Module 2: Radiography Lecture Flashcards
What are the three areas of importance related to radiographs in endo?
Diagnosis
Treatment
Recall
What are the three primary ways in which Radiographs are used in diagnosis?
Identifying Pathosis
Determining Root and Pulpal Anatomy
Charaterizing normal structures
What are radio graphs used for in the treatment phase?
Determining working lengths
Locating Canals
Obturation
What are radiographs used for in the recall phase?
Healing of the pathos
Determining other treatment options
What is the most common recall duration
1 year
What is the primary type of radiograph used in endo?
PA
How much bone should be visible beyond the apex of the tooth in an endo PA?
At least 2mm
Besides 2mm of bone, what else should be clearly visible in an endo PA?
The entire periapical lesion
What is the complete series of endo PA’s for a treament?
Pre-procedure
During Procedure
Post-op
Recall
What are the primary limitations of Radiographs?
Two dimensional representation of tooth
Superimposition of anatomic structures
Lesions only appear after a certain amount of bone destruction has already occurred.
The buccal object rule is also known as the S.L.O.B. rule. What does SLOB stand for?
Same
Lingual
Opposite
Buccal
What does the SLOB rule tell us about an object that we are taking a “shift-shot” of?
When the tube head is moved mesially:
If the object also moves mesially, then the object is on the lingual side of the root. SLob Same=Lingual
If the object moves distally then the object is on the buccal side of the root slOB Opposite = Buccal
What is the ideal shift (in degrees) for utilizing the SLOB rule?
20 degrees (Enough to separate objects in question without distorting them)
What exactly does the SLOB rule allow for clinically?
Location of additional canals and/or roots
Distinction b/w superimposition of structure
Determination of buccal or lingual position of anatomical features of iatrogenic mishaps.
PA images are easily distorted, how can this be accommodated?
Take BW in addition to PA’s in order to minimize elongation or foreshortening
What do BW’s do better than PA’s?
Depth of caries Extent of restorations Morphology of Pulp Chambers Presence of Open Margins Size, position and depth of posts
What technique results in the most accurate PA’s
The paralleling technique
What does the paralleling technique entail?
Film is placed parallel to the long axis of the tooth and the central beam is directed at a right angle to the film
What is it called when the central beam is directed at an imaginary line that bisects the angle between the tooth and the film?
Bisecting Angle Technique
When would the bisecting angle technique be used?
To allow for anatomic restrictions, like a shallow palate
Is actual tissue destruction better or worse than it appears in the x-ray?
Worse. 12.5% of the cortical plate and/or 7.5% of the mineralized bone has to be destroyed before it appears on the xray.
What is the most common mimic of a periapical lesion?
Periapical cemental dysplasia
What are the 4 Key Steps of a Differential Diagnosis?
- Conduct vitality testing
- Take multiple radiographs from different angles and use SLOB to evaluate
- For anatomical radiolucencies, the healthy tooth in question should also exhibit and intact lamina dura
- Knowing anatomy will prevent misdiagnoses
Why must we practice reading radiographs?
Learned Skill
Dentists interpret their own x rays
What did the Goldman study from the 70s show?
That a group of professionals agreed on the diagnoses less than 50% of the time.
6 months later, the same docs agreed with their own previous diagnoses only 75% of the time
What did the follow up study in 2011 show?
That years of experience and familiarity with digital systems is the most important factors of accurate xray reading
What are the 4 tools for diagnosis?
- Chief Complaint
- History of symptoms
- Clinical Exam
- X rays
When might a vertical root fracture not show up well on a radiograph?
When the fracture is in the same plane as the radiograph
What radiographs are ordered prior to RCT?
2-3
1 Straight Angle
1 Shift shot
+/- BWX
What is a WL radiograph?
Working Length
What does EAL stand for RE: WL radiographs
Electronic Apex Locator
What does MAF stand for
Master Apical File
what is an important tip when taking shift shots in terms of consistency?
Always write down what direction the shift was in!
What is ALARA
As Low As Reasonably Achievable
When is conventional film used
In an emergency when the computer system is down
What does CBCT stand for?
Cone Beam Computed Tomography
