THE EFFECT OF SURFACE TREATMENT

ON FIBER REINFORCED POSTS

Presented by – Dr. Amit

PG 1st year

The prognosis of endodontically treated teeth depends not only on the success of the endodontic treatment but also on the type of

reconstruction

INTRODUCTION

Endodontically treated teeth may be damaged by decay, excessive wear, previous restorations, lack of

coronal tooth structure.

LEADS TO

Therefore , Require the placement of a post to ensure adequate retention core

CAST METAL POSTS VS FIBER REINFORCED POST

METAL POSTS FIBER POSTS

Why do we need various surface treatments??Fogel via fluid filtration microleakage test evaluated found that none of the post systems tested were capable of consistently achieving a fluid-tight seal.

Similar results were reported by Tjan et al, who used second generation dental adhesives and found that all teeth showed leakage.

In vitro and in vivo studies indicate that failure of glass fiber reinforced post-and-core restorations often occurs because of debonding at the post-resin interface and/or resin- dentin interface as a result of bond deficiencies.

What can we do about the failures??

Authors have investigated

different procedures for improving the

interfacial bond strength between posts and resin-based materials .

These procedures may be divided

into 3 categories:

Pretreatment procedures

Silanization and/or adhesive applicatio

n

Acid etching, airborne-particle

abrasion, and silica coating;

Treatments that

combine both

micromechanical and a chemical component

PRETREATMENT PROCEDURES

Silanization and/or adhesive application

Solvent evaporation

plays an important role

since an incomplete

removal may compromise

coupling

To optimize the chemical

interaction between silane and inorganic surfaces, the

reaction may be catalyzed by acid

treatment or heating.

The chemical bond may be achieved only between the composite resin and the exposed glass fibers of the post.

Bond strength between the epoxy resin-based fiber posts and the methacrylate based resin are not fully enhanced by

silanization

ACID ETCHING , SANDBLASTING AND SILICA COATING

CERAMIC ETCHING WITH HF

CREATES ROUGH SURFACE

MICROMECHANICAL INTERLOCKING WITH RESINOUS CEMENT

DAMAGES GLASS FIBERS, MICROCRACKS, CORROSIVE EFFECTS

Nontreated fiber posts have a relatively smooth

surface which limits mechanical interlocking with resin cements and purely adhesive failure modes are commonly

recorded at the post/composite interfaces

RELIES ON USE OF ALUMINIUM OXIDE PARTICLES MODIFIED BY SILICA.

SILICATE LAYER WELDED ON TO THE TREATED SURFACE BY HIGH SPOT HEAT PRODUCED BY BLASTING PRESSURE IN A PROCESS CALLED TRIBOCHEMICAL COATING.

FOLLOWED BY SILANIZATION OF PRETREATED LAYER; COMBINING CHEMICAL AND MICROMECHANICAL RETENTION.

BLASTING – REMOVES SUPERFICIAL LAYER OF RESINOUS MATRIX

CREATING MICRORETENTIVE SPACES ON POST SURFACE

CO-

JET

SYSTE

M

AIR ABRASION

USING SILICA COATED ALUMINIUM OXIDE PARTICLES; CREATES A SILICA LAYER ON THE POST SURFACE.

PENETRATES 15 MICRONS EFFICIENT WHEN COMPARED TO ACID ETCHING, BUT MAY

MODIFY THEIR SHAPE AND FIT INTO ROOT CANALS

EPOXY BASED FIBRE POSTSABRADED WITH 50 MICRONS ALUMINA PARTICLES,2.5 BAR PRESSURE,5 SEC, AT 30MM DISTANCE

BALBOSH AND ASUMUSSEN ET AL – REGIMEN

THIS REGIMEN DID NOT PRODUCE VISIBLE CHANGES OF THE SHAPE OF THE POST AND RESULTED IN INCREASED SURFACE AREA AND MECHANICAL INTERLOCKING WITH THE RESIN CEMENT.

