This document summarizes 4 articles related to dental implants. The first article discusses a case study of one-piece implant design and concludes that it eliminates structural weaknesses of two-piece implants and increases success rates of immediately loaded implants with high insertion torque. The second article discusses factors affecting dental implant success including biocompatibility, tissue interactions, osteointegration and surface treatments. The third article assesses bone quality for implants and categorizes bone quality into 4 types. The fourth article provides an overview of corrosion aspects of titanium and its alloys used in dental implants.

1. A Combined Report of 4
Articles Related to Implants
By – Vikram Sachan
128/04/2020

2. Outline
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3. The one-piece implant design
Prospective case report
* Eli Raviv, DMD., ** Roy Raviv, DMD,
** Jan Hanna, DMD, *** Mili Harel-Raviv, DMD.
Department of Dentistry, Sir Mortimer B. Davis Jewish General Hospital, McGill
University, Montreal, Canada.
Published - Sometime after 200928/04/2020 3

4. Goal – One piece implant case study.
Methodology –
1. Two implant dimensions used - 5mm diameter/11.5mm length and 4.2mm
diameter/11.5mm length respectively.
2. One-piece implant used in the case study, was self-tapping with sharp threads.
3. Scanned first with panoramic radiograph and then Cone Beam Computed
Tomography (CBCT) used to scan.
4. Anaesthesia was given to reduce pain during the implant installation procedure.
Conclusions –
1. The one-piece implant design was originally created to eliminate the structural
weakness built into the two-piece implant design (the micro gap).
2. To increase the success rates of immediately loaded implants the implants must
have high insertion torque and primary stability (this can be achieved by slightly
under-preparing the implant site).
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5. Advantage Disadvantage
No micro gap, therefore least chance of
bacterial colonization.
The implant angulation must be ideal as
it is not possible to correct more than a
150 error.
No loosening or fracture of the
abutment screw.
The implant abutment is not as
versatile as a two-piece abutment.
Less time-consuming procedure for
impanation.
When considering a one-piece implant
design, one must assess whether the
conventional implant criteria is met.
Increased strength due to unified
structure of implant and abutment.
Not significant over the two-piece
implant design.
Minimal early bone resorption.
Less components are used.
No alveolar bone loss.
Table 1. Advantages and disadvantages of one piece implant
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6. Outline
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7. Factors Effecting the Success
of Dental Implants
Carlos Nelson Elias
Instituto Militar de Engenharia, Biomaterials Laboratory Rio de Janeiro,
RJ, Brazil
Published -2011
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8. Goal – Discuss dental implants success effecting factors (Study report).
Introduction –
1. In order to shorten the healing time, the strategy is to alter the biocompatibility of titanium
implant surfaces, modifying the surgical technique and changing the implant design.
2. Tapered implants have a higher compression capacity than cylindrical ones.
3. Osteoblastic cells adhere more quickly to rough surfaces of titanium than to smooth surfaces.
4. By reducing the healing time, we can improve the mechanical strength of implant in bone.
Biocompatibility –
1. The main factors influencing the biocompatibility of biomaterials are chemical composition,
mechanical properties, electrical charge and surface features.
2. Soft tissue is responsible establishing a kind of seal that isolates implant and the bone from the
mouth environment.
3. Cu, Ni and V give rise to increased degradation and the degree of toxicity in the same order.
4. The behaviour of corrosion passivation is observed with Pt, Ta, Nb, Zr and Ti.
5. A high corrosion resistance does not ensure biocompatibility; the tissue reaction depends on
the concentration and toxicity of the corrosion products.
Tissue and dental implant interactions -
1. The mechanical retention is not dependent on the implant material.
2. Commercially pure (cp) titanium implants were shown to establish very close contacts with
bone.
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9. 3. The implant surface treatment positively influences the early bone healing.
