Indian Journal of Dental ResearchIndian Journal of Dental ResearchIndian Journal of Dental Research
HOME | ABOUT US | EDITORIAL BOARD | AHEAD OF PRINT | CURRENT ISSUE | ARCHIVES | INSTRUCTIONS | SUBSCRIBE | ADVERTISE | CONTACT
Indian Journal of Dental Research   Login   |  Users online: 3774

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

 


 
ORIGINAL RESEARCH Table of Contents   
Year : 2010  |  Volume : 21  |  Issue : 2  |  Page : 201-206
Evaluation of the effect of different surface treatments on the retention of posts: A laboratory study


Department of Prosthodontics, Government Dental College and Research Institute, Fort, Bangalore, India

Click here for correspondence address and email

Date of Submission28-Jan-2009
Date of Decision08-Aug-2009
Date of Acceptance04-Mar-2010
Date of Web Publication22-Jul-2010
 

   Abstract 

Background and Objectives : There are numerous post and core systems variety of materials. Several methods are used to increase the retentive strength.The present study was conducted with the purpose of analysis of the effect of surface treatment with ethyl alcohol, resin primer and air-borne alumina particle abrasion on retention of glass fiber posts, carbon fiber posts and cast metal posts
Materials and Methods : Surface treatment of glass fiber posts, carbon fiber posts and cast metal posts was done with ethyl alcohol, resin primer and air-borne alumina particle abrasion and cemented with dual cure resin cement into the post spaces prepared in the teeth. For the Retentive force test, a screw driven universal testing machine was used to apply tensile load to the post. The force required to dislodge each post from prepared post space was recorded.
Statistical Analysis
: Comparison of the mean retentive strength was done using two-way Analysis of Variance (ANOVA) followed by Bonferroni method for multiple comparisons.
Results : Significant difference in the retentive strength between air borne alumina particle abrasion and resin primer treated posts was (P < 0.001) noticed. Further, there was no significant difference between ethyl alcohol and resin primer treated posts
Conclusion : Air-borne alumina particle abrasion increased the retentive strength of all the type of posts used in this study. Treating the surface of the posts with resin-primer and ethyl alcohol produced no statistically significant difference in the retentive strength.

Keywords: Airborne alumina particle abrasion, retentive strength, surface treatment, tensile load

How to cite this article:
Prithviraj D R, Soni R, Ramaswamy S, Shruthi D P. Evaluation of the effect of different surface treatments on the retention of posts: A laboratory study. Indian J Dent Res 2010;21:201-6

How to cite this URL:
Prithviraj D R, Soni R, Ramaswamy S, Shruthi D P. Evaluation of the effect of different surface treatments on the retention of posts: A laboratory study. Indian J Dent Res [serial online] 2010 [cited 2020 Feb 25];21:201-6. Available from: http://www.ijdr.in/text.asp?2010/21/2/201/66637
Post and core systems have been used to restore endodontically treated tooth for more than 250 years. [1] They are available in a variety of materials. Cast metal post and core systems have a long history of successful use due to their superior physical properties. However, esthetic properties of these materials are limited since gray-colored post and core is apparent when used to support translucent all-ceramic restorations. Additionally, their high elastic modulus can cause stress concentration within the surrounding radicular dentin, resulting in root fractures. Prefabricated post systems are also popular because they can provide satisfactory results while saving time and reducing the costs. However, prefabricated post should adequately adapt to the prepared root canal otherwise a cast post and core should be used. [2]

Carbon fiber posts have also come into use for prosthodontic applications. [3] Properties such as biocompatibility and corrosion resistance make the carbon fiber post a potential replacement for conventional metallic post in many clinical situations. However, the modulus of elasticity of carbon fiber is much greater than that of dentin. Further, the use of carbon posts has generally limited esthetic expectations. Their dark underlying color can adversely influence the shade of the overlying gingival tissue and prosthetic restorations. [4]

Post made up of tooth-colored material such as glass fibers have become popular because they increase the transmission of light within the root and the overlying gingival tissues. Glass fiber posts are composed of glass fibers, inorganic filler and a resin matrix. The low modulus of elasticity of fiber-reinforced epoxy resin post has been reported to reduce the risk of root fracture. In addition, the restoration of endodontically treated teeth with metal-free materials eliminates the potential hazards of corrosion and hypersensitivity. Fiber-reinforced posts also have the advantage of easy removal if endodontic retreatment is required. [5]

Many in vitro studies have investigated various factors that affect the retention of a post. However, very few studies have been performed to evaluate the effect of different surface treatment on retention of the glass fiber post, carbon fiber post and cast metal posts. Hence, this study was carried out to compare the effect of surface treatment with ethyl alcohol, resin primer and airborne alumina particle abrasion on the retention of glass fiber post, carbon fiber post and cast metal posts.


