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Biotech Health Sci. 2015 February; 2(1): e25815.
Published online 2015 February 21. Research Article
The Assessment of Dentists’ Knowledge Regarding Indications of Cone
Beam Computed Tomography in Qazvin, Iran
Maryam Tofangchiha 1; Faraz Arianfar 1; Mahin Bakhshi 2; Mansour Khorasani 3,*
1Department of Oral Radiology, Dental Faculty, Qazvin University of Medical Sciences, Qazvin, IR Iran
2Department of Oral Medicine, Dental Faculty, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran
3Department of Oral and Maxillofacial Surgery, Dental Faculty, Qazvin University of Medical Sciences, Qazvin, IR Iran
*Corresponding author: Mansour Khorasani, Department of Oral and Maxillofacial Surgery, Dental Faculty, Qazvin University of Medical Sciences, Qazvin, IR Iran. Tel: +98-2813353061,
E-mail: vkhorasani1342@yahoo.com
Received: December 4, 2014; Accepted: January 18, 2015
Background: Cone beam computed tomography (CT) has recently become effective for oral and maxillofacial imaging.
Objectives: The aim of this study was to assess the knowledge of dentists regarding cone beam computed tomography.
Materials and Methods: In this descriptive cross sectional study, a questionnaire regarding cone-beam computed tomography (CBCT)
was distributed amongst 100 dentists (general and specialist) in Qazvin, Iran. Their level of knowledge was compared in each section on
the basis of age, gender, years of employment and last educational status and analyzed by the SPSS software and Mann-Whitney test.
Results: Data analysis showed that 4% of dentists had very low, 16% had low, 50% had medium, 19% had good and 11% had in very good
level of knowledge. The average of dentists’ knowledge was 57 ± 18. According to the statistical results, there was a significant difference
between level of knowledge and age, years of employment and educational degree (P < 0.05). Age and years of employment had a
reverse relationship with level of knowledge and specialists had greater awareness. There was no significant difference between level of
knowledge and sex (P > 0.05).
Conclusions: Overall, dentists had an average level of knowledge for CBCT. It is recommended for qualification programs to be held for
dentists to strengthen their awareness toward cone beam computed tomography.
Keywords:Knowledge; Dentist; Cone - Beam Computed Tomography
Copyright © 2015, School of Paramedical Sciences, Qazvin University of Medical Sciences. This is an open-access article distributed under the terms of the Creative
Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the mate-
rial just in noncommercial usages, provided the original work is properly cited.
1. Background
Cone-beam computed tomography (CBCT) is a new
technology, in which two-dimensional detectors and
conical beam are used instead of fan X-rays in conven-
tional computed CT. In this technique, volumetric data
are collected by rotating of beam and detectors around
the desired structure (1). The main advantage of CBCT is
its high sharpness of axial images compared to conven-
tional CTs (2). Ludlow and colleagues showed that CBCT
dosages can be different according to the manufacturer
company, type of machine, type of observer and level of
elective exposure factors (3).
In the recent years, this technology has been used to
prepare cross-sectional images from maxillofacial struc-
tures. Cone-beam computed tomography has less expo-
sure time and cost compared to conventional CT. The
beams rays are confined for head and neck only. Lower
dosage of X-rays and ability to take different images from
a certain structure and also possibility of reconstruction
in sagittal and coronal views, all make CBCT a conve-
nient technology (4-6). The disadvantages of CBCT are its
low resolution of soft tissue and scattering beams from
tooth tissue (6). Usual indications of CBCT in dentistry
are implantation, orthodontic treatments, assessment
of temporomandibular joint (TMJ), relationship of third
mandibular molar with inferior alveolar nerve block and
presence of tumors and cysts (7). Cone-beam computed
tomography makes images by centralizing the X-ray
beam with a conical form on a two-dimensional detec-
tor, which rotates 360 degree around the patients’ head
to make images. Next the algorithm of conical beam is
applied on this data, and thus the technologist can make
reconstructions of the curve and two-planar with differ-
ent thicknesses on each side and achieve clear and actual
three-dimensional images from bone and tooth tissue
(8-10).
According to the significance of CBCT in dental treat-
ments, it seems that assessment of dentists’ awareness
for indications of this system is important. There is only
one research related to this subject which has been done
at Ankara University among dental students (11).