Osteointegration
1. Necrosis occurs during drilling, when the temperature exceeds 47oC for 1 min.
2. Bioactive materials bond to bone tissue through bridges of calcium and phosphorus.
3. The formation and stability of new bone about the implant is a combination of resorption and
bone apposition.
Influence of movement on the osseointegration
1. The dental implant insertion torque is higher than 40 N.cm, the success rate increases.
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10. Importance of titanium oxide layer in osseointegration
1. The thickness of the oxide layer increases with time and incorporates ions of Ca, P and S from
the physiological environment.
2. The contact between the implant and the body established through a titanium oxide film;
there is no contact between metallic titanium and the body.
3. Surface topography on the submicrometric scale and oxide thickness influence the bone
response to titanium.
Interaction of cells with the biomaterial surface
1. In the case of bioinert materials (stainless steel, Co-Cr alloy, zirconia, alumina, nylon, etc.) the
body induces the formation of a capsule of fibrous tissue surrounding the biomaterial.
2. Bioactive materials (titanium, niobium and tantalum), on the other hand, induce mechanisms
that lead to osseointegration.
3. For bioreative biomaterials (hydroxyapatite, calcium phosphate, bio glass), ionic changes occur
in the body and the biomaterial is resorbed.
4. The liquid is seemed wetting when 90 < θ < 180 degrees and non-wetting when 0 < θ < 90.
When θ = 180 degrees corresponds to perfect wetting and the drop spreads forming a film on
the surface.
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11. 3. Reactions between the environment and the biomaterial surface increases
when the energy per unit area at the metal surface increases. More the
surface energy more thickness of the protein coating on the implant surface.
4. Different cell types use different mechanisms when attaching to different
surfaces and, as a rule, cells do not interact with the surface directly, but via
proteins secreted by the cells and adsorbed by the surface, forming a distinct
layer.
 Types of Dental Implants
1. The screw shape provides a large contact area between implant and bone,
increase primary stability, reduces the shear stress in the bone-implant
interface, reduces the stress concentration in the cervical region and relieves
stress concentration.
2. The rounded thread top relieves stress concentration and reduces the stress
on the bone.
3. large thread steps increase bone-implant interface shear stresses which
should be avoided because bones have a lower strength to shear than to
tension and compression.
4. The larger the number of components, the greater the possibility of failure.
5. Cylindrical implant maximizes the importance of maximum resistance to shear
stress.
6. Dimensional tolerances (implant connections) and internal and external
hexagons are important factors in designing to minimize screw loosening and
increase stability.
Fig. 5. Dental implants design.
(Courtesy of Conexão Sistemas e
Prótese, Brazil).
Fig. 6. Dental implant with external
hexagon and internal Morse taper.
(Courtesy of Conexão Sistemas e Prótese)28/04/2020 11

12.  Roughness
1. On smooth surfaces
osteoblasts seem to have
decreased adhesion, but
proliferate at a high
extent.
2. As the surface become
rougher the tendency of
cell attachment increase.
Fig. 11. Osteoblast cell
attachment on titanium
surfaces acid etched
after 20, 40 and 60
seconds. (Adapted from
Menezes et al., 2003)
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Table 2. Mean value ± SD of titanium cylinder surface roughness parameters.

13. • Wettability
Fig. 13. Effect of the implant surface
treatment on the insertion torque (N.cm).
(adapted from Santos et al., 2009).
Fig. 14. Effect of the dental implant design and
surface treatment on the insertion torque
(N.cm). (adapted from Santos et al., 2009).
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14.  Surface treatment with acid
1. Through acid etching, it is possible to control the roughness, number, size and porous
distribution on micrometre and nanometre scales.
2. Acid treatments provide homogeneous roughness, increased active surface area and improve
cells adhesion.
3. The removal torque of acid etched implants is higher than that of machined implants, which
means that the osseointegration mechanisms are faster in acid treated implants than
machined implants.
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15. Sandblasting surface treatment
1. Part of the kinetic energy of the particles is stored
in the form of crystal defects, such as dislocations,
twins and grain boundaries, and these
modifications increase the material surface energy.
The superficial layer with residual compressive
stress increases the material’s fatigue resistance.
2. The residual stress values obtained from blasting
procedures depend on both hardness and particles
size distribution.
3. Experiments showed higher values for removal
torque and bone-to-implant contact for samples
blasted with 25 μm and 75 μm sized particles
compared with those machined or blasted with
250-μm particles.
4. Strawmann ITI, Germany are sandblasted and acid
etched. Alumina particles in size 25-50 μm for sand
blast and HCl/H2SO4 for acid etched is used. The
roughness achieved was 1.98 ± 0.08 μm and
implant has Sa = 1.42 μm, waviness parameter Scx =
16.60 μm and the surface parameter Sdr increased
33%.
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16.  Surface Treatment with Fluoride
1. With high doses of fluoride, the tensile mechanical
properties of the bone are reduced.
2. The amount of new bone that formed in the voids and
the amount of bone-to-implant contact within the first 2
weeks of healing was larger at fluoride-modified implants
(test) than at TiOblast™ (control) implants.
3. The hydrofluoric acid treatment does not only change
the microstructure, but also the surface chemistry.
 Anodizing surface treatment and crystalline oxide
structure
1. Anodizing increases the thickness and change the
crystalline structure of Titanium Oxide layer on the
surface of implant.
2. The anodized surface implant has a higher polarity
compared with that of acid-treated samples, which
causes adsorption of water and molecules.
3. Incorporated calcium ions on the implant surface
increase the adhesion of human bone cells to the
implant, when compared to unmodified titanium
implants and implants with incorporated phosphate
ions.
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17. Conclusion
1. The results show that the acid etching, sandblasting and electrochemical implant surface
treatments are better than plasma spray or laser treatment. But, there is not a consensus
among researchers as to the best surface and even the shape of the implants.
2. The implants submitted to a surface treatment have a higher roughness, higher friction
coefficient and higher primary stability than the machined one.
3. The torque to install a conical implant is larger than the torque to install a cylindrical implant.
Fig. 20. X-ray diffraction pattern of the anodized titanium surface
showing the presence of titanium oxides with crystalline structure in
the form of rutile and anatase (dental implant Vulcano Actives™).
Fig. 21. Torque for removal (N.cm) and percentage of bone
contact with implant surface Mg, TiUnite™ and Osseotite™.
(Adapted from Sul et al. (Sul et al., 2006).
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18. Outline
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19. Bone Quality assessment for
Dental Implants
Ayse Gulsahi
Baskent University Faculty of Dentistry, Ankara,
Turkey
Published - 2011
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20. Bone quality and quantity
1. Bone quality is not only a matter of mineral content, but also of structure. It has been shown
that the quality and quantity of bone available at the implant site are very important local
patient factors in determining the success of dental implants. Studies revealed that Maxillary
BMD is lower than mandibular BMD.
2. Bone quality is broken down into four groups according to the proportion and structure of
compact and trabecular bone tissue. Bone quality is categorized into four groups: groups 1-4 or
type I to IV.
Type I: homogeneous cortical bone;
Type II: thick cortical bone with marrow cavity;
Type III: thin cortical bone with dense trabecular bone of good strength;
Type IV: very thin cortical bone with low density trabecular bone of poor strength.
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21. Outline
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22. An Overview of the Corrosion
Aspect of Dental Implants
(Titanium and its Alloys)
TP Chaturvedi
Professor, Division of Orthodontics and General Dentistry, Faculty of Dental
Sciences, Institute of Medical Sciences, 4GF Jodhpur Colony, Banaras Hindu
University, Varanasi 221005,
Uttar Pradesh, India
Published - 2009
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23. Goal – A study overview to corrosion effect and it’s significance of dental implants.
Full Text
High noble alloys used in dentistry are so stable chemically that they do not undergo significant
corrosion in the oral environment, the major component of these alloys are gold, palladium,
and platinum.
