Basic Research—Technology Effects of Photodynamic Therapy on the Adhesive Interface of Fiber Posts Cementation Protocols Anna Thereza Peroba Rezende Ramos, DDS, MSc, Lauriê Garcia Beliz�ario, DDS, MSc, Ana Carolina Venç~ao, DDS, MSc, PhD, Keren Cristina Fagundes Jord~ao-Basso, DDS, MSc, PhD, Alessandra Nara de Souza Rastelli, DDS, MSc, Marcelo Ferrarezi de Andrade, DDS, MSc, PhD, and Milton Carlos Kuga, DDS, MSc, PhD Abstract Significance Microbial contamination is a common clinical situ- ation during post space preparation that compro- mises the success of endodontic treatment. Antisepsis protocols have been recommended; however, it is still unclear whether these protocols affect post adhesion. Introduction: The aim of this study was to evaluate the effects of photodynamic therapy (PDT) on the bond strength and dentinal penetrability of cementation pro- tocols using conventional resin cement (Relyx ARC; 3M ESPE, St Paul, MN) or self-adhesive (Relyx U200, 3M ESPE) after the glass fiber post cementation. Methods: Forty human canine roots were endodontically treated and prepared for a fiber post. The roots were divided into 4 groups according to the cementation protocol and PDT use: conventional cement (CC), Relyx ARC; self-adhesive cement (SAC), Relyx U200 cement; PDT/ CC, PDT + Relyx ARC; and PDT/SAC, PDT + Relyx U200. After cementation of the fiber posts, the roots were cross sectioned, and then specimens from the cer- vical, middle, and apical thirds of the prosthetic space were obtained. The specimens were submitted to the pushout test and dentinal penetration evaluation of the cementation protocol using laser confocal micro- scopy. Results: PDT/CC presented the lowest bond strength to root dentin in the cervical third (P < .05). In the middle and apical thirds, all groups presented a similar bond strength (P > .05). PDT/CC presented the lowest dentinal penetration of the adhesive system in the cervical and apical thirds (P < .05). Conclusions: PDT presented negative effects on the bond strength to dentin in the cervical third after cementation using Relyx ARC and on the dentinal penetrability of the etch-and-rinse adhesive system in the cervical and api- cal thirds of the prosthetic space. (J Endod 2018;44:173–178) Key Words Bond strength, fiber posts, photodynamic therapy, push- out bond strength, self-adhesive cement Department of Restorative Dentistry, S~ao Paulo State University Address requests for reprints to Dr Anna Thereza Peroba Rezende Humait�a Street, 1680, Araraquara, SP 14801-903, Brazil. E-mail add 0099-2399/$ - see front matter Copyright ª 2017 American Association of Endodontists. https://doi.org/10.1016/j.joen.2017.08.035 JOE — Volume 44, Number 1, January 2018 Intracanal preparation ofthe prosthetic space for a fiber post requires a par- tial removal of root canal obturation. During this procedure, local contami- nation may occur, which compromises the success of endodontic and/or restorative treatments (1, 2). Sodium hypochlorite and chlorhexidine digluconate have been recommended for prosthetic space irrigation, but they have shown negative effects on the bond strength of the resin cements to root dentin (3–5). Free radicals participate in the polymerization process of resinous compounds inducing chemical reactions in the methacrylate structure (6). Thus, the degree of con- version and the adhesion of resinous materials to the dentin are compromised by the substances that interact with these free radicals, such as sodium hypochlorite, which degrades in sodium hydroxide and hypochlorous acid and, consequently, leads to singlet oxygen formation (7–9). Moreover, the presence of oxygen can also work as a barrier in the adhesive interface, which hampers hybrid layer formation in dentin (10). Because sodium hypochlorite may cause undesirable effects, other alternatives have been sought to perform prosthetic space antisepsis. Henceforth, photodynamic therapy (PDT) with specific photosensitizers, such as 0.005% or 0.01% methylene blue, has been an interesting option (11) because of its satisfactory antimicrobial ac- tivity in contaminated root canals (12). The mechanism of action of PDT occurs when a photosensitizing substance ab- sorbs the photons from the irradiation source and their electrons enter an excitation state. Then, the energy is transferred to a specific substrate, forming reactive oxygen species (ROS) (mainly singlet oxygen), which