Indian Journal of Dental ResearchIndian Journal of Dental ResearchIndian Journal of Dental Research
Indian Journal of Dental Research   Login   |  Users online:

Home Bookmark this page Print this page Email this page Small font sizeDefault font size Increase font size         


Table of Contents   
Year : 2014  |  Volume : 25  |  Issue : 1  |  Page : 32-35
Analysis of the surface deformation of dental implants submitted to pullout and insertion test

1 Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirao Preto, Sao Paulo, Brazil
2 Department of Biomechanics and Orthopaedics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
3 Teacher at the University of Uberaba, Uberaba, Minas Gerais, Brazil

Click here for correspondence address and email

Date of Submission14-Dec-2012
Date of Decision23-Apr-2013
Date of Acceptance19-Jan-2014
Date of Web Publication21-Apr-2014


Objective: The aim of the present study was to evaluate the possible deformations in the surface of dental implants submitted to pullout and insertion test in polyurethane synthetic bone, using scanning electron microscopy.
Material and Methods: Four different types of implants were used: Master Screw, Master Porous, Master Conect AR and Master Conect Conical (n = 8). These implants were into the femoral head synthetic bone (Synbone) and removed through the pullout test, performed with a universal testing machine (EMIC MEM 2000). All the screws, before and after the mechanical tests, were micro structurally analyzed in a Scanning Electron Microscope (SEM - Zeiss EVO50), utilizing a magnification of 35 times. The results were subjected to ANOVA and Tukey tests (α =0.05).
Results: Only the Master Conect Conical and Master Porous implants presented statistically significant difference to pullout and maximum deformation (P = 0.014 and P = 0.009, respectively). The SEM images did not show morphological changes of the implants when compared before and after the mechanical tests.
Conclusion: We concluded that Master Porous presented higher pullout resistance, suggesting a greater primary stability.

Keywords: Dental implants, osseointegration, scanning electron microscopy, torque, traction

How to cite this article:
da Costa Valente ML, Shimano AC, Mazzo CR, Lepri CP, dos Reis AC. Analysis of the surface deformation of dental implants submitted to pullout and insertion test. Indian J Dent Res 2014;25:32-5

How to cite this URL:
da Costa Valente ML, Shimano AC, Mazzo CR, Lepri CP, dos Reis AC. Analysis of the surface deformation of dental implants submitted to pullout and insertion test. Indian J Dent Res [serial online] 2014 [cited 2023 Sep 23];25:32-5. Available from:
The clinical success of oral rehabilitation with dental implants depends mainly on the osseointegration, defined by Branemark in 1977 [1] as the direct microscopic contact of bone-implant interface without the interposition of fibrous tissue over a significant portion of it. However, for this to occur it is necessary to take into account biological factors, such as bone quantity and quality, and mechanical factors, such as the primary stability, responsible for preventing the micro movement of the implant in the bone site, promoting natural healing and effective bone formation. [2],[3],[4],[5]

Considering the primary stability as one of the pre-requisites for osseointegration, it is necessary to evaluate and control the factors that directly affect in this condition, as the surgical technique used, the bone type, the implant geometry and the surface treatment. [6],[7],[8],[9]

Despite the surface treatment be extensively studied by researchers, the implants geometry is still a underexplored factor in the literature and deserves special attention, since changes in the implant body design and on its surface can increase the treatments success, by the promotion of increased surface area and bone/implant contact, induction of bone growth and load distribution, thus allowing maximum surface anchorage, insertion with lower bone trauma and resistance to insertion and removal torques. [10],[11],[12]

The morphology involves several factors related to the implants such as shape, size, type, number, depth and screw-thread and the screws prosthetic connection. [13],[14] Thus, the dentist must be able to choose the best characteristics that a implant must have taking into consideration each specific clinical case.

There are surgical situations in which there occur the insertion of implants with unfavorable inclinations, due to bone quantity and quality, necessitating their removal and reinsertion in the same surgery. Considering that manufacturers do not recommend the reuse of dental implants, the purpose of this study was to evaluate the influence of insertion torque and pullout test in different implants and analyze the occurrence of possible macro and microstructure deformations on their surfaces, evaluated by using a scanning electron microscope.

   Materials and Methods Top

A total of thirty-two dental implants (Conexao®, Aruja, Sao Paulo, Brazil) were used in this study, divided in the following four groups with n = 8: Master Screw (11.5 × 3.75 mm) - cylindrical of machined surface, Master Porous (11.5 × 3.75 mm) - cylindrical with Porous double surface treatment, Master Conect AR (11.5 × 3.75 mm) - cylindrical with Porous single surface treatment and Conect Conical (11.5 × 3.5 mm) - conical with Porous surface treatment.

