a histomorghometric study of screw-shaped and removal torque titanium implants with three different...

A histomorghometric study of screw-

shaped and removal torque titanium

implants with three different surface

topographies

ALI ALENEZI

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

The aim of the study:

To investigate bone response in relation to well defined

surface over short time of follow-up.

Turned surfaceBlasted with TiO2

25µm particles

Blasted with Al2O3

75µm particles

Surface quality

One of the six factors that influence the biological response to implant ( alberktsson et al. 1981)

The remaining 5 factors:

• Implant biocompatibility

• Implant design

• State of host bed

• Surgical Technique

• Loading conditions

Surface quality

Implant biocompatib

ility

Implant design

State of host bed

Surgical Technique

Loading conditions

Osseointegration

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).

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).

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

The blasting process

Basic due

(renfert, Germany)

After blasting process, all

the implants cleaned

ultrasonically in

trichloroethylene and 70%

ethanol

Surface topography

examination

Optical profilometer, topscan 3D .

Non contact mode

Visual images

Numerical values for surface roughness.

240x245 μm measurement area

Surface roughness parameters

In this paper, 7 different height parameters used

to describe the roughness.

RaThe arithmetic mean of departures of the roughness profile

from the mean lines

Rqthe root mean square parameter corresponding to Ra

Rtthe maximum peak to valley height in the evaluation area

RskThe measures of the symmetry of the profile

RkuThe measures of the sharpness of the surface profile.

∆ qthe root mean square slope of the surface

π qthe root mean square measure of spacings between local

peaks and valleys

Surgical technique

1 rabbit = 6 implants

RIGHT LEFT

FEMUR Al2O3 turned

PROXIMAL

TIBIA

TiO2 turned

DISTAL TIBIA TiO2 turned

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.

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.

ResultsThe blasting procedure was responsible for

decreasing the (outer &core) diameter of implants

ResultsRemoval torque values necessary to remove the

screws after 12 weeks:

In femur:

Screw blasted with Al2O3 > turned.

In tibia:

Screw blasted with TiO2 > turned.

Results

Histomorphometric analysis:

- Bone metal contact % :

Higher for TiO2 25-µm

implants compared

with turned implants.

Results

Histomorphometric analysis:

- Bone surface area:

Greater bone area for turned

implants when compared

with TiO2-blasted implants

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.

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.

Thank you