irreversibly oxidize the cellular compo- nents causing bacterial death (11, 13, 14). However, it is still unknown whether the free radicals from the ROS release affect the adhesive interface between the dentin and fiber post cement after different cementation protocols, similar to the decontamination protocols using sodium hypochlorite. Therefore, the aim of this study was to evaluate the effects of PDT using 0.005% methylene blue in the intracanal prosthetic space on the bond strength and intradentinal penetrability using conventional (Relyx ARC; 3M ESPE, St Paul, MN) or self-adhesive (Relyx U200, 3M ESPE) resin cements in different root thirds after the fiber post cemen- (Unesp), Araraquara, S~ao Paulo, Brazil Ramos, Department of Restorative Dentistry, Araraquara Dental School, S~ao Paulo State University, ress: annatherezaramos@hotmail.com Effects of Photodynamic Therapy on Fiber Posts 173 Delta:1_given name Delta:1_surname Delta:1_given name Delta:1_surname Delta:1_given name Delta:1_surname Delta:1_given name mailto:annatherezaramos@hotmail.com https://doi.org/10.1016/j.joen.2017.08.035 http://crossmark.crossref.org/dialog/?doi=10.1016/j.joen.2017.08.035&domain=pdf TABLE 1. Materials, Manufacturers, Origin, and Chemical Composition of Materials and Groups Material Composition Groups Relyx ARC (3M ESPE, St Paul, MN) Paste A: BisGMA, TEGDMA, zirconia silica, pigments, amine, and photoinitiator system Paste B: BisGMA, TEGDMA, zirconia silica, benzoyl peroxide Groups 1 and 3 Relyx U200 (3M ESPE) Base paste: glass powder treated silane, 2-propenoic acid, 2-metil 1,1’-[1- (hydroxymetil)-1,2- ethanodlyl] ester, triethylene dimethylacrylate with silane, glass fiber, sodium persulfate, and t-butyl per-3,5,5– trimethylhexanoate Catalyst paste: silane-treated glass powder, substituted dimethacrylate, silanated silica, sodium p-toluene sulfonate, 1-benzyl-5-phenyl-baric acid, calcium salts, 1,12-dodecane dimethacrylate, calcium hydroxide and titanium dioxide Groups 2 and 4 Adper Scotchbond Multipurpose (3M ESPE) Primer: 2-hydroxyethyl methacrylate in aqueous solution (HEMA) and polyalkenoic acid copolymer Adhesive: bisphenol diglycidyl dimethacrylate solution (Bis-GMA), 2-hydroxyethyl methacrylate (HEMA), and Camphorquinone Groups 1 and 3 Basic Research—Technology tation protocols. The null hypothesis was that PDT does not affect the adhesion and the dentinal penetration of fiber post cements. TABLE 3. Mean and Standard Deviation of the Penetration (%) of Fiber Post Materials and Methods The study was approved by the Research Ethics Committee of Ara- raquara School of Dentistry (S~ao Paulo State University-Unesp) (1.603.859). Forty human canines with a similar root anatomy and the absence of structural alterations were selected and kept in 0.1% thymol solution at 4�C. The dental crowns were removed about 15mm from the root apex. Then, chemical-mechanical preparation and root canal obturation were performed according to Aranda-Garcia et al (15). After vertical condensation obturation, the cervical opening was sealed using tempo- rary cement (Coltosol; Coltene, Rio de Janeiro, Brazil), and the roots were stored under 100% relative humidity at 37�C for 7 days. The preparation of the intracanal prosthetic space was performed using a #2 bur (White Post DC System; FGM, Joinville, SC, Brazil) with an 11-mm length. Then, it was irrigated using 10 mL distilled water and dried with absorbent paper points. The specimens were randomly divided into 4 groups (n = 10) according to the cementation protocol and PDT application in the prosthetic space: conventional cement (CC), Relyx ARC; self-adhesive cement (SAC), Relyx U200; PDT/CC, PDT + Relyx ARC; and PDT/SAC, PDT + Relyx U200. The fiber post surface was cleansed using 95% ethanol and etched with 37% phosphoric acid (Power Etching; BM4, Palhoça, SC, Brazil) for 1 minute, and then silane (Prosil, FGM) and dentin adhesive (Adper Scotchbond Multiuso Plus, 3M ESPE) were applied throughout its length. Afterward, the whole set was light cured for 60 seconds (Blue- phase; Ivoclar Vivadent, Barueri, SP, Brazil). PDT was performed in the PDT/CC and PDT/SAC groups. Initially, the prosthetic space was filled with 1000 mL 0.005% methylene blue TABLE 2. Mean and Standard Deviation of Bond Strength (in MPa) in the Root Thirds of the Prosthetic Space according to Photodynamic Therapy (PDT) Use in the Prosthetic Space Groups Cervical Middle Apical Group 1: Relyx ARC 4.21 � 1.06a 3.56 � 1.13a 3.96 � 1.96a Group 2: Relyx U200 6.09 � 1.66a 4.38 � 2.22a 3.51 � 1.54a Group 3: PDT + Relyx ARC 2.45 � 0.78b 3.27 � 1.56a 3.65 � 1.52a Group 4: PDT + Relyx U200 4.55 � 1.57a 4.71 � 1.06a 4.66 � 1.37a Different superscript letters in the same column indicate significant differences (P < .05). 