Pretend you are a teacher preparing a quiz for the text I will provide. 
            Each quiz question should follow the format below. 
            Ensure that you carefully recheck the questions and answers for accuracy. 
            The output should be a ready-to-use list of dictionaries for the Python eval function:

            [

                    "question": "WRITE THE QUESTION HERE",
                    "options": ["A) OPTION_1", "B) OPTION_2", "C) OPTION_3", "D) OPTION_4"],
                    "answer": INDEX_OF_CORRECT_ANSWER_IN_OPTIONS_LIST,
                    "explanation": "EXPLAIN WHY THE ANSWER IS CORRECT"

            ]

            Text:
            ating the adequacy of tissue displacement, the clinician should view 
the tooth preparation from the occlusal aspect:  
The clinician should be able to see the preparation margin circumferentially  
& a width of the uninterrupted cord, with no free gingival tissue folded over it  
or in contact with tooth (a moat around castle).  
✓ The entire preparation margin should be clearly visible  
& remain directly accessible for 30-60 seconds.  
✓ If any G tissue folds back into contact with the preparation sooner →  
2nd cord is inserted immediately after this evaluation.  
The placement of 2nd cord is usually fairly straight forward,  
as the periodontal fibers have been stretched by 1st displacement effort.  
85
 
If the result is acceptable, 2nd cord is typically inserted quickly to maintain the 
displacement while the impression material is mixed.  
✓ To be successful, this technique requires that about 1 mm of intact tooth structure 
remains between the top of 1st cord & the preparation margin. 
➢ Hemorrhage Control with an Infuser Syringe:  
• Minor hemorrhage can sometimes be controlled with either: 
1) an astringent (Astringedent or ViscoStat [20% Fe2(SO4)3] used with the  
Dento-Infusor Tips according to the recommendations of Ultradent Products). 
 
2)  infiltrating a local anesthetic directly into the adjacent gingival papillae. 
• Step-by-Step Procedure: 
1) Fill the syringe with Fe2(SO4)3 solution & attach the infuser tip.  
This hollow metal tip contains a cotton filament to control the flow of Fe2(SO4)3.  
2) Rub the tip back & forth for about 30 seconds over the hemorrhaging area while 
slowly replenishing the solution by continuous injection.  
3) Irrigate the area with an air-water syringe →  gently dry the tissues with air. 
Inspect to determine the degree to which bleeding ↓.  
Repeat several times if necessary. 
4) Place a displacement cord.  
5) Before cord removal, slightly moisten the cord with water  
→ to ↓ risk of dislodgment of blood clots →  renewed hemorrhage.  
6) Gently dry the tissues → impression making.  
• Evaluation:  
✓ On many occasions, the correct decision is to delay impression making & 
concentrate on improving tissue health; 
1) reassessing the quality of the interim restoration.  
2) reinforcing oral hygiene instructions.  
3) a chlorhexidine mouth rinse. 
86
 
➢ Displacement Pastes: 
 
 
 
  
 
 
 
 
1) Some dentists advocate displacement paste (Expasyl) as an alternative to cord.  
✓ AlCl3-containing paste is injected into the dried sulcus with a special delivery gun. 
✓ Advantages: Good hemostasis with less discomfort than with the cord.  
▪ However, less tissue displacement is achieved than with cord, → 
may make subsequent laboratory steps e.g., die trimming more problematic. 
✓ Improved displacement may be achieved if the paste is directed into the sulcus by 
applying pressure with a hollow cotton roll (Roeko Comprecap).  
 
2) Other displacement pastes rely on volumetric expansion, as 1st described by

            Quiz: