It is generally accepted that partial or complete edentulism adversely affects an individual's quality of life and can negatively contribute to the maintenance of optimal health.1–3 Structural and functional adaptations of the soft and mineralized tissues of the maxilla and mandible occur overtime after tooth extraction and can directly influence the therapeutic alternatives.4 Because mineralized tissue changes may not be clinically apparent, radiographic imaging analysis is paramount for successful diagnosis and treatment planning in dental implantology and directly contributes to the implant's long-term success.5
Until recently, the most common diagnostic radiographic modalities used to assist clinicians during implant treatment planning were limited to intraoral periapical and panoramic radiography.5 These radiographic modalities only provide two-dimensional (2D) representations of three-dimensional (3D) structures. In an effort to overcome this limitation, the use of medical computed tomography (CT) for dental implant applications became available in the mid 1980s; however, this practice received some criticism due to the level of radiation exposure during image acquisition. The introduction of Cone Beam Computed Tomography (CBCT) in the late 1990s represented an unparalleled advancement in the field of dental and maxillofacial radiology because it greatly reduced the radiation exposure to patients undergoing scans.6,7 The 3D information generated by this technique offers the potential of improved diagnosis and treatment planning for a wide range of clinical applications in implant dentistry.8,9 The goal of this consensus report is to discuss key elements needed for the sound, scientifically based use of CBCT in the area of dental implantology.
Cone Beam Computed Tomography
CBCT is an advanced digital imaging technique that allows the operator to generate multiplanar slices of a region of interest and to reconstruct a 3D image of these structures of interest by using a cone-shaped rotating x-ray beam via a series of mathematical algorithms.6 The advent of CBCT has made it possible to visualize the dentition, the maxillofacial skeleton, and the relationship of anatomical structures in three dimensions.6 The use of CBCT in the dental profession is increasing exponentially due to an increase of equipment manufacturers and the growing acceptance of this imaging modality.8
Field of view.
The size of the field of view (FOV) describes the scan volume of a particular CBCT machine and is dependent on the detector size and shape, the beam projection geometry, and the ability to collimate the beam which differs from manufacturer to manufacturer. Beam collimation limits the patient's ionizing radiation exposure to the region of interest and ensures that an appropriate FOV can be selected based on the specific case.
In general, CBCT units can be classified into small, medium, and large volume based on the size of their “FOV.” Small volume CBCT machines are used to scan from a sextant or a quadrant to one jaw only. They generally offer higher image resolution because x-ray scattering (noise) is reduced as the FOV decreases. Medium volume CBCT machines are used to scan both jaws while large FOV machines allow the visualization of the entire head that is commonly used in orthodontic and orthognathic surgery treatment planning. The main limitation of large FOV CBCT units is the size of the field irradiated. Unless the smallest voxel size is selected in the larger FOV machines, there is a reduction in image resolution as compared with intraoral radiographs or small FOV CBCT machines with inherent small voxel sizes.
Limiting the scan volume should be based on the clinician's judgment for the particular situation. For most dental implant applications, small or medium FOV is sufficient to visualize the region of interest. Small volume CBCT machines are becoming more popular and provide the following advantages over larger volume CBCT:
- Increased spatial resolution.
- Decreased radiation exposure to the patient.
- Smaller volume to be interpreted.
- Less expensive machines.
Advantages and Limitations of CBCT
CBCT has made it possible for clinicians to directly visualize the dentition including the maxillofacial skeleton in 3D as opposed to “imaging” it two dimensionally (2D). The advantages of CBCT are the weaknesses of 2D intraoral periapical and panoramic radiographic representations. The ability to visualize the complete geometric shape of the area of interest and avoid superimposition or planar viewing permits accurate radiographic interpretation without assumption (Table 1). Therefore, spatial proximity of vital structures such as the inferior alveolar nerve, the incisive canal, the mental foramen, and inherent concavities can be accurately assessed and measured. However, the quality of the interpretation is based on the clinician's diagnostic ability, thoroughness, utilization of native and third-party treatment planning software, and determination of the appropriate FOV for each particular case. There are several CBCT equipment manufacturers in the dental imaging field. This has resulted in significant variability in radiation dose, scanning times, ease of use, image resolution, and software dynamics among CBCT machines.
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Table 1: Advantages and Limitations of CBCT
CBCT has limitations similar to all interpretive technologies. The most significant limitations of CBCT are the lack of accurate representation of the internal structure of soft tissues such as the muscles, salivary glands, and soft-tissue lesions, the limited correlation to Hounsfield units for standardized quantification of bone density, and the various types of artifacts produced mainly by metal restorations that can interfere with the diagnostic process by masking underlying structures (Table 1). To improve visualization of the contour and thickness of the gingival soft tissues, techniques such as the use of a cotton roll or air to separate the lip from the vestibule have been described and proven successful.9
A large number of commercial third-party software packages are available to import and analyze CBCT data exported in a DICOM format (Digital Imaging and Communication in Medicine). The most differentiating aspects of the available software applications include their ease of navigation, cost, quantity and quality of available diagnostic tools, and their implant planning modules. Advanced software applications can significantly reduce the “scatter” effect or artifact so that an accurate diagnosis can be established, thus helping to mitigate one potential limitation of this imaging modality.
Dose Considerations
As it is well known, the main concern of exposure to dental x-rays in general is the risk of potential stochastic effects, which are those effects that can be caused regardless of how small the radiation exposure might be and include radiation-induced cancer and hereditable effects. Risks versus benefits decisions are made daily in a dental office. As with any surgical procedure, conventional dental and CBCT imaging require similar types of decisions.
This risk is age dependent, being highest for the young and least for the elderly. Published estimated risks are given for the adult patient at 30 years of age that represent averages for both genders. At all ages, risks for females are slightly higher than those for males. To calculate individual risks, these estimates should be modified using the appropriate multiplication factors derived from the International Commission on Radiologic Protection report published in 2007.10,11 The NCRP report No. 145 published in 2003 provides guidelines to help minimize radiation risks from common dental radiographic examinations.12
There are multiple CBCT radiation dosimetry studies in the literature (Table 2). Based on these reports, it can be concluded that a significant variation in effective dose exists among CBCT machines; however, when compared to medical CT, CBCT can be recommended as a dose-reducing technique for dental implant applications.13–17 The effective dose from CBCT examinations ranges from 13 μSv with the 3D Accuitomo CBCT machine using the 4 × 4 cm FOV to 479 μSv with the CB Mercuray CBCT machine (Table 2). For comparison, the effective dose from one panoramic radiograph is approximately 10 to 14 μSv and that of a complete series of radiographs can range from 34.9 μSv (when using PSP plates or F-speed film and the use of a rectangular collimator) to 388 μSv (when using D-speed film and a round collimator).14 Furthermore, the exposure from a maxillomandibular medical CT ranges from 474 to 1160 μSv.18 The average background radiation in the United States is 3000 μSv (3 mSv) per year or 8 μSv per day (Table 2).
Table 2: CBCT Machines
As with any other dental imaging modality, CBCT examinations must be justified on an individual basis by demonstrating that the benefits to the patients outweigh the potential risks. CBCT examinations should potentially add significant new information to aid in the patient's management. CBCT must not be selected unless a review of the medical and dental histories and a thorough clinical examination has been performed.
It is important to understand that every effort must be made to reduce the effective radiation dose to the patient. By using the smallest possible FOV, the lowest mA setting, the shortest exposure time, and a pulsed exposure mode of acquisition, it is possible to accomplish effective dose reduction to the patient.19 If visualization of structures beyond the region of interest for implant placement is required, imaging made with the appropriate larger FOV protocol should be selected on a case-by-case basis.