   Materials and Methods Top


Ninety extracted caries-free and visually assessed fracture-free, human maxillary anterior teeth and mandibular premolar teeth were selected. The selected teeth were cleaned of both calculus deposits and soft tissue, and stored in distilled water .

A custom-made device made up of stainless steel was fabricated [Figure 1] and [Figure 2]. The custom-made device consisted of a hollow cubical mold (without roof) with the following dimensions: length, 40 mm; width, 40 mm; height, 25 mm, with uniform wall thickness of 6 mm. For easy holding of the cubical mold during testing, a 2-mm-thick stainless steel plate was welded below it.

A thin layer of petroleum jelly (Nice Chemicals Pvt. Ltd., Cochin, India) was applied to the inner walls of the hollow cubical mold. Thereafter, the mold was filled with a mix of autopolymerizing acrylic resin (DPI-RR Cold Cure, DPI, Mumbai, India). After polymerization, the polymethyl methacrylate (PMMA) block was removed from the cubical mold. The PMMA block was subsequently duplicated using elastomeric impression material (Aquasil, Soft Putty/regular set, Dentsply, Germany). All the PMMA blocks were tested for the fit in the cubical mold. If there was any interference, it was removed by trimming. After the fit of the PMMA blocks was checked, a hole was made in the center of these blocks. A total of 90 PMMA blocks were prepared for mounting the teeth. Notches were prepared in the root of the teeth to prevent dislodgement during testing and, subsequently, each tooth was mounted in the hole made in the PMMA block till the cemento-enamel junction with a fresh mix of autopolymerizing acrylic resin.

Each tooth was sectioned with a diamond rotatory cutting instrument under water spray, 1 mm coronal to the cemento-enamel junction [Figure 3]. Roots with distinctly oval canal and a diameter of more than 2 mm were excluded from the study. The pulpal tissue was removed and the canal was enlarged with Endo files up to a size of 40. Three percent sodium hypochlorite solution (Vensons India, Bangalore, India) was used to irrigate the canal throughout instrumentation.

Specific drill bit (R.T.D, France) of size 2 supplied for the prefabricated fiber post size 2 was marked at 9 mm length from the tip using a permanent marker and post spaces of 9 mm in length were prepared. A new instrument was used for every eight specimens. Throughout the preparation, the post spaces were irrigated with 3% sodium hypochlorite solution. The prepared post spaces were dried.

Acrylic patterns of the post spaces of 30 specimens were made for cast metal posts and were numbered. Subsequently, they were invested and casted with Ni-Cr alloy (Wiron, Bego, Bremen, Germany) using an induction casting machine (Degutron, Degussa AG, Germany).

All the specimens were divided into nine groups. Each group contained 10 specimens.

Group 1: Carbon fiber posts (D.T.Carbon post, R.T.D, France) cleaned with 57.1% ethyl alcohol (Surgical Spirit, Reliance Pharmaceutical Laborateries, Hyderabad, India) for 3 min.

Group 2: Carbon fiber posts conditioned with resin primer (Rely a Bond, Reliance Products , USA) for 60 s.

Group 3: Carbon fiber posts air abraded with 50-μm alumina particles (Korox 50, Bego, Bremen, Germany) for 5 s from a distance of 30 mm.

Group 4: Glass fiber posts (D.T. Light Post, R.T.D, France) cleaned with 57.1% ethyl alcohol for 3 min.

Group 5: Glass fiber posts conditioned with resin primer for 60 s.

Group 6: Glass fiber posts air abraded with 50-μm alumina particles for 5 s from a distance of 30 mm.

Group 7: Cast metal posts cleaned with 57.1% ethyl alcohol for 3 min.

Group 8: Cast metal posts conditioned with resin primer for 60 s.

Group 9: Cast metal posts air abraded with 50-μm alumina particles for 5 s from a distance of 30 mm.

All the surface-treated posts were marked at 9 mm from the apex using a permanent marker and subsequently luted with dual cure resin cement (Rely x ARC, 3M ESPE, USA) [Figure 4], [Figure 5] and [Figure 6]. The cement was not light cured to standardize the study as carbon fiber post and cast metal posts were also used.

For the retentive force test, a screw-driven universal testing machine (Instron 33R 4467, Instron Limited, Buckinghamshire, UK) was used to apply tensile load to the post at a cross-head speed of 2 mm/min [Figure 7]. The force required to dislodge each post from the prepared post space was recorded. The data were subjected to statistical analysis.


