Oral implant surfaces part 1 /certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


ORAL IMPLANT
SURFACES;PART 1 REVIEW
FOCUSING ON
TOPOGRAHIC AND
CHEMICAL PROPERTIES OF
DIFFERENT SURFACES
AND INVIVO RESPONSES
TO THEM

ABSTRACT
 This article reviews the topographic and

chemical properties of different oral implant
surfaces and in vivo responses to them
 The article consider detailed
mechanical,topographic,and physical
characteristic of implant surfaces. anchorage
mechanisms such as biomechanical and
biochemical bonding are examined


INTRODUCTION



The surface quality will determine tissue reactions to an oral
implant.
Surface quality may be divided in to 3 categories
1.mechanical properties
2.topographic properties
3.physicochemical properties



SUL et al2002-anodizing an implant lead to change in surface
roughness as well as alteration of oxide crystallinity and embedding
of ions in the surface



MORRA et al2003-machined implants display a lower concentration
of titanium on the surface and a higher concentration of carbon
that’s in sandblasted, acid etched, or plasma sprayed

ASPECTS OF SURFACE QUALITY
MECHANICAL PROPERTIES
 Relates to potential stress on the surface that
may result in increased corrosion rate and wear
relating to hardness of material
 KOHO 1990 related decreased fatigue strength
of implant surfaces with porous coating
 MCKELLOP1995described a technique to
minimize wear is ion implantation
 Wear is related to strength of material, but also
surface roughness

TOPOGRAPHIC PROPERTIES
 The surface topography relates to the degree

of roughness of surface and orientation of
surface irregularities
 The original BRANEMARK implant was
turned screw of minimal surface roughness
between 0.5 and 1 in sa value-gold standard
 In mid 1990s implant roughness of 1.5 shows
stronger bone response than turned,
smoother and rough plasma sprayed
implants-WENNERBERG 1996

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
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Potential drawback of roughening the implant surface
include greater problem with peri-implantitis (BECKER
2000 AND ASTRAND 2000) and a greater risk of ion
leakage.greater surface roughness greater tissue
implant contact and hence ionic leakage.
ALBEIT related to very rough (more than 2 sa) plasma
sprayed implants
Moderately roughened surfaces (Tioblast screw) shows
no incidence of peri implantitis and maintained bone
height. Majority of commercially availlable implants are
moderatlyroughened.


CHARACTERISTIC OF IMPLANT
SURFACES






O.o4-smooth-machined experimental abutments-no
benefits
0.5-1-minimal roughness- turned,osseotite,before1995longest clinical document-not for untrained surgeons
1-2-moderatly rough-tio blast, SLA, TiUNITE,Fralit-2,
most implants today-stronger bone response, better
clinical results-only short clinical follow up
more than 2- rough- plasma sprayed titanium, hydroxy
apatite coated-positive 5yr documentation, increased
incidence of peri implantitis in 2 studies

 Currently considerable interest is in nano

structure.
 WOJICIAK1998-study on nanotopographies.
 Macrophage cell lines react to microgrooves at
the nanometer level
 RICE2003-no significant effects in cell adhesion
 WENNERBERG2000- for clinical purpose the
relevant way is to describe an oral implant
surface by referring to its micro sized
irregularities.

PHYSICAL CHARACTERISTICS

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Physical characteristic refers to factors such as surface
energy and charge.
HENCH AND ETHRIDGE 1982-surface energy is a
measure of extent to which bonds are unsatisfied at the
surface.
A surface with high energy has a high affinity for
adsorption i.e. stronger osseointegration
BAIER1982-glow discharge treatment result in high
surface energy as well as implant sterilization
BAIER1986-high surface energy influences protien to
form an advantageous primary coat on implants

 HENCH1982- practical way to measure surface

energy is contact angle measurements
 Hydrophobic or hydrophillic
 Wettability of surface(BAIER1986)
 the hypothesis that implants with high surface
energy results in stronger osseointegration was
not verified. High surface energy changed
immediately when implants are changed from
glow discharge container to patient through air.

ANCHORAGE MECHANISM OF
ORAL IMPLANTS
 Many oral implants companies

launch
new products claiming unique bioactive
surfaces. Hence the focus has shifted
from surface roughness to surface
chemistry.

 Opinion on bone anchorage and emphasis

on biochemical bonding


BIOMECHANICAL BONDING
 A turned titanium implant,such as the

original Branemark screw, is anchored
to bone through in growth into small
irregularities of the implant surface by
biomechanical bonding.
 Thus osseointegration depends on
biomechanical bonding.
 Blasted acid-etched and other
moderately roughened implants show a
stonger bone response than turned
devices.




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The potentially negative aspect with biomechanical
bonding is that it is time consuming .
There are weeks of delay before bone has started to
grow into surface irregularities of the implant.
Before bone interlocking ,the implant is dependent on its
macro design for retention.
Bone needs a minimum of 50 to 100 micrometer pores
for proper growth.
Irregularities of atleast of 1micrometer may be invaded
by bone ,although complete Haversian system need a
large space.-WENNERBERG2000

 Electropolished titanium surfaces

of roughness
similar to abutments do not become properly
osseointegrated-CARLSSON1988,
BURSER1991
 The strongest biomechanical bonds are seen to
surfaces of roughness of about 1.5 micrometer
whereas rougher, plasma-sprayed implants
shows weaker bone ingrowthWENNERBERG1996

BIOCHEMICAL BONDING


Bioactivity is the charecteristic of an implant material which allows it
to form a bond with living tissues.



