This document discusses dental composite materials, including their chemical and light activation methods, filler types, and shrinkage properties. It provides information on methyl methacrylate and Bis-GMA as common resins, as well as camphoroquinone and tertiary aromatic amines as typical photoinitiators and light absorbers. Details are given on densified and microfine composites, with filler particles less than 3 micrometers. The concepts of C-factor and methods to reduce composite shrinkage stresses at the tooth restoration interface are also summarized.
33. CHEMICAL ACTIVATED LIGHT ACTIVATED
FORM: Two paste system One paste system
MIXING: Mix equal parts ~ entrapped air voids Readily available with no mixing
WORKING TIME: Limited Flexible
SETTING:
Start upon mixing
Extended until consuming all initiator
Command
Extended until light emission stopped
CONVERSION: Homogenous maximum curing
Un-homogeneous
Affected by time and depth of light
34. CHEMICAL ACTIVATED LIGHT ACTIVATED
COLOR
REPRODUCTION:
Poor quality of color reproduction High quality of color reproduction
TECHNIQUE
SENSITIVITY:
Only limited working time Problems with ambient light
159. HIGH C-FACTOR
In such a case, to reduce the C-factor:
1. Lining with GIC or flowable composite
2. Incremental packing in vertical or oblique pattern
3. If it is difficult, split the horizontal increment