These implants were inserted into the femoral head of a polyurethane artificial human bone (Symbone®, Malans, Switzerland). Due to the difficulties in handling, acquisition and storage of the natural bone, we decided to use artificial bones, because there are similarities in relation to geometry, flexion and density when compared to natural bone, as well as greater standardization of the study utilizing few samples. [15],[16]

Before insertion, performed with standardized torque of 35, the implants were analyzed morphologically using a scanning electron microscope (Zeiss - EVO50), under magnification of 35 times. After insertion, the implants were removed from the samples by using the pullout test, conducted with a universal testing machine (Emic - DL-10000) with load cell of 200 kgf and software Tesc 3.13. To perform the test, the screw head was fixed to the testing machine by connectors that allow multidirectional movements and application of axial tensile load without the application of torque. A preload of 5N was applied for 10 s to accommodate the system and then the axial tensile load was applied using 0.2 mm/min until the complete implant pullout. These variables were defined according to the need for implant adaptation to the Universal Machine. [17] Afterwards, these implants were subjected to a new SEM morphological analysis for comparison purposes.

Data were submitted to ANOVA and Tukey tests (α =0.05%) using SPSS Statistics 17.0 (SPSS, Chicago, USA). The images obtained using SEM were qualitatively evaluated, comparing the implants surface before insertion and after the pullout test.

   Results Top

Comparing the types of implants with each variable [Table 1], it was observed that there was significant difference between the implants on the variables Maximum Force (P = 0.0120), Maximum EF (P = 0.024) and Relative Rigidity (P = 0.01). To the Maximum Deformation, it wasn't observed any significant difference between the implants (P = 0.440). It was observed that Master Porous dental implants presented higher values and statistically different (P < 0.05) from Master Conect Conical in relation to maximum pullout force (P = 0.009), maximum EF (P = 0.014) and relative rigidity (P = 0.006).

The comparison of photomicrographs SEM evaluation, before insertion and after pullout test, showed no surface morphological changes that may have been caused by mechanical tests. There was only substrate accumulation between the screw-threads due to artificial bone debris that remain adhered to the screws [Figure 1], [Figure 2], [Figure 3], [Figure 4].
Figure 1: Implant conect conical - before the fi rst insertion

Click here to view
Figure 2: Implant conect conical - after the fi rst extraction

Click here to view
Figure 3: Implant master porous – before the fi rst insertion

Click here to view
Figure 4: Implant master porous – after the fi rst extraction

Click here to view
Table 1: Mean±standard deviation in the different groups

Click here to view

   Discussion Top

Many studies have evaluated the biomechanical characteristics of the different types of implants searching an ideal format for use in several clinical cases, however, there are many factors associated with failure of the implants such as the diameter and type, thickness of cortical bone, receiver bone site, insertion torque and inflammation of the peri-implant tissues, making this search difficult. [18]

Conical and cylindrical implants have different geometries, screw shapes and contact surface, which leads to differences in insertion torque results. Some studies [19] show that the conical implants have smaller screw-threads and, therefore, have greater surface area, which increases the friction between bone and implant and results in a greater insertion torque. In this study, we selected the mechanical pullout test for evaluating the screws, however, the results were different from those commonly found in the literature, because in this case the cylindrical implants and with double surface Porous treatment (Master Porous) demonstrated greater resistance when compared to the conical.

Given the difference in the surface treatment of the implants Master Porous and Conect Conical, the result suggests that the roughness plays great influence on the strength of them, because it increases the friction between the implant and the bone and modulates the cell behavior. [20],[21],[22] In addition, studies show that implants submitted to more than one treatment technique may show an enhanced bone apposition and higher values of removal torque in biomechanical testing. [23],[24] The best performance of the cylindrical implants may also have been influenced by the slightly smaller diameter of the conical implants.

There are several types of surface treatment available on the market. In the present study, the tested implants have the surface treated by acid attack, which produces micro depressions on the titanium surface, ranging from 0.5 to 2 μm of diameter. [22],[25] This acid treatment has been shown to improve the osseointegration, [26] a fact that could be confirmed with the results of the study, once that the implants with Porous-treated surface showed higher pullout strength when compared to the machined implants (Master Screw), suggesting a higher primary stability. The surface treatment, regardless of the type, causes a greater roughness on the titanium surface, favoring the osseointegration and the initial stability by promoting a greater mechanical imbrication between the substrate and the screw.

