Effect of flowability on the flow rate, polymerization shrinkage, and mass change of flowable composites

Abstract

As a lining or restoration material, flowable composites are popular due to their ease in use and agreeable marginal adaptation of tooth cavity. The purpose of the present study was to evaluate various properties of flowable composites which were claimed to be of high or low flowability by the manufacturers. For the study, twelve flowable composites from six different manufacturers were used. Based on the manufacturers' claim, they were divided into two groups: high or low flowability. The products grouped in high flowability showed significantly higher (p<0.05) flow rate (flow distance), polymerization shrinkage, and microhardness (on the top surface), regardless of light-curing unit, than those grouped in low flowability. On the other hand, water sorption and solubility showed nonsignificantly different values regardless of flowability. Through the study, flow rate had low correlation with microhardness (R<0.23), polymerization shrinkage (R<0.60), and water sorption and solubility (R<0.36) regardless of light-curing unit.

Overviews on the Progress of Flowable Dental Polymeric Composites: Their Composition, Polymerization Process, Flowability and Radiopacity Aspects

“…Ku et al, investigated 12 flowable composites from six manufacturers, divided into groups of high or low flowability, according to the manufacturers’ claim. Those of high flowability showed significantly higher polymerization shrinkage, regardless of the light-curing unit used [ 35 ]. In another study, the incremental filling with a flowable composite liner showed higher spot deflection than that without a flowable liner, and the difference was maintained until 2000 s after the initiation of light curing.…”

Characteristics of low polymerization shrinkage flowable resin composites in newly-developed cavity base materials for bulk filling technique

“…The reason for non-linear correlation between filler content and polymerization shrinkage is not clear. Ku et al reported that polymerization shrinkage was less correlated with filler content for commercially available flowable resins 9) . It is well known that the degree of photo polymerization of photo-curable composite resins depends on the differences of refractive indexes, kinds of monomers or fillers, shape and distribution of fillers and photo polymerization initiators, etc., besides filler content.…”

“…The increase of filler content in flowable resin composite is limited in order to maintain its flowability. This decrease of inorganic filler content corresponds with an increase of monomer content, leading to the increase of polymerization shrinkage 9) . The occurrence of polymerization shrinkage in a restoration can lead to secondary caries, pulpal damage, and debonding of restorative appliances due to gap formation between restorative materials and cavity walls.…”

Akıcı Kompozitler: Bir Literatür Derlemesi

“…Bununla birlikte, bir akışkanlık derecesi olarak akış hızının uygulanan ışık kaynağı ve polimerizasyondan bağımsız olarak mikrosertlik, polimerizasyon büzülmesi, su emme ve çözünürlüğü ile düşük korelasyona sahip olduğu bildirilmiştir. 82…”