The effects of cavity size and incremental technique on micro-tensile bond strength of resin composite in Class I cavities

He, Zhengdi; Shimada, Yasushi; Tagami, Junji

doi:10.1016/j.dental.2006.03.012

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Volume 23, Issue 5 , Pages 533-538, May 2007

The effects of cavity size and incremental technique on micro-tensile bond strength of resin composite in Class I cavities

Zhengdi He
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
- Corresponding author. Tel.: +81 3 5803 5483; fax: +81 3 5803 0195.
Yasushi Shimada
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
Junji Tagami
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
- Center of Excellence Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University, Tokyo 113-8549, Japan

Received 8 June 2005; received in revised form 26 December 2005; accepted 9 March 2006.

Abstract

Objective

The purpose of this study was to investigate if incremental-filling technique and cavity size would affect the bond strength of resin composite.

Methods

Two sizes of Class I cavities were prepared in bovine dentin (large cavities: π×(5/2)²×5mm³; small cavity: π×(3/2)²×3mm³). Light-cure resin composite (Clearfil Photocore) with a self-etching primer adhesive (Clearfil SE Bond) was placed into the cavities by bulk filling (C-factor=5) or incremental filling (two layers, C-factor=3) and light-cured. As a control, 3 or 5mm thick resin composite was bonded to the flat dentin surface. After 24h storage in 37°C water, the micro-tensile bond strength was measured at a crosshead speed of 1mm/min. The results obtained were statistically analyzed using two-way ANOVA and t-test at a significance level of P=0.05.

Results

The results obtained showed that there was no significant difference among the filling techniques in small cavities (P>0.05). However, in large cavities, bulk filling presented the lowest bond strength (P<0.05).

Significance

Not only the filling technique affected the bonding strength to the cavity floor, but the cavity size was also an influential factor in Class I cavities.

Keywords: Cavity size, Incremental technique, C-factor, Micro-tensile bond strength, Self-etching primer