CBCT in Implant Dentistry
The use of 3D information in the areas of diagnosis and treatment planning has been greatly enhanced through the availability of CBCT. Its application in the area of implant dentistry assists the clinician in assessing individual patient anatomy in 3D. This analysis can be made through native software that initially reconstructs the CBCT data after acquisition and through advanced third-party software applications that can aid in the determination of dental implant receptor sites and related procedures. The ideal receptor site for dental implant placement can be defined as one with adequate bone quality and volume where an osteotomy can be prepared and the implant can be stabilized in a favorable position whereby the prosthetic goals can be achieved. The 3D visualization and evaluation of the structures of interest during the treatment planning phase allows for the analysis of the following parameters:
- Determination of the available bone height, width, and relative quality.
- Determination of the 3D topography of the alveolar ridge.
- Identification and localization of vital anatomical structures such as the inferior alveolar nerve, mental foramen, incisive canal, maxillary sinus, ostium, and floor of the nasal cavity.
- Identification and 3D evaluation of possible incidental pathology.
- Fabrication of CBCT-derived implant surgical guides.
- Communication of the diagnostic and treatment planning information to all members of the implant team.
- Evaluation of prosthetic/restorative options through implant software applications.
In addition, the CBCT scan in combination with software modeling can be used as a virtual treatment planning platform to simulate the ideal implant placement with consideration of surgical, prosthetic, and occlusal factors.
Review of the Literature
The literature regarding CBCT and implant dentistry was systematically reviewed. A PubMed search that included studies published between January 1, 2000, and July 31, 2011, was conducted.
The use and potential of CBCT have been reported in a number of scientific papers for a number of purposes. The most commonly cited uses include the following: (1) identifying the 3D characteristics of individual patienst anatomy, (2) identifying potential risks of intrusion into vital anatomical structures including nerves, blood vessels, and impacted or supernumerary teeth, (3) ancillary bone grafting procedures including sinus augmentations, (4) assessing bone quality including facial and lingual cortical plates and intermedullary bone, (5) assessing potential dental implant receptor sites for the placement of standard, narrow-diameter, and zygomatic implants, (6) the fabrication of surgical guides/templates and prostheses, and (7) postoperative assessment of grafting procedures.
Level of evidence and other considerations.
More than 40% of the published studies between 2000 and 2011 represent laboratory trials which include ex-vivo (ie, cadaver) studies and other types of models. Approximately 30% of the published studies are randomized clinical trials, and more than 20% represent case reports.
It is also important to keep in mind that published research that applies to one CBCT machine may not apply to other equipment because the image quality and resolution varies among machines and there are more than 30 CBCT machines currently available in the market.
Based on the currently available literature, the adjunctive use of CBCT in implant dentistry can be divided into four main categories:
- Diagnostics
- Implant planning
- Surgical guidance
- Postimplant and/or post grafting evaluation
CBCT and Diagnostics
CBCT is an excellent diagnostic modality in implant dentistry that should be used for the evaluation of the proposed implant site to exclude the presence of occult pathology, foreign bodies, and/or defects and to determine the suitability of the site in terms of 3D morphology and proximity to vital anatomical structures.
CBCT and Implant Planning
In dental implant treatment planning, one of the most frequently reported applications of CBCT is linear measurement of the ridge. CBCT images have been found to provide reliable bone quantity information for preoperative implant planning in different areas of the maxilla and mandible both in clinical and experimental studies.27–31 It has been shown that magnification of CBCT-obtained linear measurements does not occur and measurements have been found to be more accurate than those obtained with medical CT.32,33 Furthermore, dental metallic artifacts do not alter the accuracy of linear measurements obtained with CBCT.34
Another important advantage of CBCT in preimplant treatment planning is the ability to evaluate the ridge topography and proximity to vital anatomical structures three dimensionally to determine whether advanced grafting is necessary for appropriate implant site development. CBCT images have proven to be superior in this regard compared with other 2D imaging modalities.35–38 CBCT can accurately assess the thickness of cortical bone such as the facial/buccal and lingual/palatal cortical plates, the floor of the nasal cavity, and the medial and lateral walls of the maxillary sinuses.
