Bond strength of Epiphany (TM) Sealer combined with different adhesive systems photo-activated with LED and QTH

The Epiphany (TM) Sealer is a new dual-curing resin-based sealer and has been introduced as an alternative to gutta-percha and traditional root canal sealers. The canal filling is claimed to create a seal with the dentinal tubules within the root canal system producing a `monoblock` effect between the sealer and dentinal tubules. Therefore, considering the possibility to incorporate the others adhesive systems, it is important to study the bond strength of the resulting cement. Forty-eight root mandibular canines were sectioned 8-mm below CEJ. The dentine discs were prepared using a tapered diamond bur and irrigated with 1% NaOCl and 17% EDTA. Previous the application Epiphany (TM) Sealer, the Epiphany (TM) Primer, AdheSE, and One Up Bond F were applied to the root canal walls. The LED and QTH (Quartz Tungsten Halogen) were used to photo-activation during 45 s with power density of 400 and 720 mW/cm(2), respectively. The specimens were performed on a universal testing machine at a cross-head speed of 1 mm/min until bond failure occurred. The force was recorded and the debonding values were used to calculate Push-out bond strength. The analysis of variance (ANOVA) and Tukey`s post-hoc tests showed significant statistical differences (P < 0.05) to Epiphany (TM) Sealer/Epiphany (TM) Primer/QTH and EpiphanyTM Sealer/AdheSE/QTH, which had the highest mean values of bond strength. The efficiency of resin-based filling materials are dependent the type of light curing unit used including the power density, the polymerization characteristics of these resin-based filling materials, depending on the primer/adhesive used.

Bond Strength of Epiphany Sealer Prepared with Resinous Solvent

This study evaluated in vitro the bond strength of Epiphany sealer prepared with resinous solvent of Epiphany system (Thinning resin) by using a push-out test. Forty maxillary canines were sectioned transversally below the cementoenamel junction to provide 4-mm-thick dentin disks that were centered in aluminum rings and embedded in acrylic resin. Root canals were prepared with tapered diamond bur. Intraradicular dentin was treated with 1% NaOCl for 30 minutes, 17% ethylenediaminetetraacetic acid for 5 minutes, and flushed with distilled water for 1 minute. The specimens were randomly distributed into 4 groups (n = 10) according to the filling material: GI, Epiphany without photoactivation; GII, Epiphany prepared with solvent without photoactivation; Gill, Epiphany followed by photoactivation; and GIV, Epiphany prepared with solvent followed by photoactivation. After the setting time, the specimens were submitted to the push-out test. The highest mean value (14.91 +/- 2.82 MPa) was obtained with Epiphany prepared with solvent followed by photoactivation (GIV), which was statistically different (P < .01) from the other groups. Groups I (8.15 +/- 2.47 MPa), II (9.46 +/- 2.38 MPa), and III (9.80 +/- 2.51 MPa) had inferior bond strength values and were statistically similar among themselves (P > .01). The resinous solvent of Epiphany system increased the bond strength of Epiphany sealer to dentin walls when followed by photoactivation. (J Endod 2009;35: 251-255)

Quantitative 3D profilometry and SEM analysis of the adaptation of root-end filling materials placed under an optical microscope

P>Aim To evaluate by 3D profilometry and scanning electron microscopy (SEM), the marginal adaptation of mineral trioxide aggregate (MTA) and Sealer 26 placed in root-end cavities with direct vision or under an optical microscope. Methodology The root ends of 52 root filled canine teeth were filled with MTA or Sealer 26 under direct vision or optical microscope (n = 13). In each group, eight specimens were analysed by profilometry for measurement of the area and depth of gaps. In the other five specimens, gap area was measured using SEM to verify marginal adaptation and surface characteristic. Data were analysed by parametric (anova and Tukey) and non-parametric (Kruskal-Wallis and Dunn) tests. Results The assessment of the adaptation of both materials to dentine was not influenced by the mode of visualization, which was confirmed by both profilometry and SEM observations. The voids measured with profilometry for Sealer 26 under direct vision were significantly wider and deeper than those for MTA under direct vision (P < 0.05). In SEM, significantly larger gap areas were observed with Sealer 26 (P < 0.05). Conclusion Root-end cavities filled with MTA had smaller gaps and better marginal adaptation than Sealer 26.