174 Ramos et al. (Chimiolux; DMC, S~ao Carlos, SP, Brazil), and the root cervical face was covered with laminated paper and left untouched for 5 minutes. Af- ter that, an optical fiber (Twin Flex Evolution; MMO Opto-Electronic Equipment, S~ao Carlos, SP, Brazil) was inserted into the entire pros- thetic space in a static position, and the prosthetic space was irradiated for 30 seconds using a laser emission source (Twin Flex Evolution) with an output power of 30 J/cm2. Afterward, methylene blue was aspirated, and the prosthetic space was irrigated with 3 mL saline solution and dried with absorbent paper points. Before fiber post cementation, 0.01% (by mass) Rhodamine B isothiocyanate was added to the primer of the adhesive system (Adper Scotchbond Multiuso Plus) and used in the CC and PDT/CC groups. Rhodamine B isothiocyanate was also added to the cements and used in the SAC and PDT/SAC groups. All specimens were subjected to laser confocal microscopic evaluation. Specimens in the CC and PDT/CC groups were acid etched (Power Etching) for 15 seconds, irrigated with distilled water for 30 seconds, and dried with absorbent paper points. The adhesive system (Adper Scotchbond Multiuso Plus) was applied throughout the prosthetic space and light cured for 20 seconds (Bluephase). The cements were handled according to the manufacturers’ rec- ommendations and are described in Table 1. Immediately after the cementation of #2 (FGM) fiber posts, the roots were vertically central- ized inside a polyvinyl chloride matrix (16.5 diameter � 15.0-mm length) and checked using a parallelogram (BioArt B2, S~ao Carlos, SP, Brazil). The matrices were filled with polyester resin (Maxi Rubber, Diadema, SP, Brazil), leaving 1.0 mm of the root cervical outside the inclusion. The whole set was left undisturbed for 24 hours. Then, the Cement in Root Dentin in All Thirds of the Prosthetic Space according to the Cementation Protocol and Photodynamic Therapy (PDT) Use Groups Cervical Middle Apical Group 1: Relyx ARC 34.85 � 6.60a 39.14 � 19.80a 16.01 � 1.46a Group 2: Relyx U200 42.89 � 12.44a 49.29 � 19.33a 19.56 � 5.18a Group 3: PDT + Relyx ARC 11.82 � 3.02b 26.52 � 16.08a 6.36 � 3.18b Group 4: PDT + Relyx U200 41.28 � 16.10a 41.76 � 23.78a 18.19 � 3.21a Different superscript letters in the same column indicate significant differences (P < .05). JOE — Volume 44, Number 1, January 2018 Figure 1. Representative images of the dentinal penetrability in the groups evaluated. (A–C) CC, cervical, middle, and apical thirds, respectively. (D–F) SAC, cer- vical, middle, and apical thirds, respectively. (G–I) PDT/CC, cervical, middle and apical thirds, respectively. (J–L) PDT/SAC, cervical, middle, and apical thirds, respectively. CC, Relyx ARC; SAC, Relyx U200; PDT/CC, PDT + Relyx ARC; and PDT/SAC, PDT + Relyx U200. Basic Research—Technology JOE — Volume 44, Number 1, January 2018 Effects of Photodynamic Therapy on Fiber Posts 175 Figure 2. Distribution of the failure mode in each group. Basic Research—Technology specimens were removed from the matrices and sectioned perpendic- ular to their long axis with a diamond disk using a hard tissue cutting machine (Isomet; Buehler Ltd, Lake Bluff, IL) under running water cooling. Three sections were performed with 2.0 mm� 0.1 mm thick- ness from the apical, middle, and cervical thirds of the prosthetic space. The cervical, medial, and apical radicular sections were carried out from 1.0 mm, 5.0 mm, and 8.0 mm from the root cervical face, respec- tively. The section irregularities were removed using #1200 (Norton, S~ao Paulo, SP, Brazil) sandpaper. The specimens of each root third were submitted to a pushout test using an electromechanical test machine (EMIC, S~ao Jos�e dos Pinhais, PR, Brazil) at 0.5-mm/min speed using a 5-kN load cell until complete displacement of all root canal walls. The force required for the displace- ment to occur was obtained in newtons, and it was transformed into bond Figure 3. Failure mode representative images. (A) Type 1, adhesive failure betwee and the luting material; (C) type 3, cohesive failure