2-Impression Techniques for Complete Dentures 2025 - Copy.pptx

وتت

1. بسم الله الرحمن الرحيم 9/23/2025 Periclincal Removable Prosthodontics I 1

2. Impression Lecture: Impression Techniques for Complete Dentures Preclinical Complete Denture Semester 3 rd Year First semester Department of Removable Prosthodontics Periclincal Removable Prosthodontics I 9/23/2025 2

3. Foundation for Success Title: Foundation for Success: Impression Techniques for Complete Dentures Subtitle: Preclinical Complete Denture Course Semester: 5 Presenter: Dr Nasr Elsheikh University UTS Aden Periclincal Removable Prosthodontics I 9/23/2025 3

4. Learning Objectives By the end of this lecture, you will be able to: Define the purpose and objectives of making an impression for a complete denture. Differentiate between anatomic and functional impression techniques. . Periclincal Removable Prosthodontics I 9/23/2025 4

5. Learning Objectives By the end of this lecture, you will be able to: Identify the key anatomic landmarks of the maxillary and mandibular arches. Explain the clinical significance of each landmark in border molding and impression making. Describe the basic steps involved in a primary impression. Periclincal Removable Prosthodontics I 9/23/2025 5

6. Learning Objectives By the end of this lecture, you will be able to: Describe the basic steps involved in a primary impression. Periclincal Removable Prosthodontics I 9/23/2025 6

7. What is an Impression & Why is it Important ? Definition: An impression is a negative replica of the oral tissues. The cast poured from it becomes the positive replica on which the denture is fabricated. Periclincal Removable Prosthodontics I 9/23/2025 7

8. What is an Impression & Why is it Important ? 1 2 3 Periclincal Removable Prosthodontics I 9/23/2025 8

9. Cast Periclincal Removable Prosthodontics I 9/23/2025 9

10. The Primary Goal: To achieve maximum extension within the physiologic limits of the oral structures to enhance retention, stability, and support . Retention: Resistance against vertical displacement. Stability: Resistance against horizontal displacement. Support: Resistance against vertical forces toward the ridge. Periclincal Removable Prosthodontics I 9/23/2025 10

11. The Primary Goal: To achieve maximum extension within the physiologic limits of the oral structures to enhance Retention, Stability, and Support . Periclincal Removable Prosthodontics I 9/23/2025 11

12. "A denture is only as good as the impression it was built on." Periclincal Removable Prosthodontics I 9/23/2025 12

13. Classification of Impression Techniques 1. Based on Theory: Mucostatic (Passive) Mucocompressive (Active) Selective Pressure: Combines both. Periclincal Removable Prosthodontics I 9/23/2025 13

14. Classification of Impression Techniques A- Mucostatic (Passive): Records mucosa in its undisplaced state. Minimal pressure. (e.g., use of low-viscosity material). Periclincal Removable Prosthodontics I 9/23/2025 14

15. Classification of Impression Techniques B- Mucocompressive (Active): Records mucosa in its functionally displaced state. Uses pressure. (e.g., use of high-viscosity material). Periclincal Removable Prosthodontics I 9/23/2025 15

16. Classification of Impression Techniques C. Selective Pressure: Combines both. Places pressure on stress-bearing areas (e.g., buccal shelf) and relieves pressure on non-bearing areas (e.g., mid-palatal raphe). Periclincal Removable Prosthodontics I 9/23/2025 16

17. Based on Stage: Preliminary (Primary) Impression: Initial impression for making a diagnostic cast by a stock tray. Periclincal Removable Prosthodontics I 9/23/2025 17

18. Based on Stage: Final (Secondary) ( Definitive ) Impression: Accurate impression made using a custom tray. Periclincal Removable Prosthodontics I 9/23/2025 18

19. Based on Stage: Final (Secondary) ( Definitive ) Impression: Accurate impression made using a custom tray. Periclincal Removable Prosthodontics I 9/23/2025 19

20. Maxillary Landmarks (Limiting Structures (The Borders): Labial Frenum Labial Vestibule Buccal Frenum Buccal Vestibule Hamular Notch Vibrating Line (Ah-Line) Posterior Palatal Seal Area Periclincal Removable Prosthodontics I 9/23/2025 20

21. Maxillary Landmarks ( Periclincal Removable Prosthodontics I 9/23/2025 21

22. Support areas Those areas of the maxillary and mandibular edentulous ridges that are considered best suited to carry the forces of mastication when the dentures are in function. Periclincal Removable Prosthodontics I 9/23/2025 22

23. Maxillary Landmarks Supporting Structures: Hard Palate Residual Alveolar Ridge Rugae ( Secondary ) Periclincal Removable Prosthodontics I 9/23/2025 23

24. Maxillary Landmarks Relief Areas: Mid-Palatal Raphe Incisive Papilla Maxillary torus Periclincal Removable Prosthodontics I 9/23/2025 24

25. Mandibular Landmarks ( Limiting Structures (The Borders): Labial Frenum Labial Vestibule Buccal Frenum Buccal Vestibule (External Oblique Ridge) Retromolar Pad Lingual Frenum Mylohyoid Ridge (influences lingual flange) Retromylohyoid Fossa Periclincal Removable Prosthodontics I 9/23/2025 25

26. Mandibular Landmarks ( Limiting Structures (The Borders): Periclincal Removable Prosthodontics I 9/23/2025 26

27. Mandibular Landmarks Primary Supporting Structure: Buccal Shelf Area (Widest and most stress-resistant area) Periclincal Removable Prosthodontics I 9/23/2025 27

28. Mandibular Landmarks Relief Areas: Mental Foramen Torus Mandibularis (if present) Periclincal Removable Prosthodontics I 9/23/2025 28

29. The Clinical Sequence: From Start to Finish A Step-by-Step Overview: Patient Assessment & Diagnosis: Review medical/dental history, examine oral tissues. Primary Impression: Using a stock tray and alginate. Periclincal Removable Prosthodontics I 9/23/2025 29

30. The Clinical Sequence: From Start to Finish A Step-by-Step Overview: 3. Fabrication of Custom Tray: Made on the primary cast to fit the patient's unique anatomy. 4. Border Molding: The most crucial step! Using a low-fusing compound to functionally shape the borders of the custom tray . Periclincal Removable Prosthodontics I 9/23/2025 30

31. The Clinical Sequence: From Start to Finish A Step-by-Step Overview: 5. Final Impression: Using a precise elastomeric material (e.g., PVS, Polyether) in the border-molded custom tray. 6. Master Cast Pouring & Evaluation. Periclincal Removable Prosthodontics I 9/23/2025 31

32. Preclinical Lab Exercise Preview What you will be doing this semester: Identify landmarks on the provided casts. Fabricate special trays on primary casts. Practice border molding techniques on typodonts. Make final impressions on typodonts. Understand the rationale behind every step . Periclincal Removable Prosthodontics I 9/23/2025 32

33. Remember: Mastery (( Genius )) in the lab translates to confidence in the clinic. Periclincal Removable Prosthodontics I 9/23/2025 33

34. Key Take-Home Messages Knowledge of anatomy is non-negotiable. You must know the landmarks. The custom tray is essential for a accurate final impression. Border molding is the key to defining the functional denture borders and achieving a peripheral seal. The objective is to maximize support from stress-bearing areas and relieve pressure from delicate areas. Precision and attention to detail at this stage prevent problems later (sore spots, poor retention). Periclincal Removable Prosthodontics I 9/23/2025 34

35. Key Take-Home Messages Knowledge of anatomy is non-negotiable. You must know the landmarks. The custom tray is essential for an accurate final impression. Periclincal Removable Prosthodontics I 9/23/2025 35

36. Key Take-Home Messages 3. Border molding is the key to defining the functional denture borders and achieving a peripheral seal. 4. The objective is to maximize support from stress-bearing areas and relieve pressure from delicate areas. Periclincal Removable Prosthodontics I 9/23/2025 36

37. Key Take-Home Messages 5. Accuracy and attention to detail at this stage prevent problems later (sore spots, poor retention). Periclincal Removable Prosthodontics I 9/23/2025 37

38. References & Questions Recommended Texts: Zarb , Bolender , et al. - Boucher's Prosthodontic Treatment for Edentulous Patients Heartwell , Rahn - Syllabus of Complete Dentures . Periclincal Removable Prosthodontics I 9/23/2025 38

39. Thanks, A lot 9/23/2025 Periclincal Removable Prosthodontics I 39