1. A histomorghometric study of screw-
shaped and removal torque titanium
implants with three different surface
topographies
ALI ALENEZI

2. The authors
• A. Wennerberg, T. Albrektsson, B. Andersson, J. J. Krol.
• Published by: Clinical Oral Implants Research
Volume 6, Issue 1, pages 24–30, March 1995

3. The aim of the study:
To investigate bone response in relation to well defined
surface over short time of follow-up.
Blasted with TiO2
Turned surface
25µm particles
Blasted with Al2O3
75µm particles

4. Surface quality
One of the six factors that influence the biological response to
implant ( alberktsson et al. 1981)
Surface
quality
The remaining 5 factors:
• Implant biocompatibility Loading Implant
biocompatib
conditions ility
• Implant design
• State of host bed Osseointegration
• Surgical Technique Surgical Implant
Technique design
• Loading conditions
State of
host bed

5. The concept of surface quality
It includes:
All Surface properties
(mechanical, physical, chemical, topographical).
The influence of surface quality on implant integration
investigated in many studies at that time (1980s &1990s).

6. Implant surface roughness
- better bone-forming capability around rough implant in
compared with smooth ones ( carlsson et al. 1988).
The suggested explanations:
1- more advantageous stress transfer.
2- better mechanical interlocking (kasemo 1983).

7. Materials and methods
The implant have been characterized in to 3 different
topographies.
10 new Zealand rabbits.
60 screw shaped commercially pure titanium.
Implants length; 6mm, diameter: 3.75, pitch height: 0.6mm
Surface topography Number of implants
Turned surface 30
Blasted with TiO2 particles, with a diameter 25µm 20
Blasted with Al2O3 particles, with a diameter 75µm 10

8. The blasting process
Basic due
(renfert, Germany)
After blasting process, all
the implants cleaned
ultrasonically in
trichloroethylene and 70%
ethanol

9. Surface topography
examination
Optical profilometer, topscan 3D .
Non contact mode
Visual images
Numerical values for surface roughness.
240x245 μm measurement area

10. Surface roughness parameters
In this paper, 7 different height parameters used
to describe the roughness.
Ra The arithmetic mean of departures of the roughness profile
from the mean lines
Rq the root mean square parameter corresponding to Ra
Rt the maximum peak to valley height in the evaluation area
Rsk The measures of the symmetry of the profile
Rku The measures of the sharpness of the surface profile.
∆q the root mean square slope of the surface
πq the root mean square measure of spacings between local
peaks and valleys

11. Surgical technique
1 rabbit = 6 implants
RIGHT LEFT
FEMUR Al2O3 turned
PROXIMAL TiO2 turned
TIBIA
DISTAL TIBIA TiO2 turned

12. Torque measurement and
histomorphometrical analysis
For torque measurement:
40 implants (20 from femur and 20 from distal tibia).
Slowly increasing torque was gradually applied until loosening of
implant.
For histomorphometrical analysis:
20 implants ( proximal tibia)
Cutting & grinding by (Exakt equipments)
10 μm section thickness.
To measure: 1- % bone to metal contact.
2- The amount of bone area.

13. Results
Turned screws :
exhibited the smoothest surface
Surface with clear direction of irregularities.
Screws blasted with TiO2:
More homogenous surface.
Increased roughness.
Screws blasted with Al2O3:
the roughest surface.
homogenous surface.

14. Results
The blasting procedure was responsible for
decreasing the (outer &core) diameter of implants

15. Results
Removal torque values necessary to remove the
screws after 12 weeks:
In femur:
Screw blasted with Al2O3 > turned.
In tibia:
Screw blasted with TiO2 > turned.

16. Results
Histomorphometric analysis:
- Bone metal contact % :
Higher for TiO2 25-µm
implants compared
with turned implants.

17. Results
Histomorphometric analysis:
- Bone surface area:
Greater bone area for turned
implants when compared
with TiO2-blasted implants

18. discussion
The implants that been treated with blasting
procedures show higher removal torque values and
higher percentage of contact bone to the metal
surface.
On the other hand,,,
Turned implants had more bone surface area after 12
weeks.

19. In this study:
The same surgical instrument were used for all implants,
which not have the same exact diameter (the blasting
process cause a minor reduction).
But, the blasted implants showed better interfacial healing
response.
Furthermore, we have different surface irregularities
between blasted and turned implants.
Its short term results. Not to be generalized especially
For clinical reality.

20. Thank you