Bond strength of AH Plus and Epiphany sealers on root dentine irradiated with 980 nm diode laser

Aim To evaluate the bond strength of AH Plus and Epiphany sealers to human root canal dentine irradiated with a 980 nm diode laser at different power and frequency parameters, using the push-out test. Methodology Sixty canine roots were sectioned below the cementoenamel junction to provide 4-mm-thick dentine discs that had their root canals prepared with a tapered bur and irrigated with sodium hypochlorite, ethylenediaminetetraacetic acid and distilled water. The specimens were assigned to five groups (n = 12): one control (no laser) and four experimental groups that were submitted to 980 nm diode laser irradiation at different power (1.5 and 3.0 W) and frequency (continuous wave and 100 Hz) parameters. Half of specimens in each group had their canals filled with AH Plus sealer and half with Epiphany. The push-out test was performed and data (MPa) were analysed statistically by ANOVA and Tukey`s test (P < 0.05). The specimens were split longitudinally and examined under SEM to assess the failure modes after sealer displacement. Results The specimens irradiated with the diode laser and filled with AH Plus had significantly higher bond strength values (8.69 +/- 2.44) than those irradiated and filled with Epiphany (3.28 +/- 1.58) and the nonirradiated controls (3.86 +/- 0.60). The specimens filled with Epiphany did not differ significantly to each other or to the control (1.75 +/- 0.69). There was a predominance of adhesive failures at Epiphany-dentine interface (77%) and mixed failures at AH Plus-dentine interface (67%). Conclusions The 980 nm diode laser irradiation of root canal dentine increased the bond strength of AH Plus sealer, but did not affect the adhesion of Epiphany sealer.

Interfacial evaluation of experimentally weakened roots restored with adhesive materials and fibre posts: An SEM analysis

Objectives: To evaluate the bonding interface in experimentally weakened roots reinforced with adhesive restorative materials and quartz fibre posts, varying the light-exposure time of the composite resin used for root reinforcement. Methods: Twelve extracted human maxillary incisors teeth were used. The crowns were removed and the roots were endodontically treated. After post space preparation, the roots were assigned to four groups. The thickness of the root dentine was reduced and adhesively restored with composite resin light-activated through a translucent fibre post for either 40 s (group 1), 80 s (group 2) or 120 s (group 3). In the case of control (group 4), the roots were not weakened. One day after post cementation, the specimens were sectioned transversally in three slices and processed for scanning electron microscopic analysis to observe bonding interface formation, quality of the hybrid layer and density of resin tags using a four-step scale method. Results: Formation of a hybrid layer and resin tags were evident in all groups. There was no statistically (p > 0.05) significant difference between the regions analysed in each group (Friedman test) and between groups in each section depth (Kruskal-Wallis test). Furthermore, comparison of the flared/reinforced groups showed that the different time;; used for composite resin cure did not affect the results significantly (Kruskal-Wallis test, p = 0.2139). Conclusions: Different light-exposure times used for composite resin polymerisation during root canal reinforcement did not affect significantly the formation and quality of the dentine/adhesive/composite resin bonding interface. (C) 2008 Elsevier Ltd. All rights reserved.

Effects of light exposure time on composite resin hardness after root reinforcement using translucent fibre post

Objectives: The purpose of this in vitro study was to evaluate the Vickers hardness (VHN) of a Light Core (Bisco) composite resin after root reinforcement, according to the light exposure time, region of intracanal reinforcement and lateral distance from the light-transmitting fibre post. Methods: Forty-five 17-mm long roots were used. Twenty-four hours after obturation, the root canals were emptied to a depth of 12 mm and the root dentine was artificially flared to produce a 1 mm space between the fibre post and the canal walls. The roots were bulk restored with the composite resin, which was photoactivated through the post for 40 s (G1, control), 80 s (G2) or 120 s (G3). Twenty-four hours after post-cementation, the specimens were sectioned transversely into three slices at depths of 2, 6 and 10 mm, corresponding to the coronal, middle and apical regions of the reinforced root. Composite VHN was measured as the average of three indentations (100 g/15 s) in each region at lateral distances of 50, 200 and 350 mu m from the cement/post-interface. Results: Three-way analysis of variance (alpha = 0.05) indicated that the factors time, region and distance influenced the hardness and that the interaction time x region was statistically significant (p = 0.0193). Tukey`s test showed that the mean VHN values for G1 (76.37 +/- 8.58) and G2 (74.89 +/- 6.28) differed significantly from that for G3 (79.5 +/- 5.18). Conclusions: Composite resin hardness was significantly lower in deeper regions of root reinforcement and in lateral areas distant from the post. Overall, a light exposure time of 120 s provided higher composite hardness than the shorter times (40 and 80 s). (C) 2008 Elsevier Ltd. All rights reserved.

