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COMPARISON OF DIFFERENT METHODS OF EXCAVATION CONTROL FOR MINIMALLY INVASIVE CARIES TREATMENT
Figure 2 . Hue / Saturation / Brightness ( HSB ) scheme
Figure 1 . Scheme of the arrangement of the lines in the object of the analysis
- In the visual and tactile control method - yellow or light yellow dentine ; hard consistency , slightly creaking and resistance when probing ; - In the fluorescence control method with Facelight - pale red fluorescence disappears . Criteria for excavation up to affected dentine : - In the visual and tactile control method - dark yellow or light brown dentine ; medium-hard consistency , a slight resistance when probing with a white trail ; - In the fluorescence control method with Facelight - a weak pale red fluorescence only at the bottom of the cavity . The cavity preparation was conducted by one examiner and the evaluations were made by 3 examiners after preliminary calibration .
2.1 . Preparation of extracted teeth for the experiment The extracted teeth used in this study were stored in a solution of distilled water with thymol . At least 24 hours prior to the excavation they were left in pure distilled water . After completion of the excavation and clinical assessments the roots were separated from the clinical crowns , then the samples were dried in alcohol solutions of increasing concentrations ( 30 %, 70 %, 90 %). The cavities were isolated by restoration using temporary filling material ( Adhesor , SpofaDental a . s . HQ , Jičín , Czech Republic ). Then samples were packed with an epoxy resin in plastic cylinders 1.5 cm in diameter of and 3.5 cm in height . After resin polymerisation , the specimens were bisected in the axial axis of the tooth in the mesio-distal direction . Temporary restorations were removed from both halves , and then they were used for the purposes of that in vitro study about the applying of photographic equipment for dentinal changes characterisation during the excavation .
2.2 . Original authors method Developing of methods for valuation of changes in dentine during excavation , using highly specialized digital photographic equipment and software :
Dental samples were documentary evidenced using highly specialised digital photographic equipment consisting of the following components : body - Nikon D90 , lens - Nikon AF-S Micro-Nikkor 105mm f / 2.8G VR , flash - Nikon SB-R 200 Speed light Remote Kit R1 ( Nikon Corp ., Tokyo , Japan ). Photographing the objects was carried out under the following conditions - focal distance 105 mm , coefficient of approximation - 1 : 1 . The resulting images underwent software analysis of the color under the developed original methodology , as follows : First we put Line D - parallel to the enamel dentine junction . Then Line A - forming an angle of 94 ° with the line parallel to the enamel dentine junction and intersecting the pulp chamber , Line B and Line C - bisectors of the angle between Line A and Line D , were drawn . Three levels of depth were determined : - Level 1 – on the surface of the excavation - Level 2 – 80 pixels ( 0,4 mm ) down the non excavated dentine - Level 3 – 160 pixels ( 0,8 mm ) down the non excavated dentine The points where the three Lines cross the three Levels ( Fig . 1 ) were analysed with the use of specialised digital software ( Adobe Photoshop CS 5.5 , Adobe Systems , San Jose , CA , USA ). A randomly chosen point on the area of healthy dentine was used as control point . In each of the three points , as well as in the control point the color was measured for each parameter according to the color system - HSB ( Hue , Saturation , and Brightness ) ( Fig . 2 ). HSB system is defined as a device-independent way for determining the color , i . e ., once the color defined by this system ; it can be reproduced isometrically by different devices . This system presents a color as a relationship of three parameters : - Hue - shade of color . Practically it is the color itself . Measured in linear degrees - 0 - 360 °; 0 ° = red , 60 ° = yellow , 120 ° = green , etc .
- Saturation - color saturation . Measured in percentages -0 %= no color , 100 % = highest color intensity .
- Brightness - the brightness of the color . It is expressed in percentage of the black ( 0 %) to white ( 100 %).
Changes in the color of all points were used to

100 STOMA . EDUJ ( 2016 ) 3 ( 1 )