Direct and indirect restorative materials (Ch 6) Flashcards
what is aesthetic
- meaning to replace or bring something back to a pleasing appearance
what are aesthetic materials
- materials that replace lost tooth structure
what are direct-placement aesthetic materials
- tooth coloured materials that can be placed directly into the cavity preparation without being constructed outside of the oral cavity first
- restorative materials are applied to the tooth while the material is pliable and one is able to carve and finish the material
what are indirect-placement aesthetic materials
- tooth coloured materials that are used to construct restorations outside of the oral cavity in the dental lab or at chair side on replicas of the prepared teeth. they are cemented or bonded to the teeth after tooth preparation
what are some examples of direct restorative materials
- composite resins
- glass ionomers
- hybrid (resin-modified) ionomers
- compomers
what are composite resins
- becoming the most widely accepted material of choice by dentists and patients because of their aesthetic qualities and new advances in strength
what are the 2 main characteristics of composite resins
- tooth coloured
2. general usage
what are some indications for using composite resins
- withstand the environments of the oral cavity
- be easily shape to the anatomy of a tooth
- match the natural tooth colour
- be bonded directly to the tooth surface
what is the composition of composite resins
- resin matrix: BidGMA = monomer used to make synthetic resins = Bis-phenol A = BPA
- polymerization additives: allow the material to take form through a chemical process. made of initiator, accelerator, retarder, UV stabilizers
- fillers: add the strength, increase wear resistance
what is Bis-phenol A (BPA)
- a plasticizer used in many products
- plastic food storage containers (plastic bottles)
- plastic lining in autoclavable food and beverage cans
what are monomers used for in dentistry (like BPAs)
- composite resins
- pit and fissure sealants
when using BPAs…
- use light-cure materials
- BPA monomer leaches out of cured resin after light-curing (20-40 seconds)
- to remove residual monomer: polish the surface with a mild abrasive (pumice); wash with air-water spray for 30 seconds using HVS
what do fillers do in composite resins
- control the handling characteristics and reduce shrinkage
- inorganic fillers: colourants = pigments in varying amounts to approximate tooth colours
what are macrofilled composites
- contains the largest size of filler particles
- provides greater strength
- duller rougher surface
what are microfilled surfaces
- filler particles are much smaller
- highly polished finished restoration
- primarily used for anteriors because of lack of strength
what are hybrid composites
- contains both macrofilled and microfilled particles