TOPIC: IMPRESSIONS IN FIXED PARTIAL DENTURE
🎯 KEY POINTS:
🔸Electrosurgical procedure for impression making is contraindicated in patients with pacemakers.
🔸Epinephrine should be avoided in patients suffering from hypertension or cardiovascular disease, as it increases the heart rate and blood pressure.
🔸Rubber dam should not be used when impression is made with polyvinyl siloxane, as it inhibits the polymerization of the impression material.
🔸Svedopter is usually used in mandibular arch when the patient is seated in nearly upright position.
🔸Automix polyvinyl siloxane is loaded onto the tray and seated on the segment of the arch.
🔸Dento-infusor with 20% of ferric sulphate chemical is commonly used to control the haemorrhage during cervical margin preparation.
🔸Electrosurgery is also called surgical diathermy.
🔸Rotary curettage method is also called gingettage.
🔸Mechanico-chemical method (retraction cord) is supplied in three basic designs which include knitted cord,
braided cord and twisted cord.
🔸Rubber dam was introduced by S.C. Barnum.
🔎 METHODS OF FLUID CONTROL
👉 There are essentially two methods of fluid control, namely, Mechanical and Chemical Methods.
📌 MECHANICAL METHODS:
- Rubber dam
- High-volume suction
- Saliva ejector
- Svedopter
📌 CHEMICAL METHODS
- Antisialagogues
- Local anaesthetics (adrenaline)
📢 METHODS OF GINGIVAL RETRACTION:
- Mechanical methods
- Mechanico-chemical methods
- Surgical methods
📢 COMMONLY USED ELECTROSURGICAL ELECTRODES:
- Coagulating probe
- Diamond loop
- Round loop
- Small straight probe
- Small loop
📢 COMMON TECHNIQUES FOR GINGIVAL RETRACTION:
- Single cord technique
- Double cord technique
- Infusion technique
📌 CLASSIFICATION OF IMPRESSION TECHNIQUES
✳️ On the Basis of the Type of Impression Trays Used:
- Stock trays/putty wash impression technique
- Custom tray
- Dual arch or closed bite or triple tray impression technique
- Segmental impression technique
- Post-space impression technique