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 Table of Contents  
ORIGINAL ARTICLE
Year : 2022  |  Volume : 19  |  Issue : 3  |  Page : 105-109

Effect of different framework materials on stresses induced at the implant/bone interface in all-on-four implant treatment concept: three-dimensional finite element analysis


1 Department of Dental Biomaterials, Modern University for Technology and Information, Cairo, Egypt
2 Department of Mechanics, Giza Systems, Cairo, Egypt

Date of Submission15-Apr-2022
Date of Decision20-May-2022
Date of Acceptance05-Jun-2022
Date of Web Publication14-Sep-2022

Correspondence Address:
Ahmed M Sayed
PhD, Modern University for Technology and Information, Al Gamea Al Haditha Street, 5th District, El.Hadaba El.Wosta, Mokatam, Cairo
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/tdj.tdj_10_22

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  Abstract 


Background and aim
Treatment of mandibular edentulous ridge with all-on-four treatment concept is a reliable choice. However, the framework material may affect the stresses transmitted to the implant and bone.
The aim of the study was to compare stresses transferred to implant–bone interface on using glass fiber-reinforced composite (GFRC), zirconia (Zr), titanium (Ti) and poly-ether-ether-ketone (PEEK) as framework materials.
Patients and methods
Three-dimensional finite element model of completely edentulous mandible restored with four implants (two axial anterior implants and two posterior implants 30° distally tilted) connected with a framework of different materials (Zr, Ti, GFRC, and PEEK) was constructed. A unilateral axial load of 250 N was applied at the distal end of the cantilever and the resultant von Mises stresses at implant–bone interface were calculated.
Results
The lowest von Mises stresses at implant/crestal bone area was recorded with Zr framework followed by Ti then GFRC while the highest von Mises stresses were recorded with PEEK framework.
Conclusions
Within the limitations of this study, it could be concluded that the stiffer framework material transmits more stresses to the implants. The stress distribution of GFRC, as a framework material, is better than PEEK.

Keywords: all on four, finite element analysis, framework, glass fiber-reinforced composite, implants


How to cite this article:
Sayed AM, Abdelazim IA. Effect of different framework materials on stresses induced at the implant/bone interface in all-on-four implant treatment concept: three-dimensional finite element analysis. Tanta Dent J 2022;19:105-9

How to cite this URL:
Sayed AM, Abdelazim IA. Effect of different framework materials on stresses induced at the implant/bone interface in all-on-four implant treatment concept: three-dimensional finite element analysis. Tanta Dent J [serial online] 2022 [cited 2023 Jan 31];19:105-9. Available from: http://www.tmj.eg.net/text.asp?2022/19/3/105/356076




  Introduction Top


After restoring the edentulous patients, especially with atrophied residual ridges, with a complete denture, they reported suffering from many complications related to complete denture such as function, retention, phonetics, pain and excessive salivation [1],[2]. However, implant supported restorations improved this unpleasant condition as they reported a significantly more patient satisfaction as a result of their better function, esthetics, phonetics, retention, and comfort [3],[4],[5].

Unfortunately, alveolar bone resorption limits the placement of dental implants on the posterior regions due to presence of vital structure such as mandibular canal that contains inferior alveolar nerve. Therefore, in 2003, Malo and his colleagues proposed the all-on-four treatment concept to avoid insertion of the posterior implants. This concept involves using of four implants in the anterior region of the jaws; the two most anterior implants are straight while the most posterior implants are angulated with 30–45° [6],[7],[8].

The definite restoration of the all-on-four treatment concept could be a removable overdenture or a fixed bridge over a framework. The framework may be fabricated from different alloys as gold alloy, cobalt–chromium, titanium (Ti) or non-metallic materials as zirconia (Zr), poly-ether-ether-ketone (PEEK) and poly-ether-ketone-ketone [9]. Due to difference in the modulus of elasticity of these materials, different stress distribution patterns had been obtained at the peri-implant–bone and at the framework [10],[11],[12],[13]. Stress distribution may be assessed in-vitro by photo-elastic models, strain gauges and virtually by finite element analysis (FEA) [10],[11],[12],[13],[14],[15].

Glass fiber-reinforced composites (GFRC) showed promising mechanical, optical and biological properties that allowed their uses in the field of dentistry. They used for fabrication of fixed partial prothesis, temporary fixed crown and bridges, endodontic posts, orthodontic retainers, and periodontal splints [16].

Many manufacturers supplied the GFRC in machinable CAD-CAM disks which give a possibility for machining a framework for all-on-four restoration. However, the stress distribution patterns still a question.

Stress distribution pattern within complex structures as implant supported prostheses is a complicated process. Due to the difference in the geometry of jaw bones, implants, abutments and definitive prosthesis in addition to the difference in material properties of the entire system and complex masticatory force, FEA can be a consistent analyzing tool of the stress distribution patterns [17].

