SciELO - Scientific Electronic Library Online

vol.36 número2Evaluación de diferentes métodos de extracción de gADN en Candida albicans y Candida dubliniensis en muestras subgingivales en Argentina índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados




  • Não possue artigos citadosCitado por SciELO

Links relacionados

  • Não possue artigos similaresSimilares em SciELO


Acta Odontológica Latinoamericana

versão impressa ISSN 0326-4815versão On-line ISSN 1852-4834

Acta odontol. latinoam. vol.36 no.2 Buenos Aires ago. 2023  Epub 31-Ago-2023 


Precision of polyether ether ketone (PEEK) or cobalt-chrome implant bar fit to implants after mechanical cycling

Precisão da adaptação de barras tipo protocolo confeccionados em polyetheretherketone (PEEK) ou cobalto cromo sobre implante após ciclagem mecânica

1Faculdade São Leopoldo Mandic, Programa de Pós-Graduação, Campinas, Brasil


Based on its mechanical properties, PEEK (polyether-ether-ketone) might be useful in restorative procedures. In oral rehabilitation, its viability has been studied mainly for prostheses and dental implants. Aim: The aim of this study was to evaluate the fit accuracy of dental implant bars made of either PEEK or cobalt-chrome submitted to cycling mechanics. Materials and Method: This was an experimental in vitro study, where units were treated with two implants and mini-abutments, joined by cobalt-chrome or polyether-ether-ketone PEEK bars. A total 20 bars were prepared (n=10 per group) and subjected to mechanical cycling tests (1 million cycles on the distal cantilever of the bar in the vertical direction, 120N and sinusoidal loading, at a frequency of 2Hz). The fit at the abutment/implant interface was measured before and after cycling, and the counter-torque of the vertical screw of the mini abutments was measured after cycling, using a digital torquemeter. Data were analyzed by three-way ANOVA and Tukey’s test at 5% significance level. Results: No statistically significant interaction was found among the three factors considered (bar material, implant positioning and mechanical cycling) (p = 0.592). No significant difference was identified in the interaction between bar material and implant positioning (p = 0.321), or between implant positioning and mechanical cycling (p = 0.503). The association between bar material and mechanical cycling was statistically significant (p = 0.007), with the cobalt-chrome bar resulting in greater misfit with mechanical cycling. There was no difference in counter-torque values between groups. Conclusions: The PEEK bar provided better fit of the mini abutments to the implants, even after mechanical cycling. The counter-torque of the screws was similar in all scenarios considered.

Keywords: PEEK; Dental prosthesis; Mouth rehabilitation


O PEEK (Poli-éter-éter-cetona) é um material considerado para uso em procedimentos restauradores devido às suas propriedades mecânicas. Na reabilitação oral, sua viabilidade tem sido estudada principalmente para uso em próteses e implantes dentários. Objetivos: O objetivo deste estudo foi avaliar a precisão da adaptação de duas barras diferentes do tipo protocolo confeccionadas em PEEK ou Cobalto-Cromo, após serem submetidas à mecânica ciclística. Materiais e Método: As unidades experimentais foram constituídas por barras confeccionadas em Poli-ether-ether-Ketone (PEEK) e em Cobalto-Cromo (Co-Cr). Trata-se de um estudo experimental, in vitro, onde verificou-se unidades constituídas por dois implantes e mini pilares unidos com barras de Cobalto-Cromo ou PEEK. Foram confeccionados um total de 20 barras (n=10 em cada grupo) e as barras foram submetidas a ensaios de ciclagem mecânica (1 milhão de ciclos no cantilever distal da barra no sentido vertical, 120N e carregamento senoidal, a uma frequência de 2Hz). Antes e após a ciclagem realizou-se a mensuração da desadaptação na interface pilar/implante e após a ciclagem foi medido o contra-torque do parafuso vertical dos mini-pilares através de torquímetro digital TQ 8800 (LT Lutron, Taiwan). Os dados foram submetidos a ANOVA a três critérios e teste de Tukey ao nível de significância a 5%. Resultados: Constatou-se que não houve interação estatisticamente significativa entre os três fatores estudados, ou seja, entre o material da barra, o posicionamento do implante e a ciclagem mecânica (p = 0,592). Também não se identificou diferença estatística significativa da interação entre o material da barra e o posicionamento do implante (p = 0,321), nem entre o posicionamento do implante e a ciclagem mecânica (p = 0,503). Já a associação entre o material da barra e a ciclagem mecânica foi estatisticamente significativa (p = 0,007), onde a barra de Cobalto-Cromo resultou em maior desadaptação com a ciclagem mecânica. Não houve diferença nos valores dos contra-torques entre os grupos. Conclusões: Conclui-se que a barra de protocolo fabricada em PEEK proporcionou melhor adaptação dos mini pilares aos implantes mesmo após a ciclagem mecânica. Por fim, o contra-torque dos parafusos foi semelhante em todos os cenários avaliados.