ALTERNATIVE ETCHING TECHNIQUES : CONDITIONING OF EPOXY RESINS WITH KMNO4 – DESMEARING.

FOR METAL PLATING. FIBER POSTS – IMMERSED INTO SOLUTION(H2O2) – 10-15 MIN. REMOVING SURFACE LAYER – MORE SPACES FOR SILANIZATION.

MAIN PROBLEM WITH CONDITIONING TECHNIQUES ----LACK OF SENSITIVITYBOTH THE MATRIX AS WELL AS THE FIBERS OF THE POST AFFECTED BY TREATMENT – RESULTING IN DAMAGE OF THE POST’S INNER STRUCTURE.

SWELLINGETCHING

NEUTRALIZING

REVIEW OF LITERATURE

Main aim of the study was to evaluate the effects of sandblasting combined with silanization as a surface treatment on the bond strength between fiber posts and resin cement. Both sandblasting and silanization can improve the bonding of fiber posts to resin cement. The effect of sandblasting is predominant.This study suggested that fiber posts should be pretreated with sandblasting or combined with silanization before clinical use.COMBINATION OF SANDBLASTING AND SILANIZATION ON THE

BOND STRENGTH BETWEEN FIBER POST AND RESIN CEMENT. WANG YJ, ZHANG L, CHIEFFI N, CHEN JH, FERRARI M INTERNATIONAL DENTISTRY SA VOL. 8, NO. 6

Investigated the effects of pretreatment (silanization) on bond strengths between three different types of fibre posts and 4 resin cements.Concluded that fibre post revealed a significant influence on the bond strengths, whereas the effects of silanization appeared to be clinically negligible

EFFECTS OF SILANIZATION ON BOND STRENGTHS OF FIBRE POSTS TO VARIOUS RESIN CEMENTS. Bitter K, Noetzel J, Neumann K, Keilbassa AM , Quintessence Int 2007;38:121-128

Evaluated the effect of post-silanization heat treatment of a silane agent and rinsing with hot water of silanized CAD/CAM feldspathic ceramic surfaces on the microtensile bond strength between resin cement and the ceramic, before and after mechanical cycling. They concluded that oven drying at 77°C improved the bond strength between the resin cement and feldspathic ceramic, but hot water rinsing reduced the bond strength and should not be recommended.

Effect of Post-silanization Heat Treatments of Silanized Feldspathic Ceramic on Adhesion to Resin Cement. Corazza, Cavalcanti PH, Queiroz SCM J Adhes Dent - 2013

Evaluated the effect of post silanization on the microtensile bond strength (MTBS) of translucent fiber posts to seven flowable composite resins used as core material. The different resin composite materials and the post silanization procedures had a significant effect on MTBS. The application of a silane coupling agent increased MTBS of flowable composite resins to translucent posts.

Post silanization improves bond strength of translucent posts to flowable composite resins. Albaladejo A, Osorio R et al. Journal of Biomedical Materials Research Part B Applied Biomaterials 2007; 82(2):320-4.

This study evaluated the effect of three post surface treatments on quartz-fiber post (a) retention and (b) morphology. Different treatments were performed for the other posts: silanization; etching by hydrofluoric acid 9.5%; sandblasting with 50 μm Al2O3. Retentive post bond strengths were significantly enhanced with any tested post surface pretreatment. The increase in retentive strength was more remarkable in sandblasted and etched posts. Significant changes of post surfaces were SEM observed after different conditioning treatments.Effect of Surface Treatments on Tensile Bond Strength and on

Morphology of Quartz-fiber Posts. Arcangelo C, Amario M et al. 2007

 

Evaluated the tensile bond strengths and the effect of silanization of fiber posts inserted with different adhesive systems. Concluded that Silanization had no significant effect. Tensile bond strengths were significantly influenced by the type of resin cement. Silanization of fiber post surfaces seemed to have no clinical relevance.

