Comparison of Shear Bond Strength of Two Commercially Available Bondable Molar Tubes

Amrita Shrestha,Luna Joshi,Prabesh Sherchan,Prakash Poudel,Vivek Bikram Thapa

doi:10.3126/ojn.v9i1.25683

Amrita Shrestha, Luna Joshi + Show 3 more

Open Access

https://doi.org/10.3126/ojn.v9i1.25683

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Abstract

Introduction: Direct and indirect bonding has revolutionized clinical orthodontics by reducing chair-side time and enhancing patient comfort. Clinicians often hesitate to bond molars due to ambiguity on shear bond strength. This study was conducted to compare shear bond strengths of two commercially available bondable molar tubes. And asses mesh if the mesh design had a role to play in differences in shear bond strength. Materials & Method: 30 extracted maxillary molars were divided into Group I and II (n=15).Group I bonded with Victory series MBT (3M Unitek). And Group II bonded with Ortho classic proprietary Pad- Lok (Navy orthodontics). Teeth were mounted on a jig and Shear Bond Strength was evaluated on an Instron universal testing machine at a cross head speed of 1mm/minute. They were also subjected to scanning microscopic examination to check the base pattern. Result: Shear bond strength of navy orthodontic tubes were (18.0675+/- 4.0187 MPa) was significantly higher than 3M victory series (8.93 +/2.493MPa). Unpaired T-test shows a higher significant difference in SBS between two groups at 1% of significance. SME showed that navy orthodontic tube base was pad-lock mesh design, while 3M was a single mesh base design. Conclusion: 3M victory series molar tube exhibited a near ideal while other sample showed far higher shear bond strength than recommended. Higher values may result in enamel fracture.

Highlights

Direct and indirect bonding has revolutionized clinical orthodontics by reducing chair-side time and enhancing patient comfort
It has been reported that mesh based brackets with larger mesh spaces provide a greater shear bond strength than do bases with smaller mesh apertures.[4]
The two areas in which improvements have taken place are in the design of the mesh as well as the use of bond enhancing metal surface treatments applied to the mesh.[4,5]

Summary

INTRODUCTION

Direct and indirect bonding of orthodontic attachments has revolutionized clinical orthodontics by reducing chair-side time and enhancing patient comfort. It has been reported that mesh based brackets with larger mesh spaces (apertures) provide a greater shear bond strength than do bases with smaller mesh apertures.[4] The number of openings per unit of area of the bracket base is determined by the wire diameter and the mesh spacing. Thapa VB, Shrestha A, Sherchan P, Poudel P, Joshi L : Comparison of Shear Bond Strength of Two Commercially Available Bondable Molar Tubes the bracket base is determined by the wire diameter and the mesh spacing. The two areas in which improvements have taken place are in the design of the mesh as well as the use of bond enhancing metal surface treatments applied to the mesh.[4,5] The various types of treatment applied to bracket bases have entailed micro-etching, sandblasting, polymer coating or a spray with fine particles of molten metal[1].The current trend is for a less dense mesh to be used so as to ensure a larger aperture or open area in the base.[9].

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