Evaluation of bone density has also been an area of increasing interest. Because of the volumetric data acquisition and reconstruction of CBCT data, linear attenuation coefficients and true Hounsfield units which originated from medical CT scans are challenging to calculate from CBCT scans. To date, it has been possible to obtain only relative bone quality information. However, several research studies have been done to assess the reliability of bone density measurements obtained with CBCT in an effort to overcome this limitation and provide a method to standardize imaging variables to better estimate true tissue density.39 Some studies have found that CBCT might hold potential with regard to the structural analysis of trabecular bone and that bone quality evaluated by CBCT shows a high correlation with the primary stability of dental implants.40–43 Furthermore, the use of the quantitative CBCT (QCBCT) method holds promise as an alternative diagnostic tool for preoperative bone density evaluation.44
In addition to implant planning, the use of CBCT has been found to be effective in locating blood vessels in the lateral wall of the maxillary sinus – which should be appreciated before sinus augmentation procedures. Significant vessels also reside in the mandibular symphysis region that can cause life-threatening events if perforated during implant surgery. CBCT can aid clinicians in identifying these important anatomical features to avoid potential serious complications.
CBCT and Surgical Guidance
CBCT-aided implant surgery can be divided into the following: passive, semi-active, and active.
- Passive CBCT-aided implant surgery refers to the use of CBCT information such as linear measurements, relative bone quality, 3D evaluation of ridge topography, and proximity to vital anatomical structures to help in the implant treatment planning process. Passive CBCT-aided implant surgery can be accomplished with or without third-party interactive treatment planning software.
- Semi-active CBCT-aided implant surgery includes the use of CBCT data imported into third-party interactive treatment planning software where virtual implants are simulated as a precursor to the fabrication of surgical guides that will be used at the time of implant placement. Depending on the software application's protocol to relate implant position to the underlying bone and restorative needs of the patient, a scanning template may need to be fabricated before the scan acquisition. The scanning template can be made with a radiopaque material (barium sulfate), contain gutta-percha markers, or other specific fiduciary markers that aid in the fabrication of the surgical guide. The scanning template is positioned intraorally, and the CBCT scan is acquired. The data from the scan are then imported into the interactive treatment planning software for implant planning. Surgical guides can be fabricated by several different methods, based on the particular software application and are not all equally accurate. The use of stereolithography or rapid prototyping has been successful in the ability to reconstruct the patient's bony anatomy, and facilitates the fabrication of CBCT-derived surgical guides. This process can be completed with or without a scanning appliance worn during the CBCT scan acquisition. Other methods involve laboratory-drilled templates that require registration of the scanning template to the CBCT data. Each type of template contains metal cylinders that correspond to the diameter of the osteotomy drills specific to the implants to be placed. The registration of 3D surface data has been found to be reliable and sufficiently accurate for dental implant planning. Thereby, in certain situations and with certain software applications, barium-sulfate scanning templates can be avoided and dental implant planning can be accomplished fully virtual.45 The process to perform virtual implant treatment planning involves the use of third-party software to decide the most appropriate location and orientation of the proposed implant.27,46 Moreover, the use of surgical guides facilitates flapless implant placement.47,48 The use of CBCT-derived surgical guides has been enhanced to allow for implants to be placed directly through the surgical template with manufacturer specific hardware to control depth and rotation of the implants. Therefore, extra equipment and cost is associated with these protocols. CBCT-generated surgical guides and the integration of CAD/CAM and CBCT to determine the appropriate restorative modality have been found to be precise27,49,50 and will continue to evolve as a link between the treatment planning and the restorative processes.
