Because the biomechanical behavior of dental implants is different from that of natural tooth, clinical problems may occur. The mechanism of stress distribution and load transfer to the implant/bone interface is a critical issue affecting the success rate of implants. Therefore, the aim of this study was to conduct a brief literature review of the available stress analysis methods to study implant-supported prosthesis loading and to discuss their contributions in the biomechanical evaluation of oral rehabilitation with implants. Several studies have used experimental, analytical, and computational models by means of finite element models (FEM), photoelasticity, strain gauges and associations of these methods to evaluate the biomechanical behavior of dental implants. The FEM has been used to evaluate new components, configurations, materials, and shapes of implants. The greatest advantage of the photoelastic method is the ability to visualize the stresses in complex structures, such as oral structures, and to observe the stress patterns in the whole model, allowing the researcher to localize and quantify the stress magnitude. Strain gauges can be used to assess in vivo and in vitro stress in prostheses, implants, and teeth. Some authors use the strain gauge technique with photoelasticity or FEM techniques. These methodologies can be widely applied in dentistry, mainly in the research field. Therefore, they can guide further research and clinical studies by predicting some disadvantages and streamlining clinical time.

Introduction

The introduction of osseointegrated implants has provided a significant improvement in the quality of life for countless edentulous patients by allowing for the replacement of missing teeth and restoration of chewing function.13  Despite this success, however, clinical problems may occur with implants because their biomechanical behavior is considerably different from that of natural teeth. The implant/bone interface demonstrates much less resilience compared with that of the tooth/bone interface.49  Although natural teeth move around 100 μm when loaded, the movement of dental implants is limited to 10 μm.10,11  Therefore, the stress created during implant-supported prosthesis insertion and masticatory function can be more directly transmitted to the bone.10  The absence of implant resilience necessitates higher precision in the planning, treatment, and fabrication of implant-borne dental appliances.12 

It is known that the mechanisms of stress distribution and load transfer to the implant/bone interface are critical issues that can affect the success rate of implants. Overload can lead to mechanical complications and bone loss.10  In addition, implant-supported prostheses present a better biomechanical behavior when no excessive occlusal force is transmitted.6 

Therefore, it is essential to understand and improve the load distribution from the prosthesis to the implants and bone.4,10  During the past three decades, researchers in this area have emphasized the importance of the biomechanical aspect of implant treatments, and they have sought to define the limit of force transmission to the implants and to develop methods to evaluate the biomechanics of dental implants.7 

Direct clinical evaluation (immediate or longitudinal) would be the surest method to analyze the biomechanical response of implant treatment. However, the complexity of the structures involved makes direct clinical evaluation of the biomechanical behavior of intraosseous structures nearly impossible, considering the difficulty of the methodology, the potential ethical issues, and the long period of time that would be required for this type of study.2,5 

To overcome these limitations, several studies have used computational, analytical, and experimental models by means of finite element analysis, photoelasticity, and strain gauges to evaluate the biomechanics of dental implants.4,1319  In order to reduce the limitations and determine the advantages of each of these methods, several studies2030  have used a combination of these methods as they have been shown to be complementary. The aim of the present study was to conduct a literature review of the stress analysis methods used to investigate the biomechanical behavior of implant-supported prosthesis and to discuss their contributions in the biomechanical evaluation of oral rehabilitation with implants.

Finite Element Method

The finite element method (FEM) was developed in the early 1960s by the aerospace industry, and its use has spread.31  In 1976, Weinstein et al32  were the first researchers to use the FEM in the implantology field. Since then, several studies have used this method to evaluate new components, configurations, materials, and shapes of implants.31,3345 

The FEM uses virtual models to simulate and test the progressive resistance and stress distribution of complex estructures. According to FEM studies,31,3345  this method enables the investigation of mechanical problems, dividing the element-problem into many smaller and simpler elements to create a mesh of elements and to solve the problem by using mathematical functions. Thus, it is possible to simulate and evaluate the biomechanical behavior of bone, implants, and prosthetic components interfaces, which would be impossible to analyze experimentally in vitro or in vivo.2,3,14,41,46,47  The FEM enables researchers to apply different loadings and to obtain the displacement and the stress levels this load causes on the tooth, prosthesis, implant, and bone.2,3,14,46,47 

The mechanical modeling of the structures can be performed in 2 or 3 dimensions. The 3-dimensional analysis allows for the development of models that are more true to real life and have complex geometry, thereby creating more consistent results.14,31,33,35,38,43 

However, the FEM has some disadvantages and criticisms. An important issue is the creation of very complex models. Some simplifications and assumptions must be made to make the solution possible, which affects the final result. Some simplifications and assumptions usually adopted in studies of dental implants are simplification of the geometry of bone or implant system assuming that the bone is homogeneous and isotropic, boundary conditions, inconsistent type of bone-implant interface, etc.3,14,35,38 

The FEM has been widely used in dental implantology as described in Table 1.

Table 1

Use of the finite element method to evaluate the stress of oral rehabilitation with implants

Use of the finite element method to evaluate the stress of oral rehabilitation with implants
Use of the finite element method to evaluate the stress of oral rehabilitation with implants

Photoelasticity

The photoelastic analysis was introduced in dentistry by Noona in 1949.48  Since then, this method has been widely used in restorative dentistry.48  In the implantology field, photoelasticity was first used by Haraldson51  in 1980 to assess the quality of fringes at different levels of implant insertion.

The photoelastic analysis technique is based on the optical property of certain colorless plastic materials that, when subjected to stress/deformation, present alterations on the refraction indices (or optical anisotropy) promoting color change.5254 

The greatest advantage of the photoelastic method is the ability to visualize the stresses in complex structures, such as oral structures, and to observe the stress patterns in the whole model, allowing the researcher to localize and quantify the stress magnitude.1,2,8,15,18,52–,55 

Experimental tests using the photoelasticity technique have been applied in several studies involving an implant-supported prosthesis2,13,15,18,51,5561  to evaluate stress distribution. This method allows for the qualitative analysis of stress through the observation of optical effects in the photoelastic models.52,54  Stresses inside the models can be measured and photographed, whereas in other analytical methods, graphs and diagrams of stress distribution must be constructed from numeric data.1,2,8,15,18,5255  The photographic records are qualitatively analyzed to investigate the propagation and intensity of stress. Most of the stress evaluations are performed visually. In 1995, Mahler and Peyton,54  described the sequence of fringes based on the values of fringe order (N) N: 0 (black), 1 (transition of red/blue), 2 (transition of red/green),3  (transition of pink/green)* as reference for comparisons between samples in vitro. The higher the N (fringe order) and fringes number are, the greater the stress intensity. And the closer the fingers are, the higher the stress concentration (Figure 1).*

Figure 1.

Stress distribution in axial load by photoelastic analysis.

Figure 1.

Stress distribution in axial load by photoelastic analysis.

According to Goiato et al15  3 techniques of photoelasticity are available: 2-dimensional, 3-dimensional, and quasi-3-dimensional (the model is 3-dimensional but the fringes are observed and analyzed in 2 dimensions). In addition, the reflection photoelasticity technique has been described.26 

In 2003, Fernandes et al26  showed the effectiveness of reflective photoelasticity as a quantitative technique, and similar stress values were noted when compared with the strain gauge technique. Thus, the authors considered reflective photoelasticity to be a valid, applicable, and necessary method to evaluate the biomechanical behavior of in vivo structures. However, this technique has had been limited study, so further studies are warranted.

Photoelasticity also presents some limitations. Because it is an indirect technique, it requires similar patterns of reproduction to be compared with clinical situations. Another factor to consider is the limit of applied external force, which may not exceed the limit of resistance of the photoelastic material; this could alter the outcome or promote material rupture.23,60,62 Although the resin used to fabricate the experimental models has an elasticity modulus similar to bone tissue, no differentiation between cortical and trabecular bones is possible, which alters the magnitude of stress induced by the load. However, not only the stress location but also the stress behavior are similar to those observed clinically.60,62 

Currently, photoelasticity has been used to evaluate stress in implant-supported prosthesis and bone tissue in several studies that simulate the mechanical-clinical situations presented in this type of rehabilitation, as shown in Table 2.

Table 2

Use of the photoelastic method to evaluate the stress of oral rehabilitation with implants

Use of the photoelastic method to evaluate the stress of oral rehabilitation with implants
Use of the photoelastic method to evaluate the stress of oral rehabilitation with implants

Strain Gauges

Strain gauges are small electric resistors that under slight deformation alter the resistance created in their current.11,64,65,66  They measure the deformation of an object where they are applied. The captured electrical signal is sent to a data acquisition board, turned into a digital signal, and read by the computer. The gauges are able to precisely record the deformation of any object subjected to stress.15,17,67,68  Strain gauges can be used to assess stress in prostheses, implants, and teeth both in vivo and in vitro.6871  Methods based on strain gauges have been used to calculate rather than measure tissue stress and strain.1  The use of a strain gauge to evaluate the stresses induced in the implants presents clinical reliability.11,17,6468  In numeric analysis, several assumption are necessary to represent the physical problem into a mathematical model, and this accuracy should be checked.72  Some authors use the strain gauge technique along with either the photoelasticity technique22,24,26,29  or the FEM.25,27,28 

However, there is no conclusive information about the ideal model to perform this type of study. Some claimed to place the strain gauges directly on prosthetic pieces,17,66  while others indicated that they placed the gauges on similar bone material.31,65,67  Strain gauges have been used extensively on bone in vivo or ex vivo and even in coagulum around immediate implants, but the measurements are limited to the area where the gauge is bonded or embedded.70,72 

The use of strain gauge to evaluate stresses induced on the implants is reliable, as observed in the literature (Table 3).

Table 3

Use of strain gauge method to evaluate the stress of oral rehabilitation with implants

Use of strain gauge method to evaluate the stress of oral rehabilitation with implants
Use of strain gauge method to evaluate the stress of oral rehabilitation with implants

Discussion

Laboratory and clinical research has shown that the clinical success and the longevity of dental implants can be controlled by biomechanical factors in most cases. Also, the load should be transmitted to the bone in a manner similar to the physiological way.110,12  Furthermore, changes in the magnitude and distribution of load can affect the quality and quantity of stress in a prosthesis/implant/bone system.4,6,10 

The biomechanical mechanisms related to implant failure remains unknown. Bone resorption, fracture, and loss of implant linked to biomechanical factors are inconclusive.4,6,7,13,23  Understanding these factors is necessary for the development and mastery of new techniques and protocols to treat edentulous patients.17,58,59 

The stress analysis as photoelastic resin model and 2- and 3-dimensional FEM are limited to a single structure. Some authors consider those methods unreliable,67,70  as they do not allow the quantification of stress. Methodologies that enable the analysis of stress generated directly on the implant-retained systems via elastic deformation, such as strain gauges, have been broadcast.4,1319,60  However, when complex geometry is involved in the analysis, it is difficult to determine the analytical solution; therefore, the FEM, by using numeric procedures, helps to solve this problem in order to understand the mechanical behavior and calculate the stress.3,14,46 

According to these studies,2,3,14,31,3347  by understanding the basic theory, method, application, and limitations of the FEM, clinicians can interpret the results of this methodology and extrapolate the results to clinical situations. In the FEM, von Mises stress distribution indicates that stress is great around the top of the implant, bone, and prosthetic structure with different intensities in different loading cases,80 as illustrated in Figure 2.

Figure 2.

The maximum equivalent Von Mises stress on the implant.

Figure 2.

The maximum equivalent Von Mises stress on the implant.

Similar to the FEM, photoelasticity can be evaluated in 2 or 3 dimensions. Additionally, both techniques require similar patterns of reproduction in order to be compared with clinical situations.

On the other hand, strain gauge analysis can be used to assess stress in prostheses, implants, and teeth both in vivo and in vitro.6871  The Reflective photoelasticity can also be used in vivo.

Based on several studies2030,72  no one method can be classified as better than the others. Thus, there is consensus among the researchers that all methods are complementary, and this association has been used as described in Table 4.

Table 4

Use of association of stress methods to evaluate the stress of oral rehabilitation with implants*

Use of association of stress methods to evaluate the stress of oral rehabilitation with implants*
Use of association of stress methods to evaluate the stress of oral rehabilitation with implants*

Conclusion

Numeric methods of stress analysis estimate stress level with high accuracy in terms of intensity and location. The FEM has been used to evaluate new components, configurations, materials, and shapes of implants. The greatest advantage of the photoelastic method is the ability to visualize the stresses in complex structures, such as oral structures, and to observe the stress patterns in the whole model, allowing the clinician to localize and quantify the stress magnitude. Strain gauges can be used to assess stress in prostheses, implants, and teeth both in vivo and in vitro. Some authors use the strain gauge technique accompanied by either the photoelasticity technique or the FEM.

These methodologies can be widely applied in dentistry, mainly in the research field. Therefore, they can guide further research and clinical studies by predicting some disadvantages and streamlining clinical time.

Abbreviation

     
  • FEM

    finite element model

References

References
1
Bernardes
SR
,
de Araujo
CA
,
Neto
AJ
,
Simamoto
P
, Junior
das Neves
FD
.
Photoelastic analysis of stress patterns from different implant-abutment interfaces
.
Int J Oral Maxillofac Implants
.
2009
;
24
:
781
789
.
2
Goiato
MC
,
Ribeiro Pdo P, Pellizzer EP, Garcia Júnior IR, Pesqueira AA, Haddad MF. Photoelastic analysis of stress distribution in different retention systems for facial prosthesis
.
J Craniofac Surg
.
2009
;
20
:
757
761
.
3
Rubo
JH
,
Capello Souza EA. Finite-element analysis of stress on dental implant prosthesis
.
Clin Implant Dent Relat Res
.
2010
;
12
:
105
113
4
Glantz
PO
,
Nilder
K
.
Biomechanical aspects of prosthetic implant-bone reconstructions
.
J Periodontol
.
2000
;
17
:
119
124
.
5
Kan
JYK
,
Rungcharassaeng
K
,
Bohsali
K
,
Goodacre
CJ
,
Lang
BR
.
Clinical methods for evaluating implant framework fit
.
J Prosthet Dent
.
1999
;
81
:
7
13
.
6
Sahin
S
,
Çehreli
MC
,
Yalçin
E
.
The influence of functional forces on the biomechanics of implant-supported prostheses—a review
.
J Dent
.
2002
;
30
:
271
282
.
7
Sahin
S
,
Çehreli
MC
.
The significance of passive framework fit in implant prosthodontics: current status
.
lmplant Dent
.
2001
;
10
:
85
92
.
8
Tanino
F
,
Hayakawa
I
,
Hirano
S
,
Minakuchi
S
.
Finite element analysis of stress-breaking attachments on maxillary implant-retained overdentures
.
Int J Prosthodont
,
2007
;
20
:
193
198
.
9
Ueda
C
,
Markarian
RA
,
Sendyk
CL
,
Laganá
DC
.
Photoelastic analysis of stress distribution on parallel and angled implants after installation of fixed prostheses
.
Braz Oral Res
.
2004
;
18
:
45
52
.
10
Skalak
R
.
Biomechanical considerations in osseointegrated prostheses
.
J Prosthet Dent
.
1983
;
49
:
843
868
.
11
Watanabe
F
,
Uno
T
,
Haia
Y
,
Neuendorff
G
,
Kirsch
A
.
Analysis of stress distribution in a screw-retajned implant prosthesis
.
lnt J Oral Maxillofac Implants
,
2000
;
15
:
209
218
.
12
Takahashi
T
,
Gunne
J
.
Fit of implants frameworks: an in vitro comparison between two fabrication techniques
.
J Prosthet Dent
.
2003
;
89
:
256
260
.
13
Celik
G
,
Uludag
B
.
Photoelastic stress analysis of various retention mechanisms on 3-implant-retained mandibular overdentures
.
J Prosthet Dent
.
2007
;
97
:
229
235
.
14
Geng
JP
,
Tan
KBO
,
Liu
GR
.
Application of finite element analysis in implant dentistry: a review of the literature
.
J Prosthet Dent
,
2001
;
85
:
585
598
.
15
Goiato
MC
,
Tonella
BP
,
Ribeiro Pdo P, Ferraço R, Pellizzer EP. Methods used for assessing stresses in buccomaxillary prostheses: photoelasticity, finite element technique, and extensometry
.
J Craniofac Surg
.
2009
;
20
:
561
564
.
16
Maeda
Y
,
Miura
J
,
Taki
I
,
Sogo
M
.
Biomechanical analysis on platform switching: is there any biomechanical rationale
.
Clin Oral Impl Res
.
2007
;
18
:
581
584
.
17
Naconecy
MM
,
Teixeira
ER
,
Shinkai
RS
,
Frasca
LC
,
Cervieri
A
.
Evaluation of the accuracy of 3 transfer techniques for implant-supported prostheses with multiple abutments
.
Int J Oral Maxillofac Implants
.
2004
;
19
:
192
198
.
18
Turcio
KH
,
Goiato
MC
,
Gennari Filho H, dos Santos DM. Photoelastic analysis of stress distribution in oral rehabilitation
.
J Craniofac Surg
.
2009
;
20
:
471
474
.
19
Van de Velde
T
,
Collaert
B
,
De Bruyn
H
.
Immediate loading in completely edentulous mandible: technical procedure and clinical results up to 3 years of functional loading
.
Clin Oral Implants Res
.
2007
;
18
:
295
303
.
20
Akça
K
,
Çehreli
MC
,
Iplikcioglu
H
.
A comparison of three-dimensional finite element stress analysis with in vitro strain gauge measurements on dental implants
.
Int J Prosthodont
.
2002
;
15
:
115
121
.
21
Akça
K
,
Çehreli
MC
.
A photoelastic and strain-gauge analysis of interface force transmission of internal-cone implants
.
Int J Periodontics Restorative Dent
.
2008
;
28
:
391
399
.
22
Brosh
T
,
Pilo
R
,
Sudai
D
.
The influence of abutment angulation on strains and stresses along the boné/implant interface: comparison between two experimental techniques
.
J Prosthet Dent
.
1998
;
79
:
328
334
.
23
Cehreli
M
,
Duyck
J
,
Cooman
M
,
Puers
R
,
Naert
I
.
Implant desing and interface force transfer. A photoelastic and strain-gauge analysis
.
Clin Oral Imp Res
.
2004
;
15
:
249
257
.
24
Clelland
NL
,
Papazoglou
E
,
Carr
AB
,
Gilat
A
.
Comparison of strains transferred to a bone simulant among implant overdenture bars with various levels of misfit
.
J Prosthodont
.
1995
;
4
:
243
250
.
25
Davis
DM
,
Zarb
GA
,
Chao
YL
.
Studies on frameworks for osseointegrated prostheses: Part 1. The effect of varying the number of supporting abutments
.
Int J Oral Maxillofac Implants
.
1988
;
3
:
197
201
.
26
Fernandes
CP
,
Glantz
PJ
,
Svensson
AS
,
Bergmark
A
.
Reflection photoelasticity: a new method for studies of clinical mechanics in prosthetic dentistry
.
Dent Mater
.
2003
;
19
:
106
117
.
27
Iplikçioglu
H
,
Akça
K
,
Çehreli
MC
,
Sahin
S
.
Comparison of non-linear finite element stress analysis with in vitro strain gauge measurements on a Morse taper Implant
.
Int J Oral Maxillofac Implants
,
2003
;
18
:
258
265
.
28
Karl
M
,
Winter
W
,
Taylor
TD
,
Heckmann
SM
.
Fixation of 5-unit implant-supported fixed partial dentures and resulting bone loading: a finite element assessment based on in vivo strain measurements
.
Int J Oral Maxillofac Implants
,
2006
;