Temperature variation at the external root surface during 980-nm diode laser irradiation in the root canal

Objective: To assess the temperature variation in the cervical, middle and apical thirds of root external wall, caused by 980-nm diode laser irradiation with different parameters. Methods: The roots of 90 canines, had their canals instrumented and were randomly distributed into 3 groups (n = 30) according to the laser potency (1.5 W, 3.0 W and 5.0 W). Each group was subdivided into 3 (n = 10) according to the frequency (CM, 100 Hz and 1000 Hz), and each subgroup divided into 2 (n = S): dried canal or filled with distilled water. The maximum temperature values were collected by 3 thermocouples located at each third of the root external wall and recorded by digital thermometers. Results: The groups irradiated in the continuous mode (CM) presented the highest values (11.82 +/- 5.78), regardless of the canals were dry or not, which were statistically different (p < 0.01) from those obtained with 100 Hz (6.22 +/- 3.64) and 1000 Hz (6.00 +/- 3.36), which presented no statistical difference between them (p > 0.01). The groups irradiated with 5.0 W presented the greatest temperature variation (12.15 +/- 5.14), followed by 3.0 W (7.88 +/- 3.92) and 1.5 W (4.02 +/- 2.16), differing between them (p < 0.01). The cervical third of the root presented the highest temperature rises (9.68 +/- 5.80), followed by the middle (7.66 +/- 4.87) and apical (6.70 +/- 4.23), with statistical difference among them (p < 0.01). After 30 s from the end of irradiation, all the specimens presented temperature variation lower than 10 degrees C. Conclusions: Application of 980-nm diode laser in the root, at 1.5 W in all operating modes, and 3.0 W, in the pulsed mode, for 20 s, can safely be used in endodontic treatment, irrespective of the presence of humidity. (C) 2008 Elsevier Ltd. All rights reserved.

Influence of Filling Materials on the Bonding Interface of Thin-walled Roots Reinforced with Resin and Quartz Fiber Posts

Introduction: A common complication during the restoration of severely destroyed teeth is the loss of coronal root dentine. The aim of this study was to evaluate the influence of different sealers on the bonding interface of weakened roots reinforced with resin and fiber posts. Methods: Sixty extracted maxillary canines were used. The crowns were removed, and the thickness of root dentine was reduced in the experimental (n = 40) and positive control (n = 10) groups. The specimens of experimental group were assigned to four subgroups (n = 10) according to the filling material: gutta-percha + Grossmann`s sealer, gutta-percha + AH Plus (Dentsply De Trey Gmbh, Konstanz, Germany), gutta-percha + Epiphany (Pentron Clinical Technologies, Wallingford, CT), and Resilon (Resilon Research LLC, Madison, CT) + Epiphany. In the negative control group (n = 10), canals were not filled. After post space preparation, the roots were restored with composite resin light-activated through a translucent fiber post. After 24 hours, specimens were transversally sectioned into 1-mm-thick slices. Push-out test and scanning electron microscopic (SEM) analyses of different regions were performed. Data from push-out test were analyzed by using Tukey post hoc multiple comparison tests. The percentage of failure type was calculated. Data from SEM analysis were compared by Friedman and Kruskal-Wallis tests (alpha = 0.05). Results: The mean bond strength was significantly higher in the negative control group as compared with the other groups (P < .05). In all groups, the most frequent type of failure was adhesive. Overall, apical and middle regions presented a lower density of resin tags than the coronal region (P < .05). Conclusions: The push-out bond strength was not affected by sealer or region. The canal region affected significantly the resin tag morphology and density at the bonding interface. (J Endod 2011;37:531-537)

Assessment of the biocompatibility of Epiphany root canal sealer in rat subcutaneous tissues

Objective. The aim of this study was to evaluate the biocompatibility of the root canal sealer Epiphany in rat subcutaneous tissues. Study design. Polyethylene tubes were filled with the sealer (I: Epiphany; II: photoactivated Epiphany; III: Epiphany associated with self-etch primer; IV: photoactivated Epiphany associated with primer; and V: control group) and later implanted into 4 different regions of the dorsum of 15 adult male rats (Rattus novergicus, Albinus Wistar). After 7, 21, and 42 days, 5 animals were killed, obtaining 4 samples per group, in addition to the control group, at each analyzed time. Results. In all periods, Epiphany induced a mild inflammatory reaction. However, in group II, in which the primer was not used, extensive necrosis and a moderate to intense inflammatory reaction were observed, mainly after 7 and 21 days. Conclusion. Epiphany sealer appears biocompatible when tested on rat subcutaneous tissues.