Consequently, this study was conducted to evaluate the stress distribution pattern at peri-implant–bone due to load application over the GFRC framework and compare them with the stresses developed with Zr, Ti and PEEK material.


  Material and methods Top


Modeling of the mandible

A three-dimensional geometrical model of a completely edentulous mandible was created from a cone beam computed tomography scan of a completely edentulous patient with the aid of Mimics 21.0 software (Materialise, Belgium). The bone segments were modeled as an outer shell of cortical bone with 2 mm thickness and an inner volume of cancellous bone.

Modeling of implants and frameworks

The implants and the denture frameworks were created using SOLIDWORKS CAD software (DS Solidworks Crop., USA). The implants were designed as a threaded with a diameter of 4 mm and length 16 mm. The implants were inserted in edentulous mandible and distributed according to all-on-four concept. The two most anterior implants are placed axially, whereas the two posterior implants were placed tilted 30° distally to the crest of the ridge and multi-unit abutments were connected to implants.

The framework was designed as a solid bar of 5 mm in thickness, 6 mm in width and following the curvature of the mandible and with 2 mm away from the crest of the ridge. The distance between each two implants was 21 mm and with 16 mm distal cantilever extension [Figure 1] [12].
Figure 1: Model of the mandible with implants and bar with all-on-four concept.

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Material properties

The used materials were assumed to be isotropic, homogenous and linearly elastic with properties listed in [Table 1].
Table 1: Properties of the used materials

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Defining meshing

The assembly was meshed by tetrahedral mesh element with parabolic edges to produce a high-quality solid mesh that produced a total number of nodes equals 1 238 571 nodes and a total number of elements equals 837 484 element [Figure 2]a.
Figure 2: (a) Meshing of the geometric model. (b) Axial load application.

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Defining contacts and gaps between components

The fixation of the three-dimensional model was performed at the distal part of the assembly to prevent movements in the 6-degrees of freedom.

Load application

An axial static load of (250 N) was applied onto the most distal part of the bar cantilever extension [Figure 2]b.

Resultant stresses

Von Mises' equivalent stresses were selected as they are most commonly reported in FEA studies to summarize the overall stress state at a point [12]. Consequently, von Mises stress distribution pattern was calculated at the implant–bone interface after load application with each framework material. The resultant stresses from FEA calculations were based on Euler–Bernoulli equation and method of weighted residuals.


  Results Top


The highest von Mises stresses at implant–bone interface for both anterior and posterior implants were represented in [Table 2] and [Figure 3].
Table 2: Maximum von Mises stresses (MPa) at the crestal bone for anterior and posterior implants with different framework materials

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Figure 3: Stress distribution patterns at the crestal bone/implant interface with different framework materials.

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For all tested framework materials, the highest stresses were detected at the areas of the two posterior implants than anterior one.

Zr framework material has reported the lowest stresses at both anterior and posterior implants compared to the other three (Ti, GFRC, and PEEK) studied materials 36.758 and 178.207 MPa, respectively.

Slightly higher von Mises stresses were detected in Ti than Zr framework 42.673 and 203.223 MPa, followed by GFRC 58.964 and 277.804 MPa.

On the other hand, PEEK framework had reported the highest stresses at both anterior and posterior implants 77.066 and 409.459 MPa, respectively.


  Discussion Top


The all-on-four dental implant concept provides a reliable treatment option for patients with atrophic residual ridges either by high patient satisfaction or clinical success rate [4],[18]. However, the prosthetic materials play a significant role in the stresses and strains developed at implant–bone interface [10],[11],[12],[13],[19].

The present study had utilized FEA to evaluate the stress distribution pattern in four framework materials with different mechanical properties at the implant/bone interface in mandibular all-on-four implant treatment concept.

FEA had been utilized as a noninvasive preliminary evaluating method that can predict the behavior of the materials without any morbidity to patients [17]. Moreover, FEA is an appropriate technique for measuring complex structures that cannot be standardized clinically [10],[17],[19].

The angulation of the distal abutment was set at 30° with accordance with previous FEA studies [11],[12],[20].

The cantilever length was 16 mm and the load was applied at the most distal part of the cantilever to maximize the stresses over the implant as it was reported the proportional relation between cantilever length and stresses over the implants [21],[22].

The equivalent stresses developed at the cortical bone plates surrounding the anterior straight implant and posterior angled implant were evaluated with four different framework materials.

The results of this study had shown that the least von Mises stresses at implant/crestal bone interface were created with Zr framework followed by Ti then GFRC. However; the highest stresses were noticed on using PEEK as framework material.

This finding may be due to high the modulus of elasticity of the Zr framework material followed by Ti and GFRC. This may be due to the fact that materials with high elastic modulus may induce high internal stresses but better stress dissipation to the adjacent prosthetic structures and less stresses transmitted onto the implant/bone interface.

