Polyglycolic acid Dexon suture material

# Polyglycolic acid (Dexon) suture material is:
A. Absorbable natural suture
B. Absorbable synthetic suture
C. Non-absorbable natural suture
D. Non-absorbable synthetic suture

The correct answer is B.

Polyglycolic acid (Dexon) and Polygalactin 910 (vicryl), Polyglyconate, Glycomer 631, Polyglytone 6211, Polydioxanone (PDS) are synthetic absorbable suture.

Polygalactic acid (Dexon) is green dyed and Polygalactin 910 (vicryl) is purple dyed while remaining are undyed.

Polygalactin (coated vicryl) is braided. It is commonly used for bowel anastomosis, as a general tie for vessels and as a subcuticular suture for skin. It has 75 percent of its strength at 2 weeks and 50 percent at three weeks. It causes a minimal tissue reaction and is very close to being the ideal suture for almost all purposes.

Polyglyconate has some some superior strength. It retains 75 percent of original strength at two weeks of post-implantation. Advantages over other sutures, such as improved handling properties, lacks memory, passes easily through tissues and demonstrates good strength. Absorption is essentially complete by 180 days.

 Polydioxanone (PDS) suture has greater pliability than polypropylene suture and has greater strength than that of other monofilament sutures. In the body, Polydioxanone suture retains its strength for longer periods than other synthetic absorbable sutures.

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Maxillary root removal technique

# Elevators should not be used to remove palatal root of an:
A. Upper incisor
B. Upper canine
C. Upper premolar
D. Upper molar

The correct answer is D. Upper molar. 

- Elevators should not be used to remove the palatal root of an upper molar.

- The buccal wall of socket does not form satisfactory fulcrum and can be crushed by the elevating force. 

- Furthermore, there is always the danger of forcing the root into antrum.

- The palatal root must be seen clearly, which usually implies the removal of both buccal roots and if necessary some surrounding bone, which can be done with a bur.

- Gentle dislocation with a narrow coupland chisel or rotation with upper root forceps should deliver the root.

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Radix Entomolaris / Radix Paramolaris

The radix entomolaris is an additional root in human's mandibular molar teeth. The human mandibular teeth have two roots usually. In rare cases, however, a root may develop between the distal and the mesial roots which is called entomolaris, if it is located lingual to the tooth.

Such a phenomenon is named radix paramolaris in case an extra root is buccal to a molar tooth. It is important to remember that an extra root can appear both in the first and second molars.

Three roots on mandibular molar, radix entomolaris

Radix entomolaris on a mandibular left first molar

Mandibular molar three roots, Radix Entomolaris

Radix entomolaris, apical view

Straight Elevator

# A straight elevator is properly used to advantage when the:
A. Adjacent tooth is the fulcrum
B. Tooth is isolated
C. Interdental bone is fulcrum
D. Adjacent tooth is not to be extracted

The correct answer is C. Interdental bone is fulcrum.

Straight elevator (Coupland, London Pattern) is the most commonly used. Usually used to luxate and elevate mandibular third molar and when multiple extractions are needed. It is not recommended in upper arch. This utilizes principle of lever mechanism. Alveolar crest acts as fulcrum. Adjacent teeth should never be used as fulcrum.

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Teeth in Line of Fire

# Teeth in line of fire means:
A. Teeth in the area of planned therapeutic radiation
B. Teeth in the line of fracture
C. Teeth within the cancerous region
D. None of the above

The correct answer is A. Teeth in the area of planned therapeutic radiation.

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EACA in Hemophilia Mechanism of Action

# Epsilon aminocaproic acid (EACA) is one of the agents useful in the treatment of haemophilia A. Mechanism of action of EACA is:
A. It is rich in factor VIII, which is deficient in hemophilia
B. Antifibrinolytic activity
C. It accelerates the coagulation process which is delayed in hemophilia
D.By unknown mechanism

The correct answer is B. Antifibrinolytic activity.

The main action of epsilon aminocaproic acid (EACA) is by its antifibrinolytic activity.

EACA is replaced by tranexamic acid, because of its more potent and longer acting properties and less side effects.

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MCQs on Hand Instruments and Instrumentation - Conservative Dentistry and Endodontics

# Which of the following is not true about hand instruments used in operative dentistry?
A. They are generally made of stainless steel
B. Nickel-cobalt-chromium is never used in its fabrication
C. Carbon steel is more efficient than stainless steel
D. It can be made with stainless steel with carbide inserts

# Most of the hand cutting instruments are made up of:
A. Chromium cobalt
B. Carbon steel
C. Tungsten carbide
D. Stainless steel