RERMOVING SMEAR LAYER DURING ENDODONTIC TREATMENT BY DIFFERENT TECHNIQUES- A INVITRO STUDY. A CLINICAL CASE- ENDODONTIC TREATMENT WITH ER: YAG LASER
In group 3. Er: YAG LAI with 17 % EDTA showed the best smear-layer removal from the entire root canal surface, including apical area with open dentinal tubules( Fig. 3).
The best effect on smear-layer removal and tubules were open in all parts of the canal was present when we used 17 % EDTA with Er: YAG LAI.
Figure 3. SEM X 10,000 picture presents clean root canal wall with open dentinal tubules after Er: YAG laser with 17 % EDTA for 60 seconds
4. Discussion This ex vivo study was designed to evaluate the effectiveness of using a 17 % EDTA irrigation solution with laser irradiation compared to conventional syringe irrigation. Intact teeth were used to simulate the clinical situation as closely as possible. The maximum irrigation time was 1 minute of 10 ml to minimize detrimental effects on the dentin surface. Prolonged application of the EDTA solution might increase Ca2 + removal from the root dentin. Spangberg 25 showed that EDTA solution removes the smear layer within 1 minute of reaching the canal surface. In our study, exposure to 17 % EDTA was limited to 1 minute to prevent potential changes in the dentin’ s microhardness, permeability, and solubility characteristics 26. The generation of shockwaves by dental lasers inside the root canals can play an important role in smear layer removal 19-24. Similarly, smear layer removal can be achieved when water is activated in root canals using erbium lasers( Er, Cr: YSGG or Er: YAG) 19, 23. 24, causing the formation of vapor bubbles that expand and implode 19, 21, 22, 24. Apparently, there is no difference in the efficacy of both wavelengths in terms of smear layer removal In our study we used the laser light here at subablative settings, which does not damage the root canal wall.( we tested before the EDX at this energy). The position of the laser tip inside the root canal is important. when using the laser fibers in the root canal, as apical extrusion of the irrigant after laser activation has been described 20. A previous study by George et al. 20 showed that there was twice as much dye penetration through the apical constriction with the fiber tip at 4 mm than at 5 mm. Therefore, in our vitro study, we insert the laser tip at upper part of the root canal, to avoid
the irrigation extrusion. The standard irrigation technique during endodontic treatment employs a syringe and needle. Its effectiveness is unpredictable in the apical part of the canal, since the solution is only effective 1.5 mm beyond the needle tip 27, 28, 31, 32. The depth of needle penetration depends on the size and morphology of the canal 28. The results of the present study confirm that 17 % EDTA irrigation with a syringe does not affect the apical segment of the root and the smear layer remains intact on this important part of the root surface.
5. A Clinical case- Endodontic treatment with Er: YAG laser A clinical case of a male, 42 years old suffers from diabetes. The clinical examination demonstrated maxillary lateral incisor tooth no 12 # with metal ceramic crown. The sinus- tract was present in the apical area. There was no pain to percussion, pocket depth was normal. According to the patient story the sinus-tract was there for over 2 years. The radiographic examination reveled a large radiolocency at the apical part of the lateral incisor tooth.( Figure 4). The crown was removed and endodontic retreatment was started. During cleaning and shaping the root canal system with inter-appointment intracanal medicaments such as: Calcium hydroxide, 3mix( it is mixing of 3 antibiotic: Metronidazole, Minocycline, and Ciprofloxacin), and with Ledermix, the Sinus-tract persisted. We decided to treat this patient with Laser Activated Irridation, using the Er: YAG laser( LiteTouch™, Light Instruments, Yokneam, Israel) at energy, 0.5 W, 50 mJ, 10 HZ for 60 seconds with 17 % EDTA as an irrigation solution.( Fig. 5)
164 STOMA. EDUJ( 2016) 3( 2)