within the luting material; and 176 Ramos et al. strength (MPa) according to Magro et al (16). Subsequently, each spec- imen was assessed using a stereomicroscope at 20� magnification to determine the failuremode. The failure mode was classified as type 1 (ad- hesive) when it occurred between the fiber post and the cement, type 2 (adhesive) when it occurred between the dentin and the cement, type 3 (cohesive) when it occurred within the cement, and type 4 (mixed) when both types of failure were combined, according to Elnaghy (17). The sections were analyzed using a laser confocal microscope at 100�magnification to determine the root canal perimeter with the ma- terial penetration within the dentinal tubules. The images were evalu- ated using ImageJ software (National Institutes of Health, Bethesda, MD). The perimeter of the root canal and cement penetration in dentin were measured, and the percentage of material penetration in the dentinal tubules was obtained. n the post and luting material; (B) type 2, adhesive failure between the dentin (D) type 4, mixed failure. JOE — Volume 44, Number 1, January 2018 Basic Research—Technology Statistical Analysis Data were submitted to analysis of variance and Tukey tests at a 5% significance level. Results Regarding the bond strength of the fiber post cements to root dentin, all groups presented similar results in the middle and apical thirds of the prosthetic space (P > .05). The PDT/CC group was the only group that presented the lowest value in the cervical third (P < .05). Table 2 shows the mean and standard deviation of bond strength (in MPa) of each third according to PDT use in the prosthetic space. In relation to the dentinal penetration of the fiber post cementation protocols, all groups presented similar results in the middle third (P> .05). In the cervical and apical thirds, the PDT/CC group presented the lowest dentinal penetration (P < .05). Table 3 shows the mean and standard deviation of the dentinal penetration (%) of the fiber post cementation protocols in all thirds of the prosthetic space according to the cementation protocol and PDT use. Figure 1A–L shows the dentinal penetration pattern of the groups. Regarding the failure mode, the PDT/CC and PDT/SAC groups pre- sented a higher incidence of type 2 failure. The CC group presented a higher incidence of type 1 failure. The SAC group presented a higher incidence of type 4. Figure 2 displays the failure mode distribution and Figure 3A–D representative images of the failure mode. Discussion PDT negatively affected the bond strength of the Relyx ARC system to the cervical third of the prosthetic space. In addition, the dentinal penetration of this cementation systemwas compromised in the cervical and apical thirds of the intracanal prosthetic space. Thus, the null hy- pothesis was rejected. Oxygen affects the adhesive interface of resinous compounds in dentin (18) due to the competition of free radicals responsible for the methacrylates polymerization reactions. Moreover, the accumula- tion of ROS in dentin hampers hybrid layer formation (19). Because PDT releases ROS, it is assumed that it also affects the adhesion of fiber post cementation protocols (13). However, bond strength reduction was only observed in the cervi- cal third of the prosthetic space after conventional cement (Relyx ARC) use. Before resin cement use, the etch-and-rinse (Adper Scotchbond Multi-Purpose Plus) adhesive system was applied; therefore, it is possible that products from the photoactivation of 1% methylene blue, mainly the singlet oxygen, competed with the free radicals, which reacts in the chemical reaction of camphorquinone and aliphatic amines. It negatively affected the polymerization and adhesion of the ad- hesive system in dentin (20, 21). Furthermore, Garcez et al (11) have reported that light distribu- tion and oxygen formation were uniform when the optical fiber was used in spiral movements for approximately 10 minutes. These steps may have influenced the results because this study used an optical fiber in a static position for 30 seconds; consequently, the irradiation may have been concentrated mainly in the radicular cervical third. PDT did not present an effect on the interface when Relyx U200 cement was used. The mechanism of adhesion of this cement is mainly based on the chemical interaction between acidic mono- mers and hydroxyapatite, and it does not only depend on