Prefabricated Metal Posts Research Articles

Introduction to Fiber Reinforced Composite (FRC) Post, A New Era in Reinforcing Esthetics: A Case Report

The restoration of a root canal treated or, endodontically treated teeth, is often can be achieved with post and core because of the significant loss of tooth structure. Until the mid-1980s, the safest way to restore an endodontically treated tooth was considered to be the cast-metal post, made indirectly by a dental technician. Also prefabricated metal posts in combination with different core materials under artificial crowns were used. The development and use of fiber reinforced composite (FRC) root canal posts over metallic posts make possible of the attachment & reinforcement of the crown with maximum esthetics. This paper illustrates a technique for rehabilitation of an endodontically treated maxillary central incisor of both sides (UL1 & UR1) with a fiber reinforced composite post (FRC post) & discusses the advantages, disadvantages of metallic post over fiber reinforced composite (FRC) posts.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16595 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 45-48

Effect of eugenol-containing and resin endodontic sealers on retention of prefabricated metal posts cemented with zinc phosphate and resin cements

PurposeThe aim of this study was to compare the effects of two endodontic sealers on the retention of posts cemented with zinc phosphate or resin cement. Materials and methodsCrowns of 72 mandibular premolars were removed at the cementoenamel junction. Root canals were prepared and specimens were randomly divided into two groups of 36. In each group, 12 specimens were obturated with gutta percha only; 12 specimens with gutta percha/ZOE sealer and 12 specimens with gutta percha/AH26. In the first group, 10mm Post spaces were prepared with Peeso reamers size 4 and, size 5 stainless steel Paraposts were cemented in with zinc phosphate. In the second group, 10mm Post spaces were prepared with Fiber Lux size 5.5 drills and size 5 Paraposts were cemented with Panavia F2.0. After mounting in resin blocks, posts were pulled out by universal testing machine at 1mm/min and results were analyzed by two-way ANOVA and Dunnett test. ResultsMean forces (in Newtons) required to remove posts cemented with zinc phosphate in canals obturated without sealer, with ZOE, and with AH26 sealers were 270±83, 281±128 and 266±67, respectively; and for posts cemented with Panavia F2.0 were 520±290, 464±212 and 229±108, respectively. Statistical analysis showed that AH26 significantly reduced retention of posts cemented with Panavia F2.0 (p<0.05). ConclusionDifferent sealers had no significant effect on retention of posts cemented with zinc phosphate. However posts cemented with Panavia F2.0 showed reduced retention in canals obturated with AH26.

Influence of coronal restorations on the fracture resistance of root canal‐treated premolar and molar teeth: A retrospective study

To evaluate the influence of coronal restorations on the fracture resistance of endodontically treated teeth, 676 root canal-filled and restored posterior teeth were evaluated after a mean period of 9.7 (± 2.8; minimum: 5) years. A total of 86.2% of the endodontically treated and restored teeth survived the mean observation period of 9.7 years without fracture. The overall survival period was 13.6 (± 0.2) years. All teeth with gold partial crowns survived without fractures (n = 24). Teeth with crowns and adhesively sealed access cavities showed a mean survival period of 15.3 (± 0.4) years, with crown and bridge restorations 14.0 (± 0.3), with individual metal posts 13.9 (± 0.2), with composite fillings 13.4 (± 0.5), with prefabricated metal posts 12.7 (± 0.6), with amalgam fillings 11.8 (± 0.6) and with glass ionomer cements (GIC) 6.6 (± 0.5) years. Teeth with one or two surfaces restored by amalgam, composite or GIC showed a significantly lower fracture rate than teeth with three and more restored surfaces (P < 0.05). The mean fracture rate of teeth restored with GIC was significantly higher when compared with all other groups (P < 0.001). In general, endodontically treated teeth restored with prosthetic restorations demonstrated a significantly lower mean fracture rate than teeth restored with fillings. Cavities with up to three surfaces may well be successfully restored adhesively with composite filling material.

Effect of eugenol-based root canal sealers on retention of prefabricated metal posts luted with resin cement

This study evaluated the effect of two different eugenol-based root canal sealers on the retention of prefabricated metal posts luted with adhesive resin cement. Thirty prefabricated ParaPosts randomly divided among three groups of 10 each were luted into extracted single-rooted teeth with adhesive resin cement. Two of the groups had been obturated with Gutta-Percha and one of two eugenol-based root canal sealers (Endofil and Tubli-Seal), respectively. The third group was not obturated and served as the control. The forces required for dislodgment of posts from their prepared post spaces were recorded using a universal testing machine. Data were statistically analyzed using one-way ANOVA and Tukey's multiple range test was used to determine the mean differences. Endofil and Tubli-Seal groups demonstrated significantly reduced retention compared to the unobturated (control) group (P<0.05). Eugenol-based sealers significantly reduced the retention of prefabricated posts luted with adhesive resin cement.

Fracture resistance of endodontically treated teeth restored with fiber posts and prefabricated metal posts

Fracture resistance of endodontically treated teeth restored with fiber posts and prefabricated metal posts

In vitro fracture behavior of maxillary premolars with metal crowns and several post‐and‐core systems

The in vitro fracture behavior of severely damaged premolars, restored with metal crowns with limited ferrule and several post-and-core systems, was investigated. Crowns of maxillary premolars were removed and canals were prepared with Gates Glidden drills and with Parapost drills. Groups of 11 samples were each treated with cast post-and-cores (Parapost XP, Wironium Plus) (group 1), prefabricated metal posts (Parapost XH) (group 2), prefabricated glass fiber posts (Parapost FiberWhite) (group 3), and custom-made glass fiber posts (EverStick Post) (group 4). Posts and composite cores and metal crowns in groups 2, 3, and 4 were adhesively cemented. Post-and-cores and crowns in group 1 were cemented with phosphate cement. Thermocycling was performed (6,000x, 5-55 degrees C). Two static load tests (30 degrees ) were applied. During the first load test (preloading) no failures occurred. Failure modes from the second load test were categorized into favorable and unfavorable failures. Mean failure loads among the four groups (group 1, 1,845 N; group 2, 1,718 N; group 3, 1,812 N; and group 4, 1,514 N) were not significantly different. Unfavorable failures were root fractures and favorable failures were postcrown displacements. No differences in frequencies of unfavorable/favorable failures were seen among the groups. The results suggest that different post-and-core systems have no influence on the fracture behavior of severely damaged premolars restored with metal crowns with limited ferrule.

Ex vivo fracture resistance of direct resin composite complete crowns with and without posts on maxillary premolars

To investigate ex vivo the fracture resistance and failure mode of direct resin composite complete crowns with and without various root canal posts made on maxillary premolars. The clinical crowns of 40 human extracted single-rooted maxillary premolars were sectioned at the cemento-enamel junction. The canals were prepared with Gates Glidden drills up to size 4. Thirty samples were provided with standardized post spaces in the palatal canal and all roots were embedded in acrylic. Minimal standardized preparations in the canal entrances were made. Groups of 10 samples were treated with (i) prefabricated metal posts, (ii) prefabricated glass fibre posts, (iii) custom-made glass fibre posts, and (iv) no posts (control). Posts were cemented with resin cement and resin composite complete crowns were made. All specimens were thermocycled (6000x, 5-55 degrees C). Static load until fracture was applied using a universal loading device (crosshead speed 5 mm min(-1)) at a loading angle of 30 degrees . Failure modes were categorized as favourable and unfavourable failures. No significant difference was observed between the mean failure loads (group 1: 1386 N, group 2: 1276 N, group 3: 1281 N, and group 4: 1717 N, P > 0.05), nor between frequencies of failure modes (P > 0.05). All failures were fractures of the resin composite crown in combination with tooth material (cohesive failures). Within the limits of this laboratory investigation it is concluded that severely damaged and root filled maxillary premolars, restored with direct resin composite complete crowns without posts have similar fracture resistances and failure modes compared to those with various posts, which suggest that posts are not necessarily required.