2. Objectives
This study was done to assess the knowledge of dentists
regarding indications of CBCT images during 2012 and
2013 in Qazvin city, Iran.
Tofangchiha M et al.
Biotech Health Sci. 2015;2(1):e258152
3. Materials and Methods
This study received an exemption from the Institutional
Review Board (registration number: 591) of the dentistry
faculty, Qazvin University of Medical Sciences. Out of
124 dentists, who received the self-administered ques-
tionnaires (Figure 1), 100 dentists participated in this
research. The statistical society included both general
dentists and specialists. The questionnaire was designed
considering the studies of Kamburoglu et al. (11), which
were done in two universities in Ankara (4). The question-
naire included demographic data (age, sex, years of em-
ployment, educational degree) and fifteen questions re-
garding the CBCT technology. The questions assessed the
knowledge of dentists about indications of CBCT. There
was no compulsion for answering the questionnaire and
dentists were ensured, that the results of this study will
be used only for educational purposes of the dental soci-
ety and will not be used for evaluating the dentists.
In this pilot survey, analysis of data was done by the SPSS
software version 11.5 (IBM, New York, NY) and Mann-Whit-
ney and Kruskal-Wallis tests.
9. For which of followings, indication of CBCT is not indispensable?
a. Doubt in severe bone resorption
b. Doubt in position of mandibular canal for implantation in the anterior part of lower jaw
c. Doubt in morphology of ridge
d. Doubt in position of mandibular canal for implantation in the posterior part of jaw
2. Which of followings is justifiable for indication of CBCT?
1. A single CBCT examination
a. can be complementary for panoramic views
b. can be prescribed on the basis of patien‘s complaint
c .must be justified for each patient to demonstrate the benefits
outweigh the risks
d. referring for a CBCT practitioner must not supply result and
history of clinical investigations
a. only be used when traditional techniques cannot give new information
b .can be apply without taking clinical examinations
c .CBCT can be used routinely for effective treatments
d. none of the above
10. Orthodontics application of CBCT cannot be for
a. lip cleft
b. palatal cleft
c. impacted canine
d. assessment of airways
3. Which of following specifications for the CBCT compared CT is true?
a. More contrast
b. More cost
c. Higher dose
d. lower accuracy for soft tissue
11. Which of followings in implant surgery is not correct?
a. CBCT images must be taken after clinical examination and conventional radiographies
b. CBCT technique must be applied with minimum dose
c. CBCT is a standard technique for implantation
d. In some cases per apical radiography can be helpful
4. The major indication of CBCT in Iran is for assessment of
a. inferior alveolar nerve block for removing wisdom teeth
b. implant sites
c. pathological lesions
d. bone density
12. Which of followings is not the indication of CBCT?
a. CBCT images can only asses the quantity of bone
b. CBCT images can assess quantity and quality of bone
c. CBCT images can assess the success of bone graft
d. Diagnosis of osteomyelitis
5. For which of following diagnostic imaging tasks, CBCT cannot be used?
a. position of temporomandibular disk
b. position of condyle in glenoid fossa
c. condyle fracture
d. ankylosis
13. CBCT cannot be indicated for
a. impacted mandibular third molars adjacent the mandibular canal
b. alveolar bone assessment in edentulous area for implant placement
c. diagnostic accuracy instead of panoramic view as an alternative technique
d. assessment of condylar erosion
6. Which of followings is not an indication for use of CBCT?
a. assessment of apical cyst
b. soft tissue evaluation
c. sinus evaluation
d. detection of fractures in the posterior part of mandible
14. Intra oral radiographies compare to CBCT are justifiable for
a. interproximal caries
b. measuring the ridge height
c. extension of pathological lesions
d. (a) and (b)
7. Which of following statements regarding CBCT is correct?
a. It can show only vertical root fractures
b. It can show only horizontal root fractures
c. All kinds of root fractures can be detected by CBCT
d. CBCT cannot detect root fractures
15. Which of following orders for prescription is correct? (implantation of 6 and 7
mandibular right teeth)
76
a.