Influence of endodontic sealers on the bond strength of carbon fiber posts

Objective: The aim of this study was to verify the influence of endodontic sealers on the bond strength of an adhesive system and a resin cement used for carbon posts cementation. Methods: Thirty extracted human premolars were instrumented and randomly divided into three groups according to the tested sealer: EndoFill, Sealapex, or EndoREZ. Specimens were stored at 37 degrees C. After 48 h, half of specimens were prepared to receive the post and the others after 7 days. The posts were cemented with Adper Single Bond/Rely X ARC and stored in distilled water at 37 degrees C for 7 days. After this period, the specimens were sectioned in three slices (coronal, middle, and apical). The push-out test was performed in a universal machine and the debonded area was examined in a stereomicroscope. Results: Data were submitted ANOVA and Tukey test (alpha = 0.05). The EndoFill showed lower bond strength than other sealers (p < 0.01). The EndoREZ sealer was statistically greater than other groups for coronal and middle portions and similar for apical portion (P > 0.05). Coronal and middle portions showed the best results for all groups, mainly when the canal preparation was performed after 48 h (p < 0.01). Mixed failure occurs with more frequency (55.6%) followed by failure in adhesive-dentin interface (34.4%) and adhesive-post interface (10.0%). Conclusion: The use of EndoREZ sealer promoted higher bond strength in root coronal and middle portions when carbon post was fixed with a resin cement. (C) 2007 Wiley Periodicals, Inc.

Clinical management and subsequent healing of teeth with horizontal root fractures

Horizontal root fractures are uncommon, mainly occurring on the cervical and middle third of the root of permanent upper incisors. The diagnosis is essentially radiographic and requires different healing patterns, depending on some pre- and postinjury factors. The aim of this article was to report the clinical management and different healing types in three cases of horizontal root fractures on permanent dentition. In case 1, the pulp tissue was vital and no treatment was necessary. In case 2, a root canal treatment of the cervical fragment was necessary and in case 3, pulpal necrosis was verified and an apical surgery was performed.

Influence of different endodontic filling materials on root fracture susceptibility

Objective: To evaluate the influence of different endodontic materials on root fracture susceptibility. Methods: Seventy-two mandibular incisors were sectioned 1 mm below the cementoenamel junction to obtain roots of 12 mm length. Roots were submitted to chemomechanical preparation with the rotary instruments of Profile system. The obturation of root canals were performed with the following filling materials (n = 12): GI, unfilled teeth (control); GII, Endofill + gutta-percha; GIII, Sealer 26 + gutta-percha; GIV, AH Plus + gutta-percha; GV, Epiphany + gutta-percha; GVI, Epiphany + Resilon. After the sealers setting time, each root was embedded in acrylic resin. The specimens were then submitted to fracture resistance test using an Instron testing machine at 1 mm/min. Results: The ANOVA test showed no significant statistical difference (p > .05) among GI (162.16 +/- 41.4N), GII (168.46 +/- 37.5N), GIII (164.83 +/- 35.7N), GIV (168.29 +/- 38.7N), GV (172.36 +/- 20.6N) and GVI (193.11 +/- 42.8N). Conclusion: The core materials (gutta-percha or Resilon) combined with the tested endodontic sealers are not able to increase the root fracture resistance in canals submitted to chemomechanical preparation. (c) 2007 Elsevier Ltd. All rights reserved.