Despite that conical implants did not present the best results of pullout resistance, they demonstrated greater resistance than the cylindrical machined surface implants (Master Screw). Comparing the cylindrical implants with and without surface treatment, those treated (Master Porous and Master Conect AR) obtained better results than machined (Master Screw). These results demonstrate the positive influence of the roughness on the increase of resistance and primary stability. [16]

After performing the mechanical tests, all implants were evaluated in scanning electron microscope. A comparison was done by comparing the photomicrographs before and after those mechanical tests. The evaluation of the screw morphological structure showed no change in the surface that may have been caused by the realization of insertion torque and pullout test. The only difference found between the images was the accumulation of organic matter due to the debris of the polyurethane substrate that remained between the screw threads. The greatest deposition of organic matter was seen in the implants with double Porous surface treatment (Master Porous), probably due to the increased roughness of these screws, showing the imbrications effect caused by the surface treatment. In a clinical situation, this factor could increase the friction between bone-dental implant, promoting the primary stability.

This result suggests that an implant inserted in a specific surgical site can be reinserted into another one, on the same patient and on the same surgical procedure without causing damage to osseointegration. [27],[28]

Two aspects found in this study demonstrate the importance of the work: The first shows the positive influence of surface treatment on the pullout resistance of the tested implants, suggesting a higher primary stability. The second demonstrates the possibility of reuse of screws that were inserted in an incorrect inclination or improperly set.

   Conclusions Top

The Master Porous cylindrical implants showed higher pullout resistance when compared to the other groups, suggesting a greater primary stability. The SEM evaluation did not identify any structural alteration after the mechanical tests.

