ENDO Flashcards
Which of the following is NOT true concerning gutta percha?
A. It should be stored at room temperature. B. It is freely soluble in ether. C. It is freely soluble in chloroform. D. It is produced in standardized and nonstandardized cones.
A. It should be stored at room temperature:
Gutta percha is a rubberlike material used for obturation. Different manufacturers have varying formulas for its fabrication. It tends to oxidize and gets brittle over time and should be discarded if brittleness is noted. It will last longer if refrigerated. It is freely soluble in ether (choice B), chloroform (choice C), and xylol. These solvents can be used in removing gutta percha during retreatment. It is fabricated in standard cones (with taper similar to that of endodontic files) and nonstandard cones (more heavily tapered) (choice D). Standard cones are used primarily for master points.
An adult patient sustains trauma to the maxillary lateral incisor that results in the intrusion of this tooth. The MOST likely change to occur to the pulp would be:
A. hyperemic pulp. B. internal resorption. C. pulp stones. D. pulpal necrosis.
D. Pulpal necrosis:
When a tooth is traumatically pushed apically, pulpal necrosis is very likely (>90%). The chance of necrosis (or cell death) increases with the degree of trauma the tooth receives. In hyperemia (choice A), the tooth is often sensitive to cold or sweets, but the associated pain is short in duration, lasting only a few seconds. It subsides after the stimulus is removed. Pulp stones (choice C) are less common, usually associated with less traumatic cases. Internal resorption (choice B) is also possible following pulpal necrosis, but again, is not as common as necrosis itself.
Which of the following components makes up approximately 70% of a gutta percha point?
A. Gutta percha rubber B. Zinc oxide C. Barium salt D. Waxes and resins
B. Zinc oxide:
The chief component of gutta percha points is not gutta percha rubber but zinc oxide.
Zinc oxide makes up approximately 60% to 70% of this material.
Heavy metal barium sulfates compose approximately 5% to 15%, and waxes and resins compose about 1% to 4%. The variety in the composition shows that there is no distinct formulation for this material and that different manufacturers follow their own recipes. Gutta percha rubber itself is very soft and is usable only with a stiffening agent such as zinc oxide
A standard 25 mm #45 endodontic file would have the color:
A. violet. B. white. C. yellow. D. red. E. blue.
B. White:
The standard colors for the files are based on the width of the blade, not the length. Standard file colors are: #8, gray #10, violet #15, white #20, yellow #25, red #30, blue #35, green #40, black #45, white.
The colors then repeat themselves (yellow, red, etc.). It should be noted that both gray and violet are used only once and are not repeated.
Which of the following can be used in a walking bleach technique?
A. 15% phosphoric acid B. 37% phosphoric acid C. 10% carbamide peroxide D. 30% aqueous hydrogen peroxide
D. 30% aqueous hydrogen peroxide:
Bleaching is a technique to remove or reduce undesirable discoloration of the teeth. It can be classified as vital (or extracoronal) or nonvital (or intracoronal) bleaching. Vital bleaching is used on teeth with vital pulp, and nonvital bleaching is used on root canal teeth. “Walking bleach” refers to an intracoronal bleaching method in which a 30% aqueous solution of hydrogen peroxide is mixed with powdered sodium perborate into a paste. This combination is sealed into the pulp chamber for 3 to 7 days. This procedure can be repeated until the desired result is achieved.
A solution of 10% carbamide peroxide is associated with vital (custom tray) bleaching.
Both 15% and 37% phosphoric acid are used in the acid-etch technique associated with resin bonding.
When beginning an access preparation through the porcelain of an existing crown, it is BEST to begin with a(n):
A. end-cutting fissure bur. B. round carbide bur. C. tungsten-tipped bur. D. small, round diamond.
D. small, round diamond:
The small, round diamond on a water-cooled, high-speed handpiece is the best way to begin access on porcelain crown surfaces. Use of the diamond minimizes the chance that the porcelain will fracture or craze.
An end-cutting fissure bur is used for most standard-access preparations in natural tooth structure.
Round carbide burs are often used following the fissure bur to open the chamber and remove the roof.
Tungsten-tipped burs can be used for very resistant casting metals,
A patient presents with a tooth that is sensitive to cold and is accompanied by prolonged intense pain that subsides in about 5 minutes after the thermal stimulus is removed. The patient also complains of spontaneous pain. The tooth is NOT sensitive to percussion or palpation. The MOST likely diagnosis is:
A. hyperemic pulp. B. reversible pulpitis. C. irreversible pulpitis. D. necrotic pulp. E. symptomatic apical periodontitis.