mechan- ical microretention in root dentin (6), thus, the ROS interference on the adhesion of this cement to root dentin was null in accor- dance with Barreto et al (22). JOE — Volume 44, Number 1, January 2018 Laser confocal microscopy has been used to evaluate the mate- rial’s penetrability and adaptation in root dentin (23). The PDT/CC group presented lower dentinal penetrability in the cervical and apical thirds. It can be associated with the high concentration of oxygen, which worked as a mechanical barrier and hampered the penetration of the adhesive system in the dentinal tubules (10). Moreover, Grandini et al (24) have observed that higher incidences of gaps and cementation failures occurred in the apical third of the prosthetic space, similar to the specimens in the PDT/CC group, because of the presence of oxygen. The PDT/CC and PDT/SAC groups presented the highest incidence of failure mode between the root dentin and the cementation protocol because of ROS release in the adhesive interface. On the other hand, the protocol using the etch-and-rinse adhesive system is considered as a reference standard in fiber post cementation, which favored type 2 failure mode occurrence (6, 25). The SAC group showed a mixed failure mode, which agreed with previous studies that used this cement (6, 26, 27). Failure mode analysis shows where the adhesive failure occurred. The present study showed PDT with methylene blue favored the failure mode between the dentin substrate and the Relyx ARC luting system in the cervical third, suggesting that PDT-generated ROS may affect dentin hybridization. The results showed that the methods that have been used in anti- sepsis of fiber post space can affect the adhesion of the luting systems to root dentin. Therefore, it is relevant to use materials, such as rubber dam isolation, in order to avoid contamination during post space preparation. Despite PDT prosthetic space antisepsis performance, it releases ROS, mainly singlet oxygen. The present study has shown that PDT af- fects fiber post cementation protocols; however, further studies should be performed to evaluate the interaction of PDT with other photosensi- tizing substances and new protocols for fiber post cementation, such as ionomer cements (28). In conclusion, PDT with 0.005% methylene blue presented nega- tive effects on the bond strength of the cementation protocol using con- ventional cement (Relyx ARC) in the cervical third and on the dentinal penetrability of the etch-and-rinse adhesive system in the cervical and apical thirds of the prosthetic space. Acknowledgments The authors would like to thank professor Marco Antonio Hungaro Duarte for his relevant assistance with the confocal laser microscopy. The authors deny any conflicts of interest related to this study. References 1. Bitter K, Kielbassa AM. Post-endodontic restorations with adhesively luted fiber- reinforced composite post systems: a review. Am J Dent 2007;20:353–60. 2. Cheung W. A review of the management of endodontically treated teeth. Post, core and the final restoration. J Am Dent Assoc 2005;136:611–9. 3. Lima JF, Lima AF, Humel MM, et al. Influence of irrigation protocols on the bond strength of fiber posts cemented with a self-adhesive luting agent 24 hours after end- odontic treatment. Gen Dent 2015;63:22–6. 4. Martinho FC, Carvalho CA, Oliveira LD, et al. Comparison of different dentin pre- treatment protocols on the bond strength of glass fiber post using self-etching ad- hesive. J Endod 2015;41:83–7. 5. Saraiva LO, Aguiar TR, Costa L, et al. Effect of different adhesion strategies on fiber post cementation: push-out test and scanning electron microscopy analysis. Con- temp Clin Dent 2013;4:443–7. 6. Monticelli F, Ferrari M, Toledano M. Cement system and surface treatment selection for fiber post luting. Med Oral Patol Oral Cir Bucal 2008;13:e214–21. 7. Estrela C, Estrela CR, Barbin EL, et al. Mechanism of action of sodium hypochlorite. Braz Dent J 2002;13:113–7. 