Research for Improved Dental Restorative Materials

Published

October 16, 2008

Author(s)

Francis W. Wang, Joseph M. Antonucci, J W. Stansbury

Abstract

In Part A of this report, the interfacial bonding between resin and filler in dental composites is probed by use of the microdrop bead test in a single fiber model study. The microbond test has been shown to be a useful method for comparing silane treated and untreated fiber-polymer shear bond strengths. In an effort to assess the relative hydrolytic stabilities of silane coatings derived from 3-methacryloxpropyltrimethoxysilane [MPTMS] and 10-methacryloxydecltrimethoxysilane [MDTMS], the microbond test protocol was modified to include conditioning the cured microdroplets in distilled water for 24 hours at 60 degrees Celsius}. The aqueous conditioned MDTMS fibers gave mean interfacial shear bond strengths similar to those obtained with the control MDTMS fibers [conditioned in air at 23 degrees Celsius}. By contrast, MPTMS fibers conditioned in water at 60 degrees Celsius} exhibited a marked decrease in interfacial shear bond strength yielding values similar to those obtained with unsilanized fibers. These results lend further support to the hypothesis that the MDTMS-treated glass fillers would provide more durable interfaces in composites than glass fillers similarly treated with MPTMS. Part B of this report describes the efforts directed toward the development of low-shrinking or nonshrinking dental resins. Methods were examined to simplify the preparation of spiro orthocarbonate [SOC] monomers that would lead to practical expanding resin systems. In another study, fluorinated methacrylate oligomers capable of cyclopolymerization were synthesized and evaluated as prospective components of low shrinkage, hydrophobic dental resins. An alternate fluorinated oligomeric resin with a relatively high fluorine content gave composites with excellent strength negligible water sorption and extremely low polymerization shrinkage values.

Citation

NIST Interagency/Internal Report (NISTIR) - 6084

Report Number

6084

NIST Pub Series

NIST Interagency/Internal Report (NISTIR)

Pub Type

NIST Pubs

Keywords

composites, dental materials, fluoropolymers, silane coupling agents

Citation

Wang, F. , Antonucci, J. and Stansbury, J. (2008), Research for Improved Dental Restorative Materials, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD (Accessed April 24, 2024)