Palavras-chave: PEEK; Prótese dentária; Reabilitação bucal


Science and technology are increasingly investing in implant dentistry, which is one of the main specialties requiring innovative materials 1 . One of these materials is PEEK (polyether-ether-ketone), an aromatic semicrystalline polymer developed in England in the late 1970s. PEEK is a high-perfor-mance thermoplastic material being researched in dentistry 2-5 .

PEEK has been considered for use in restorative procedures due to its mechanical properties 6 . In oral rehabilitation, its viability has been studied mainly for prostheses and dental implants. In Implantology specifically, it is studied as a potential altemative to titanium and zirconia, considering its biocompatibility and physical properties such as elasticity, resistance and radiolucency 7-9 .

PEEK has high resilience, resistance to fracture and corrosion and shock absorption, and low transmission of forces to the adjacent bone 10 , which can prevent abutment screw fractures, transmission of occlusal overloads to the marginal bone around dental implants, and bone loss 10 .

PEEK has an elastic modulus similar to that of bone, so it can absorb mechanical shocks. Prosthetic abutments and dental implants made from PEEK can therefore absorb and foster dissipation of masticatory loads to the peri-implant bone, thereby preventing implant failures 10 . Its main disadvantages are that it is bioinert, which may be a problem for osseointegration, and susceptible to stress deformation 9-10 . In thermal cycling with artificial saliva, PEEK has low retention in prostheses, especially at very acidic or very alkaline pH values 11-12 . There are few randomized controlled clinical studies to ensure effectiveness in its clinical use 9-10 .

Passive fit is one of the most important prerequisites for maintaining the implant-bone interface. To achieve a passive fit or stress-free framework, the framework should theoretically not induce stress on the implant components or surrounding bone in absence of external load application 13 . However, according to the available literature, it is practically impossible to achieve completely passive fit 13 . Prosthetic complications such as loosening or fracture of the prosthetic abutment screw, infrastructure and ceramic covering have been documented and may be related to poor fit of the framework 13 . In bone tissue, complications such as infections, oronasal communication or peri-implantitis are quite rare 14 .

In implant-supported bars, there is a direct relationship between the amount of deformation and the force of occlusion, while there is an inverse relationship with the modulus of elasticity of the framework material of the implant-supported bar 15 . The most usual techniques for making bars for protocol-type prostheses ultimately produce heavy structures and use laboratory procedures requiring extensive execution time, fostering failures in their manufacture. In this regard, PEEK could be an altemative material. However, due to the scarce evidence and protocol-type prostheses, further studies are required. Considering as a null hypothesis that PEEK promotes fit similar to that of cobalt-chrome, which is the material traditionally used, the aim of this study was to evaluate the fit accuracy of PEEK and cobalt-chrome implant bars, after being submitted to cycling mechanics.


Experimental design

This was an experimental in vitro study. Experimental units consisted of two implants and mini abutments seated on them, numbered as mini abutment I and mini abutment II, the latter being closest to the cantilever. The mini abutments were connected with bars that had two levels, one made of cobalt-chrome and other made of PEEK. The positioning of the implant/mini prosthetic abutment and bars was measured before and after dry mechanical cycling. As a dependent variable, there was an assessment of the mismatch between mini abutments I and II to cylinders made of Co-Cr alloy and PEEK and the counter-torque of the screws of the mini abutments after the dry mechanical cycling test.

Sample and master model preparation

Twenty solid rectangular bars were prepared, half of them (n=10) made of polyether-ether-ketone (PEEK), and the other half (n=10) of cobalt-chrome, to be used as a control group. Aluminum molds 30 mm long x 6.97 mm wide x 12.60 mm tall were made for fixing the implants. To guide the positioning of the two external hexagon implants (3.75 x 11mm) and 4.1mm platform (Neodent), a lathe was used to make perforations 3.5 mm in diameter in the aluminum mold.

The perforations were equidistant and parallel, with precision of one micrometer (1 pm), and numbered I and II. The implants were subsequently placed using a ratchet, and standardizad with torque of 60 (Fig. 1).

Fig. 1 Master die. Dimensions: 12.60 mm high x 30 mm long x 6.97 mm thick. The distance between implants I and II was 15.24 mm. 

HE 4.1 mini conical abutments (Neodent, Curitiba, Brazil) were installed on the implants with a regular transmucosal height of 1 mm and torque, as recommended by the manufacturer. Then, proto-col-type bars were made, a PEEK-type polymeric disc (Juvora Dental Discs, Cleveleys, UK) and a wax disc (Vitazanfabrik, Bad Sackingen, Germany) were positioned on a five-axis milling machine for machining the bars (Juvora Dental Discs, Cleveleys, UK).

After installing all the implants in the master molds with their respective mini abutments, they were scanned with a 3shape scanner, and an adapted solid body protocol-type bar project 16 was executed in the Dental System 3Shape program (Fig. 2). Ten PEEK polymer bars and ten wax bars were made in the same design, as a quadrilateral figure with dimensions 30 mm long x 6.97 mm wide x 12.60 mm tall. The wax bars were subjected to the induction casting process. The passivity of all bars was tested by visual verification in their respective metallic molds. The metal bars and polymer (PEEK) bars were screwed into the mini abutments on the implants with torque of, as recommended by the manufacturer, and then submitted to the dry mechanical cycling test.

Fig. 2 Digital design of the bars to be milled. Dimensions: 6.07 mm high x 33.3 mm long X 4.03 mm thick. 

Mechanical cycling

The cyclic load tests were performed in a device for mechanical cycling (MSFM, Elquip, Sao Carlos, SP, Brazil), dry and at room temperature, applying

1 million cycles on the distal cantilever of the bar in the axial direction, which simulates 50 years 17 . The cylinder drive speed and frequency were controlled by the control box that moved the pistons located inside these cylinders, compressing the specimens with a controlled force of 120N and sinusoidal loading, at a frequency of 2Hz 18 (Fig. 3).

Fig. 3 Loading positioning during mechanical cycling. 

Mini abutment/implant interface fit assessment

Before and after the mechanical cycles, the samples of the implant - mini abutment/bar set were positioned in a microhardness tester to measure the mismatch of the implant/prosthetic abutment interface and respective bars, with an increase of 100 times (Pantec, Campinas, SP - Brazil). Eight readings were performed, two on the anterior face and two on the posterior face of each implant/mini-abutment and bar set, totaling 80 measurements for each group of 10 sets. Two measurements were taken on each mini-plier, I and II, at the point where the bar was adapted to the mini-abutment. The other measurements were taken in exactly the same locations on the opposite side. Thus, four measurements were

taken on the anterior side and four on the posterior side, totaling eight measurements. An arithmetic mean of the measurements of each implant was used for analysis.


Before and after the mechanical cycles, the samples of the implant - mini abutment/bar set were placed in a microhardness tester (Pantec, Campinas, SP, Brazil) to measure the mismatch of the implant/ prosthetic abutment interface and respective bars, with an increase of 100 times. A TQ 8800 digital torquemeter (LT Lutron, Taiwan) was used to measure the counter-torque of the mini abutment screws after cycling and check the abutment/implant interface mismatch. All the analyses were performed by the same operator.

Statistical analysis

Fit data were checked for adherence to normal distribution. In order to investígate the effects of bar material, implant positioning and mechanical cycling, as well as the triple and dual interactions among these three factors, the three-way analysis of variance for repeated measures was used. For multiple compari-sons, Tukey’s test was used. For counter-torque val-ues, the effects of bar material and implant position-ing, non-parametric Mann-Whitney tests were used. Statistical calculations were performed using SPSS 23 software (SPSS Inc., Chicago, IL, USA), setting the significance level at 5%.


Table 1 summarizes the mean values and standard deviations of the fit between the mini abutments and the protocol-type cylinder made of PEEK or cobalt-chrome, before and after mechanical cycling. Three-way analysis of variance for repeated measurements showed that there was no statistically significant interaction among the three study factors (bar material, implant positioning and mechanical cycling) (p = 0.592). No statistically significant effect was identified between the bar material and implant positioning (p = 0.321), or between implant positioning and mechanical cycling (p = 0.503). The association between bar material and mechanical cycling was statistically significant (p = 0.007).

Table 1 Means and standard deviations of the fit (pm) between the mini abutments and the cylinder of protocol-type bars made of PEEK or cobalt-chrome, before and after mechanical cycling. 

Bar material

Before cycling

After cycling

Mini abutments I

Mini abutments II

Mini abutments I

Mini abutments II



















Table 2 shows the results of the statistically significant interaction. Both before and after mechanical cycling, the misfit was significantly greater with the cobalt-chrome bar than with the PEEK bar. Only cobalt-chrome resulted in greater misfit with mechanical cycling. For the PEEK bar, the misfit between the mini abutments and their cylinder was not significantly affected by mechanical cycling.

Table 2 Means and standard deviations of misfit (pm) between the cylinder of protocol-type bars made of PEEK or cobalt-chrome and the mini abutments, without considering their positioning, before and after mechanical cycling. 

Bar material

Before cycling*

After cycling*


6.17 Aa


5.89 Aa



7.26 Ba


9.89 Bb


The Mann-Whitney tests showed no significant difference (Table 3) in the values of counter-torque in the screws of the mini-abutments I and II with either cobalt-chrome (p = 0.257) or PEEK (p = 0.473) bars.

Table 3 Medians, means and standard deviations of the counter-torque ( of mini abutment screws, according to their positioning and the material used in making the protocol-type bar. 

Bar material

Mini abutment I

Mini abutment II


3 Aa

2.50 (1.4)

2 Aa

1.90 (1.4)


4 Aa

2.3 (5.36)

1 Aa

0.40 (3.9)


The search for alternative materials for implant-supported bars is justified by the concern about a possible release of metals from cobalt-chrome alloys into the bloodstream 3 . The present study sought to evalúate the properties of PEEK by comparing fit accuracy between PEEK and conventional Co-Cr bars. The findings refuted the null hypothesis because the experimental bar had lower misfit values.

The results demonstrated that the interaction between the bar’s composition material and the performance of mechanical cycling affected the marginal fit of the mini abutment. In this context, PEEK bars achieved better marginal fit before and even after mechanical cycling. This might be explained by the fact that PEEK has a lower modulus of elasticity and absorbs more tension, distributing the load on the bar more evenly 18-20 .

These findings complement existing evidence for use in dentistry, which point to aesthetic feasibility 21 , biocompatibility and elasticity 10 , with several studies suggesting optimistic results regarding physical, chemical and mechanical properties 19-21 . In the present study, the cantilever region was chosen because it is the most affected by masticatory forces, as noted in other studies 16, 23 . Room temperature was used without impact on the results since the critical temperature to modify the properties of PEEK is above 75 °C 24 .