21
:
756
762
.
29
Kim
WD
,
Jacobson
Z
,
Nathanson
D
.
In vitro stress analyses of dental implants supporting screw-retained and cement-retained prostheses
.
Implant Dent
.
1999
;
8
:
141
151
.
30
Ozçelik
TB
,
Ersoy
AE
.
An investigation of tooth/implant-supported fixed prosthesis designs with two different stress analysis methods: an in vitro study
.
J Prosthodont
.
2007
;
16
:
107
116
.
31
Yang
J
,
Xiang
HJ
.
A three-dimensional finite element study on the biomechanical behavior of an FGBM dental implant in surrounding bone
.
J Biomech
.
2007
;
40
:
2377
2385
.
32
Weinstein
AM
,
et al
.
Stress analysis of porous rooted dental implants
.
J Dent Res
.
1976
;
55
:
772
777
.
33
Akpinar
I
,
Anil
N
,
Parnas
L
.
A natural tooth's stress distribution in occlusion with a dental implant
.
J Oral Rehabil
.
2000
;
27
:
538
545
.
34
Arataki
T
,
Adachi
Y
,
Kishi
M
.
Two-dimensional finite element analysis of the influence of bridge design on stress distribution in bone tissues surrounding fixtures of osseointegrated implants in the lower molar region
.
Bull Tokyo Dent Coll
.
1998
;
39
:
199
209
.
35
Daas
M
,
Dubois
G
,
Bonnet
AS
,
Lipinski
P
,
Rignon-Bret
C
.
A complete finite element model of a mandibular implant-retained overdenture with two implants: comparison between rigid and resilient attachment configuration
.
Med Eng Phys
.
2008
;
30
:
218
225
.
36
Kitamura
E
,
Stegaroiu
R
,
Nomura
S
,
Miyakawa
O
.
Influence of marginal bone resorption on stress around an implant–a three-dimensional finite element analysis
.
J Oral Rehabil
.
2005
;
32
:
279
286
.
37
Kunavisarut
C
,
Lang
LA
,
Stoner
BR
,
Felton
DA
.
Finite element analysis on dental implant-supported prostheses without passive fit
.
J Prosthodont
.
2002
;
11
:
30
40
.
38
Lang
LA
,
Kang
B
,
Wang
RF
,
Lang
BR
.
Finite element analysis to determine implant preload
.
J Prosthet Dent
.
2003
;
90
:
539
546
.
39
Menicucci
G
.
Mandibular implant-retained overdenture: finite element analysis of two anchorage systems
.
Int J Oral Maxillofac Implants
.
1998
:
13
:
369
376
.
40
Nagassao
T
,
Kobayashi
M
,
Tsuchiya
Y
,
Nakayjima
T
.
Finite element analysis of the stresses around endosseous implants in various reconstructed mandibular models
.
J Craniomaxillofac Surg
.
2002
;
30
:
170
177
.
41
Natali
AN
,
Pavan
PG
,
Ruggero
AL
.
Evaluation of stress induced in peri-implant bone tissue by misfit in multi-implant prosthesis
.
Dent Mater
.
2006
:
22
:
388
395
.
42
Pietrabissa
R
,
Contro
R
,
Quaglini
V
,
Soncini
M
,
Gionso
L
,
Simion
M
.
Experimental and computational approach for the evaluation of the biomechanical effects of dental bridge misfit
.
J Biomech
.
2000
:
33
:
1489
-–
1495
.
43
Sertgoz
A
.
Finite element analysis study of the effect of superstructure material on stress distribution in an implant-supported fixed prosthesis
.
Int J Prosthodont
.
1997
:
10
:
19
27
.
44
Simsek
B
,
Erkmen
E
,
Yilmaz
D
,
Eser
A
.
Effects of different inter-implant distances on the stress distribution around endosseous implants in posterior mandible: a 3D finite element analysis
.
Med Eng Phys
.
2006
;
28
:
199
213
.
45
Tada
S
.
Influence of implant design and bone quality on stress/strain distribution in bone around implants: a 3-dimensional finite element analysis
.
Int J Oral Maxillofac Implants
.
2003
;
18
:
357
368
.
46
Geng
JP
,
Ma
QS
,
Xu
W
,
Tan
KBC
,
Liu
GR
.
Finite element analysis of four thread-form configuration in a stepped screw implant
.
J Oral Rehabil
.
2004
;
31
:
233
239
.
47
Akça
K
,
Iplikçioglu
H
.
Finite element stress analysis of the effect of short implant usage in place of cantilever extensions in mandibular posterior edentulism
.
J Oral Rehabil
.
2002
;
29
:
250
356
.
48
Sevimay
M
,
Turhan
F
,
Kilirslan MA, Eskitascioglu G. Three-dimensional finite element analysis of the effect of different bone quality on stress distribution in an implantsupported crown
.
J Prosthet Dent
.
2005
;
93
:
227
234
.
49
Falcón-Antenucci
RM
,
Pellizzer
EP
,
de Carvalho
PS
,
Goiato
MC
,
Noritomi
PY
.
Influence of cusp inclination on stress distribution in implant-supported prostheses. a three-dimensional finite element analysis
.
J Prosthodont
.
2010
;
19
:
381
386
.
50
Manda
M
,
Galanis
C
,
Venetsanos
D
,
Provatidis
C
,
Koidis
P
.
The effect of select pulp cavity conditions on stress field development in distal abutments in two types of fixed dental prostheses
.
Int J Prosthodont
.
2011
;
24
:
118
126
.
51
Haraldson
T
.
A photoelastic study of some biomechanical factors affecting the anchorage of osseointegrated implants in the jaw
.
Scand J Plast Reconstr Surg
.
1980
;
14
:
209
214
.
52
Caputo
AA
.
Stress analysis
.
In
:
Seminário de Biomateriais, Science Section. Abstracts
.
Los Angeles
:
UCLA School of Dentistry
:
1993
.
53
Dally
JW
,
Riley
WF
.
Experimental Stress Analysis. 4th ed
.
Tokyo
:
McGraw-Hill Kogakusha, Ltda;
2005
.
54
Mahler
DB
,
Peyton
FA
.
Photoelasticity as research technique for analyzing stresses in dental structures
.
J Dent Res
.
1955
;
34
:
831
838
.
55
Barbosa
GA
,
Bernardes
SR
,
das Neves
FD
,
Fernandes Neto AJ, de Mattos Mda G, Ribeiro RF. Relation between implant/abutment vertical misfit and torque loss of abutment screws
.
Braz Dent J
.
2008
;
19
:
358
363
.
56
Hellden
LB
,
Dérand
T
.
Description and evaluation of a simplified method to achieve passive fit between cast titanium frameworks and implants
.
Int J Oral Maxillofac Implants
.
1998
;
13
:
190
196
.
57
Kenney
R
,
Richards
MW
.
Photoelastic stress patterns by implant-retained overdentures
.
J Prosthet Dent
.
1998
;
80
:
559
564
.
58
Sadoswsky
SJ
,
Caputo
A
.
Effect of anchorage systems and extension base contact on load transfer with mandibular implant-retained overdentures
.
J Prosthet Dent
.
2000
;
84
:
327
334
.
59
Sadoswsky
SJ
,
Caputo
A
.
Stress transfer of four mandibular implant overdenture cantilever designs
.
J Prosthet Dent
.
2004
;
92
:
328
336
.
60
Ochiai
KT
,
Ozawa
S
,
Caputo
AA
,
Nishimura
RD
.
Photoelastic stress analysis of implant-tooth connected prostheses with segmented and no segmented abutments
.
J Prosthet Dent
.
2003
;
89
:
495
502
.
61
Markarian
RA
,
Ueda
C
,
Sendyk Cl, Laganá D, Souza RM. Stress distribution after installation of fixed frameworks with marginal gaps over angled and parallel implants: A photoelastic analysis
.
J Prosthodont
.
2007
;
16
:
117
122
.
62
da Silva
EF
,
Pellizzer
EP
,
Quinelli Mazaro JV, Garcia Júnior IR. Influence of the connector and implant design on the implant-tooth-connected prostheses
.
Clin Implant Dent Relat Res
.
2009
;
12
:
254
262
.
63
Pellizzer
EP
,
Falcón-Antenucci
RM
,
de Carvalho
PS
,
Santiago
JF
,
de Moraes
SL
,
de Carvalho
BM
.
Photoelastic analysis of the influence of platform switching on stress distribution in implants
.
J Oral Implantol
.
2010
;
36
:
419
424
.
64
Bassit
R
,
Lindstrom
H
,
Rangert
B
.
In vivo registration of force development with ceramic and acrylic resin occlusal materials on implant-supported prostheses
.
Int J Oral Maxillofac Implants
.
2002
;
17
:
17
23
.
65
Heckmann
SM
,
Karl
M
,
Wichmann
MG
,
Winter
W
,
Graef
F
,
Taylor
TD
.
Cement fixation and screw retention: parameters of passive fit
.
Clin Oral Implants Res
.
2004
;
15
:
466
473
.
66
Karl
M
,
Taylor
T
,
Wichmann
MG
,
Herckmann
SM
.
In vivo stress behavior in cemented and screw-retained five-unit implant FPDs
.
J Prosthodontics
.
2006
;
15
:
20
24
.
67
Cehreli
MC
,
Akkocaoglu
A
,
Comert
A
,
Tekdemir
I
,
Akca
K
.
Human ex vivo bone tissue strains around natural teeth vs. immediate oral implants
.
Clin Oral Implants Res
.
2005
;
16
:
540
548
.
68
Glantz
PO
,
Rangert
B
,
Svensson
A
,
et al
.
On clinical loading of osseointegrated implants
.
Clin Oral Implants Res
.
1993
;
4
:
99
105
.
69
Duyck
J
,
Van Oosterwyck
H
,
Sloten
JV
,
De Cooman
M
,
Naert
I
.
Influence of prosthesis material on the loading of implants that support a fixed partial prostesis: In vivo study
.
Clin Impl Dent Relat Res
.
2000
;
2
:
100
109
.
70
Koke
U
,
Wolf
A
,
Lenz
P
,
Gilde
H
.
In vitro investigation of marginal accuracy of implant-supported screw-retained partial dentures
.
J Oral Rehabil
.
2004
;
31
:
477
482
.
71
Wang
RR
,
Welsch
GE
.
Joining titanium materials with tungsten inert gas welding, laser welding and infrared brazing
.
J Prosthet Dent
.
1995
;
74
:
521
530
.
72
Eser
A
,
Akça
K
,
Eckert
S
,
Cehreli
MC
.
Nonlinear finite element analysis versus ex vivo strain gauge measurements on immediately loaded implants
.
Int J Oral Maxillofac Implants
.
2009
;
24
:
439
446
.
73
Hegde
R
,
Lemons
JE
,
Broome
JC
,
McCracken
MS
.
Validation of strain gauges as a method of measuring precision of fit of implant bars
.
Implant Dent
.
2009
;
18
:
151
161
.
74
Karl
M
,
Graef
F
,
Heckmann
S
,
Taylor
T
.
A methodology to study the effects of prosthesis misfit over time: an in vivo model
.
Int J Oral Maxillofac Implants
.
2009
;
24
:
689
694
.
75
Nishioka
RS
,
de Vasconcellos
LG
,
de Melo Nishioka
LN
.
External hexagon and internal hexagon in straight and offset implant placement: strain gauge analysis
.
Implant Dent
.
2009
;
18
:
512
520
.
76
Nishioka
RS
,
de Vasconcellos
LG
,
de Melo Nishioka
GN
.
Comparative strain gauge analysis of external and internal hexagon, Morse taper, and influence of straight and offset implant configuration
.
Implant Dent
.
2011
;
20
:
24
32
.
77
Rungsiyakull
P
,
Rungsiyakull
C
,
Appleyard
R
,
Li
Q
,
Swain
M
,
Klineberg
I
.
Loading of a single implant in simulated bone
.
Int J Prosthodont
.
2011
;
24
:
140
143
.
78
Yang
TC
,
Maeda
Y
,
Gonda
T
.
Biomechanical rationale for short implants in splinted restorations: an in vitro study
.
Int J Prosthodont
.
2011
;
24
:
130
132
.
79
Nissan
J
,
Ghelfan
O
,
Gross
O
,
Priel
I
,
Gross
M
,
Chaushu
G
.
The effect of crown/implant ratio and crown height space on stress distribution in unsplinted implant supporting restorations
.
J Oral Maxillofac Surg
.
2011
;
69
:
1934
1939
.

* References 2, 13, 15, 18, 51, 54, 55, 57, 60, 61.