Glass Ionomer Cements Flashcards

Question

What can you do to prevent adverse effects when using RMGIC

Answer 1

Trimming and polishing under water coolant to prevent dehydration and shrinkage

Answer 2

Powder and liquid ratio measurement prone to errors Less expensive Increased porosity Centrifugal frequency 2950 rpm 3 seconds in 80 mm diameter orbit

Answer 3

Careful to find balance between desiccation and excessive moisture contamination during placement Avoid salivary contamination of the cavity - use cotton wool rolls and slow suction

Answer 4

No separate bonding agent needed- can sometimes use a conditioner Mechanism is micromechanical interlocking (cement tags) and chemical bonding (ionic bond between calcium in the enamel and dentine and carboxyl ions in the GIC), (calcium phosphate polyalkenoate bond) Bond is compromised if the tooth surface is contained with blood or saliva

Answer 5

Finishing - contouring for optimal marginal finish and occlusal anatomy Polishing- smoothing the surface with abrasives to create low surface roughness and high surface lustre Initially use hand instruments to shape Use steel burs with Vaseline (avoid water to prevent expansion) to remove excess Place protective resin When fully set (24 hours+ for conventional) Use rotary abrasives (so flex disks, tungsten carbide burs and diamond finishing burs) Note the manufacturer’s instructions- may vary by brand, RGMI less susceptible it can be placed on the same day as placement

Answer 6

Heat generation may damage the pulp. Resins may be placed as a varnish after placement and hardening to protect the GIC during the setting process

Answer 7

Flouride enters the tooth from the restoration Equilibrium is reached between tooth surface and restoration Flouride leaches into salvia Tooth and restoration depleted of flouride Topical replenishment of flouride reacharges the cement

Answer 8

Fuji II LC primary teeth, triple cure Fuji triage - temp, paediatric, elderly, fissure protection, root surface protection Fuji IX - temp, self cure

Answer 9

Bacteriostatic Thermal insulation But Does not lay down reparative dentine Need 0.5mm thickness of dentine - if less than 0.5mm between it and pulp then CaOH liner first

Answer 10

Similar composition to GIC restorative material Smaller glass particle size to allow thinner film thickness

Answer 11

Minimally invasive approach which involves removal of caries using hand instruments alone Usually without use of anaesthesia Then restoration with adhesive materials e.g. GIC Technique has helped to bridge the gap in the provision of treatment to rural communities, senior citizens, children and dental phobic patients. Combines both restorative and preventive care, and causes minimal discomfort to patients.

Answer 12

Isolate the tooth to be restored with cotton wool rolls. Clean the tooth with water and cotton wool pledgets. Widen the entrance to the lesion with hand instruments. Remove all carious tissues with an excavator Clean the cavity and occlusal surfaces with cotton wool pledgets and water. Provide pulpal protection with calcium hydroxide liner if necessary. Condition the cavity walls and occlusal surfaces of the tooth according to the manufacturerís instructions. Mix the glass-ionomer cement according to instructions and insert the material into the cavity, overfilling slightly. Apply pressure with a gloved finger to the occlusal surface of the tooth, thus condensing the restoration (finger-press technique) Check for correct occlusion. Remove any excess material with a carver or similar flat plastic instrument Readjust the bite if necessary, making sure that the occlusal fissures are sealed Apply Vaseline to the restoration to protect the glass-ionomer during the initial setting reaction. Instruct the patient to avoid eating for about an hour to allow the material to set completely.