PEEK is limited to use in healing abutments or prosthetic dental devices. Further, more complex investigations are needed, including histopathological studies investigating how to improve osseointegration, since PEEK is bioinert 9, 10-25 . However, it has been proven that osseointegration occurs in implants with PEEK 26 , and surface modification with laser, bioactive materials or chemical treatments has been proposed 27 .

The need for further research on protocol bars is confirmed by the fact that the literature is mainly related to overdentures. Corroborating the results of the present research, other studies have reported that structures made of PEEK provide better retention, and lower stress concentration or misfit than those made of Co-Cr alloy 20,28, 29 . Clinical and longer-term studies have shown good outcomes and patient satisfaction with PEEK 30 . Despite the lack of studies with protocol bars, the findings mentioned above suggest that PEEK is a promising material for im-plant dentistry.

In other situations, for example, when the All-on-Four® technique was used, the stress peak was higher for PEEK bars than conventional bars 31 . For zygomatic implants, there was no difference in tension between PEEK and the cobalt-chrome alloy 32 . Compressive strength was lower in PEEK bars than in nickel-chrome bars 16 .

The results of this study support the use of PEEK as an alternative for protocol bars, since it promoted a smaller misfit, being a functionally viable option, in addition to being a good aesthetic option, according to other studies 31, 33 . The differences between PEEK and cobalt-chrome bars can be explained by their surface features, regarding which the influence of particle size and uniformity, as well as the mechanical properties, have been reported 3 . Moreover, evidence is emerging that PEEK bars improve mastication performance, bite force capacity and occlusal pattern, in addition to providing greater patient sat-isfaction 34 .

The “counter-torque” response variable did not indicate any difference between materials. It is speculated that PEEK promoted the same passivity as the cobalt-chrome alloy, protecting the screw similarly. Like the current study, most studies on PEEK in oral rehabilitation are still experimental. Despite the need for larger long-term clinical studies, it is important to reinforce the evidence of experimental studies that support and increase the safety of using the material in clinical practice, which reinforces the relevance of the present study.

It is concluded that the PEEK protocol bar provided better fit of the mini abutments to the implants, even after mechanical cycling. The counter-torque of the screws was similar in all evaluated scenarios.


We acknowledge Sao Leopoldo Mandic College for support this study.


1 Valadas LAR, Oliveira Filho RD, Francischone CE, Lotif MAL, Bandeira MAM, Fonteles MMF, Simoes TC, Girao Júnior ACM, Martiniano CRQ. Prospective study of dental implantology related patents in Brazil. African Journal of Biotechnology, 2021; 20(1):9-15. ]

2 Han KH, Lee JY, Shin SW. Implant- and Tooth-Supported Fixed Prostheses Using a High-Performance Polymer (Pekkton) Framework. Int J Prosthodont. 2016 Sep-Oct;29(5):451-4. ]

3 Elawadly T, Radi IAW, El KhademA, Osman RB. Can PEEK Be an Implant Material? Evaluation of Surface Topography and Wettability of Filled Versus Unfilled PEEK With Different Surface Roughness. J Oral Implantol. 2017;43(6):456-61. ]

4 Skirbutis G, Dzinguté A, Masiliñnaité V, Sulcaité G, Zilinskas J. PEEK polymer’s properties and its use in prost-hodontics. A review Stomatologija, Baltic Dental and Maxillofacial Journal 2018; 20(2):54-8. ]

5 AL-Rabab’ah M, Hamadneh Wa, Alsalem I, Khraisat A, Abu Karaky A. Use of high performance polymers as dental implant abutments and frameworks: a case series report. J Prosthodont. 2019;28(4):365-72. ]

6 Bathala L, Majeti V, Rachuri N, Singh N, Gedela S. The Role of Polyether Ether Ketone (Peek) in Dentistry - A Review. J Med Life. 2019;12(1):5-9. ]

