REGISTRATION OF INTERNAL MORPHOLOGICAL CHARACTERISTICS OF THE TOOTH USING DENTAL PHOTOGRAPHY

Todor Ts. Uzunov1, Dimitar Kosturkov2, Tsonko Uzunov3, Dimitar Filchev1, Boiko Bonev4, Andon Filchev1. 1) Department of Prosthetic dentistry, 2) Dentist in private practice, 3) Department of Conservative dentistry, 4) Department of Social medicine and public dental health; Dental photography workshop, Faculty of Dental Medicine, Medical University Sofia, Bulgaria. Journal of IMAB Annual Proceeding (Scientific Papers) 2015, vol. 21, issue 1 Journal of IMAB ISSN: 1312-773X http://www.journal-imab-bg.org


INTRODUCTION:
With the development of modern technologies, methods for registration of patient's condition significantly increased.Dental photography and especially digital dental photography provides an excellent opportunity for recording and storing data of the clinical condition of the patient.Photography is a powerful tool by which dentists can forward the information that cannot be described with words [1].
Clinical dental photography allows dentists to analyze the patient's condition carefully and to plan their treatment, without the necessity of patient's physical presence.Information obtained from clinical photographs is of significant importance in establishing the best treatment plan [2].
Most of the modern computer dental programs allow photographs of the patient to be kept in their file.Thus, the extraction of information about the patient is facilitated [2].Some of these programs have options for photo processing and preparation of preliminary vision for the outcome of a treatment.
Dental photography plays very important role in the exchange of information from the main dentist to the patient, to another dental specialist or dental technician.In the field of prosthetic dentistry it is extremely important that all clinical information is submitted absolutely right to the dental laboratory where all the external and internal characteristics of teeth -enamel cracks, translucency, transparency, opalescence, opacity, mamelons, should be recreated when making prosthetic constructions [3,4,5].
Ring, twin flash or external flash can be used to capture the external characteristics of the teeth.Most authors suggest using lingual contraster, and some -making a black and white copy of the image in order to create a real topographic map of teeth's characteristics [3,4,6,7].
The literature describes various methods for recording the internal characteristics of the tooth [3,4,6,7].The most popular is the technique with camera positioned at 60° angle above the teeth and the image is underexposed in order to register translucency [7].This projection leads to shortening of the teeth in the photography, which may mislead the dental technician when mapping the internal characteristics of teeth.
Another alternative is to use two flashes with a different power directed at different angles to the tooth surface, but the correct positioning can be time consuming.This technique can be modified by placing a diffuser of a different kind on the flashes [3,4,6].Some authors describe a method for capturing the internal characteristics of the tooth using special polarizing http://dx.doi.org/10.5272/jimab.2015211.677filter which passes only light polarized at a certain angle that removes unwanted reflections [8,9].
The aim of this study is to create an original protocol for recording internal morphological characteristics of tooth by means of digital dental photography.For registration of internal morphological characteristics of teeth the following original methodology was used (Fig. 7): 1. Positioning of the patient in dental chair 2. Setting up the camera with the following parameters: -Aperture -F = 40 (between 36-45 or maximum closed) -Speed -between 1 / 100s and 1 / 200s -ISO -100 (minimum) -Intensity of flashes -full power on the side of the tooth being photographed, minimum power (or close to the minimum -1/128, 1/64) on the opposite side.
3. Placing the cheek retractor on patient's mouth 4. Drying the teeth in order to reduce glare and to record easier the internal morphological characteristics 5. Placing the lingual contraster behind the tooth row 6.Positioning of the camera to capture the tooth row.The front of the lens must be parallel to the frontal plane (imaginary extension of the lens perpendicular to the tooth surface) 7. Positioning of reflective disk with a silver surface on the side of tooth being photographed near the patient's head 8. Positioning of the flash heads: -The head of the flash on the side of the reflector is directed to it (set to maximum intensity) -The head of the flash on the opposite side is directed to the tooth row (set to minimum intensity) Fig. 7.A method for capturing internal morphological characteristics of the teeth using macro twin flash and reflective disk We applied an alternative technique in which as a source of light external flash with a specific type of diffuser was used instead of a macro flash.Any other conditions were equal (Fig. 8) Fig. 8.A method for capturing the internal morphological characteristics of teeth with external flash, specific diffuser and reflective disk

RESULTS
Results obtained from the research are as follows: (Table . 1 and Fig. 9):

Table 1. Results
Among more than 95% of the upper central incisors, the internal characteristics of the teeth -enamel cracks, translucency, transparency, opacity and opalescence are successfully recorded using both original photographic techniques.
Clinically detectable enamel cracks and areas of opacity were recorded in all 60 examined teeth (100%) with the two photographic techniques.Clinically visible areas of translucency were captured using a macro twin flash in 59 teeth (98.3%) and in 57 teeth (95%) by the method with external flash.Clinical areas that appear transparent were registered in all 60 teeth using the first technique and in 59 teeth (98.3%) with the second technique.Clinically identifiable zones of opalescence were captured in 57 of studied teeth (95%) and 58 teeth (96.7%), respectively with the first and second photographic methods.
As a result of the photographic techniques used by us, an image of the tooth with high sharpness and contrast is obtained.Due to the asymmetry of the light sources on the left and the right side, the peripheral zone of the image near to the registered toothis underexposed (Fig. 9).

Methodology
Twin

Fig. 9 .
Fig. 9. Registered internal morphological characteristics of teeth by photographic techniques proposed by us.