8. Guida A. Mechanism of action of sodium hypochlorite and its effects on dentin. Minerva Stomatol 2006;55:471–82. Effects of Photodynamic Therapy on Fiber Posts 177 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref1 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref1 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref2 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref2 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref3 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref3 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref3 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref4 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref4 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref4 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref5 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref5 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref5 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref6 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref6 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref7 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref7 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref8 http://refhub.elsevier.com/S0099-2399(17)31036-1/sref8 Basic Research—Technology 9. Kuga MC, Gouveia-Jorge �E, Tanomaru-Filho M, et al. Penetration into dentin of so- dium hypochlorite associated with acid solutions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:155–9. 10. Jord~ao-Basso KCF, Kuga MC, Dantas AA, et al. Effects of alpha-tocopherol on fracture resistance after endodontic treatment, bleaching and restoration. Braz Oral Res 2016;30:e-69. 11. Garcez AS, Fregnani ER, Rodriguez HM, et al. The use of optical fiber in endodontic phododynamic therapy. Is it really relevant? Lasers Med Sci 2013;28:79–85. 12. de Oliveira BP, Aguiar CM, Câmara AC, et al. Antimicrobial activity of different disin- fection methods against biofilms in root canals. Photodiagnosis Photodyn Ther 2015;12:436–43. 13. Konopka K, Goslinski T. Photodynamic therapy in dentistry. J Dent Res 2007;86: 694–707. 14. Singh S, Nagpal R, Manuja N, Tyagi SP. Photodynamic therapy: an adjunct to con- ventional root canal disinfection strategies. Aust Endod J 2015;41:54–71. 15. Aranda-Garcia AJ, Kuga MC, Vitorino KR, et al. Effect of the root canal final rinse protocols on the debris and smear layer removal and on the push-out strength of an epoxy-based sealer. Microsc Res Tech 2013;76:533–7. 16. Magro MG, Kuga MC, Aranda-Garcia AJ, et al. Effectiveness of several solutions to prevent the formation of precipitate due to the interaction between sodium hypo- chlorite and chlorhexidine and its effect on bond strength of an epoxy-based sealer. Int Endod J 2015;48:478–83. 17. Elnaghy AM. Effect of QMix irrigant on bond strength of glass fiber posts to root dentine. Int Endod J 2014;47:280–9. 18. Lee TY, Guymon CA, Sonny Jonsson E, Hoyle CE. The effect of monomer structure on oxygen inhibition of (meth)acrylates photopolymerisation. Polymer 2004;45: 6155–62. CORRIGE Corrigendum to ‘Outcome of Direct Pulp Capping with Mineral Trioxide 1026–1031] Miguel Seruca Marques, DDS, Paul R. Wesselink, DDS, PhD, and Hagay From the Academic Centre for Dentistry, Amsterdam, the Netherlands The authors would like to correct the title of the article published in the J Capping with Mineral Trioxide Aggregate: A Prospective Study.’’ The title Aggregate,’’ as the words ‘‘Prospective Study’’ are misleading. The authors would like to apologize for any inconvenience caused. 178 Ramos 19. Santos JN, Carrilho MR, De Goes MF, et al. Effect of chemical irrigants on the bond strength of a self-etching adhesive to pulp chamber dentin. J Endod 2006;32: 1088–90. 20. Erickson RL, Barkmeier WW, Latta MA. The role of etching in bonding to enamel: a comparison of self-etching and etch-and-rinse adhesive systems. Dent Mater 2009; 25:1459–67. 21. Liu Y, Tj€aderhane L, Breschi L, et al. Limitations in bonding to dentin and experi- mental strategies to prevent bond degradation. J Dent Res 2011;90:953–68. 22. Barreto MS, Rosa RA, Seballos VG, et al. Effect of intracanal irrigants on bond strength of fiber posts cemented with a self-adhesive resin cement. Oper Dent 2016;41:e159–67. 23. Ordinola-Zapata R, Bramante CM, Cavenago B, et al. Antimicrobial effect of end- odontic solutions used as final irrigants on a dentine biofilm model. Int Endod J 2012;45:162–8. 24. Grandini S, Goracci C, Monticelli F, et al. SEM evaluation of the cement layer thick- ness after luting two different posts. J Adhes Dent 2005;7:235–40. 25. Calixto LR, Band�eca MC, Clavijo V, et al. Effect of resin cement system and root re- gion on the push-out bond strength of a translucent fiber post. Oper Dent 2012;37: 80–6. 26. Daleprane B, Pereira CN, Bueno AC, et al. Bond strength of fiber posts to the root canal: effects of anatomic root levels and resin cements. J Prosthet Dent 2016;116: 416–24. 