- Active CBCT-aided implant surgery refers to the use CBCT data and surgical navigation systems to perform fully computer-guided implant placement. The accuracy of navigation systems has been tested in some studies; however, more research is need in this area.51
CBCT and Postimplant/Postgrafting Evaluation
The usefulness of CBCT for postimplant evaluation has also been studied. One of the main concerns of postimplant evaluation with CBCT is the presence of beam hardening and partial volume artifacts around implants which in some cases prevent the visualization of the bone-implant interface. However, scattering artifacts caused by metal are significantly less with CBCT as compared with medical CT. Naitoh et al52 2010 evaluated the rate of bone-to-implant contact in a clinical study and reported that the bone configuration surrounding anterior dental implants with and without bone grafting can be adequately assessed using CBCT. Similar findings have also been obtained in human skulls.31 However, controversial results are also found in the literature using other animal models where the evaluation of periimplant bone defect regeneration by means of CBCT was not accurate for sites providing bone width of <0.5 mm. Research to reduce artifacts caused by titanium implants in CBCT images is being done.53
Interpretation of CBCT Scans
Clinicians ordering CBCT scans are responsible for interpreting the entire image volume because incidental findings that may be significant to the health of the patient could be present. These incidental findings may include, but are not limited to, osseous or sinus pathology, intracranial or vascular calcifications, and airway asymmetry. The likelihood of seeing these types of findings increases with a larger FOV where a larger head volume is included in the scan. There is no informed consent process or signature of waiver that allows the clinician to interpret only a specific area of an image volume. Therefore, the clinician may be considered liable for a missed diagnosis, even if it is outside of his/her area of practice.54 If questions regarding image data interpretation occur, prompt referral to a specialist in oral and maxillofacial or medical radiology is recommended. If incidental findings are considered clinically significant, appropriate referral for medical consultation should follow.
Recommendations
The decision to order a CBCT scan must be based on the patient's history and clinical examination, and justified on an individualized needs basis that demonstrates that the benefits to the patient outweigh the potential risks of the patient's exposure to ionizing radiation, especially in the case of children or young adults and large FOV scans. Because the 3D information obtained with CBCT cannot be obtained with other 2D imaging modalities, it is virtually impossible to predict which treatment cases would not benefit from having this additional information before obtaining it.
Based on the available evidence and the type of information acquired with 3D imaging modalities, the consensus panel suggests that use of CBCT should be considered as an imaging alternative before cases where the proposed implant receptor or bone augmentation site(s) are suspect, and conventional radiography may not be able to assess the true regional 3D anatomical presentation as indicated below:
- Computer-aided implant planning and placement including flapless techniques (eg, interactive treatment planning software applications, surgical guides, and navigation systems)
- Implant placement in a highly esthetic zone or where concavities, ridge inclination, inadequate bone volume or quality, undeterminable proximity to vital structures, and insufficient inter-radicular spacing is suspected
- Pre- and postadvanced bone grafting evaluation (eg, sinus lift, ridge splitting, block grafting)
- History or suspected trauma to the jaws, foreign bodies, maxillofacial lesions, and/or developmental defects
- Evaluation of postimplant complications (eg, postoperative neurosensory impairment, osteomyelitis, acute rhinosinusitis)
It is important to keep in mind that the smallest possible FOV should be used and the entire image volume should be interpreted.
Additional recommendations
Education.
The use of CBCT requires a specific skill set, that until recently has not been taught in dental schools at either the undergraduate or postgraduate levels. Therefore, it is also recommended that clinicians who are providing dental implant procedures for their patients become knowledgeable in 3D diagnosis and treatment planning concepts, and become familiar with interactive treatment planning software applications.
Protocols.
3D imaging technology does not supersede sound surgical and restorative/prosthetic fundamentals. Clinicians should understand that the scan process often starts before the scan itself. Diagnostic wax-ups, mounted articulated study casts, and the use of scanning templates helps to improve the diagnostic accuracy of the CBCT data as it relates to the desired implant placement or ancillary grafting procedure. The use of scanning and surgical templates helps to improve surgical accuracy, reduce postoperative morbidity, and aid in the restorative phase of treatment.
Acknowledgments
This work was supported by the International Congress of Oral Implantologists (ICOI).