7 Chaturvedi TP. Allergy related to dental implant and its clinical significance. Clin Cosmet Investig Dent. 2013;5(1):57-61. ]

8 Agarwal A, Tyagi A, Ahuja A, Kumar N, De N, Bhutani H. Corrosion aspect of dental implants—an overview and literature review. Open Journal of Stomatology. 2014;4(2):56-60. ]

9 Najeeb S, Zafar MS, Khurshid Z, Siddiqui F. Applications of polyetheretherketone (PEEK) in oral implantology and prosthodontics. J Prosthod Res. 2016;60(1):12-9. ]

10 Blanch-Martínez N, Arias-Herrera S, Martínez-González A. Behavior of polyether-ether-ketone (PEEK) in pros-theses on dental implants. A review. J Clin Exp Dent. 2021;13(5):e520-6. ]

11 Fathy SM, Emera RMK, Abdallah RM. Surface Microhardness, Flexural Strength, and Clasp Retention and Deformation of Acetal vs Polyether-ether Ketone after Combined Thermal Cycling and pH Aging. J Contemp Dent Pract. 2021;22(2): 140-5. ]

12 Micovic D, Mayinger F, Bauer S, Roos M, Eichberger M, Stawarczyk B. Is the high-performance thermoplastic poly-etheretherketone indicated as a clasp material for removable dental prostheses? Clin Oral Investig. 2021;25(5):2859-66. ]

13 Sahin S; Qehreli MC. The significance of passive framework fit in implant prosthodontics: current status. Implant Dent. 2001;10(2):85-92. ]

14 Hamsho R, Mahardawi B, Assi H, Alkhatib H. Poly-etheretherketone (PEEK) Implant for the Reconstruction of Severe Destruction in the Maxilla: Case Report. Plast Reconstr Surg Glob Open. 2022;10(8):e4473. ]

15 Gonzalez J. The Evolution of Dental Materials for Hybrid Prosthesis. Open Dent J. 2014;8(1):85. ]

16 de Carvalho GAP, Franco ABG, Kreve S, Ramos EV, Dias SC, do Amaral FLB. Polyether ether ketone in protocol bars: Mechanical behavior of three designs. Journal of Interna-tional Oral Health. 2017;9(5):202. ]

17 Wiskott HW, Nicholls JI, Belser UC. Stress fatigue: Basic principles and prosthodontic implications. Int J Prosthodont 1995;8:105-16. ]

18 Markarian RA, Galles DP, Gomes Franja FM. Scanning Electron Microscopy Analysis of the Adaptation of Sin-gle-Unit Screw-Retained Computer-Aided Design/Com-puter-Aided Manufacture Abutments After Mechanical Cycling. Int J Oral Maxillofac Implants. 2018;33(1):127-36. ]

19 Schwitalla AD, Abou-Emara M, Zimmermann T, Spintig T, Beuer F, Lackmann J, Müller WD. The applicability of PEEK-based abutment screws. J Mech Behav Biomed Mater. 2016;63(1):244-51. ]

20 Villefort RF, Tribst JPM, Dal Piva AMO, Borges AL, Bi-nda NC, Ferreira CEA, Bottino MA, von Zeidler SLV. Stress distribution on different bar materials in implant-re-tained palatal obturator. PLoS One. 2020;15(10):e0241589. ]

21 Frankenberger T, Graw CL, Engel N, Gerber T, Frerich B, Dau M. Sustainable Surface Modification of Poly-etheretherketone (PEEK) Implants by Hydroxyapatite/Sil-ica Coating-An In Vivo Animal Study. Materials (Basel). 2021;14(16):4589. ]

22 Peng TY, Shih YH, Hsia SM, Wang TH, Li PJ, Lin DJ, Sun KT, Chiu KC, Shieh TM. In Vitro Assessment of the Cell Metabolic Activity, Cytotoxicity, Cell Attachment, and Inflammatory Reaction of Human Oral Fibroblasts on Polyetheretherketone (PEEK) Implant-Abutment. Poly-mers (Basel). 2021;13(17):2995. ]

23 Sertgoz A, Güvener S. Finite element analysis of the effect of cantilever and implant length on stress distribution in an implant-supported fixed prosthesis. The Journal of Pros-thetic Dentistry. 1996;76(2):165-9. ]

24 Brillhart M, Botsis J. Fatigue fracture behaviour of PEEK: 2. Effects of thickness and temperature. Polymer. 1992;33(24): 5225-32. ]

25 Kom P, Elschner C, Schulz MC, Range U, Mai R, Schel-er U. MRI and dental implantology: two which do not ex-clude each other. Biomaterials. 2015;53:634-45. ]

26 Deng Y, Zhou P, Liu X, Wang L, Xiong X, Tang Z, Wei J, Wei S. Preparation, characterization, cellular response and in vivo osseointegration of polyetheretherketone/nano-hydroxyapatite/carbon fiber temary biocomposite. Colloids Surf B Biointerfaces. 2015;136:64-73. ]

27 Almasi D, Iqbal N, Sadeghi M, Sudin I, Abdul Kadir MR, Kamarul T. Preparation Methods for Improving PEEK’s Bioactivity for Orthopedic and Dental Application: A Re-view. Int J Biomater. 2016;2016:8202653. ]

28 Mangano F, Mangano C, Margiani B, Admakin O. Combin-ing Intraoral and Face Scans for the Design and Fabrication of Computer-Assisted Design/Computer-Assisted Manufac-turing (CAD/CAM) Polyether-Ether-Ketone (PEEK) Im-plant-Supported Bars for Maxillary Overdentures. Scanning. 2019;2019:4274715. ]

29 Mangano FG, Marchiori F, Mangano C, Admakin O. Solid index and reverse implant library for the fabrication of a bar for overdenture: a proof of concept. Int J Comput Dent. 2021;24(3):331-343. ]

30 Abdraboh AE, Elsyad MA, Mourad SI, Alameldeen HE. Milled Bar with PEEK and Metal Housings for Inclined Implants Supporting Mandibular Overdentures: 1-Year Clinical, Prosthetic, and Patient+-Based Outcomes. Int J Oral Maxillofac Implants. 2020;35(5):982-9. ]

31 Jaros OAL, De Carvalho GAP, Franco ABG, Kreve S, Lopes PAB, Dias SC. Biomechanical Behavior of an Implant System Using Polyether Ether Ketone Bar: Finite Element Analysis. J Int Soc Prev Community Dent. 2018;8(5):446-50. ]

32 Heboyan A, Lo Giudice R, Kalman L, Zafar MS, Tribst JPM. Stress Distribution Pattern in Zygomatic Implants Support-ing Different Superstructure Materials. Materials (Basel). 2022;15(14):4953. ]

33 Villefort RF, Diamantino PJS, Zeidler SLVV, Borges ALS, Silva-Concílio LR, Saavedra GDFA, Tribst JPM. Mechan-ical Response of PEKK and PEEK As Frameworks for Implant-Supported Full-Arch Fixed Dental Prosthesis: 3D Finite Element Analysis. Eur J Dent. 2022;16(1): 115-21. ]

34 Montero J, Guadilla Y, Flores J, Pardal-Peláez B, Quispe-López N, Gómez-Polo C, Dib A. Patient-Centered Treatment Outcomes with Full-Arch PEEK Rehabilitation Supported on Four Immediate or Conventionally Loaded Implants. A Randomized Clinical Trial. J Clin Med. 2021;10(19):4589. ]


Received: December 01, 2022; Accepted: May 01, 2023

Corresponding Author: Eduardo V Silva Júnior

DECLARATION OF CONFLICTING INTERESTS The authors declare no potential conflicts of interest regarding the research, authorship, and/or publication of this article.

Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License