C. Irreversible pulpitis:
A prolonged, lingering pain after the thermal stimulus is removed that takes several minutes to subside is usually associated with a more advanced pulpal disease like irreversible pulpitis. Symptomatic irreversible pulpitis will often include a complaint of unprovoked discomfort or spontaneous pain. A hyperemic pulp (Choice A) and reversible pulpitis (Choice B) are conditions that are often associated with a sensitivity to cold or sweets, but with pain that is short in duration, lasting only a few seconds after the thermal stimulus is removed. Sensitivity to heat is also a sign of a more advanced stage. With a necrotic pulp (Choice D), a tooth is normally not sensitive to cold but may be sensitive to heat and possibly to pe
An endo-perio combined lesion is characterized by:
A. vital pulp. B. necrotic pulp, plaque, and calculus with varying degrees of periodontal disease. C. vital pulp with severe periodontal disease. D. independent presence of both periodontal and pulpal disease, which never unite.
B. necrotic pulp, plaque, and calculus with varying degrees of periodontal disease:
A true combined lesion is defined in the following ways:
1) the tooth must have a nonvital (necrotic) pulp
2) there must be a periodontal defect in the attachment that can be probed
3) the tooth requires both endodontic and periodontal therapy in order to achieve complete resolution of the lesion.
These lesions involve the periodontal attachment from the sulcus to an area of involvement, a lateral canal or the apex. Diagnosis is essential in distinguishing these lesions from secondarily involved lesions for optimal treatment planning and healing potential. The two lesions must connect. Remember, the lesion must be able to be probed from the sulcus to the area of involvement.
Several days after the placement of an amalgam, the patient returns to your office with a chief complaint of mild to moderate pain to heat, cold, and sweets. The MOST likely diagnosis is which of the following?
A. Irreversible pulpitis B. Reversible pulpitis C. Pulpal necrosis D. Wrong choice of restorative material
B. Reversible pulpitis:
Placement of a restoration may irritate the pulpal tissue. This may be caused by the mechanical preparation, or through the heat generated during instrumentation, or from excess drying of the pulpal floor of the preparation. Also, a slightly high restoration can cause pulpal irritation. This reversible pulpitis is characterized by general sensitivity to most stimuli, with mild pain that usually decreases over time. The discomfort associated with reversible pulpitis is not spontaneous and not present upon percussion or palpation. Irreversible pulpitis (choice A) is usually associated with acute pain and with sensitivity to heat and percussion, and can be sensitive to cold or sweets as well. Pulpal necrosis (choice C) is not generally sensitive to heat or cold but may be extremely sensitive to palpation or percussion and may have pain that is spontaneous in nature. Although the operative process may be irritating for the patient, the type of material is not responsible for the discomfort (choice D). Choosing a different restorative material may still result in irritation in this case.
For cases of small carious exposures on permanent teeth, which treatment usually offers the BEST long-term prognosis?
A. Glass ionomer restoration B. Calcium hydroxide pulp cap C. Root canal therapy D. Formocresol pulpotomy
C. RCT:
Although pinpoint mechanical exposures are often successfully treated with a calcium hydroxide pulp cap, carious exposure treatment with pulp cap is usually less successful. Root canal therapy is recommended for most carious exposures.
A glass ionomer may be used as a restoration, but it does not address the carious exposure in this scenario. A glass ionomer is often used to promote remineralization in compromised tooth structure. Glass ionomer is not typically used directly over the exposed carious pulp. It has a sedative effect on pulpal tissue but is contraindicated if there is a carious exposure.
Formocresol pulpotomy is indicated in primary teeth where the coronal pulp is inflamed, but the radicular pulp is still healthy.
An adult patient fractures a maxillary central incisor, yielding a small pulpal exposure (1 mm in size), approximately 20 minutes prior to seeking dental care. The MOST appropriate treatment plan would be which of the following?
