Polymerization quality testing of composite resins cured by led light source

Abstract

The quality of interface between composite resin materials and hard dental tissues is highly dependent on the polymerization light source. Newly developed blue light- emitting diode units for light polymerization of dental restorative materials are the most innovative light source technology in dentistry nowadays. The aim of this work was to estimate the depth of cure of five different light-activating composite resins exposed to different irradiation times (5s, 10s, 20s and 40s) when the experimental LED light source was used. The tested materials were: Tetric Ceram (Vivadent), Point 4 (Kerr), Admira (VOCO), Filtek Z250 (3M) and Diamond Lite (DRM Lab., Inc). The depth of cure testing was determined using a penetrometer. Results after 40s curing time were as following: the deepest depth of cure was achieved after application of Filtek Z 250, Diamond Lite Point 4 and Tetric Ceram. For the restorative material Admira was found the lowest depth of cure for the light exposure of 40s. An experimental LED light source achieved a sufficient depth of cure (over 2 mm) for all tested materials after curing time of 10s. The polymerization light source spectral distribution should be considered in addition to irradiance as a depth of cure indicator.

Kvalitet veze ostvaren u međuspoju zub-kompozitni ispun u velikoj meri zavisi od procesa svetlosne polimerizacije. Svetlosni izvori sa plavim svetlosno-emitujućim diodama (LED) predstavljaju najaktuelnije polimerizacione izvore u savremenoj stomatologiji. Prezentovana istraživanja su imala za cilj određivanje dubine polimerizacije kod pet restaurativnih kompozitnih materijala polimerizovanih eksperimentalnim LED izvorom nakon ekspozicija od 5s, 10s, 20s i 40s. U istraživanju su testirani sledeći materijali: Tetric Ceram (Vivadent), Point 4 (Kerr) Admira (VOCO), Filtek Z 250 (3M) i Diamond Lite (DRM Lab., Inc). Dubina polimerizacije je determinisana penetrometrom. Rezultati su ukazali da je najveća dubina polimerizovanog sloja materijala nakon ekspozicije od 40s ostvarena kod restaurativnog materijala Filtek Z 250, zatim kod materijala Diamond Lite, Point 4 i Tetric Ceram, dok je kod materijala Admira uočena najmanja debljina polimerizovanog sloja. Dobijeni rezultati takođe ukazuju da je vreme ekspozicije od 10s dovoljno za ostvarivanje polimerizovanog sloja debljine preko 2 mm kod svih testiranih materijala. Dubina polimerizacije ne zavisi samo od emitovane snage izvora.