OSBORN AND NEWESLY1980- titanium is bioinert material
Potential chemical bonding between implant and host tissues was
first suggested by HENCHet al 1970and referred then to a certain
glass-ceramic composition and its reaction to the host tissues.





Instead ,calcium phosphate ceramics were launched as potentially
bioactive surface coatings for titanium implants HULBERT et al
1990



Bioactive implants in addition to chemical bonding show
biomechanical anchorage also.


 Commercially pure titanium (cp) in its native form

is only capable of biomechanical bonding,
chemical modifications of cp titanium may lead to
a bioactive material.
 Surface modifications have consisted of NaOH
and heat treatment( KIM AND
SKRIPITIS1998)or, ion implantation with calcium
or anodizing with electrolytes containing
phosphorus ,sulphur,calcium(HANAW1991)
magnesium ions(SUL 2002)







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Two types of implant surfaces are potentially bioactive
1.surface represented by calcium phosphate coated
implants
2.flouridated osseospeed implants (Ash tech) implants.
oxidized surfaces are bioactive. whether there is any
evidence of oxidised
TiUnite implants being bioactive
has been nvestigated- SUL 2002
Failed to explain any bioactivity on oxidised surface with
embedded phosphorous ions


CALCIUM PHOSPHATE COATED
IMPLANTS




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

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LEGEROS2002 –Calcium phosphate has similarities to bone
mineral. They form bone apaite like mineral or carbonate HA on
their surfaces
They are able to promote cellular function, leading to formation of
strong calcium phosphate interface and they are osteoconductive
and may bind to bone morphogenic protein to become
osteoinductive
JARCO et al1977- were the first to present indication of direct bone
bonding to HA.
NEO AND OGEOS 1992 believe that calcium phosphate has
bioactive capacities
It is hypothetised that inter facial bone mineral like carbonated
apatite layer is formed by ion dissoltion from bio ceramic material
(DUCHYENE 1999)
(JANSEN 2003) other potential mechanism include direct effect
from ca and phosphorus concentration and high affinity of growth
factor

FLUORIDATED IMPLANTS


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Introduced by FILLINGSEN 1995
Push out tests
flouridated implants sustained
Indication of bioactivity
JOHANSSON et al 2002 – greater bone contact 1-3
months
ELLINGSEN 2003- rabbit, blasted intermediate rough
implants with and with out fluoridating of surfaces.
Fluoridated, blasted implants show higher removal
torque than blasted

EVIDENCE FOR A BIOACTIVE
IMPLANT SURFACE
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HENCH 1971- TISSUE COALESCENCE-this theory is based on
high power trans electron micrography demonstrating that the tissue
floats in to the surface of the biomaterial
the distance is so small that biochemical bonding is possible
DAVIESet al 1990- similar inter facial morphology between bioactive
HA and cp titanium when implant is removed rupture occurs
This occurs not at interface but in the bone
tissue(ELLINGSEN1995)
hence finding bone on the implant surface is conclusive of
biomechanical inter locking.
CHEMICAL EVIDENCE such as formation of calcium carbonate
apatite layers on the calcium phosphate ceramic
implants(DACULSI1990)


ORAL IMPLANT SURFACES
SUGGESTED TO BE
OSSEOATTRACTIVE



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

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Do not use bio active
510k designation substantial equalization may be denied
and then prospective , RCT must be performed before
sale
Lack proper 5 yr clinical trial
OSSETITE ACID ETCHED IMPLANTS- give rise to a
particular fibrin retention that allows osteogenic cell to
migrate to implant surface,enabling what DAVIES1998
calls “De Novo bone formation”.
Seen in novel cellpllus implant.

 SLA implant and DPS implant surface-

blasted and etched, moderately
roughened
 TiUnite implant-anodised,oxide thickness
of 1000nm, porous
 Osteoattractive-moderatly
roughened,more attractive to bone
formation

DOPED SURFACES
 Implant surfaces have been doped with

potentially bone stimulating factors such as
BMP or other bone growth factors
 Hypothetical solution for future
 FRANKE-STENPORT2002- external
application of growth factors have effect in
ordinarily placed oral implants.
 WIKEJSO2002- observation does not
contradict evidence of positive effect of BMP
in cases with lack of bone support- resorbed
ridges

TO CONCLUDE…




.

Moderately roughened surfaces have some clinical advantages
compared to the turned smoother and rougher plasma sprayed
surfaces
bioactive implants may present some promise for future



Infact it seems probable that improvement in surgical technique will
present good prospect for improving clinical results.



Some surgeons have fewer good clinical results than others working
with the same implants
this is an important observation to avoid being misled by the
commercial side of oral implantologist; who things that osteoattrative
surface modifications are claimed as the only way to improve clinical
success




THANK YOU


Oral implant surfaces part 1 /certified fixed orthodontic courses by Indian dental academy

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Oral implant surfaces part 1 /certified fixed orthodontic courses by Indian dental academy