A. Pulpectomy B. Pulpectomy with formocresol C. Pulpectomy with CaOH D. Indirect pulp-capping procedure with CaOH E. Direct pulp-capping procedure with CaOH
E. Direct pulp-capping procedure with CaOH:
Small, noncarious exposures are best treated with a calcium hydroxide pulp cap, but not indirectly. Often, a healthy pulp can heal and form new dentin. Pulpotomy, or pulpectomy, is usually restricted to primary teeth with necrotic pulpal tissue but healthy radicular pulp. It can also be used as a temporary palliative treatment with adult teeth.
Pulpotomy with or without formocresol, is indicated with a large exposure and symptomatic carious exposures where pulp-capping has a minimal chance of success.
The calcium hydroxide used in an apexification procedure acts by:
A. creating an alkaline area at the apex. B. creating an environment conducive to osteoclast activity. C. creating a low pH environment conducive to bone growth. D. stimulating secondary dentin to protect the pulp.
A. creating an alkaline area at the apex:
The goal of apexification is to induce further root closure in a pulpless tooth by stimulating the formation of a hard substance at the apex, so as to allow obturation of the root canal. A paste of calcium hydroxide is placed into the root canal. This is used in apexification to stimulate the formation of a hard tissue bridge at the apex of an incompletely formed root. The bridge has been described as being an osteoid (bone-like) tissue. Once it is formed, conventional endodontics is more likely to be successful. The osteoid tissue requires an alkaline environment in order to form. This high pH environment is produced by the calcium hydroxide. Osteoclasts (choice B) will stimulate the breakdown of bone; it is the osteoblasts that are responsible for the formation of dentin. Establishing a low pH (choice C) is conducive to osteoclast activity that would cause the breakdown of bone. The apexification procedure is carried out on a tooth that is pulpless therefore has no pulp to protect (choice D) and has a fairly large open apex.
All of the following would indicate that a lesion is endodontic rather than periodontal in nature EXCEPT one. Which of the following is this EXCEPTION?
A. Pain to palpation at the apex on the buccal B. Acute pain associated with percussion with no swelling present C. Sulcular pocket to the apex with exudate D. Pain to lateral percussion with a wide sulcular pocket E. Prolonged pain for 5 minutes upon exposure to endo ICE
D. Pain to lateral percussion with a wide sulcular pocket:
Pain to lateral percussion with a wide sulcular pocket generally indicates a periodontal problem. The wide sulcus is a sign of attachment destruction, and the pain on lateral percussion is caused by pressure on the inflamed and infected periodontal ligament. Pain associated with palpation of the buccal mucosa at the apex (choice A) is usually a sign of a necrotic pulp with a pressure buildup at the apex. The infected necrotic pulp forms pus, which escapes through the narrow pocket. Acute pain on percussion (choice B) often occurs in endodontic cases of irreversible pulpitis. A deep, narrow pocket to the apex with exudates (choice C) is often a sign of an endodontic problem. Prolonged pain upon exposure to endo ICE (choice E) is indicative of irreversible pulpitis, an endodontic problem.
The chemical of choice in the bleaching of endodontically treated teeth would be:
A. sodium perchlorate. B. hydrogen peroxide. C. sodium hypochlorite. D. sodium chloride.
B. hydrogen peroxide:
Two chemical agents commonly used to bleach endodontically treated teeth are:
- 30% hydrogen peroxide (Superoxyl)
- sodium perborate
They are used in the “walking bleach” technique. Sodium perborate is different from sodium perchlorate, which is not a bleaching agent. Sodium hypochlorite is used to irrigate the canals during root canal therapy and is commonly used to bleach clothing. Sodium chloride is table salt and is used in saline solution.
A patient had a direct pulp-cap placed 6 weeks ago. During examination, the tooth is asymptomatic. What conclusion can be made at this point?
A. Reparative dentin has formed at the site exposure. B. The pulp-capping procedure was successful, and it is time to place a final restoration. C. The tooth should be asymptomatic for at least 3 to 4 months before a final restoration is placed. D. No conclusions can be drawn.
C. The tooth should be asymptomatic for at least 3 to 4 months before a final restoration is placed:
The treated tooth has been asymptomatic for 6 weeks. When a small exposure is made in the pulp chamber, pulp-capping with a material such as calcium hydroxide sometimes induces reparative dentin to form. This would obviate the need for endodontic treatment. A pulp-capped tooth should be observed for 3 to 4 months before a final restoration is placed. Even if it is asymptomatic after 8 weeks, this might be temporary.
With only 6 weeks since the procedure, complete reparative dentin formation has not yet occurred.