   Results Top


The retentive strength of the glass fiber post, carbon fiber post and cast metal post surface treated with ethyl alcohol, resin primer and airborne alumina particle abrasion were compared. The mean retentive strength and significant differences were calculated [Table 1]. Comparison of the mean retentive strength using two-way Analysis of Variance (ANOVA) was performed [Table 2]. From the two-way ANOVA test, it was observed that the type of post is a significant factor influencing retentive strength, and there was a significant difference between the different posts used in the study (P<0.001). "Surface Treatment" was also a significant factor influencing retentive strength, and there was a significant difference between the different surface treatments (P<0.001).

From the Bonferroni method, multiple comparisons were made [Table 3]. There was a significant difference in the retentive strength of carbon fiber posts and cast metal posts (P<0.001). A significant difference between the glass fiber posts and the cast metal posts (P<0.001) was also noticed. There was no significant difference in the retentive strength between the carbon fiber posts and the glass fiber posts (P> 0.05). There was a significant difference in the retentive strength between airborne alumina particle abrasion and ethyl alcohol-treated posts (P<0.001). Significant difference in the retentive strength between airborne alumina particle abrasion and resin primer-treated posts (P<0.001) was also noticed. Further, there was no significant difference between ethyl alcohol and resin primer-treated posts [Graphs 1-3][Additional file 1][Additional file 2][Additional file 3].

The results indicated that airborne alumina particle-abraded cast metal posts had the highest retentive strength compared to all other surface-treated or untreated posts used in the study, followed by primer-treated cast metal posts and ethyl alcohol-treated cast metal posts. Airborne alumina particle-abraded glass fiber posts and carbon fiber posts had the next highest retentive strengths. Airborne alumina particle abrasion increased the retentive strength of all the type of posts used in this study. Treating the surface of the posts with resin primer and ethyl alcohol produced no statistically significant difference in the retentive strength of all the type of posts used in the study. There was no significant difference in the retentive strength obtained between glass fiber posts and carbon fiber posts.


   Discussion Top


Restorative methods for pulpless teeth with postcore systems have been widely investigated with the aim of achieving long-term promising prognosis. Use of the post is still regarded as the accepted method of core retention for restoration of pulpless teeth that have suffered significant loss of the coronal structure. [6]

Many in vitro studies have investigated various factors that affect retention of the post. These factors include length, design, diameter and the surface treatment of the post. A study performed by Ibrahim Nergis, Dr. Med Dent and Peter Schamage [5] showed that roughening the prepared dentinal surface also increased the retention of posts or artificial crowns by increasing the surface area and enhancing the mechanical interlocking between the dentin surface and the cement. Material used in fabrication of the post can also influence the retentive strength of the posts. Gallo and Miller, [4] in their study, have reported that fiber-reinforced resin posts provided lower retention when compared with metal posts.

The findings obtained in the present study indicate that airborne alumina particle abrasion of the surface increased the retention of all the posts. However, resin primer and ethyl alcohol surface treatment of the posts do not significantly affect the retentive strength. These findings were similar to the findings of Balbosh and Kern. [5] The findings observed may be because the nonabraded posts had a relatively smooth surface area, which limited mechanical interlocking between the post's surface and the resin cement. A careful visual observation with a magnifying lens of the dislodged posts revealed purely adhesive failure mode at the resin cement/post interface for all nonabraded posts. The airborne alumina particle-abraded posts were rougher and appeared to provide an increased surface area, which improved mechanical interlocking for the resin. Among all the specimens tested, two teeth that were cemented with airborne alumina particle-abraded cast metal posts, fractured during testing at 45 kgf and 46 kgf, respectively. However, none of the teeth of the test specimens cemented with glass fiber posts and carbon fiber posts fractured during testing. The above finding also supported that airborne alumina particle abrasion of the posts increases the retentive strength.

The test for retention of different surface-treated posts in this study was carried out shortly after cementation. However, clinically, the dislodgement of post-retained restorations commonly occurs after several years of function. Long-term retention may be influenced by various factors such as temperature changes and dynamic mechanical loading. In this study, artificial aging, which simulates oral conditions, was not carried out. Further, other post systems like threaded posts, serrated posts, parallel posts and zirconia posts were not considered in the study.

All the posts were cemented with dual cured resin cement, which was not light cured. If dual cured resin cement used in the study was light cured, then the glass fiber posts would have probably given different retentive values during testing as light can transmit through it. Further, the surface details of the dislodged posts were also not analyzed under scanning electron microscope (SEM). Visualization under SEM can provide better insight for the findings observed in the study.


   Conclusion Top


The retentive strength of the post depends on several factors like length, design, diameter and the surface treatment of the post. Hence, all the factors must be thoroughly understood in order to know their effect on the retentive strength of the posts. Type of surface treatment is one of the important factors influencing the retentive strength of the posts. The present in vitro study was conducted to compare the effect of different surface treatments on the retentive strength of the glass fiber post, carbon fiber post and cast metal posts with ethyl alcohol, resin primer and airborne alumina particle abrasion. It was concluded that airborne alumina particle abrasion increased the retentive strength of all the types of posts used in this study. Treating the surface of the posts with resin primer and ethyl alcohol produced no statistically significant difference in the retentive strength.

 
   References Top

1.Artopoulou II, O'Keefe KL, Powers JM. Effect of core diameter and surface treatment on the retention of resin composite cores. J Prosthodont 2006;15:172-8.  Back to cited text no. 1      
2.Dilmener FT, Sipahi C, Dalkiz M. Resistance of three new esthetic post and core system to compressive loading. J Prosthet Dent 2006;95:130-6.  Back to cited text no. 2      
3.Martνnez-Insua A, da Silva L, Rilo B, Santana U. Comparison of the fracture resistances of pulpless teeth restored with a cast post and core or carbon-fiber post with a composite core. J Prosthet Dent 1998;80:572-32.  Back to cited text no. 3      
4.Torbjφrner A, Karlsson S, Syverud M, Hensten-Pettersen A. Carbonfiber reinforced root canal posts. Eur J Oral Sci 1996;104:605-11.  Back to cited text no. 4      
5.Balbosh A, Kern M. Effect of surface treatment on retention of glass fiber endodontic posts. J Prosthet Dent 2006;95:218-23.  Back to cited text no. 5      
6.Hayashi M, Sugeta A, Takahashi Y, Imazato S, Ebisu S. Static and fatigue fracture resistances of pulpless teeth restored with post-cores. Dent Mater 2008;24:1178-86.  Back to cited text no. 6      

Top
Correspondence Address:
D R Prithviraj
Department of Prosthodontics, Government Dental College and Research Institute, Fort, Bangalore
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0970-9290.66637

Rights and Permissions


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]

This article has been cited by
1 Microtensile bond strength of root canal dentin treated with adhesive and fiber-reinforced post systems
Güvenç BASARAN,Emine GÖNCÜ BASARAN,Emrah AYNA,Yalçin DEGER,Buket AYNA,Mehmet Cudi TUNCER
Brazilian Oral Research. 2019; 33
[Pubmed] | [DOI]
2 Comparative evaluation of the effect of surface treatment of fiber-reinforced posts and prefabricated metal posts on adhesion of a resin-based luting cement: An in vitro study
ZarirR Ruttonji,PreethiB Kusugal,Ajaykumar Nayak,Deepa Mahajan,KM Sushma,VirajN Patil
Journal of Conservative Dentistry. 2019; 22(3): 245
[Pubmed] | [DOI]
3 Comparative evaluation of the effect of surface treatment of fiber-reinforced posts and prefabricated metal posts on adhesion of a resin-based luting cement: An in vitro study
ZarirR Ruttonji,PreethiB Kusugal,Ajaykumar Nayak,Deepa Mahajan,KM Sushma,VirajN Patil
Journal of Conservative Dentistry. 2019; 22(3): 245
[Pubmed] | [DOI]
4 Microtensile bond strength of root canal dentin treated with adhesive and fiber-reinforced post systems
Güvenç BASARAN,Emine GÖNCÜ BASARAN,Emrah AYNA,Yalçin DEGER,Buket AYNA,Mehmet Cudi TUNCER
Brazilian Oral Research. 2019; 33
[Pubmed] | [DOI]
5 A comparative evaluation of the effect of phototherapy of fiber post on its bond strength to dental composite
Amal Saeed Al-Qahtani,Sahar Asaad AlZain,Eman Mohammed AlHamdan,Huda Ismail Tulbah,Hana Mohammed Al Alsheikh,Mustafa Naseem,Fahim Vohra
Photodiagnosis and Photodynamic Therapy. 2018; 24: 228
[Pubmed] | [DOI]
6 Comparative evaluation of effects of different surface treatment methods on bond strength between fiber post and composite core
Ramin Mosharraf,Najmeh Baghaei Yazdi
The Journal of Advanced Prosthodontics. 2012; 4(2): 103
[Pubmed] | [DOI]
7 Effect of storage time on microtensile bond strength between quartz fiber post and composite core after different post surface treatments
Khamverdi, Z., Abbasi, S., Habibi, E., Kasraei, S., Azarsina, M., Ebadi, S.
Journal of Conservative Dentistry. 2011; 14(4): 361-365
[Pubmed]



 

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


    Abstract
    Materials and Me...
    Results
    Discussion
    Conclusion
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed4795    
    Printed144    
    Emailed11    
    PDF Downloaded326    
    Comments [Add]    
    Cited by others 7    

Recommend this journal