Clinical Significance of Corrosion
Corrosion can lead to roughening of the surface, weakening of the restoration, liberation of
elements from the metal or alloy, and toxic reactions.
The Effect of Corrosion on Dental Implants
Even though titanium alloys were exceptionally corrosion resistant because of the stability of
the TiO2 oxide layer, they are not inert to corrosive attack. When the stable oxide layer is
broken down or removed and is unable to reform on parts of the surface, titanium can be as
corrosive as many other base metals.
Fracture of Dental Implant
Titanium in a biological environment absorbs hydrogen and this may be the reason for delayed
fracture of a titanium implant.
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24. The effect of fluoride ion concentration
1. Fluoride ions are very aggressive on the protective TiO2 film formed on Ti and Ti alloys.
2. Odontogenic fluoride gels should be avoided because they create an acidic environment that
leads to the degradation of the titanium oxide layer and possibly inhibits osseointegration.
In Vitro and in Vivo studies
1. No current or change in pH was registered when gold, cobalt chromium, stainless steel, carbon
composite, or silver palladium alloys came in metallic contact with titanium. Changes occurred
when amalgam was in contact with titanium.
2. The osseointegration of the commercially pure titanium (CPTi) dental implant is improved
when the metal is shot blasted to increase its surface roughness. This roughness is colonized by
bone, which improves implant fixation.
3. Toothbrushes used in contact with titanium surfaces should be as nonabrasive as possible, and
that long lasting contamination with topical fluorides should be avoided.
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25. Outline
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26. A Critical Review of Dental Implant
Materials with an Emphasis on
Titanium versus Zirconia
Reham B. Osman and Michael V. Swain
Published - 2015
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27. Goal
To provide a comprehensive literature
review on the topic of dental implant
materials (Titanium and Zirconia).
Introduction –
The design principles of the implant should
be compatible with the physical properties
of the material.
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28. Titanium and Its Alloys
 Physical and Mechanical Properties of Titanium and Its Alloys
1. Since the Titanium implants modulus is closer to bone compare to other implant materials,
results in favorable distribution at the bone implant interface.
2. The modulus of elasticity (E) of recently developed β-phase alloys is between 55 to 85 GPa,
which is much lower than that of α + β alloys (113 GPa), yet still greater than that of cortical
bone with a value ranging between 17 and 28 GPa and cancellous bone with E values between
0.5 and 3 GPa.
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29.  Failure Mode of Titanium
1. Titanium implant fractures found the majority of fractures to be more common with 3.75-mm
diameter implants made from commercially pure Grade I titanium, supporting partially edentulous
restorations and proceeded with screw loosening.
2. The proposed mechanism of titanium implant failure is metal fatigue from high cyclic occlusal loading.
3. The galvanic corrosion between non-precious metal alloy restorations supported on titanium implants
might initiate a cytotoxic reaction, as well as potentially assist with fatigue crack initiation.
Figure 1. (a) Low magnification (×25) SEM
image of fractured titanium implant. The
crack in this instance was initiated on the
lower left edge of the implant (lower
straight arrow) and extended around the
thread, finally breaking when the cracks
overlapped on the upper right-hand side;
(b) higher magnification (×500) view of the
rectangular outlined area of the fractured
surface in Figure 1a showing fatigue
striations in a vertical pattern that mark the
crack position as it progressed.28/04/2020 29

30. Ceramics
 Ceramics as Dental Implant Coatings
1. For different bioactive materials like - calcium phosphates and bioglasses, and inert ceramics,
including aluminium oxide and zirconium oxide, different methods like plasma spraying,
sputter-deposition, sol-gel coating, electrophoretic deposition or biomimetic precipitation, can
be used to coat. Denser coatings are characterized by higher strengths and lower solubility.
2. Bioactive ceramics have been shown to release calcium phosphate ions around the implants,
resulting in enhanced bone apposition compared with the more inert ceramic and metallic
surfaces.