However, the highest stresses induced at the implant/bone interface with PEEK framework material that having low elastic modulus. This finding agreed with previous studies reported that high stresses were induced at the crestal bone on using framework materials with low elastic modulus as PEEK or poly-ether-ketone-ketone compared to other materials that have higher elastic modulus such as cobalt–chromium, Ti, and Zr [10],[11],[12],[19],[23],[24].

Lee et al. [23], had reported that the framework material with low elastic modulus may induce less internal stresses but has poor stress dissipation and transmit more stresses to adjacent prosthetic structure with subsequent lower long-term safety.

Therefore, the using GFRC with its intermediate modulus of elasticity, between PEEK and Zr, affords a suitable solution for making a framework with appropriate internal stress and stress dissipation ability. Moreover, its lower density, compared with Zr and Ti leading to lower weight which is more favorable criterion for the patient to have a lighter restoration.

Regarding the stress distribution pattern at the anterior and posterior implants, the results of the present study revealed increase in the stresses at the posterior implant. This is in correspondence with other studies [11],[19],[25]. The higher the stresses induced onto bone, the more bone resorption [25].

This finding may agree with Korsch et al. [26] had reported more biological and severe complications in posterior implants compared to anterior implants when they follow up all-on-four success rate.

The limitations of the FEA in the current study include considering the anisotropic tissues, like bone, as isotropic material. The applied load was performed as a unilateral static load while the actual load has a dynamic behavior.

Moreover, the tilting of posterior implant was set at 30° while in clinical situation the angle of the posterior implant may be set up to 45°. Furthermore, the design considered that the contact between implant and bone is 100% which is impossible in the clinical scenario.

Within the limitations of the current study and regarding all-on-four treatment concept, it may be concluded that:

  1. The stiffer framework material, the less stresses transmitted to the implants.
  2. GFRC, as a framework material, has better stress distribution than PEEK and lower density than Zr and Ti which enables it as a reliable solution.


Acknowledgements

The authors thank Prof. Azza Farahat for her technical support.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Manikantan NS, Balakrishnan D, Joseph S, Manojkumar AD. Post insertion problems in complete denture prosthodontics – a survey of frequency of different types. Int J Recent Sci Res 2018; 9:27233–27235.  Back to cited text no. 1
    
2.
Sharma A, Singh R, Sharma R, Dhanda A, Neha, Thakur V. Post insertion problems in complete denture: a review. IP Ann Prosthodont Restor Dent 2020; 6:189–193.  Back to cited text no. 2
    
3.
Wang Y, Bäumer D, Ozga AK, Körner G, Bäumer A. Patient satisfaction and oral health-related quality of life 10 years after implant placement. BMC Oral Health 2021; 21:30.  Back to cited text no. 3
    
4.
Abdou ELsyad M, Elgamal M, Mohammed Askar O, Al-Tonbary YG. Patient satisfaction and oral health-related quality of life (OHRQoL) of conventional denture, fixed prosthesis and milled bar overdenture for all-on-4 implant rehabilitation. A crossover study. Clin Oral Implant Res 2019; 30:1107–1117.  Back to cited text no. 4
    
5.
Bajunaid SO, Alshahrani AS, Aldosari AA, Almojel AN, Alanazi RS, Alsulaim TM, Habib SR. Patients' satisfaction and oral health-related quality of life of edentulous patients using conventional complete dentures and implant-retained overdentures in Saudi Arabia. Int J Environ Res Public Health 2022; 19:557.  Back to cited text no. 5
    
6.
Singh R, Sharma S, Sultan K, Dadwal R, Kaushal A, Mongra A. Concept of all on four for dental implants: a review. IP Int J Maxillofac Imaging 2020; 6:93–96.  Back to cited text no. 6
    
7.
Shakhawan MA, Zanyar MA, Rebwar AH, Hawbash OM, Rozhyna PK, PaymanKh M. All-on-four treatment concept in dental implants: a review articles. Surg Case Stud 2019; 2:4.  Back to cited text no. 7
    
8.
Taruna M, Chittaranjan B, Sudheer N, Tella S, Abusaad M. Prosthodontic perspective to all-on-4® concept for dental implants. J Clin Diagn Res 2014; 8:ZE16–ZE19.  Back to cited text no. 8
    
9.
Soto-Penaloza D, Zaragozí-Alonso R, Penarrocha-Diago M, Penarrocha-Diago M. The all-on-four treatment concept: systematic review. J Clin Exp Dent 2017; 9:e474–e488.  Back to cited text no. 9
    
10.
Mohamed S. A finite element analysis of stress distribution in all on four system using different framework materials in the mandible. Egypt Dent J 2020; 66:2423–2430.  Back to cited text no. 10
    