27. Sim~oes TC, Luque-Martinez�I, Moraes RR, et al. Longevity of bonding of self-adhesive resin cement to dentin. Oper Dent 2016;41:e64–72. 28. Pereira JR, Rosa RA, S�o MV, et al. Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements. J Appl Oral Sci 2014;22:390–6. NDUM Aggregate: A Prospective Study’ [Journal of Endodontics 41 (2015) Shemesh, DMD, PhD uly 2015 issue of Journal of Endodontics, ‘‘Outcome of Direct Pulp should be ‘‘Outcome of Direct Pulp Capping with Mineral Trioxide JOE — Volume 44, Number 1, January 2018 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref9 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref9 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref9 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref9 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref10 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref10 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref10 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref10 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref11 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref11 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref12 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref12 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref12 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref12 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref13 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref13 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref14 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref14 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref15 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref15 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref15 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref16 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref16 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref16 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref16 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref17 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref17 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref18 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref18 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref18 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref19 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref19 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref19 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref20 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref20 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref20 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref21 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref21 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref21 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref22 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref22 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref22 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref23 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref23 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref23 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref24 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref24 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref25 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref25 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref25 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref25 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref26 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref26 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref26 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref27 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref27 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref27 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref27 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref28 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref28 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref28 http://refhub.elsevier.com/S0099-2399(17)31266-9/sref28 Effects of Photodynamic Therapy on the Adhesive Interface of Fiber Posts Cementation Protocols Materials and Methods Statistical Analysis Results Discussion Acknowledgments References