Accessory Post Bibliography

Post-root canal adaptation represents an important role in the biomechanical performance of teeth and the post-core systems. Close canal adaptation with minimal tooth structure removal provides a conservative and long-lasting treatment for the restoration of endodontically treated teeth. In some cases the root configuration could anatomically be an oval form rather than a circular shape or the resulting preparation of the canal during endodontic treatment may produce an oval form. The purpose of this study is to evaluate the effect of different fibre reinforced post systems of different geometrical cross sections, oval and circular, on the fracture resistance of endodonticallytreated teeth with oval-shaped root canals. Methods: 40 maxillary intact human canines were selected for this study.The crowns of each root were sectioned at the cemento-enamel junction.The roots were divided into 4 groups of io teeth following endodontic treatment; Quartz fibre post with oval section (0FibOv); (2) Flexible resin-impregnated glass fibre stick (GFibSti); (3) Small diameter quartz fibre post with circular section and accessory cone (0FibCirAcces); (4) Glass fibre post with circular section (GFibCir). Root canal preparations were performed with the special preparation drills provided in each system. All posts were cemented with self-adhesive dual polymerizing resin cement and light-polymerized composite cores were formed. Specimens were then embedded in auto polymerizing acrylic resin melds and secured in a universal testing machine with the use of a device that allowed loading of the specimens lingually at 135 degrees to the long axis. A compressive force was applied at a crosshead speed of 1 mm/min until fracture occurred. The fracture loads (N) were determined and the data were analyzed by 1-way ANOVA with interaction followed by Tukey HSD tests. Results: The mean failure loads (Newtons) and standard deviations (SDs) of the different post groups were calculated. The highest fracture resistance was recorded for group 3 teeth (0FibCirAcces) at 635.6 N; followed by group 1 (0FibOv); group 4 (GFibCir); and group 2 (GFibSti) at 488.4 N, 449.3 N, and 314.8 N respectively. Between-group differences in the fracture resistance of teeth were significant (p <.001) except for groups 1 and 4 (p >.o5). Teeth in all 4 experimental groups displayed favourable fractures. No catastrophic failures were present and there were no root fractures. All fractures displayed favourable, repairable modes. Conclusions: It can be speculated that cross-sectional similarity between the root canal configuration and the geometric form of the prefabricated post system is an effective variable on the fracture resistance of endodontically treated teeth. Using accessory posts to fill the post space and decrease the cement layer thickness may result in higher values. PDF Alkumru, H., Akkayan, B, et al, Fracture strength of teeth in oval-shaped root canals restored with posts and accessory post systems. Canadian Journal of Restorative Dentistry & Prosthodontics/— Vol. 6, No. 1 — Spring, 2013. In contemporary restorative dentistry, post-root canal adaptation always represents an important role in successful and long-lasting treatment for the restoration of endodontically treated teeth. In some cases posts have to be placed in wide oval-formed root canal spaces. However, the impact of the treatment outcome of the increasing non-uniform cement thickness around the posts has not yet reached a consensus. The purpose of this research is to assess the treatment outcome of post systems with three different post geometries, combined with/without accessory posts as an alternative technique in the oval-shaped canals. Seventy-two teeth with oval-shaped canals were selected for the study. Crowns were sectioned at the cemento-enamel junction and endodontically treated. The roots were randomly divided into 2 groups of 36 specimens and each group was split into 3 subgroups of 12 as follows; G1-A, Quartz fiber post with double tapered cross-section (QFibDT); G1-B, Quartz fiber post with circular cross-section (QFibCir); G1-C Quartz fiber post with oval cross-section (QFibOv); G2-A Quartz fiber post with double tapered cross-section + two accessory quartz fiber posts (QFibDTAcces); G2-B Quartz fiber post with circular cross-section + two accessory quartz fiber posts (QFibCirAcces); G2-C Quartz fiber post with oval cross-section + two accessory quartz fiber posts (QFibOvAcces). Root canal preparations were performed with low-speed Torpan Drill tips of ISO 