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:
            o-step) putty-wash technique. 
7. Closed-mouth (Dual-arch) (Triple-tray) Impression Technique.  
8. Automix Technique. 
9.  Machine-Mixing Technique.  
10. 
 Direct / indirect impression for post; wax pattern, acrylic resin, or rubber base.  
11. 
 Closed & opened tray technique for implants;  
Indirect technique uses a transfer coping & direct technique uses a pick-up coping 
12. 
 Virtual (Digital) impression. 
 
1- Single (individual) copper band impression technique: 
• Cu bands are supplied in different sizes & diameters. 
Indicated for: single full metal crown preparation.  
Advantages: Cu band will displace the gingival tissues. 
Used either with: 
• Impression compound: Cu band should snugly fit  
  the cervical margin of the preparation, as it is in-elastic material.  
• Rubber base: 4 mm space between the Cu band & cervical margin  
                          of the preparation because it is an elastic material.  
• Technique:  
1. Select the suitable size of Cu-band which snugly fit the preparation in  
case of impression compound or with 4 mm space in case of rubber base.  
2. Trim the cervical margin of the band to fit the finish line  
i.e. convex MD & concave FL.  
3. Roughen 2 mm of the inner cervical edge of the band to → ↑ retention with the 
impression.  
4. Mark → 2 vertical lines at MB & DB line angle    
           → 1 horizontal line at MB & DB surface   
indicating occlusal surface of the prepared tooth.   
These marks help seating & Re-seating of Cu-band.                                                                
115
 
 
5. Cut 2 holes in the occlusal end of the band  
6. Attach a piece of dental floss in each hole to → allow easy removal of the band. 
7. Lubricate the tooth with petroleum jelly (Vaseline). 
8. Mix the impression material → apply in the Cu band.  
9. Seat the band on the tooth with steady pressure. 
10. 
 Leave it for 3-5 min till setting. 
11. 
 Remove the band with the aid of dental floss. 
12. 
 Evaluate the impression for any in-accuracy. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
2- Heavy-bodied-light-bodied combination: 
 
Steps: 
1- Evaluate the custom tray in the patient’s mouth to verify its fit.  
Correct the tray as needed. 
2- Apply tray adhesive to extend a few millimeters onto the external surface of the 
tray. → Allow the adhesive to dry.  
 
 
• N.B: If existing partial FDPs are present in the arch to be impressed,  
apply soft wax or an alternative suitable block-out material in the cervical aspect of 
all pontics → to prevent the set impression material from “locking” in the mouth.  
3- Ensure that the disposable syringe-tip has an opening of adequate size in relation 
to the viscosity of the impression material that has been selected.  
116
 
 
• For most light-bodied materials, a cross-sectional opening of about 0.8 - 1 mm is 
adequate.  
4- Isolate the abutment teeth, & place gingival displacement cord in the sulcus. 
5- On separate pads (one for the tray & one for the syringe materia

            Quiz: