Real-time measurement of dentinal fluid flow during amalgam and composite restoration

Received 8 October 2009; received in revised form 23 December 2009; accepted 25 December 2009. published online 11 January 2010.

Summary

Objectives

This study examined changes in the dentinal fluid flow (DFF) during restorative procedures and compared permeability after restoration among restorative materials and adhesives.

Methods

A class 1 cavity was prepared and restored with either amalgam (Bestaloy), or composite (Z-250) with one of two etch-and-rinse adhesives (Scotchbond MultiPurpose: MP and Single Bond 2: SB) or one of two self-etch adhesives (Clearfil SE Bond: CE and Easy Bond: EB) on an extracted human third molar which was connected to a sub-nanoliter fluid flow measuring device (NFMD) under 20cm water pressure. DFF was measured from the intact tooth state through the restoration procedures to 30min after restoration, and re-measured at 3 and 7 days post-restoration.

Results

Inward flow during cavity preparation was followed by outward flow after preparation. In amalgam restoration, the outward flow changed into an inward flow during amalgam filling, which was followed by a slight outward flow after finishing. In composite restoration, MP and SB showed an inward flow and outward flow for the rinsing and drying steps, respectively. Application of a hydrophobic bonding resin in the MP and CE systems caused a decrease in the flow rate. Air-drying of solvent for the CE and EB systems caused a sudden outward flow, whereas light-curing of the adhesive and composite caused an abrupt inward flow.

Conclusions

Each restorative step clearly changed the direction and the rate of the DFF during restoration, which could be well identified with NFMD.

Keywords: Dentinal fluid flow, Permeability, Amalgam, Composite, Etch-and-rinse, Self-etch

a Department of Conservative Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, 28-2 Yeongeon-Dong, Jongro-Gu, Seoul 110-749, South Korea

b Department of Restorative Dentistry, Division of Biomaterials and Biomechanics, School of Dentistry, Oregon Health & Science University, Portland, OR, USA

c Department of Dental Hygiene, College of Health Science, Eulji University, Seoul, South Korea

Corresponding author. Tel.: +82 2 2072 3953; fax: +82 2 2072 3859.

PII: S0300-5712(10)00002-3

doi:10.1016/j.jdent.2009.12.008

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