90, ISO 100 and ISO 120 in increasing order. All posts were cemented with self-adhesive dual polymerizing resin cement. Two specimens from each group were randomly chosen upon the cementation of all posts and processed for stereomicroscope (SM) evaluation of the fiber post-cemented interface. All sixty specimens were then embedded in auto polymerizing acrylic resin surrounded by aluminum cylinders and light-polymerized composite cores were produced. Pressed all ceramic crowns were cemented on each core. Specimens were secured in a universal testing machine with the use of a device that allowed loading of the specimens lingually at 135 degrees to the long axis. A compressive force was applied at a crosshead speed of 1 mm/min until fracture occurred. The fracture loads (N) were determined and the obtained data were analyzed by 1-way ANOVA with interaction followed by Tukey HSD tests. Student’s t test was used for between group comparisons. Representative stereomicroscope images and cement thickness measurements were performed on 2 mm sectioned specimens. Within-group comparisons for Group 1 specimens demonstrated statistically higher fracture strength values for groups cemented with G1-A, DT Light Post (590 N) and G1-B, Match Post (570,9 N) groups compared to G1-C, Ellipson Post group (400,83 N) (p<.001). The highest fracture resistance was recorded for G2-A (QFibDTAcces) at 764,18 N, followed by group G2-B (QFibCirAcces) at 726,5 N. Within-group comparisons of these two groups (G2-A, G2-B) resulted in statistically higher fracture resistance of teeth compared to G2-C (QFibOvAcces) at 574,96 N (p<.001). Regardless of the post system geometry tested in this study, Group 2 specimens resulted in statistically higher fracture strength values compared to Group 1 specimens according to between group comparisons (p<.001). No catastrophic failures were present and there were no root fractures. Conclusions: It can be speculated that when restoring with posts, especially in wide oval-shaped canals, the use of accessory posts reduces the cement thickness around the posts thus increasing the endodontically treated teeth resistance to fractures. PDF Baldissara, P.,, V., Valandro, L.F. Arena, A., Scotti, R. Non-axial Loading of crowns supported by new fiber post systems. J Dent Res. Vol 89 (Spec. Iss. B) Abstract #2195, 2010 (www.dentalresearch.org) Objectives: to evaluate the behavior of non-circular fiber post and accessory posts in supporting non-axially loaded cast metal crowns. Concerns remains about fiber posts used under crowns connected to RPDs using frictional attachments: the hypothesis tested is that an increase in the emerging section of fiber posts doesn't affect the restoration survival rate. Methods: 4 groups: 1)non-circular fiber post concept Ellipson; 2) Fibercone secondary post system (two posts) coupled with one DT Light-Post Illusion #0.5; 3) conventional DT Light-Post Illusion #1; and 4) Macro-Lock Illusion #1, all from RTD, France. 48 single rooted, crownless human teeth were selected and endodontically treated. The canal shape was standardized using the Ellipson ultrasonic diamond tip (Suprasson P5 Newtron, Satelec, France) to obtain a non-circular section, then the teeth were randomly distributed to the 4 groups. Panavia F and Photocore (Kuraray) were used as luting and core materials, respectively. Core was made using transparent shells. The specimens were prepared with chamfer margins and 1.5mm ferrule height. Cast metal crowns with 5mm off-set extensions were made using CrCo alloy (Vivi) and luted with Fuji Plus (GC). The crowns were subjected to 3.2 million cycles ranging from 100N to 150N under water irrigation. Kaplan-Meyer survival analysis was performed to compare the groups (α=. 05). Results: the Fibercone accessory post group showed the highest survival rate (0.667), followed by Ellipson (0.583) and Macro-Lock (0.500) groups. Conventional DT post showed the lowest survival rate (0.333). The difference among the groups was not statistically significant (p=0.068). Conclusion: Since non-axial loading generates torsion forces, non-circular post design could better resist this type of stress. Although the number of the specimens is too low to reject the null hypothesis, the survival data suggest that complete crowns restored with accessory and non-circular fiber posts have a higher survival rate in comparison to conventional posts. Belli, S., Eraslan, O., Eraslan, O., Eskitascioglu, G. Effect of post-restoration on stress-distribution in roots with over-flared canals. J Dent Res. Vol 91 (Spec. Iss. B) Abstract #160067, 2012 (www.dentalresearch.org) Objective: The aim of this finite element analysis (FEA) study was to test the effect of five different restorative techniques on stress distribution in roots with over-flared canals. Method: Six types of three-dimensional (3-D) FEA mathematical models simulating a maxillary incisor with supporting structures were created as follows: a) sound; b) with an over-flared root-canal restored using a prefabricated post; c) restored using one main and two accessory posts; d) restored with i-TFC system (Sun Medical, Japan); e) the thickness of the a root has been increased using composite resin and the root was then restored using a prefabricated post; f) an over-flared root restored with an anatomic post. The cores were created using composite resin. A 300-N static vertical occlusal load was applied on the node at the center of occlusal surface of the tooth to calculate stress distributions. Solidworks / Cosmosworks structural analysis programs were used for FEA analysis. Result: The analysis of the von Mises stress values revealed that accessory post and i-TFC post system showed almost similar stress distribution. They both showed high stress areas at the buccal side of the root (3.67 MPa) and at the cervical region (>3.67 MPa) and low stress accumulation within the post space (0-1 MPa). Anatomic post has kept the stress inside its body and forwarded less stress towards the remaining tooth and root structure and has showed an advantage for the remaining root structure. Conclusion: Creation of an anatomic post using composite resin and glass fiber post can save the remaining tooth structure in roots with over-flared canals. Boksman, L, Hepburn, AB, Kogan, E, Friedman, M, de Rijk, W. Fiber post techniques for anatomical root variations. Dent Today. 2011 May;30(5):104, 106-11. REVIEW ARTICLE In contemporary dental practice, there is no remaining reason to use metallic posts, custom or prefabricated. Many cases that several years ago would have required a retentive post will not require that post today, because of the many improvements in bonding agents and composite resin restoratives. However, in cases where less than 50% of coronal tooth structure remains--or in other cases wherein the judgment of the clinician a post is indicated--there are now aesthetic, non-corrosive, fracture resistant and radiopaque alternatives for all varieties that save time and money without compromise. Their most compelling advantage, regardless of the geometry or amount of residual tooth structure, is the protection from root fracture that a low modulus restoration provides. In selecting the materials (posts, resins) for these techniques, the dentist is advised not to cut corners, and to seek the strongest and most radiopaque products available. PDF Bonfante, G, Kaizer, O.B, Pegoraro, L.F, do Valle, A.L. Fracture strength of teeth with flared root canals restored with glass fibre posts. Int Dent J. 2007 Jun;57(3):153-60. Objective: to investigate the fracture strength and pattern of failure of teeth with weakened roots reconstructed by different procedures. Methods: In an in vitro study root posts were placed in 50 endodontically treated canines, divided into 5 groups (n=10) as follows: cast metallic post; glass fibre post with smaller diameter than the root canal; glass fibre post with smaller diameter than the root canal + glass fibre strips; glass fibre post with smaller diameter than the root canal + accessory glass fibre posts; anatomical post (glass fibre post with smaller diameter than the root canal, relined with low viscosity composite resin). Posts were luted with resin cement and the coronal portion of posts was constructed with composite resin. Metallic crowns were cemented on the posts. Specimens were submitted to compressive load in a universal testing machine. Fracture strength values of each group were compared. Results: Fracture strength values were for Groups 1-5 respectively: 1087.06; 745.69; 775.41; 920.64; 876.12 kgf, with significant differences between Groups 1 and 2 and between Groups 1 and 3 (p<0.05). Observed patterns of fracture were: Group 1 100% of roots fractured; Groups 2 and 4 variable fracture modes; Group 3 60% of fractures occurred in the cervical root third; Group 5 50% of failures occurred in the coronal portion of the post. Conclusions: The fracture strength of teeth with cast metallic posts, teeth with anatomical posts or teeth with glass fibre posts combined with accessory posts was similar. All teeth restored with cast metallic posts presented fractures and were unfavourable to maintenance of the remaining tooth structure. Teeth with fibre posts (Groups 2 to 5) presented variable fracture modes; however, the maximum percentage of unfavourable fractures was 30%. PDF Braz, R, Conceição, AAB, Conceição, E.N., Loretto, S.C., Lyra, A.M.V.C., Silva, .A.K.S. Evaluation of reinforcement materials used on filling of weakened roots. J Dent Res. Vol 84 (Spec. Iss. A) Abstract #1733, (www.dentalresearch.org) Objectives: The purpose was to evaluate flexural strength of glass fiber posts associated with filling materials used for root reinforcement, and fracture resistance of flared roots reinforced with the same materials. Methods: For flexural test, 10 cylinders, 3.5mm (diameter) and 14mm (length), were made for each group, according to the reinforcement material used: G1 Reforpost (Angelus)+dual resin cement Variolink II (Ivoclar/VIvadent); G2 Reforpost+dual composite core BisCore (Bisco); G3 Reforpost+three accessory posts Reforpin (Angelus)+Variolink II. Cylinders were dry stored (24h) and tested in a universal testing machine (0.5mm/min). For fracture resistance test, 30 human maxillary canines were used and their crowns removed at the cementenamel junction (CEJ). The canals were endodontically treated, after which the fillings were removed and the canals widened by 3.5mm, simulating flared canals. The dual adhesive system Excite DSC (Ivoclar/Vivadent) was applied to the roots, which were randomly divided into 3 groups as performed for flexural strength test. After the cementation, coronal complements were made with composite-resin and the roots were assembled in metallic cylinders filled with self-curing acrylic-resin 2mm below the CEJ. After storage (24h), the samples were fixed at a 45o angle to a metal funneled tip that applied a force on the lingual surface (0.5mm/min). Statistics were performed using analysis of variance and Tukey`s test (5%). Results: The flexural mean values (MPa) were: G1 206.52, G2 224.39 and G3 – 272.64, showing a statistically difference between the reinforcement materials used, with G3 presenting statistically higher flexural strength compared to other groups. For fracture resistance, mean values (Kgf) were: G1 – 47.45, G2 – 66.57 and G3 – 74.11, showing that G1 presented a statistically lower mean value than the other groups. Conclusion: Therefore, it was possible to conclude that glass fiber post, associated with accessory posts, is the method of choice for reinforcing structurally weakened roots. Cardoso, P.E., Valera, M.C., Oliveira, L.D., Camargo, C.H.R Carvalho, C.A.T. Fracture resistance of endodontically treated immature roots after different reinforcements. J Dent Res. Vol 90 (Spec. Iss. A) Abstract # 3103, 2011 (www.dentalresearch.org) Objectives: This study evaluated fracture resistance of brittleness bovine teeth simulating immature teeth, that received different reinforcements within radicular canal. This evaluation was made in comparison to teeth without reinforcements within radicular canal and teeth no brittleness. Methods: For that purpose, seventy bovine mandibular incisors were selected; of these, 56 were internally prepared, and then to simulating immature roots, were enlarged with Gates-Glidden, fast steel and videa burs. The specimens were distributed into five groups (n= 14): a) carbon fiber post and three accessory glass fiber posts; b) carbon/glass post and three accessory glass fiber posts; c) composite resin reinforcement; d) without reinforcement and e) without canal preparation and without reinforcement . The specimens were submitted to the fracture resistance testing with application of tangential compressive loading at an angle of 45o, at a speed equivalent to 1mm/min until the fracture using EMIC machine. Results: Results were subjected to statistical analysis (Tukey, t student and Dunnet), at a significance level of 5%. Results indicated statistically significant differences (p <0,05) in relation to root conditions. G1 presented higher resistance in comparison with other groups and G4 presented smaller resistance. Conclusion: It could be ended like this that the use of intra-radiculars reinforcements with different posts or resins composite increased fracture resistance of brittleness teeth under compression force. Clavijo, V.G, Reis, JM, Kabbach, W, Silva, AL, Oliveira Junior, OB, Andrade, MF. Fracture strength of flared bovine roots restored with different intra-radicular posts. J Appl Oral Sci. 2009 Nov-Dec;17(6):574-8. Objective: The aim of this study was to evaluate the fracture strength and failure mode of flared bovine roots restored with different intra-radicular posts. Methods: Fifty bovine incisors with similar dimensions were selected and their roots were flared until 1.0 mm of dentin wall remained. Next, the roots were allocated into five groups (n=10): GIcast metal post-and-core; GIIfiber posts plus accessory fiber posts; GIIIdirect anatomic post; GIVindirect anatomic post and GVcontrol (specimens without intra-radicular post). A polyether impression material was used to simulate the periodontal ligament. After periodontal ligament simulation, the specimens were subjected to a compressive load at a crosshead speed of 0.5 mm/min in a servo-hydraulic testing machine (MTS 810) applied at 135 masculine to the long axis of the tooth until failure. The data (N) were subjected to ANOVA and Tukey's post-hoc test (alpha=0.05). Results: GI and GIV presented higher fracture strength (p<0.05) than GII. GIII presented intermediate values without statistically significant differences (p>0.05) from GI, GII and GIV. Control specimens (GV) produced the lowest fracture strength mean values (p<0.05). Despite obtaining the highest mean value, GI presented 100% of unfavorable failures. GII presented 20% of unfavorable failures. GIII, GIV and GV presented only favorable failures. Conclusions: Although further in vitro and in vivo studies are necessary, the results of this study showed that the use of direct and indirect anatomic posts in flared roots could be an alternative to cast metal post-and-core. PDF Costa, R.G.,Morais, E.C.C. Moreira-Da-Silva, S.M.L. Michel, M.D., Gonzaga, C.C.,Correr G.M. Bindo, M.J.F., Campos,E.A., Fatigue and fracture resistance of customized fiber dowel. J Dent Res. Vol 90 (Spec. Iss.A) Abstract # 3103, 2011 (www.dentalresearch.org) Objectives: The aim of this study was to evaluate the root fracture strength of human uni-radicular premolars restored with customized fiberglass dowel-core systems after fatigue simulation. Methods: Forty premolars with standard dimensions were chosen, cleaned, and stored in 0.5% chloramine T. The crowns were cut and the root length was standardized to 13 mm. The teeth were endodontically treated and embedded in acrylic resin. The specimens were distributed into 4 groups (n = 10) according to the restorative material used: G1 (prefabricated fiber post), G2 (prefabricated fiber post + accessory fiber posts), G3 (prefabricated fiber post + unidirectional fiberglass), and G4 (unidirectional fiberglass customized post). All posts were luted using resin cement and the cores were build-up with a composite resin, following manufacturer instructions. The samples were stored for 24 hours at 37°C and 100% relative humidity and then submitted to mechanical cycling (250.000 cycles with 30 N at a frequency of 2 Hz). The specimens were then compressive-loaded in a universal testing machine with a 3000 N load cell at a crosshead speed of 0,5 mm/min until fracture. The failure patterns were analyzed and classified. Data was submitted to statistical analysis (oneway ANOVA and Tukey's test) at a significance level of 5%. Descriptive analysis was used to assess the failure pattern. Results: The mean values of maximum load (N) were: G1 811,4 ± 124,3; G2 729,2 ± 157,2; G3 747,5 ± 204,7; G4 762,4 ± 110. Statistical differences were not observed among the groups. G1 showed more catastrophic failures than the other groups. G2, G3, and G4 showed 100% non-catastrophic failures. Conclusions: It can be concluded that dowel-core techniques do not interfere with the fracture strength of the tooth/dowel/core system; conversely, customized posts showed reversible and favorable type of failures. Costa, RG, De Morais, EC, Campos, EA, Michel, MD, Gonzaga, CC, Correr, GM. Customized fiber glass posts. Fatigue and fracture resistance. Am J Dent. 2012 Feb;25(1):35-8 ! Purpose: To evaluate the root fracture strength of human single-rooted premolars restored with customized fiberglass post-core systems after fatigue simulation. Methods: 40 human premolars had their crowns cut and the root length was standardized to 13 mm. The teeth were endodontically treated and embedded in acrylic resin. The specimens were distributed into four groups (n=10) according to the restorative material used: prefabricated fiber post (PFP), PFP+accessory fiber posts (PFPa), PFP+unidirectional fiberglass (PFPf), and unidirectional fiberglass customized post (CP). All posts were luted using resin cement and the cores were built up with a resin composite. The samples were stored for 24 hours at 37 degrees C and 100% relative humidity and then submitted to mechanical cycling. The specimens were then compressive-loaded in a universal testing machine at a crosshead speed of 0.5 mm/minute until fracture. The failure patterns were analyzed and classified. Data was submitted to one-way ANOVA and Tukey's test (alpha = 0.05). Results: The mean values of maximum load (N) were: PFP 811.4 +/124.3; PFPa 729.2 +/157.2; PFPf747.5 +/204.7; CP 762.4 +/110. Statistical differences were not observed among the groups. All groups showed favorable restorable failures. Conclusions: Fiberglass customized post did not show improved fracture resistance or differences in failure patterns when compared to prefabricated glass fiber posts. PDF ! ! da Rosa, R. A., Barreto , M. S., da Rosa, T.A., Reis, K.R., Kaizer, O.B. Fracture resistance of weakened teeth restored using accessory glass fiber posts. Gen Dent. 2013 Mar-Apr;61(2):45-9. ! This study used differential root weakening to evaluate the fracture resistance of bovine teeth restored using glass fiber posts (with or without accessory glass fiber posts). Fifty bovine mandibular incisors were sectioned 14 mm from the apex, fixed in acrylic resin blocks, and divided into 5 groups: healthy roots with a glass fiber post (Group 1), partially weakened teeth with a glass fiber post (Group 2), partially weakened teeth with a glass fiber post and 2 accessory glass fiber posts (Group 3), extensively weakened teeth with a glass fiber post (Group 4), and extensively weakened teeth with a glass fiber post and 5 accessory glass fiber posts (Group 5). Posts were luted with resin cement, cores were prepared using composite resin, and metallic crowns were cemented. The specimens were stored in distilled water at 37°C for more than 72 hours until the fracture resistance test. Specimens were loaded at 135 degrees relative to the long axis of the tooth at a crosshead speed of 0.5 mm/minute in a universal testing machine. Conclusion: All groups predominantly exhibited favorable failure patterns and there were no statistically significant differences between groups (two-way ANOVA, α = 0.05). ! da Silva GR, Santos-Filho, PC, Simamoto-Júnior, PC, Martins, L,R, Mota, A,S,, Soares, C.J. Effect of post type and restorative techniques on the strain and fracture resistance of flared incisor roots. Braz Dent J. 2011;22(3):230-7. Restoring flared endodontically treated teeth continues to be a challenge for clinicians. This study evaluated the effect of post types and restorative techniques on the strain, fracture resistance, and fracture mode of incisors with weakened roots. One hundred five endodontically treated bovine incisors roots (15 mm) were divided into 7 groups (n=15). The two control groups were (C) intact roots restored with Cpc (cast posts and core) or Gfp (glass fiber posts). The five experimental groups were (F) flared roots restored with GfpAp (Gfp associated with accessory glass fiber posts), GfpRc (anatomic Gfp, relined with composite resin), and GfpRcAp (anatomized Gfp with resin and accessory glass fiber posts). All teeth were restored with metal crowns. Mechanical fatigue was performed with 3x10(5)/50 N. Specimens were loaded at 45o, and the strain values (μS) were obtained on root buccal and proximal surfaces. Following that, the fracture resistance (N) was measured. One-way ANOVA and Tukey's HSD tests (α=0.05) were applied, and failure mode was checked. Conclusions: No significant difference in strain values among the groups was found. Cpc presented lower fracture resistance and more catastrophic failures in flared roots. Gfp associated with composite resin or accessory glass fiber posts seems to be an effective method to improve the biomechanical behavior of flared roots. PDF Gomes, GM, Rickli, EH., Gomes, OMM, Rezende, EC, Gomes, JC, Loguercio, AD, Reis, A. Fracture strength of bonded fiber-post techniques to flared roots. J Dent Res.Vol 92 (Spec Iss A) Abstract #1852, 2013 (www.dentalresearch.org) ! Objectives: The aim of this study was to evaluate the effect of alternative techniques to improve the adaptation of pre-fabricated fiber posts (FP) to oversized dowel spaces on the tooth fracture resistance (FR) of metal-free restorations after mechanical fatigue (MF). Methods: The root canals of 24 single-rooted mandibular premolars were prepared, and they were randomly divided into 4 groups. In groups GPC (positive control), the root canal was prepared with a drill compatible with the FP # 0.5 (Whitepost DC, FGM). In groups GNC (negative control), GAP (accessories posts) and GAD (anatomical direct post), oversized root canals were prepared