An in vitro evaluation of the effect of sandblasting and laser surface treatment on the shear bond strength of a composite resin to the facial surface of primary anterior stainless steel crowns.

N Grover,B Nandlal

doi:10.4317/jced.51876

Abstract

Objectives: The present study was conducted to evaluate the optimal method of enhancing the bond strength of a composite resin to the facial surface of the primary anterior stainless steel crowns using various surface treatments namely Nd: YAG laser surface treatment, sandblasting , alloy primer application and no surface treatment. Study Design: The study sample consisted of 60 primary anterior stainless steel crowns (UnitekTM size R 4), with 15 samples randomly divided into the 4 study groups, embedded in acrylic blocks. The facial surface of these surface treated crowns was utilized as the bonding surface to which 2.5mm diameter composite resin cylinders were bonded for the evaluation of the shear bond strength. Shear bond strength measurements were made using a universal testing machine utilizing a shearing blade (jig).The mode of failure at composite-metal interface was determined using a Stereomicroscope at 10 X magnification. Results: The mean bond strength values obtained for surface treatment of Nd: YAG laser surface treated, Sandblasting ,Alloy Primer and No surface treatments were 17.01±.92 , 13.18 ± .73, 7.46 ± .70 and 7.33 ± .77 MPa respectively. The obtained bond strength values were subjected to a one way ANOVA and a Scheffe’s post-hoc comparison test. The results of the present study indicated that Laser surface treatment of the facial surface of the crowns enhanced the bond strength of the composite resin significantly compared to the other groups. Conclusions: Nd: YAG laser surface treatment produced an excellent surface roughness and obtained the highest shear bond strength values suggestive for recommendation as an optimal surface treatment to be used to enhance the resin-metal bond at the interface of the composite resin and the facial surface of primary anterior stainless steel crowns for the purpose of chairside veneering. Key words:Nd: YAG laser treatment, Sandblasting, Primary anterior stainless steel crown, Chairside veneering, Enhancing Resin-Metal Bond, Early childhood caries, Shear bond strength (SBS).

Highlights

Restorations for the primary anterior teeth have always been a challenge for the dentist for many decades (1)
To improve the mechanical bonding between metal and ceramic several methods have been introduced sandblasting, acid etching, application of bonding agents, laser sintering and laser etching among those laser etching is a surface treatment, which makes easier and enables control of micro topography because of its depth of optical penetration depending on the material irradiated and provides more surface roughness and a stable surface morphology (6)
The mean bond strength values obtained for surface treatment of Laser surface treated, Sandblasting, Alloy Primer and No surface treatments were 17.01±.92, 13.18 ± .73, 7.46 ± .70 and 7.33 ± .77 respectively (Table 2)

Summary

Introduction

Restorations for the primary anterior teeth have always been a challenge for the dentist for many decades (1). Primary anterior stainless steel crowns that have been veneered with a composite resin facing are a cost effective, aesthetically acceptable and durable restorative option for carious primary incisors. Earlier studies have evaluated the effect of mechanical preparation; sandblasting and use of metal primers in enhancing the composite to metal bond (1,3,5). Other studies have evaluated the effect of laser surface preparation using an Nd: YAG, XeCl or Er, Cr: YSGG laser as a means to improve the metal-resin bond or improve the bond at the titanium-ceramic interface (7-11). This study was conducted to evaluate the optimal method of enhancing the bond strengths of anterior primary stainless steel crowns to a composite resin using surface preparation techniques sandblasting, alloy primer and the possibility of using laser surface treatment (Nd:YAG laser). The hypothesis was that the stainless steel crown surface treated with the Nd: YAG laser would influence the bond strength of a composite resin to these crowns by producing surface roughness to enhance the bond

Objectives

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Conclusion