Addendum
The American Association of Physicists in Medicine whose members continually strive to improve medical imaging by lowering radiation levels and maximizing benefits of imaging procedures involving ionizing radiation, issued a Position Statement on radiation risks from medical imaging procedures on December 13, 2011. In part, it reads “predictions of hypothetical cancer incidents and deaths in patient populations exposed to such low doses are highly speculative and should be discouraged. These predictions are harmful because they lead to sensationalistic articles in the public media ....” Readers are urged to go to the website of the American Association of Physicists in Medicine to read this statement in its entirety.
References
1. Kuboki T, Okamoto S, Suzuki H, et al.. Quality of life assessment of bone-anchored fixed partial denture patients with unilateral mandibular distal-extension edentulism. J Prosthet Dent. 1999;82:182–187.
2. Ozhayat EB, Stoltze K, Elverdam B, et al.. A method for assessment of quality of life in relation to prosthodontics. Partial edentulism and removable partial dentures. J Oral Rehabil. 2007;34:336–344.
3. Kimura A, Arakawa H, Noda K, et al.. Response shift in oral health-related quality of life measurement in patients with partial edentulism. J Oral Rehabil 2012;39:44–54.
4. Akca K, Iplikcioglu H. Evaluation of the effect of the residual bone angulation on implant-supported fixed prostheses in mandibular posterior edentulism. Part I: Spiral computed tomography study. Implant Dent. 2001;10:216–222.
5. Chan HL, Misch K, Wang HL. Dental imaging in implant treatment planning. Implant Dent. 2010;19:288–298.
6. Sukovic P. Cone beam computed tomography in craniofacial imaging. Orthod Craniofac Res. 2003;6(suppl 1):31–36, discussion 179–182.
7. Tsiklakis K, Donta C, Gavala S, et al.. Dose reduction in maxillofacial imaging using low dose Cone Beam CT. Eur J Radiol. 2005;56:413–417.
8. Scarfe WC, Farman AG, Sukovic P. Clinical applications of cone-beam computed tomography in dental practice. J Can Dent Assoc. 2006;72:75–80.
9. Ganz SD. Cone beam computed tomography-assisted treatment planning concepts. Dent Clin North Am. 2011;55:515–536, viii.
10. Ludlow JB, Davies-Ludlow LE, White SC. Patient risk related to common dental radiographic examinations: The impact of 2007 International Commission on Radiological Protection recommendations regarding dose calculation. J Am Dent Assoc. 2008;139:1237–1243.
11. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP 2007;37:1–332.
12. Miles DA, Langlais RP. NCRP report No. 145: New dental X-ray guidelines: Their potential impact on your dental practice. Dent Today. 2004;23:128, 130, 132 passim; quiz 134.
13. Ludlow JB, Davies-Ludlow LE, Brooks SL. Dosimetry of two extraoral direct digital imaging devices: NewTom cone beam CT and Orthophos Plus DS panoramic unit. Dentomaxillofac Radiol. 2003;32:229–234.
14. Ludlow JB, Davies-Ludlow LE, Brooks SL, et al.. Dosimetry of 3 CBCT devices for oral and maxillofacial radiology: CB Mercuray, NewTom 3G and i-CAT. Dentomaxillofac Radiol. 2006;35:219–226.
15. Ludlow JB, Ivanovic M. Comparative dosimetry of dental CBCT devices and 64-slice CT for oral and maxillofacial radiology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008;106:106–114.
16. Okano T, Harata Y, Sugihara Y, et al.. Absorbed and effective doses from cone beam volumetric imaging for implant planning. Dentomaxillofac Radiol. 2009;38:79–85.
17. Qu XM, Li G, Ludlow JB, et al.. Effective radiation dose of ProMax 3D cone-beam computerized tomography scanner with different dental protocols. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;110:770–776.
18. Loubele M, Bogaerts R, Van Dijck E, et al.. Comparison between effective radiation dose of CBCT and MSCT scanners for dentomaxillofacial applications. Eur J Radiol. 2009;71:461–468.
19. Sur J, Seki K, Koizumi H, et al.. Effects of tube current on cone-beam computerized tomography image quality for presurgical implant planning in vitro. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;110:e29–e33.
20. Hatcher DC. Operational principles for cone-beam computed tomography. J Am Dent Assoc. 2010;141(suppl 3):3S–6S.
21. Silva MA, Wolf U, Heinicke F, et al.. Cone-beam computed tomography for routine orthodontic treatment planning: A radiation dose evaluation. Am J Orthod Dentofacial Orthop. 2008;133:640–645 e641–645.
22. Pauwels R, Beinsberger J, Collaert B, et al.. Effective dose range for dental cone beam computed tomography scanners. Eur J Radiol. 2010;81:267–271.
23. Coppenrath E, Draenert F, Lechel U, et al.. [Cross-sectional imaging in dentomaxillofacial diagnostics: Dose comparison of dental MSCT and NewTom 9000 DVT]. Rofo. 2008;180:396–401.
24. Ludlow JB. A manufacturer's role in reducing the dose of cone beam computed tomography examinations: Effect of beam filtration. Dentomaxillofac Radiol. 2011;40:115–122.
25. Hirsch E, Wolf U, Heinicke F, et al.. Dosimetry of the cone beam computed tomography Veraviewepocs 3D compared with the 3D Accuitomo in different fields of view. Dentomaxillofac Radiol. 2008;37:268–273.
26. Lofthag-Hansen S, Thilander-Klang A, Ekestubbe A, et al.. Calculating effective dose on a cone beam computed tomography device: 3D Accuitomo and 3D Accuitomo FPD. Dentomaxillofac Radiol. 2008;37:72–79.
27. Dreiseidler T, Neugebauer J, Ritter L, et al.. Accuracy of a newly developed integrated system for dental implant planning. Clin Oral Implants Res. 2009;20:1191–1199.
28. Madrigal C, Ortega R, Meniz C, et al.. Study of available bone for interforaminal implant treatment using cone-beam computed tomography. Med Oral Patol Oral Cir Bucal. 2008;13:E307–E312.
29. Suomalainen A, Vehmas T, Kortesniemi M, et al.. Accuracy of linear measurements using dental cone beam and conventional multislice computed tomography. Dentomaxillofac Radiol. 2008;37:10–17.
30. Veyre-Goulet S, Fortin T, Thierry A. Accuracy of linear measurement provided by cone beam computed tomography to assess bone quantity in the posterior maxilla: A human cadaver study. Clin Implant Dent Relat Res. 2008;10:226–230.
31. Shiratori LN, Marotti J, Yamanouchi J, et al.. Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography. Clin Oral Implants Res. 2011; Epub ahead of print.
32. Al-Ekrish AA, Ekram M. A comparative study of the accuracy and reliability of multidetector computed tomography and cone beam computed tomography in the assessment of dental implant site dimensions. Dentomaxillofac Radiol. 2011;40:67–75.
33. Yim JH, Ryu DM, Lee BS, et al.. Analysis of digitalized panorama and cone beam computed tomographic image distortion for the diagnosis of dental implant surgery. J Craniofac Surg. 2011;22:669–673.
34. Cremonini CC, Dumas M, Pannuti CM, et al.. Assessment of linear measurements of bone for implant sites in the presence of metallic artefacts using cone beam computed tomography and multislice computed tomography. Int J Oral Maxillofac Surg. 2011;40:845–850.
35. Angelopoulos C, Thomas SL, Hechler S, et al.. Comparison between digital panoramic radiography and cone-beam computed tomography for the identification of the mandibular canal as part of presurgical dental implant assessment. J Oral Maxillofac Surg. 2008;66:2130–2135.
36. Bornstein MM, Balsiger R, Sendi P, et al.. Morphology of the nasopalatine canal and dental implant surgery: A radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography. Clin Oral Implants Res. 2011;22:295–301.