M.PM
b.
tnardauq thgir rewol .C
d. Lower jaw
8. CBCT can be used for evaluating the
a. erosion of TMJ
b. position of disk
c. morphology of disk
d. width of disk
Figure 1. Questionnaire for Evaluation Dentist’s Knowledge Regarding Indications of Cone-Beam Computed Tomography
Tofangchiha M et al.
3
Biotech Health Sci. 2015;2(1):e25815
4. Results
Dentists
̓ relative frequency distribution for demograph-
ic data on the basis of age, gender, number of years for
employment, educational degree, as well as frequency of
distribution on the basis of knowledge are indicated in
Table 1.
Note: Out of 124 questionnaires, which were distributed
among dentists, 100 were answered.
Dentists
̓ relative frequency distribution for the fifteen
questions related to CBCT were as follows: Question 1:
prescribing CBCT: 38 (38%) answers were correct and 62
(62%) were incorrect; Question 2: justifiability for indi-
cations of CBCT: 84 (84%) were correct and 16 (16%) were
incorrect; Question 3: comparing CT and CBCT: 20 (20%)
were correct and 80 (80%) were incorrect; Question 4:
most common indications of CBCT: 83 (83%) were correct
and 17 (17%) were incorrect; Question 5: CBCT and TMJ: 48
(48%) were correct and 52 (52%) were incorrect; Question
6: contraindication of CBCT: 82 (82%) were correct and
18 (18%) were incorrect; Question 7: indication of CBCT
in root fractures: 79 (79%) were correct and 21 (21%) were
incorrect; Question 8: CBCT and articular disc: 47 (47%)
were correct and 53 (53%) were incorrect; Question 9: in-
dication of CBCT for implant surgery in edentulous pa-
tients: 41 (41%) were correct and 59 (59%) were incorrect;
Question 10: contraindication of CBCT in orthodontics:
75 (75%) were correct and 25 (25%) were incorrect; Ques-
tion 11: contraindications of CBCT in implant surgery: 23
(23%) were correct and 77 (77%) were incorrect; Question
12: contra indication of CBCT: 65 (65%) were correct and 35
(35%) were incorrect; Question 13: comparing CBCT with
orthopantomogram (OPG): 57 (57%) were correct and 43
(43%) were incorrect; Question 14: comparing CBCT with
intraoral radiographies, 70 (70%) were correct and 30
(30%) were incorrect; Question 15: order for prescription,
39 (39%) were correct and 61 (61%) were incorrect.
The grading scales for evaluating the level of knowledge
were as follows; 0 - 20 was considered as very low; 20 - 40
was considered as low; 40 - 60 was considered as average;
60 - 80 was considered as high, and 80 - 100 was consid-
ered as very high. Average level of knowledge was 57 ± 17,
lowest mark was 13 and highest mark was 100; 80% had an
average level of awareness.
A P value of < 0.05 obtained from the Kruskal-Wallis test
showed that there was a significant difference between
knowledge of different age groups. Mann-Whitney test
was done for analyzing differences among subgroups; for
less than 30 and 35 to 40 (P = 0.005), for less than 30 and
above 40 (P = 0.021), 30 to 35 and 35 to 40 (P = 0.003), 30
to 35 and above 40 yeas (P = 0.02), there was a significant
difference among subgroups. According to the mean and
median of all groups, awareness was higher in the young-
er age groups. The Pearson’s correlation coefficient was
used for further analysis of these two variables and con-
firmed the relationship between these two variables. Also
r = -0.304 showed a reverse relationship, indicating that
with increasing age there was decreasing knowledge (Ta-
ble 2). The P value obtained from the Mann-Whitney test
showed that there was no significant difference between
knowledge of different genders (Table 3).
The P value of < 0.05 obtained from the Kruskal-Wallis
test showed that there was a significant difference be-
tween knowledge of people with various numbers of
years for employment. Mann-Whitney test was done for
analyzing differences among subgroups; for less than 5
years of occupation and 10 to 15 (P = 0.002), and for less
than 5 years and over 15 years (P = 0.045). According to the
means and medians of all groups, awareness was higher
in groups with lower number of years for employment.
The Pearson’s correlation coefficient was used for further
analysis of these two variables and confirmed the rela-
tionship between these variables. A P value of 0 showed
that there was a relationship and r = -0.326 confirmed a
reverse relationship between the two variables, indicat-
ing that as the number of years of occupation increase,
there is a decrease in knowledge (Table 4). A P value of <
0.05, obtained from the Mann-Whitney test showed that
there was a significant difference between knowledge
and education degree. Means and medians confirmed
that knowledge of specialists was more than general den-
tists (Table 5).