11.
Dayan SC, Geckili O. The influence of framework material on stress distribution in maxillary complete-arch fixed prostheses supported by four dental implants: a three-dimensional finite element analysis. Comput Methods Biomech Biomed Engin 2021; 24:1606–1617.  Back to cited text no. 11
    
12.
Kelkar KC, Bhat V, Hegde C. Finite element analysis of the effect of framework materials at the bone–implant interface in the allonfour implant system. Dent Res J 2021; 18:1.  Back to cited text no. 12
  [Full text]  
13.
Shetty R, Singh I, Sumayli HA, Jafer MA, Abdul Feroz SM, Bhandi S, et al. Effect of prosthetic framework material, cantilever length and opposing arch on peri-implant strain in an all-on-four implant prostheses. Niger J Clin Pract 2021; 24:866–873.  Back to cited text no. 13
[PUBMED]  [Full text]  
14.
Papathanasiou I, Kamposiora P, Papavasiliou G, Ferrari M. The use of PEEK in digital prosthodontics: a narrative review. BMC Oral Health 2020:20:217.  Back to cited text no. 14
    
15.
Herráez-Galindo C, Torres-Lagares D, Martínez-González Á-J, Pérez-Velasco A, Torres-Carranza E, Serrera-Figallo M-A, et al. A comparison of photo elastic and finite elements analysis in internal connection and bone level dental implants. Metals 2020; 10:648.  Back to cited text no. 15
    
16.
Shivakumar S, Kudagi VS, Talwade P. Applications of finite element analysis in dentistry: a review. J Int Oral Health 2021; 13:415–422.  Back to cited text no. 16
  [Full text]  
17.
Safwat EM, Khater AGA, Abd-Elsatar AG, Khater GA. Glass fiber-reinforced composites in dentistry. Bull Natl Res Cent 2021; 45:190.  Back to cited text no. 17
    
18.
Gurrala S, Dhupar V, Akkara F. All-on-4 dental implant concept in immediate rehabilitation of failing dentition – a prospective study to evaluate the efficacy and cost effectiveness in Indian population. J Dent Health Oral Disord Ther 2020; 11:12–16.  Back to cited text no. 18
    
19.
Tribst JPM, Campanelli de Morais D, Melo de Matos JD, Lopes GDRS, Dal Piva AMO, Souto Borges AL, et al. Influence of framework material and posterior implant angulation in full-arch all-on-4 implant-supported prosthesis stress concentration. Dent J (Basel). 2022; 10:12.  Back to cited text no. 19
    
20.
Kaya İ, Tuğcu F. Evaluation of stress distribution on all-on-four concept and conventional implant designs: 3D finite element analysis. Balk J Dent Med 2021; 46–52.  Back to cited text no. 20
    
21.
Kumari A, Malhotra P, Phogat S, Yadav B, Yadav J, Phukela SS. A finite element analysis to study the stress distribution on distal implants in an all-on-four situation in atrophic maxilla as affected by the tilt of the implants and varying cantilever lengths. J Indian Prosthodont Soc 2020; 20:409–416.  Back to cited text no. 21
  [Full text]  
22.
Deste G, Durkan R. Effects of all-on-four implant designs in mandible on implants and the surrounding bone: a 3-D finite element analysis. Niger J Clin Pract 2020; 23:456–463.  Back to cited text no. 22
[PUBMED]  [Full text]  
23.
Lee KS, Shin SW, Lee SP, Kim JE, Kim JH, Lee JY. Comparative evaluation of a four-implant-supported polyetherketoneketone framework prosthesis: a three-dimensional finite element analysis based on cone beam computed tomography and computer-aided design. Int J Prosthodont 2017; 30:581–585.  Back to cited text no. 23
    
24.
Villefort RF, Diamantino PJS, Zeidler SLVV, Borges ALS, Silva-Concílio LR, Saavedra GDFA, et al. Mechanical response of PEKK and PEEK as frameworks for implant-supported full-arch fixed dental prosthesis: 3D finite element analysis. Eur J Dent 2022; 16:115–121.  Back to cited text no. 24
    
25.
Liu X, Pang F, Li Y, Jia H, Cui X, Yue Y, et al. Effects of different positions and angles of implants in maxillary edentulous jaw on surrounding bone stress under dynamic loading: a three-dimensional finite element analysis. Comput Math Methods Med 2019; 17; 2019:8074096.  Back to cited text no. 25
    
26.
Korsch M, Walther W, Hannig M, Bartols A. Evaluation of the surgical and prosthetic success of All-on-4 restorations: a retrospective cohort study of provisional vs. definitive immediate restorations. Int J Implant Dent 2021; 7:48.  Back to cited text no. 26
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]
 
 
    Tables

  [Table 1], [Table 2]



 

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