   References Top

1.Branemärk PI, Hansson BO, Adell R, Breine U, Lindstrom J, Hallem O, et al. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl 1977;16:1-132.  Back to cited text no. 1
2.Mazzo CR, Reis AC, Shimano AC, Valente ML. In vitro analysis of the influence of surface treatment of dental implants on primary stability. Braz Oral Res 2012;26:313-7.  Back to cited text no. 2
3.Bayarchimeg D, Namgoong H, Kim BK, Kim MD, Kim S, Kim TI, et al. Evaluation of the correlation between insertion torque and primary stability of dental implants using a block bone test. J Periodontal Implant Sci 2013;43:30-6.  Back to cited text no. 3
4.Ahmad OK, Kelly JR. Assessment of the primary stability of dental implants in artificial bone using resonance frequency and percussion analyses. Int J Oral Maxillofac Implants 2013;28:89-95.  Back to cited text no. 4
5.Chong L, Ahmed K, Jon BS, John G. Effect of implant design on initial stability of tapered implants. Oral Implantol 2009;35:130-5.  Back to cited text no. 5
6.Dos Santos MV, Elias CN, Cavalcanti Lima JH. The effects of superficial roughness and design on the primary stability of dental implants. Clin Implant Dent Relat Res 2011;13:215-23.  Back to cited text no. 6
7.Kahraman S, Bal BT, Asar NV, Turkyilmaz I, Tözüm TF. Clinical study on the insertion torque and wireless resonance frequency analysis in the assessment of torque capacity and stability of self-tapping dental implants. J Oral Rehabil 2009;36:755-61.  Back to cited text no. 7
8.Rosa RC, Silva P, Shimano AC, Volpon JP, Defino HL, Schleicher P, et al. Biomechanical analysis of the variables related to the pullout strength of screws in the vertebral fixation system. Rev Bras Ortop 2008;43:293-9.  Back to cited text no. 8
9.Tabassum A, Meijer GJ, Wolke JG, Jansen JA. Influence of Surgical Technique and Surface Roughness on the Primary Stability of an Implant in Artificial Bone With different Cortical Thickness: A Laboratory Study. Clin Oral Implants Res 2010;21:213-20.  Back to cited text no. 9
10.Orsini E, Giavaresi G, Trirè A, Ottani V, Salgarello S. Dental implant thread pitch and its influence on the osseointegration process: An in vivo comparison study. Int J Oral Maxillofac Implants 2012;27:383-92.  Back to cited text no. 10
11.Livne S, Marku-Cohen S, Harel N, Piek D, Ormianer Z. The influence of dental implant surface on osseointegration: review. Refuat HapehVehashinayim 2012;29:41-6, 66.  Back to cited text no. 11
12.Bilhan H, Geckili O, Mumcu E, Bozdag E, Sünbüloðlu E, Kutay O. Influence of surgical technique, implant shape and diameter on the primary stability in cancellous bone. J Oral Rehabil 2010;37:900-7.  Back to cited text no. 12
13.Desai SR, Desai MS, Katti G, Karthikeyan I. Evaluation of design parameters of eight dental implant designs: A two-dimensional finite element analysis. Níger J Clin Pract 2012;15:176-81.  Back to cited text no. 13
14.Aleo E, Varvara G, Scarano A, Sinjari B, Murmura G. Comparison of the primary stabilities of conical and cylindrical endosseous dental implants: An in-vitro study. J Biol Regul Homeost Agents 2012;26:89-96.  Back to cited text no. 14
15.Bischof M, Nedir R, Szmukler-Monder S, Bernard JP, Samson J. Implant stability measurement of delayed and immediately loaded implants during healing. Clin Oral Implants Res 2004;15:529-39.  Back to cited text no. 15
16.Baró AM, Garcia N, Miranda R, Váquez L, Aparicio C, Olivé J, et al. Characterization of Surface Roughness in titanium dental implants measured with scanning tunnelling microscopy microscopy at atmospheric pressure. Biomaterials 1986;7:463-6.  Back to cited text no. 16
17.Zheng L, Tang T, Deng F, Zhao Z. The Influence of Extraction on the Stability of Implanted Titanium Microscrews: A Biomechanical and Histomorfhometric Study. Int J Oral Maxillofac Implants 2009;24:267-4.  Back to cited text no. 17
18.Chang CL, Chen CS, Huang CH, Hsu ML. Finite element analysis of the dental implant using a topology optimization method. Med Eng Phys 2012;34:999-1008.  Back to cited text no. 18
19.Elias CN, Rocha FA, Nascimento AL, Coelho PG. Influence of implant shape, surface morphology, surgical technique and bone quality on the primary stability of dental implants. J Mech Behav Biomed Mater 2012;16:169-80.  Back to cited text no. 19
20.Le Guéhennec L, Soueidan A, Layrolle P, Amouriq Y. Surface treatments of titanium dental implants for rapid osseointegration. Dent Mater 2007;23:844-54.  Back to cited text no. 20
21.Wong M, Eulenberger J, Schenk R, Hunziker E. Effect of surface topology on the osseointegration of implant materials in trabecular bone. J Biomed Mater Res 1995;29:1567-75.  Back to cited text no. 21
22.Zinger O, Anselme K, Denzer A, Habersetzer P, Wieland M, Jeanfils J. Time-dependent morphology and adhesion of osteoblastic cells on titanium model surfaces featuring scale-resolved topography. Biomaterials 2004;25:2695-711.  Back to cited text no. 22
23.Norton MR, Gamble C. Bone classification: An objective scale of bone density using the computerized tomography scan. Clin Oral Implants Res 2001;12:79-84.  Back to cited text no. 23
24.Sul YT, Göteborgs universitet, Institutionen för kliniska vetenskaper, sektionen för anestesiologi, biomaterial och ortopedi Kang BS, Göteborgs universitet, Institutionen för kliniska vetenskaper, sektionen för anestesiologi, biomaterial och ortopedi Johansson C, Um HS, Park CJ, Albrektsson T. The role of surface chemistry and surface topography of osseointegrated titanium implant: Strength and rate of osseointegration. J Biomed Mater Res A 2009;89A: 942-50.  Back to cited text no. 24
25.Wennerberg A, Hallgren C, Johansson C, Danelli S. A histomorphometric evaluation of screw-shaped implants each prepared with two surface roughnesses. Clin Oral Implants Res 1998;9:11-19.  Back to cited text no. 25
26.Mesa F, Muñoz R, Noguerol B, Luna JD, Galindo P, O'valle F. Multivariate study of factors influencing primary dental implant stability. Clin Oral Implants Res 2008;19:196-200.  Back to cited text no. 26
27.Kreisler M, Kohnen W, Christoffers A, Götz H, Jansen B, Duschner H, et al. In vitro evaluation of the biocompatibility of contaminated implant surfaces treated with an Er: YAG laser and air powder system. Clin Oral Implants Res 2005;16:36-43.  Back to cited text no. 27
28.Mohamed S, Polyzois I, Renvert S, Claffey N. Effect of Surface on osseointegration of dental implants surrounded by circumferential bone defects. Clin Oral Implants Res 2010;5:513-9.  Back to cited text no. 28

Correspondence Address:
Andréa Cândido dos Reis
Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirao Preto, Sao Paulo
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0970-9290.131051

Rights and Permissions


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1]

This article has been cited by
1 Quantification of dental implant surface wear and topographical modification generated during insertion
Alaitz Zabala, Liam Blunt, Ricardo Tejero, Iñigo Llavori, Andrea Aginagalde, Wilson Tato
Surface Topography: Metrology and Properties. 2020; 8(1): 015002
[Pubmed] | [DOI]
2 Analysis of the influence of implant shape on primary stability using the correlation of multiple methods
Mariana Lima da Costa Valente,Denise Tornavoi de Castro,Antonio Carlos Shimano,César Penazzo Lepri,Andréa Cândido dos Reis
Clinical Oral Investigations. 2015;
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  

    Materials and Me...
    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded99    
    Comments [Add]    
    Cited by others 2    

Recommend this journal