37. Chan HL, Brooks SL, Fu JH, et al.. Cross-sectional analysis of the mandibular lingual concavity using cone beam computed tomography. Clin Oral Implants Res. 2011;22:201–206.
38. Lofthag-Hansen S, Grondahl K, Ekestubbe A. Cone-beam CT for preoperative implant planning in the posterior mandible: Visibility of anatomic landmarks. Clin Implant Dent Relat Res. 2009;11:246–255.
39. Mah P, Reeves TE, McDavid WD. Deriving Hounsfield units using grey levels in cone beam computed tomography. Dentomaxillofac Radiol. 2010;39:323–335.
40. Corpas Ldos S, Jacobs R, Quirynen M, et al.. Peri-implant bone tissue assessment by comparing the outcome of intra-oral radiograph and cone beam computed tomography analyses to the histological standard. Clin Oral Implants Res. 2011;22:492–499.
41. Isoda K, Ayukawa Y, Tsukiyama Y, et al.. Relationship between the bone density estimated by cone-beam computed tomography and the primary stability of dental implants. Clin Oral Implants Res. 2011; Epub ahead of print.
42. Naitoh M, Hirukawa A, Katsumata A, et al.. Prospective study to estimate mandibular cancellous bone density using large-volume cone-beam computed tomography. Clin Oral Implants Res. 2010;21:1309–1313.
43. Song YD, Jun SH, Kwon JJ. Correlation between bone quality evaluated by cone-beam computerized tomography and implant primary stability. Int J Oral Maxillofac Implants. 2009;24:59–64.
44. Aranyarachkul P, Caruso J, Gantes B, et al.. Bone density assessments of dental implant sites: 2. Quantitative cone-beam computerized tomography. Int J Oral Maxillofac Implants. 2005;20:416–424.
45. Ritter L, Reiz SD, Rothamel D, et al.. Registration accuracy of three-dimensional surface and cone beam computed tomography data for virtual implant planning. Clin Oral Implants Res. 2011; Epub ahead of print
46. Worthington P, Rubenstein J, Hatcher DC. The role of cone-beam computed tomography in the planning and placement of implants. J Am Dent Assoc 2010;141(suppl 3):19S–24S.
47. Fornell J, Johansson LA, Bolin A, et al.. Flapless, CBCT-guided osteotome sinus floor elevation with simultaneous implant installation. I: Radiographic examination and surgical technique. A prospective 1-year follow-up. Clin Oral Implants Res. 2012;23:28–34.
48. Nickenig HJ, Eitner S. Reliability of implant placement after virtual planning of implant positions using cone beam CT data and surgical (guide) templates. J Craniomaxillofac Surg. 2007;35:207–211.
49. Murat S, Kamburoglu K, Ozen T. Accuracy of a newly developed CBCT-aided surgical guidance system for dental implant placement: An ex vivo study. J Oral Implantol. 2011; Epub ahead of print.
50. Patel N. Integrating three-dimensional digital technologies for comprehensive implant dentistry. J Am Dent Assoc. 2010;141(suppl 2):20S–24S.
51. Heiland M, Pohlenz P, Blessmann M, et al.. Navigated implantation after microsurgical bone transfer using intraoperatively acquired cone-beam computed tomography data sets. Int J Oral Maxillofac Surg. 2008;37:70–75.
52. Naitoh M, Nabeshima H, Hayashi H, et al.. Postoperative assessment of incisor dental implants using cone-beam computed tomography. J Oral Implantol. 2010;36:377–384.
53. Schulze RK, Berndt D, d'Hoedt B. On cone-beam computed tomography artifacts induced by titanium implants. Clin Oral Implants Res. 2010;21:100–107.
54. Carter L, Farman AG, Geist J, et al.. American academy of oral and maxillofacial radiology executive opinion statement on performing and interpreting diagnostic cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008;106:561–562.