Study on the potential inhibition of root dentine wear adjacent to fluoride-containing restorations

The purpose of this in vitro study was to determine whether the vicinity of root dentine that had been restored with fluoride-releasing materials was at reduced risk for erosive/abrasive wear compared to root dentine restored with a non-fluoride-containing material. According to a randomized complete block design, standardized cavities prepared on the surface of 150 bovine root dentine slabs were restored with glass-ionomer cement, resin-modified glass ionomer, polyacid-modified resin composite, fluoride-containing or conventional composite. Specimens were coated with two layers of an acid-resistant nail varnish exposing half of the dentine surface and half of the restoration. Subsequently, specimens were either eroded in an acidic drink or left uneroded, then exposed to artificial saliva and abraded in a toothbrushing machine. Wear depth in the vicinity of restorations was quantified by a stylus profilometer, based on the nonabraded areas surrounding the erosion/abrasion region. Two-way ANOVA did not demonstrate significant interaction between restoratives and eroded-uneroded dentine (p = 0.5549) nor significant difference among restorative materials (p = 0.8639). Tukey`s test ascertained that the wear depth was higher for eroded than for uneroded groups. Fluoride-releasing materials seemed to negligibly inhibit wear in the vicinity of restored root dentine subjected to erosive/abrasive challenges.

Shear Bond Strength and Ultrastructural Interface Analysis of Different Adhesive Systems to Bleached Dentin

Background: It remains unclear as to whether or not dental bleaching affects the bond strength of dentin/resin restoration. Purpose: To evaluated the bond strength of adhesive systems to dentin submitted to bleaching with 38% hydrogen peroxide (HP) activated by LED-laser and to assess the adhesive/dentin interfaces by means of SEM. Study design: Sixty fragments of dentin (25 mm(2)) were included and divided into two groups: bleached and unbleached. HP was applied for 20 s and photoactivated for 45 s. Groups were subdivided according to the adhesive systems (n = 10): (1) two-steps conventional system (Adper Single Bond), (2) two-steps self-etching system (Clearfil standard error (SE) Bond), and (3) one-step self-etching system (Prompt L-Pop). The specimens received the Z250 resin and, after 24 h, were submitted to the bond strength test. Additional 30 dentin fragments (n = 5) received the same surface treatments and were prepared for SEM. Data were analyzed by ANOVA and Tukey`s test (alpha = 0.05). Results: There was significant strength reduction in bleached group when compared to unbleached group (P < 0.05). Higher bond strength was observed for Prompt. Single Bond and Clearfil presented the smallest values when used in bleached dentin. SEM analysis of the unbleached specimens revealed long tags and uniform hybrid layer for all adhesives. In bleached dentin, Single Bond provided open tubules and with few tags, Clearfil determined the absence of tags and hybrid layer, and Prompt promoted a regular hybrid layer with some tags. Conclusions: Prompt promoted higher shear bond strength, regardless of the bleaching treatment and allowed the formation of a regular and fine hybrid layer with less deep tags, when compared to Single Bond and Clearfil. Microsc. Res. Tech. 74:244-250, 2011. (C) 2010 Wiley-Liss, Inc.

Radiopacity Evaluation of Calcium Aluminate Cement Containing Different Radiopacifying Agents

Introduction: The aim of this study was to evaluate the radiopacity of calcium aluminate cement (Endo Binder) with 3 different radiopacifiers (bismuth oxide, zinc oxide, or zirconium oxide) in comparison with gray mineral trioxide aggregate (GMTA), white MTA, and dental structures (enamel and dentin). Methods: Eighteen test specimens of each cement with thicknesses of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm (n = 3) were made by using a stainless steel matrix and were adapted to a standardizing device (8 x 7 cm) with a graduated aluminum stepwedge varying from 2.0-16.0 mm in thickness. To compare the radiopacity of the cements with that of dental structures, slices of first molars with a thickness increasing from 0.5-3.0 mm were obtained and placed on the standardizing device. One occlusal radiograph for each tested cement was taken, with exposure time of 0.1 seconds and focus-film distance of 20 cm. Films were processed in an automatic device, and the mean radiopacity values were obtained by using a photodensitometer. Results: Mean values showed that the thicker the specimen was, the greater was its radiopacity. Only EndoBinder + bismuth oxide (EBBO) and GMTA demonstrated radiopacity values greater than 3.0 mm of the aluminum scale for all thicknesses. When zinc oxide was used as radiopacifier agent, EndoBinder only reached the desired radiopacity with a thickness of 2.0 mm, and with zirconium oxide it was 2.5 mm. Conclusions: Bismuth oxide was the most efficient radiopacifier for EndoBinder, providing adequate radiopacity in all studied thicknesses, as recommended by ISO 6876, being similar to GMTA. (J Endod 2011;37: 67-71)