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31.  Mechanical Properties of Zirconia
1. Yttria stabilized tetragonal zirconia polycrystalline (Y-TZP) materials exhibits superior corrosion
and wear resistance, as well as a high flexural strength (800 to 1000 MPa).
2. The fracture strength of one-piece unloaded zirconia implants to be 512.9 N versus 410.7 N
after artificial loading.
3. There is no influence of crown preparation on the reliability of one-piece zirconia implants at
loads under 600 N.
4. Grinding or sandblasting, can trigger a tetragonal to monoclinic transformation in the surface
region which increase the volume (~4.5%) that induces surface compressive stresses.
 Low Temperature Degradation
1. Low-temperature degradation (LTD), also known as ageing, occurs by a slow surface
transformation in the presence of water or water vapor.
2. When the microcracked and damaged zone reaches the critical size for slow crack growth to
proceed, degradation in mechanical properties of the material will occur.
3. The addition of alumina to zirconia hinders ageing and drastically reduces its kinetics, which
results in a more stable structure, outstanding mechanical and tribological properties.
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32. Failure Mode of Zirconia
1. A reduced implant diameter of 3.25 mm, associated with a higher bending moment results in
implant fracture during functional loading.
2. Peri-implant bone resorption increases the crown to implant ratio, resulting in an increase in
bending moment induced forces.
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33. Osseointegration of Y-TZP versus Titanium Dental Implants
1. Animal investigations showed that zirconia implants undergo osseointegration similar to or
even better than that of titanium implants.
2. The removal torque values were significantly higher for surface-modified zirconia and titanium
implants compared to machined-surface implants, with no significant difference regarding
bone-to-implant contact between the two different materials.
3. Sandblast-roughened ZrO2 implants enhanced the bone stability and achieved a higher stability
in the bone compared to machined-surface implants.
4. The peri-implant bone formation and mechanical stability of surface-modified zirconia implants
with sandblasted and acid-etched titanium implants and found similar degrees of bone implant
contact and bone volume density for all of the implants. However, titanium implants were
found to have a higher removal torque resistance, probably due to the difference in the surface
roughness.
5. Coating the surface of Y-TZP implants with bioactive glass was also reported to accelerate bone
healing and to improve the osseointegration process.
6. The surface roughness of zirconia improves initial bone healing and resistance to removal
torque.
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34. Peri-Implant Soft Tissues around Zirconia and Titanium Implants
1. Zirconia implants and abutments provide a very good peri-implant soft tissue interface that
achieves an irritation-free attachment.
2. Better healing response, less inflammatory infiltrate and reduced plaque adhesion on zirconium
oxide discs compared to conventionally pure titanium.
3. The zirconium oxide surfaces showed a significant reduction in bacterial adhesion when
compared to the titanium specimens.
4. The results revealed higher values of VEGF, NOS, MVD and greater extension of inflammatory
infiltrate with a subsequently higher rate of inflammation-associated processes in the titanium
specimens compared to that of zirconium oxide specimens.
5. Ti and ZrO2 surfaces displayed similar biological properties in terms of protein adsorption,
biofilm composition and bacterial adherence.
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35. Clinical Studies, Case Reports and Case Series on Zirconia Implants
1. Zirconia implants, five years with a reported survival rate of 74%–98% after 12–56 months and
success rates between 79.6% and 91.6% after 6–12 months of prosthetic restoration.
2. The increased radiographic bone loss of more than 2 mm around ceramic implants in 1 year
make impossible its recommendation for clinical use.
3. The results revealed overall success rates of 92%–95% over follow-up periods ranging from 2.5
to five years, with excellent aesthetic and functional results.
Conclusion
Mechanical properties and clinical success and failure rates of zirconia implant compared with
titanium implant presented in the article is outstanding. But due to less availability of data and
mechanical test results still questions its full potential.
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36. 28/04/2020 36
Any Questions

37. 3728/04/2020