Necdet Erdilek

A comparative study of apical leakage of apexit, Ketac-Endo, and diaket root canal sealers

The purpose of this study was to compare the apical leakage of Ketac-Endo, Apexit, and Diaket. Fifty freshly extracted human maxillary anterior teeth were used. The anatomical crowns were removed at the amelocemental junction, and step-back preparation of the roots canals was performed with K-type files to size 40 using 2 ml of 5.25% NaOCl irrigant after each file change. The roots were randomly divided into five groups of 10 roots each: three experimental and two control groups. The experimental groups were as follows: group 1, Apexit; group 2, Ketac-Endo; and group 3, Diaket. Root canals were filled with one of the sealers and gutta-percha using lateral condensation. After the specimens were stored in 100% humidity at 37 degrees C for 2 wk, the roots were covered with two layers of nail polish and immersed in 2% methylene blue for 7 days. Each tooth was split into two sections, and dye penetration was evaluated independently by three examiners using a stereomicroscope at x20 magnification. Mann-Whitney U analysis showed that there was no significant difference between Apexit and Diaket (p > 0.05). However, there was significantly more leakage with Ketac-Endo (p < 0.05).

Comparative micro‐computed tomography evaluation of apical root canal transportation with the use of ProTaper, RaCe and Safesider systems in human teeth

The aim of this study was to compare apical centring ability of nickel titanium (NiTi) ProTaper, RaCe and mainly stainless steel Safesider systems using micro-computed tomography. Thirty freshly extracted mandibular molars with two separate mesial canals and separate foramina were used for the study. Mesial roots were embedded in acrylic resin and instrumented with the ProTaper, RaCe or Safesider systems. Root canal transportation and centring ability of the instruments were evaluated using superimposed micro-computed tomography images of the apical 4 mm of the roots taken at 1 mm intervals. One-way analysis of variance and post hoc Tukeys tests were performed to compare apical transportations. Significant differences were observed between groups at the apical 1, 2 and 3 mm levels (P < 0.05). The reciprocating Safesider system transported root canals significantly more than the other two NiTi systems in the apical 1 mm level (P = 0.001) and more than RaCe system in the apical 2 mm level (P = 0.003). The ProTaper instruments caused more apical root canal transportation than did RaCe instruments at apical 3 mm (P = 0.045). NiTi instrumentation systems showed better centring ability than the mainly stainless steel Safesider system because of the flexible structure of the NiTi alloy.

Comparison of calcium hydroxide and formocresol pulpotomies in primary teeth in lambs: preliminary study

Calcium hydroxide and formocresol pulpotomieswere performed on 28 primary teeth of seven lambs. The prepared specimens were examined under the light microscope at 1-, 7-, 14-, 30-, 60-, 120-, and 180-day intervals. Treatment of 14 teeth with calcium hydroxide and 12 of 14 teeth with formocresol was histologically successful.

The effect of ultrasonically activated irrigation and laser based root canal irrigation methods on debris removal

Purpose: To test the efficacy of debris removal of 5 in vitro irrigation protocols: conventional irrigation, irrigation activated by ultrasound, Er:YAG laser with photon-induced photoacoustic streaming (PIPS) tip, and 2 diode laser techniques. Methods: The root canals of 75 extracted human canine teeth were enlarged and bisected longitudinally. Standardized grooves were prepared 2-6 mm from the root apex and filled with 0.5 mm of dentine debris. The teeth were reassembled and irrigated using 1 of the following techniques (n = 15/technique): (1) conventional irrigation, (2) diode laser irrigation - tip placed 2 mm from working length, (3) diode laser irrigation - tip placed at root canal orifice, (4) Er:YAG laser - PIPS, and (5) ultrasonically activated irrigation. The root segments were disassembled, and the amount of remaining debris was evaluated by 3 examiners under a stereomicroscope at ×20 magnification using a 4-grade scoring system. The data were statistically analyzed using Kruskal-Wallis and Dunn’s multiple comparison tests, with a 95% confidence level (p = 0.05). Cohen’s kappa test was used to evaluate inter-observer and intra-observer agreement. Results: Ultrasonically activated irrigation removed significantly more dentinal debris than conventional irrigation (p = 0.016), but there were no significant differences between the other groups. Conclusions: Ultrasonically activated irrigation was more effective than conventional irrigation in the removal of apically placed dentine debris.

Long-term microleakage trends in access cavities conditioned with phosphoric acid and deproteinizing agent for root-canal-treated teeth: an investigation of fluid filtration and microscopy analysis

Abstract This study evaluated the long-term microleakage of access cavities conditioned with phosphoric acid and deproteinizing agents for root-canal-treated teeth using fluid filtration and microscopical analysis. Occlusal surfaces of extracted human mandibular premolars (N = 90) were removed leaving a 4 mm coronal length from the cemento-enamel junction. After root canal treatment, the specimens were randomly divided into four experimental groups (n = 21) and the remaining teeth were used for positive control group (n = 6): SB: 35% H3PO4 + Adper Single Bond 2; SSB: 35% H3PO4 + 5.25% NaOCl + 10% Sodium ascorbate (C6H7NaO6) + Adper Single Bond 2; XP: 35% H3PO4+XP Bond; SXP: 35% H3PO4+5.25% NaOCl + 10% Sodium ascorbate + XP Bond. All cavities were restored with a resin composite (Filtek Z250). After removing the root filling from the apical side, teeth were subjected to fluid filtration test for 1 week, 6 and 12 months followed by ×2500 thermocycling after 1st week and 6th months each. Data were analyzed using one-way ANOVA and Dunnet T3 tests (α = 0.05). SEM analyses were carried out after each microleakage evaluation in two random teeth from all groups. Microleakage values in groups SB and XP presented no significant difference in any of the evaluated period (p > 0.05). Microleakage results of SXP (0.01665) group showed significant difference compared to XP (0.03377) and SB (0.03049) groups after 12 months. SSB group (0.00901) showed significantly less microleakage among all other groups (0.01665–0.03377) (p < 0.05). Prior to endodontic treatment, in access cavities, acid etching with 35% H3PO4 followed by the application of NaOCl and sodium ascorbate completely destroyed the collagen layer, reducing the microleakage and resin–dentin interface degradation up to 12 months.

Microleakage of 4 post-luting cements evaluated by the computerized fluid filtration method.

Purpose The aim of this study was to evaluate the microleakage of 4 fiber post-luting systems using the computerized fluid filtration method. Methods 60 extracted human mandibular permanent premolar teeth were used for the study. The teeth were instrumented with Hedstroem files up to size 60, post spaces were prepared and then Unicore fiber posts were cemented using 4 luting systems. Group1: Duolink, Group 2: Resinomer, Group 3: Fuji Plus, Group 4: Multilink Sprint, Group 5: Positive Control, and Group 6: Negative Control. The samples were stored in distilled water for 2 weeks and then microleakage was evaluated. Data were analyzed with 1 way-ANOVA and Dunett T3 tests (P<.05). Groups 2 and 3 significantly exhibited higher microleakage values than groups 1 and 4 (P<.05). Results Resin cements used with total etch-bonding systems demonstrated lower microleakage values than the other cements. Conclusions Reduction of steps in dentin conditioning of resin luting cements may have a promoting effect on microleakage.