Table 1. Demographic Characteristics of Dentists’ Relative to
Cone-Beam Computed Tomography Knowledge
Characteristic No. (%)
Gender
Male 47 (47%)
Female 53 (53)
Age
Less than 30 years 33 (33)
30 - 35 years 36 (36)
35 - 40 years 11 (11)
Over 40 years 19 (19)
Years for employment
Less than 5 years 54 (54)
5 - 10 years 22 (22)
10 - 15 years 13 (13)
Over 15 years 11 (11)
Educational degree
General 75 (75)
Specialist 25 (25)
Frequency distribution on the basis of knowledge
Very low 4 (4)
Low 16 (16)
Average 50 (50)
High 19 (19)
Very high 11 (11)
Tofangchiha M et al.
Biotech Health Sci. 2015;2(1):e258154
Table 2. Comparison of Knowledge Scores by Age
Age Mean Median Standard Deviation P value
Less than 30 years 61.4 60 18 0.003
30 – 35 years 60.5 53.5 17.7
35 – 40 years 44.3 46 13.4
Over 40 years 49 46 15.9
Table 3. Comparison of Knowledge Scores by Gender
Gender Mean Median Standard Deviation P value
Male 53.1 53.3 15.6 0.06
Female 59.8 60 19.5
Table 4. Comparison of Knowledge Scores According to Number of Years for Employment
Number of Years for Employment Mean Median Standard Deviation P value
Less than 5 years 61.3 60 18 0.008
5 - 10 years 55.4 50 18
10 - 15 years 46 46.6 9
Over 15 years 49 46.6 19
Table 5. Comparison of Knowledge Scores by Educational Degree
Educational Degree Mean Median Standard Deviation P value
General 70.4 73.3 18.6 0.000
Specialist 52.1 46.6 15.4
5. Discussion
This study was done for evaluating dentists’ knowledge
regarding cone beam computed tomography. One hun-
dred dentists including general dentists and specialists
participated in this descriptive cross-sectional study. Fe-
males and those aged 30 to 35 had maximum frequency,
according to frequency distribution. Those aged less than
30 years had the maximum level of knowledge (61.4 %),
and level of knowledge decreased with increase in age.
The inverse relationship between age and knowledge
could be because 1) technology of CBCT has only been
used in the last ten years and 2) the most common usage
of CBCT is for implantation and in Iran young dentists
are more involved in this field. Regarding the level of
knowledge on the basis of gender, no significant differ-
ences were found between males and females. This find-
ing was similar to Kamburoglu’ research that evaluated
dental student’s knowledge for CBCT (11), and assessment
of dentists’ knowledge for prescribing conventional radi-
ographies by Mahdizadeh et al. (12) and Ardakani et al. (5).
Regarding the number of years of employment, there
was a significant difference in the knowledge of individu-
als with different numbers of years of employment; as
the number of years of employment increased awareness
decreased. This was similar to Bardal’s study comparing
dentists that had graduated previously with those that
had recently graduated regarding prescription of intra-
oral radiology and panoramic views (13). According to
level of knowledge on the basis of educational degree,
there was a significant difference between level of knowl-
edge and educational degree; specialist had greater
awareness compared to general dentists. This was similar
to a study done by Mahdizadeh et al. (12), which showed
that specialists had greater knowledge about CT and MRI
compared to other convention intraoral radiographies.
Cone-beam computed tomography has one of the most
important roles for diagnosis in dentistry. This research
showed that dentists in Qazvin city had an average level
of knowledge regarding cone beam CT. It is recommend-
ed that qualification programs must be held for dentists
to increase their awareness toward cone beam computed
tomography. Dentists must gain more knowledge about
indications and contraindications of CBCT.
Acknowledgements
The authors appreciate the financial support of this re-
search by the Research Council of Qazvin University of
Medical Sciences.
Tofangchiha M et al.
5
Biotech Health Sci. 2015;2(1):e25815
Authors’ Contributions
Co-authors helped in designing, analysis of the results
and writing of the current manuscript.
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