Effect of Adhesive Resin Cements and Post Surface Silanization on the Bond Strengths of Adhesively Inserted Fiber Posts. Wrbas KT, Altenburger MJ et al. Journal of Endodontics 2007;33(7):840-843.

Main aim was to investigate the effects of pretreatment (silanization) on bond strengths between 3 different types of fiber posts and 4 resin cements, respectively. Bond strengths were significantly affected by the resin cement, the pretreatment , and the type of post, but not by thermocycling. The IPN post demonstrated significantly higher bond strengths compared to the other posts. Silanization significantly increased bond strengths compared to those of the control groups.The type of fiber post revealed a significant influence on bond strengths, whereas the effects of silanization appeared to be clinically negligible.Effect of silanization on bond strengths of fiber posts to various

resin cements.Bitter K, Noetzel J et al. Quintessence Int 2007 Feb;38(2):121-8.

The bond strength of composite resin cores to the smooth surface of prefabricated zirconia-based ceramic posts is problematic because it might not be sufficient to ensure stability of the post-and-core system. It is also not clear whether any alteration of the post surface to provide additional mechanical or chemical retention would compromise flexural strength of the posts.CONCLUDED - The use of a tribochemical silica coating process and silanization on zirconia-based ceramic posts increased both the bond strength to composite resin as well as the fracture strength of posts.Effect of silica coating and silanization on flexural and composite-

resin bond strengths of zirconia posts: An in vitro study Xible AA, Tavarez RRJ et al. 2007

Several surface treatments have been proposed for improving the bonding of resin cements or core materials to FRC (fiber-reinforced composite) posts. The possibility of combining chemical and micromechanical retention on post surface provides the most promising adhesion mechanism.This literature review summarizes the research on fiber post surface treatments and provides information related to their benefit in enhancing bond strength to composites, based on the results of original scientific full papers from peer-reviewed journals listed in Pub Med. According to the in vitro results, surface conditioning improves fiber post bonding properties, and the bond strength of pre-treated fiber posts to restorative materials is satisfactory. Long-term clinical studies are needed prior to making a general recommendation for their use.

Surface Treatments for Improving Bond Strength to Prefabricated Fiber Posts: A Literature Review. Monticelli F ,  Osorio R et al. 2008

Several post surface treatments with or without the application of a bonding agent have been recommended to improve the bond strength of resin cements to posts. A regimen that produces the maximum bond strength of glass fiber-reinforced composite resin posts has not been verified.The purpose of this study was to evaluate the influence of post surface conditioning methods and artificial aging on the retention and microleakage of adhesively luted glass fiber-reinforced composite resin posts. Treating the surface of the posts with phosphoric acid for 15 seconds before cementation produced no significant improvement in post retention. Airborne-particle abrasion of the surface of the post significantly improved post retention

Effects of endodontic post surface treatment, dentin conditioning, and artificial aging on the retention of glass fiber-reinforced composite resin posts. Albashaireh ZS, Ghazal M, Kern M. The Journal of Prosthetic Dentistry Volume 103, Issue 1, January 2010, Pages 31–39

The purpose of this study was to evaluate the effect of 2 chemical solvents, hydrogen peroxide and methylene chloride, on the shear bond strength of quartz and glass fiber posts to a composite resin. There were significant differences between the shear bond strength for LP and CB. There was no significant difference between the S and M groups. The SEM observations demonstrated that the fiber post surfaces were modified after chemical surface treatment techniques. The surface treatment of quartz and glass fiber posts with hydrogen peroxide significantly enhanced the shear bond strength of the composite resin tested due to its ability to dissolve the epoxy resin matrix used in each post

Effects of chemical surface treatments of quartz and glass fıber posts on the retention of a composite resin Yenisey M and Kulunk S , (J Prosthet Dent 2008;99:38-45)

CONCLUSION

Advances in the surface treatments of the fibre posts representing on of the most important factor which has improved the success of the esthetic post systems over the last two decades.

Long term clinical studies supporting the benefits of one technique over the other in the future is requested.