Retention of fiber posts to the optimally and over-prepared dowel spaces

Abstract

PURPOSETo assess the retention of glass fiber post cemented with self-adhesive resin cement into optimum and over-prepared root canals following obturation in the presence of either eugenol (EB) or calcium hydroxide (CB)-based sealers.MATERIALS AND METHODSRoots of extracted premolars were endodontically-treated in 5 groups (n = 10). Roots of Group 1 (control) were left with no obturation and then optimally prepared to receive endodontic dowels. Other root canals were obturated with gutta-percha in the presence of either eugenol-based (Groups 2 and 4) or calcium hydroxide-based (Groups 3 and 5) sealer. Dowel spaces were prepared with optimal diameter in Groups 2 and 3, one size larger in Groups 4 and 5. Standardized fiber posts were luted to the prepared spaces using self-adhesive resin cement and itsretention was then tested on an universal testing machine. Both one-way ANOVA and Tukey's HSD comparisons (α=0.05) were used to identifythe significance of inter-group retention differences. Scanning electron microscopy (SEM) of both optimally and over-prepared dowel spaces was also considered to figure the nature of their interior out.RESULTSThe post retention was significantly higher to the non-obturated, optimally-prepared dowel spaces of Group 1 compared to the obturated, optimally-prepared ones of Groups 2 and 3. For each dowel space diameter, root canals obturated using CB of Groups 3 and 5 showed significantly higher dowel retention compared to those obturated using EB of Groups 2 and 4. Post retention to the over-prepared dowel spaces of Groups 4 and 5 was significantly higher than that recorded for the optimally-prepared ones of Groups 1-3. SEM images revealed traces of endodontic sealer and gutta-percha on the walls of the optimally-prepared dowel spaces.CONCLUSIONDespite the adverse effect of endodontic sealers on the retention of fiber posts, the over-preparation of dowel spaces helps to improve the retention.

Influence of Relining Post on the Bond Strength of Resin Cements

“…higher BS values were obtained in the cementation of fiber posts with self-adhesive 21 and conventional resin cement 7 in root canals without previous utilization of obturation material. 7,21 In this study, the root canals were irrigated only with distilled water and were not obturated.…”

“…7,21 In this study, the root canals were irrigated only with distilled water and were not obturated. The non-accomplishment of endodontic treatment allowed avoiding any interference on adhesion of the post/ cement/dentin assembly, either due to irrigants or remnants of obturation material, enhancing analysis of the performance of each cement in the root canal.…”

Failure Mode of 2 Fiber Posts Bonded Using 3 Different Adhesive Systems

“…Unfortunately, in many studies failure patterns are recorded, yet not or only insufficiently discussed 13 . This test is one of the most important tests is also one of the most disparaged.…”

Fracture resistance of ceramic crowns supported with indirect chair-side composite cores

“…[ 6 7 8 9 ] Therefore, the use of endodontic posts is recommended to retain, support, and anchor cores. [ 7 8 10 ] Many researchers[ 11 12 ] considered the inherent biomechanical character, retention, and stability of post-core systems crucial for the success and longevity of final restorations. Metal posts were standardly employed for many years; however, the incompatibility of their biomechanical properties with those of dentin led to develop the fiber-reinforced composite (FRC) posts.…”