Impression Materials Consideration and Classification

Considerations for choosing impression material：
1. Accuracy
2. Dimensional Stability
3. Manipulative Variables




A good impression material should have the elements below：
1. 材料的氣味易被患者接受
2. 成分不會引起患者口腔組織的不良反應
3. 價格合理
4. 優良的Accuracy
5. 在口腔內及室溫能保持Dimensional Stability
6. 操作簡單
7. Working time長、Setting time短
8. 印模過程中具有足夠的強度及抗撕裂能力
9. 足夠長的保存期限
10. 和石膏印模材有良好相容性




Classification：


• Inelastic Impression Materials
1. Impression Plaster
2. Impression Wax
3. Zinc Oxide Eugenol Impression Pastes
4. Impression Compounds




• Elastic Impression Materials
1. Agar Hydrocolloid Materials (Reversible Hydrocolloid)
2. Alginate Impression Materials (Irreversible Hydrocolloid)
3. Rubber Impression Materials
4. Polysulfide
5. Condensation Silicone
6. Addition Silicone
7. Polyether