Role of conventional

radiography in implantology

1. Identify the rule of periapical radiographs in preoperative

assessment.

2. Identify the rule of periapical radiographs in evaluation of bone

quality and density.

3. Explain how the cross-sectional occlusal radiograph can be valid

in evaluation of bucco-lingual width of the alveolus.

4. Discuss the importance of conventional tomography in

localization of vital structures (Maxillary sinus & Inferior dental

canal ... etc.)

5. Know the rule of other extra-oral plain radiographs

(e.g. Panoramic & Lateral cephalometric) as

preoperative assessment aids.

6. Know the rule of radiography in the presence of any

underlying disease or abnormalities.

7. Compare between 2D and 3D imaging techniques

8. Enumerate the Diagnostic Imaging Modalities in

Dental Implantology

Introduction

Radiography has an essential role in all phases of

treatment extending from pre-surgical diagnosis

and treatment planning, through surgical

placement and postoperative assessment of the

implant, into the prosthetic restoration and

long-term surveillance phase.

Purpose of radiography

• to decide appropriate implant treatment.

• know the location of vital anatomical structures.

• assessment of bone quantity

• to estimate appropriate number, length, width, location

and orientation of implants to be inserted.

• the possible need for additional treatment before

implant placement.

• to estimate the prognosis.

PRINCIPLES OF IMAGING FOR

DENTAL-IMPLANT ASSESSMENT

• Images should have appropriate diagnostic

quality and not contain artifacts that

compromise anatomic-structure assessments.

• Images should extend beyond the immediate

area of interest to include areas that could be

affected by implant placements.

The goal of radiographic

selection criteria is to identify

appropriate imaging modalities

that complement the goals at each

stage of implant therapy.

Imaging techniques used in

dental implantology

1. Intraoral

radiography

Periapical radiographs

It produce a high resolution planner image.

It may suffer from both distortion &

magnification which is limited

by using long cone paralleling

technique.

Its rule In the pre-prosthetic phase

• Useful for identification of local bone or dental

disease.

• Identifying critical structures, but of limited value

in depicting the spatial relationship between the

structures and proposed implant site.

• Used for single tooth implants.

Advantages:

• Availability.

• High resolution image.

• Optimum and reproducible geometry if

paralleling technique used.

• Low dose technique.

• Low cost.

Periapical radiograph of an implant

taken 4 months following socket

preservation showing complete bone fill

of the socket

Failing implant restoration. Arrows

show saucerized area of bone loss.

Periapical

Limitations:

• No bucco-lingual dimension.

• Limited reproducibility unless

stents and paralleling technique used.

• Limited value in determining bone

density or mineralization.

• Limited area imaged.

• Distortion and magnification.

Direct digital intraoral imaging

Its advantages include

• rapid viewing of images, their

storage, retrieval, and tramission

to remote sites

• Enhancement of images.

• Patient Education

• Decreased Radiation

• Elimination of Chemicals and Dark Rooms

limitations

• Significant Cost .

• Use of the rigid intraoral sensors for periapical (PA) images

can be very uncomfortable for patients, especially if they

have a shallow palate, narrow palate, tori, or an exaggerated

gag reflex.

• its use is dependent on the operator’s ability to manipulate

image density and contrast to measure the bone density at

specific sites and to use it further for treatment planning.

Occlusal radiographs

Occlusal radiographs are used for the

mandible/maxilla to obtain information

regarding bucco-lingual width and

contour.

Occlusal radiograph

Occlusal

Advantages:

indication of buccal-lingual dimension of mandible

determination of jaw size, jaw

curve at proposed implant site

readily accessible to clinician

low cost to patient.

Limitations:

• only reveals maximum buccal-lingual dimension

as it shows the widest width of bone (i.e. the

symphysis)

• two dimensional

• No role in maxillary implantology.

• The degree of mineralization of trabecular bone

can be not determined

2. Extra oral

techniques

Lateral cephalometric radiographs

Lateral cephalometric radiographs

They are oriented planer radiograph for the skull,

the skull is oriented using a cephalometer.

The geometry of cephalometric imaging devices

results in a 10% magnification of the image

with a 60 inch focal object and 6 inch object to

film distance.

Lateral cephalometric radiographs

Advantages

• evaluating the relation between maxilla and mandible

for dental implant.

• The soft tissue profile is apparent on and can be used

to evaluate profile alterations after prosthodontic

rehabilitation

Disadvantages

• They are not very useful when planning placement of

implants lateral to the mid-sagittal plan.

• not useful for demonstrating bone quality.

• there is a uniform magnification of about 10%

.&superimposition.

• Resolution is less when compared to intraoral

radiographs.

PANORAMA

Although the resolution and shape of

panoramic radiograph is less than that of an

intraoral film, panoramic projection provides a

broader visualization of the jaws and adjoining

anatomic structures.

PANORAMA

PANORAMA

Advantages:

-- excellent "screening" film for pre-surgical implant

planning

-- can be preformed with convenience, ease & speed.

-- gross anatomy of the jaws & any related pathologic

finding can be evaluated.

-- vertical height of the bone initially can be assessed.

Limitations:

-- little or no information about width or ridge inclination

-- magnification is not uniform especially in the horizontal

direction

-- poor resolution and presence of artifacts may limit

diagnostic accuracy

-- image distortion (technique sensitive to patient

positioning errors)

-- Does not demonestrate bone quality / mineralization.

PANORAMA

Conventional tomography

Cross-sectional tomographic X-ray

machines produce images of slices or layers

(focal plane) of the body by using the

movement of the X-ray beam and film

(connected by a fulcrum bar) during an

exposure to blur unwanted body parts.

Conventional tomography

different types of motion of the x-ray tube and

the film are employed: linear (the simplest),

circular, trispiral, elliptical and hypocycloidal.

The images generated by complex motion

tomography are generally sharper than those

generated by linear tomography.

Conventional tomography

Image of one of the selected tomographic slices

Advantages:

-- produces cross-sectional images of specific proposed

implant sites

-- assessment of bone height, width and inclination of ridge

-- assessment of bone quality

-- determination of anatomic spatial relationship

-- little or no superimposition

-- development of treatment planning software for certain

imaging systems

Limitations:

-- equipment cost

-- recommends availability of trained Oral Radiologist to

perform imaging and calculate bone dimensions

-- time consuming when multiple sites are indicated

-- transfer of radiographic information to clinical site may

necessitate imaging stent

-- variable definition of specific anatomic structures

dependent of imaging system and availability