A study on bond strength of prefabricated metal posts to composite resin core material

A study on bond strength of prefabricated metal posts to composite resin core material

ENHANCING THE RETENTION OF PREFABRICATED METAL POSTS AND RESIN CORES

Prefabricated metal posts are the type most widely used for restoring endodontically treated teeth before full-coverage restorations.1 Retention of these posts and their cores sometimes can be problematic and has been studied extensively.2 Post space length and class of cement used are important retention factors.3,4

Influence of post placement in the fracture resistance of endodontically treated incisors veneered with direct composite

Statement of Problem: Veneer preparations are considered to weaken endodontically treated maxillary incisors. Prefabricated posts have been controversially indicated to reinforce endodontically treated teeth before final restoration. Purpose: This in vitro study evaluated whether (1) veneer preparation in enamel or in enamel/dentin weakens endodontically treated maxillary incisors, (2) bonding of direct composite veneer restores the original strength of the unprepared teeth, and (3) use of prefabricated metal posts increases fracture resistance of prepared and restored teeth. Material and Methods: Ninety extracted human maxillary central incisors were submitted to conventional root canal treatment. Specimens were randomly divided into 8 experimental groups (veneer preparation in enamel or dentin with/without post and with/without direct composite veneer restoration) and a control group (n = 10). Specimens were loaded to fracture, and the data were analyzed statistically. Results: Statistical analysis revealed that a conservative veneer preparation does not significantly reduce maxillary incisors’ fracture resistance. For prepared incisors, bonding of direct composite veneer restored their original strength, and the use of posts did not increase their fracture resistance. Conclusion: Conservative veneer preparations involving enamel and enamel/dentin did not significantly reduce the fracture resistance of endodontically treated maxillary incisors. In addition, restoration of the intraenamel preparations with direct composite resulted in teeth more resistant to fracture than teeth having restorations in dentin. The use of posts did not improve fracture resistance of endodontically treated maxillary incisors reduced and veneered with direct composite. (J Prosthet Dent 2000;84:180-4.)

接着性レジン 支台築造と接着 レジン支台築造法について

Immediately after development of composite resin, it was used not only as filling material but also as the core material. Clearfil core, which came on market in 1980, was widely accepted in dental practice, resulting in many failures because of insufficient bond strength to dentin.Since then, high polymer science has made rapid progress, and now a lot of adhesive resin core materials are available with high bond strength to dentin. It is time to check the efficiency of these materials in practice.In this study, each component and its mutual relationship of the composite resin core with prefabricated metal posts were examined. As a result, the resin core with prefabricated posts indicated the same bonding strength as the cast post and core. In addition, core resin could be used as luting materials with better bond strength than conventional adhesive resin cements.

コンポジットレジンによる支台築造の実験的研究 第１報 メタルポストによる築造体の補強効果およびメタルポストの長さと太さが築造体の維持力に及ぼす影響

The development of new dental materials and methods has enlarged the possibilities of composite resin cores. In this study we examined effects of prefabricated metal posts on reinforcement of composite cores and effects of post length and diameter on core retention. First, the bending test of both various prefabricated posts only and composite cores in which the stainless parallel posts (AD Post®) were embedded was carried out. Then, pull-out test of AD Posts which were built up with Panavia EX®in root canals of extracted human teeth was carried out.The following conclusions were drawn:1. The bending strengths of prefabricated posts were greatly different from the kind of metal to its shape. The tapered self-threading posts provided the weakest bending strength because they have deep grooves, whereas the stainless parallel posts provided the biggest.2. It was confirmed by bending test that the prefabricated metal post reinforced composite resin core significantly.3. The surface treatment, i.e. sandblasting with almina and/or application of resin adhesive, on the metal post had no significant effect on the reinforcement of composite cores.4. The retentive force of AD Post increased gradually with increasing both its length and its diameter. Especially, the increase of diameter was more effective for increasing the retention.