimal
resorption (red arrows indicate resorption zones; magnification
x 1.25). |
Specimen
augmented with autogenous bone at 180 days showing maximal
resorption (red arrows indicate resorption zones; magnification
x 1.25). |
| |
|
|
 |
| Key
words: bone resorption, bone substitutes, dental implants,
maxillary sinus, osseointegration. |
Karl
Andreas Schlegel, DDS, MD
Gabriele Fichtner, DDS
Stefan Schultze-Mosgau, DDS, MD, PhD
Jörg
Wiltfang, DDS, MD, PhD
|
|
| (*)
Extraido de la revista "The International Journal of ORAL
& MAXILLOFACIAL IMPLANTS" - 2003;18:53-58 |
|
|
|
|
volver
atrás
|
Notas
Anteriores
|
|
| Bone
Healing Following Immediate Versus Delayed Placement of Titanium
Implants into Extraction Sockets: A Prospective Clinical Study
(*) |
Purpose:
The aim of this study was to compare bone healing and crestal
bone changes following immediate (Im) versus delayed (De) placement
of titanium dental implants with acid-etched surfaces (Osseotite)
in extraction sockets.
Materials
and Methods: Forty-six patients were randomly allocated to
the Im or De group (n = 23 per group) and
received 1 implant at the incisor, canine, or premolar region
of the maxilla or the mandible. The implants were placed and average
of 10 days following tooth extraction in the Im group and approximately
3 months after extraction in De group. The widths (parallel and
perpendicular to the implant) and the depth of marginal bone defects
around the implants were measured clinically just after placement
and 3 months later at the abutment surgery. The crestal bone changes
mesially and distally to the implants were evaluated radiographically
by linear measurements.
Results:
The survival rates were 91% in the Im group and 96% in the De
group. In the Im group, the mean reductions in parallel width,
perpendicular width, and depth of the largest defect of each implant
amounted to 48% (from 4.4 to 2.3 mm), 59% (from 2.2 to 0.9 mm),
and 48% (from 6.9 to 3.6 mm), respectively. The corresponding
mean reductions in the De group amounted to 39% (from 3.1 to 1.9
mm), 77% (from 1.3 to 0.3 mm), and 34% (from 4.4 to 2.9 mm). The
reduction over time was statistically significant in both groups
(P<.04). For both groups, a higher degree of bone healing was
achieved in the infrabony defects (> 60% for depth) than in
dehiscence-type defects (approximately 25%). Furthermore, 70%
of the 3-wall infrabony defects with a parallel width of up to
5 mm, a depth of maximum 4 mm, and a perpendicular width of maximum
2 mm had a capacity of spontaneous healing within a period of
3 months.
Discussion
and Conclusion: New bone formation occurs in infrabony defects
associated with inmediately placed implants in extraction sockets.
|
| Healing
of a 3-wall infrabony defect following immediate placement
of the implant. |
| 
|
|
| Before
implant placement. |
Immediately
after implant placement. |
| 
|
|
| Radiograph
taken 1 week after implant placement. |
At abutment operation. |
| |
|
| Radiograph
taken immediately after abutment connection. |
Definitive restoration. |
| |
| Dehiscence-type
defect that did not heal following immediate placement of
the implant. |
| 
|
|
| Before
implant placement. |
Immediately
after implant placement. |
| 
|
|
| Radiograph
taken 1 week after implant placement. |
At abutment operation. |
| |
|
| Radiograph
taken 1 week after abutment operation. |
Definitive restoration. |
| |
|
|
|
| Key
words: dental implants, immediate implant placement, osseointegration,
tooth extraction, wound healing. |
|
Lars
Schropp, DDS
Lambros Kostopoulos, MS, DDS, PhD
Ann Wenzel, DDS, PhD, Dr Odont
|
|
| (*)
Extraido de la revista "The International Journal of ORAL
& MAXILLOFACIAL IMPLANTS" - 2003;18:189-199 |
| |
|
|
| |
volver
atrás
|
Notas
Anteriores |
|
