BACKGROUND AND AIM: In recent years, restoration of endodontically treated teeth with fiber reinforced composites (FRCs) posts has become increasingly popular . The most common failure mode of FRC posts is debonding at the adhesive resin-dentin interface. Obviously, dentin hybridization is very important in resin – dentin bond and can be affected by different types of dentin pretreatments .The aim of this in-vitro study was to assess the impact of three different root canal pretreatments {chlorhexidine(CHX), Er:YAG laser and CHX+ Er:YAG laser} on the microleakge of cemented fiber posts.
EFFECT OF ROOT CANAL PRETREATMENTS USING ER: YAG LASER AND CHLORHEXIDINE ON MICROLEAKAGE OF FIBER POSTS GHAZALEH AHMADIZENOUZ1, FATEMEH ZAHEDIPOUR2 1- Assistant Professor, Department of Restorative Dentistry, Babol University of Medical sciences , Iran 2- Dentist, Private Practice
RESULTS Microleakage in the specimens treated with CHX was lower than other groups. The highest microleakage mean value was found in laser-treated group. However, One-way ANOVA revealed no significant differences between the groups (p>0.05).
MATERIALS AND METHODS Thirty-two extracted human maxillary central incisors were selected and disinfected in 0.5% chloramine T solution. The crowns of the teeth were removed below the CEJ using a diamond disc perpendicular to the long axis. The root canals were instrumented using step- back technique and obturated with gutta-percha and AH26 using lateral condensation technique. The access cavities were temporized with a non- eugenole provisional material .The roots were stored in normal saline at 37°C for one week for full sealer setting. Guttapercha fillings were removed to a depth of 9 mm with No.3 Gates Glidden and post space preparation up to 9 mm was carried out with #2 White Post system drills .The specimens were randomly allocated into 4 groups (n =8) according to the dentin conditioning. Group 1: no additional canal pretreatment (Control ) . Group 2: placement of CHX 2% for 30 seconds in root canals (Fig.1) Group 3: irradiation of root canals with Er:YAG laser .(Fig2) Laser parameters were set at output power1.5W; wavelength 2940 nm, pulse frequency 25Hz; air pressure of 65% and water pressure of 100% in an irradiation of 5 s for 3 times at 10 s intervals using H4 fiber tip with a diameter of 400 µm. Group 4: combination of CHX 2% for 30seconds and Er:YAG laser fiber posts #2 ( Fig3) were then cemented with Panavia F2 resin cement. The roots were thermocycled in distilled water for 1500 cycles .Dye penetration technique was used to assess the depth of microleakage in µm at the cement – dentin interface from the orifice on both mesial and distal surfaces under stereomicroscope at 40X.(Fig 4,5,6) The data were analyzed using SPSS v.22 by one-way ANNOVA test .The accepted level of error was set at P