This document discusses a study evaluating osteoblastic activity on zirconia discs with different surface treatments. It is divided into three groups: Group I (no surface treatment), Group II (sandblasting and acid etching), and Group III (UV radiation). SEM analysis found Group I had few parallel lines and pits/cracks, Group II had a porous surface with prominent changes, and Group III had lines/pits/cracks. Results showed Group I had few osteoblastic cell colonies, Group II had more colonies, and Group III had the maximum number of colonies. The conclusion was that UV photofunctionalization (Group III) promoted the best osteoblast adhesion and activity compared to the other groups.

1. DR ROSELINE MESHRAMKAR
PROFESSOR & HEAD
DEPARTMENT OF PROSTHODONTICS
SDM COLLEGE OF DENTAL SCIENCES AND HOSPITAL
DHARWAD, INDIA

2. INTRODUCTION
 Dental implants have been accepted as a predictable and reliable
treatment modality for the rehabilitation of both partially and completely
edentulous patients.
 Titanium implants have so far been the material of choice in implant
dentistry. However the grey colour of titanium impairs esthetic results
particularly in presence of thin gingival type.
 Recently , Zirconia has been widely used as dental implant substrate due
to its excellent properties like high flexural strength and fracture
toughness , optimal esthetics and high biocompatablity.

3.  The success of endosseous implants are
directly related to principle of osseointegration,
a process of implant bone interaction that led to
Bone to implant anchorage.
 It is a biological fixation of implant relating to
direct bone to implant contact without an
intervening connective tissue layer.
 Surface properties of biomaterial play a
Fundamental role of osseointegration process.
 Different approaches are being used to effort
to improve surface properties of zirconia.They
are airborne particle abrasion , acid etching with
Hcl or hydrofluoric acid, plasma spraying,
Aggregation of bioactive material such as
Hydroxyappatite.

4. OBJECTIVES OF THE STUDY
 To evaluate the osteoblastic activity of zirconia
without surface treatment. (Group I).
 To evaluate the osteoblastic activity of zirconia
with surface treatment. (etching) (Group II).
 To evaluate the osteoblastic activity of zirconia
with surface treatment UV radiation (Group III).
 To compare and evaluate the surface roughness
and osteoblastic activity between all the groups.

5. MATERIAL AND METHODS
60 Machined Zirconia discs of 2mm diameter and
1.5mm thickness were processed -20 discs per
group
GROUP I - No surface treatment (control)
GROUP II - Surface treatment with
•sandblasting (Aluminium oxide)
•acid etching (Hydrofluoric acid)
GROUP III - Surface treatment with UV Radiation

6. CELL CULTURE –For osteoblastic activity HOS(Human
osteoblastic sarcoma) were seededon test material at density
of 1x104 cm/cm2 and incubated at 37 C under humidified
atmosphere containing 5% Co2 after 48 hours.Cell seeded
Test material is fixed with 2.5% glutaraldehyde
MATERIAL AND METHODS
SEM ANALYSIS- Dry specimen mounted on a stud
using adhesive and epoxy resin, splutter coated with
gold before examining it with microscope.It is done
before and after cell culture.
Magnification-500 x 5000
SEM ANALYSIS

7. GROUP I- Control
Without Surface treatment-We can see few
parallel
lines, pits and cracks
GROUP II-Surface treated with
etching and Sandblasting- Porous
surface with prominent surface
Changes with elevations and
depressions
GROUP III-Surface treated with
UV Radiation- surface had lines, pits and
cracks
RESULTS

8. RESULTS
GROUP I- Control
Without Surface treatment
Osteoblastic activity seen with very
Few colonies
GROUP II-Surface treated with
etching and Sandblasting
Osteoblastic activity with
More colonies seen
GROUP III-Surface treated with
UV Radiation
Osteoblastic activity with maximum
number of colonies seen

9. Scarano et al, in 2003 examined the bone-implant interface of machined
zirconia implants at 4 weeks of healing and reported BIC values of 68.4%.
Akagawa et al,observed a BIC ratio of 66% to 81% for zirconia implants inserted
into mandible of monkeys after 24 months of healing which was similar to that of
zirconia implants at the 12-month observation.In our study zirconia samples
without surface treatment had osteoblastic cell adherence.In our study,zirconia
samples without surface treatment had osteoblastic adherence.
Deprich in 2008 demonstrated increase osseointegration with acid etched
zirconia which is similar to our findings where we observed increased
oseoblastic activity with surface treated with both sand blasting and
etching shown
DISCUSSION

10. Hisbergus et al in 2009 demonstrated that acid etching of zirconia
Do not provide surface roughness,which is in contradiction with our study
Gahlert et all, 2007 reported that osseintegration capacity of machined
zirconia surface can be substantially increased after modification by Al2O3
sand blasting.Our findings were in accordance with this study.
Kohal et al in 2008 and Andreotelli et al in2009 in their report suggested
that low thermal degradation will weaker the surface stability of zirconia
materials thus possibly leading to promotion failure of sand blasted
implant.
DISCUSSION

11. Liu et al in 2005 demonstrated that zirconia posess photo catalytic
activity when exposed to UV light by removal of hydrophobic layer
of hydrocarbons from the surface of the material..
In our study we found that there was increased osteoblastic activity after UV
Radiation which is in accordance with study conducted byAtt et al in 2009 , UV
light treatment transformed the zirconia surface from hydrophobic to hydrophilic
status.It has been Particularly challenging to enhance the osteoconductive
capacity of zirconia by its surface topographical modification.
Recently, ultraviolet (UV)-mediated photo functionalization of titanium
implants has been proposed to enhance the adhesive property of titanium
to the bone. Photofunctionalized implants showed a near 100% BIC
and three times the strength of osseointegration in animal models.
DISCUSSION

12. CONCLUSION
 The cell adhesion in Group I Samples
were having less spread of
Osteoblastic cells and had fewer
osteoblastic cell colonies
 Group II Samples were having more
distinct spread of osteoblastic cells
Than group I.However they had fewer
osteoblastic cell colonies
 The cell adhesion seen in group III
(UV Photofunctionalisation) were
showing more prominent osteoblast cells
that was scattered throughout the
Sample and showed better adhesion as
compared to Group I and Group II
SCOPE FOR THE STUDY
 Further research to be done to focus on
Material changes after surface treatment
 Effect of UV light on invivo on
osteoconductive potential of zirconia
should be the target of exploration
 Further animal studies should be carried
out
LIMITATIONS
 This being an invitro study cannot
fully translate into invivo conditions
 Invivo conditions tissue response has
to be evaluated
 Intraoral conditions will also be
different.

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