and the FP # 0.5 were cemented without any additional technique (GNC), with accessories post (GAP) and after individualization of the FB with a composite resin (GAD). The luting procedures were performed with the adhesive Excite DSC and the resin cement Variolink II (Ivoclar Vivadent) according to the manufacturer's recommendations. Metal-free crowns were cemented on composite resin cores, the periodontal ligament was simulated and the specimens were submitted to MF (1.2 X 106 cycles, 30 N) followed by FR test at a compressive load (0.5 mm/min). The data were subjected to one-way ANOVA and Tukey’s tests (α = 0.05). Results: The means and standard deviations of FR (N) for each group were: GPC: 1024.1±26.5, GNC: 740.8±126.2, GAP: 1051.9±200.6 and GAD: 785.5±17.0. The highest FR values were observed for GPC and GAP (p < 0.0001), which were similar one another. Conclusion: To improve the fracture resistance of metal-free crowns bonded to oversized root canals, it is advisable to use prefabricated fiber posts in combination with accessory posts. ! Gomes, GM, Gomes, OM, Gomes, JC, Loguercio AD, Calixto AL, Reis A. Evaluation of different restorative techniques for filling flared root canals: fracture resistance and bond strength after mechanical fatigue. J Adhes Dent. 2014 Jun;16(3):26776. doi: 10.3290/j.jad.a31940. ! Purpose: To evaluate the fracture resistance (FR) and bond strength (BS) after mechanical fatigue (MF) of flared root canals restored with different restorative techniques for fiber post cementation. Methods: The root canals of 84 singlerooted premolars were endodontically treated and prepared in order to simulate an oversized root canal, except for the positive control group (PC), in which a prefabricated fiber post (PFP) with a diameter compatible with the post cavity was cemented. In the oversized root canals, alternative restorative techniques for post cementation were tested, as follows: NC: negative control (PFP with a diameter smaller than that of the root canal); AP: PFP + accessory posts; RR: root reinforcement with composite resin; DAP: direct anatomical post; IAP: indirect anatomical post. After the luting procedures using Excite DSC and Variolink II, indirect composite crowns were cemented on composite resin cores and the specimens were mechanically fatigued (1.2 x 106 cycles, 40 N). From each group, 8 specimens were subjected to the push-out BS test and the others 6 specimens to the FR test. For both tests, the data were subjected to ANOVA and Scheffe's tests (α = 0.05) Results: In terms of FR, all alternative techniques showed intermediate performance, being similar to both control groups. In terms of BS, only the groups DAP and IAP were similar to the well-adapted condition (positive control group). Conclusion: The use of DAP and IAP should be the first choice for fiber post cementation in oversized root canals. ! Latempa, A.M.A, Almieda, S.A., Nunes, N.F., deSilva, E.M., Guimaraes, LJ.G.A. and Poskus, L.T. Techniques for restoring enlarged canals: as evaluation of fracture resistance and bond strength. International Endodontic Journal, doi:10.1111/jej. 12272, 2014 Aim: To verify the influence of fiberglass post diameter, as well as the use of accessory posts on fracture resistance and bond strength, when used for restoring enlarged root canals. Methodology: 100 maxillary single rooted canine human teeth were decoronated and root canals were prepared using a number 4 drill (White Post, FGM). The roots were assigned into five groups (EC1) Post number 1 (Exacto Conical , Angelus, Londrina, PR Brazil); (EC2) post number 2, (DC3) post number 3 Exacto , (ECA) post number 1 Exacto +2 accessory posts and (WP) post number 4 (White Post, FGM). Posts 1-4 have a crescent diameter. Post were luted (Rely-X Arc, 3M ESPE, USA), and composite resin filling cores were prepared for the fracture resistance test (n =10). For the push out -test (n=10), roots were sectioned into one millimeter thick slices. Both tests were performed in the universal testing machine. Data were analyzed using ANOVA and Tukey’s Test. Results: group's WP, and DC three, had higher fracture resistance than the other groups (P < 0.05), which were statistically similar. Root fractures occurred in 14% of the specimens. Group EC1 and IC2 had lower bond strength values and groups EC3 and ECA, which were lower than the WP group (P < 0.05). Conclusions: thicker posts were associated with higher resistance to fracture and bond strength through canals. Using a post +2 accessory post improved the bond strength but not the fracture resistance. PDF