Welcome to the DIFOTI Hompage

Identifying restorations in need of replacement using the DIFOTI transillumination imaging system

By Dr. Ramin Tabib, New York, N.Y. Information provided by Electro-Optical Sciences Inc.

Porcelain inlays, onlays, and laminates are conservative treatments that are often considered simply a cosmetic solution to improving a patient's smile. Additionally, it has been proven that the placement of these bonded restorations strengthens teeth that have been weakened by directly placed amalgam restorations.

Locating fractures that weaken these teeth or determining the extent of decay under old amalgam fillings has always presented a challenge. The two-dimensional view provided by an x-ray image is many times inadequate for fully detecting decay and fractures in teeth or not particularly helpful in communicating what we see and recommend to the patient.

While transillumination of teeth has proved a successful method of finding such conditions, the problem has been how to capture the image and show it to the patient. Hand mirrors have been used, but this cumbersome technique was neither reliable nor useful, because the patient could never see what was done. With the advent of computer technology, we are now able to digitally capture transilluminated images on all tooth surfaces and view them in real time with our patients.

Following are step-by-step instructions on how to discover previously unseen fractures and decay around old restorations using the DIFOTI (Digital Imaging Fiber Optic Trans Illumination) diagnostic imaging system and how to use these images for patient education purposes to explain the need for removal and replacement of these restorations.

Getting started

1. Turn the operatory computer and the DIFOTI system on.

2. Select the patient name or ID from the database or add a new patient.

3. Advance to the "Take Picture" mode of the software.

Capturing images

1. Seat the patient in much the same manner as for a typical radiographic examination (Fig. 1).

Fig. 1 Seat the patient.

2. Select the appropriate disposable mouthpiece for the surface to image:

• The proximal-surface disposable mouthpiece is placed over the tooth in question, allowing light to be shined from one surface, through the tooth, and captured on the opposite side using a CCD camera in the DIFOTI handpiece.

• The occlusal-surface mouthpiece illuminates the tooth at angles through both the facial and lingual surfaces and images the light emerging from the top of the tooth.

3. Slide the mouthpiece from one tooth to the next (Fig. 2). Note: The image appears in real time on the computer screen.

Fig. 2 Slide the mouthpiece from one tooth to the next.

4. Scan through the mouth and capture to-be-saved images of clinically suspicious teeth using the footpedal or voice recognition software.

Note: All captured images are saved in a patient's datafile, according to tooth number, surface (occlusal, facial, lingual), and date of imaging session (for comparison of images over time).

Patient education

After the imaging is complete, display and discuss images with the patient in the "Review" mode (Fig 3).

Fig. 3 Display and discuss images with the patient.

Following are three cases that demonstrate DIFOTI's detection and patient education applications:

Case 1: Intact amalgam with no decay

The image is of an occlusal amalgam filling on tooth No. 15 (Fig 4). The cavosurface margins appear as sharp intact continuous lines against translucent healthy tooth structure with no shadows around the borders. The tooth is healthy and no treatment is necessary.

Fig. 4 An occlusal amalgam filling on tooth No. 15.

Case 2: Decay under amalgam not visible with x-ray

Fig. 5 shows an x-ray of tooth No. 30 that looked as if there was no decay upon visual and radiographic examination. The corresponding DIFOTI image (Fig. 6) shows diffuse darker cloudy areas extending from the margins of the restorations against the more translucent and brighter background of surrounding healthy tooth structure. A similar comparison of tooth No. 14 is shown in Figs. 7 and 8. Both cases show recurrent decay under an amalgam that occurs due to the continuous expansion and shrinkage of amalgam over time that allows bacteria to settle between the filling and tooth structure.

Fig. 5 Radiograph shows no evidence of decay on tooth No. 30.

Fig. 6 DIFOTI shows decay on No. 30.

Fig. 7 No decay apparent on No. 14.

Fig. 8 DIFOTI reveals diffuse and cloudy areas on No. 14.

The extent of the decay/fracture and where it is located can be easily explained to the patient to justify treatment plans.With the widespread use of fluoride it is often difficult to diagnose recurrent decay, because the fluoridated water and toothpastes remineralize the outermost portion of our enamel around our fillings, making it difficult to feel or see decay underneath.

Use of transillumination permits timely removal of existing amalgam and recurrent decay that would not have been found otherwise; the patient probably may have needed more extensive treatment by the time the problem was detected radiographically. The patient clearly saw the extent of the problem and was eager to treat the affected teeth.

Case 3: Laminate margin breakdown

The x-ray image (Fig. 9) of porcelain laminates on tooth No. 7 shows no problem with the laminates. The DIFOTI image (Fig. 10) clearly shows a breakdown in the margins of the laminate with decay present.

Fig. 9 X-ray of porcelain laminates on tooth No. 7 shows no problem.

Fig. 10 DIFOTI image shows breakdown in margins of laminate on No. 7.

The DIFOTI image illustrates exactly where the laminate begins and ends and where the decay and breakdown occurs. In this case, the veneers were removed and replaced with new porcelain veneers. The margins can be checked using the system at each recall to make sure they are intact. The images can also be shown to patients at each recall. nDPR