Esthetic considerations in restoring endodontically treated teeth with posts and cores

Comparative effectiveness of fiber and metal posts in the restoration of endodontically treated teeth: A systematic review with network meta-analysis

STATEMENT OF PROBLEM

Different varieties of fiber and metal intraradicular posts have been used for the restoration of endodontically treated teeth with insufficient sound tooth structure. Evidence on the comparative efficacy of posts in a clinical setting is insufficient to provide clear clinical guidelines and recommendations.

PURPOSE

The purpose of this systematic review with network meta-analysis was to assess the comparative efficacy of fiber and metal posts used for the restoration of endodontically treated teeth.

MATERIAL AND METHODS

A search was conducted for trials published in Medline, Scopus, PubMed, and Cochrane Central Register of Controlled Trials from inception until November 2022. The study was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42022384340). A network meta-analysis was performed on data from randomized controlled trials that assessed the comparative efficacy of fiber posts and metal posts for the restoration of endodontically treated teeth. Subgroup analyses were performed to compare all the varieties of fiber and metal posts. The types of posts were ranked according to their efficacy using the Surface Under the Cumulative Ranking (SUCRA) system. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach was used to assess the level of certainty of evidence.

RESULTS

Twenty-five articles were included in the quantitative analysis. Fiber posts (RR=0.15 [95% CI: 0.06, 0.33]) significantly prevented tooth fracture as compared with no posts. Prefabricated carbon fiber posts (RR=0.06 [95% CI: 0, 0.54]) ranked highest followed by custom glass fiber posts (RR=0.15 [95% CI: 0.04, 0.52]) and prefabricated glass fiber posts (RR=0.22 [95% CI: 0.07, 0.62]) in the outcome of tooth fracture. Metal posts (RR=0.24 [95% CI: 0.12, 0.46]) ranked higher than fiber posts (RR=0.39 [95% CI: 0.27, 0.56]) in the outcome of debonding. Custom gold alloy posts (RR=0.12 [95% CI: 0.03, 0.48]), prefabricated gold alloy posts (RR=0.04 [95% CI: 0.00, 0.87]), and prefabricated titanium posts (RR=0.21 [95% CI: 0.10, 0.45]) had higher rankings in the outcome of debonding or loss of retention of a post followed by custom glass fiber posts (RR=0.37 [95% CI: 0.21, 0.63]) and prefabricated glass fiber posts (RR=0.38 [95%CI: 0.25, 0.58]). Prefabricated glass fiber posts (RR=0.40 [95% CI: 0.20, 0.81]) had statistically significant differences in the outcome of secondary caries. The GRADE approach determined a moderate level of certainty of evidence.

CONCLUSIONS

The use of a fiber post when indicated results in reduced risk of tooth fracture as compared with no post. Prefabricated carbon fiber posts, prefabricated glass fiber posts, and custom glass fiber posts reveal a lower risk of tooth fracture. Overall, the use of prefabricated glass fiber posts had a lower risk of tooth fracture, debonding, and secondary caries. However, more trials with longer follow-up periods are recommended to enhance the certainty of evidence.

Evaluation of Retention and Fracture Strength of All Ceramic Crowns with Three Different Esthetic Cast Post-Core Systems

Purpose

This study investigates the fracture and retention strength of all-ceramic crowns with modified composite resin and ceramic cores compared to conventional casted post and core systems.

Materials and Methods

A prepared human central tooth was initially scanned to design and 3D print the post and core. Subsequently, 40 bovine teeth were adjusted to accommodate the fabricated post and cores. They were then divided into four groups of 10 each: group 1 comprised cast cores without cover (control group), group 2 involved cast cores reduced and replaced with IPS Empress material (IPS group), group 3 consisted of cast cores covered with opaque composite (composite group), and group 4 included cast cores covered with opaque ceramic (ceramic group). Zirconia crowns were cemented onto all samples. After an aging process, pull-off and fracture strength tests were conducted. Fracture strength was determined by applying a compressive force at an angle of 135° to the tooth's longitudinal axis until the fracture occurred. For retention strength assessment, a universal testing machine with a 10 mm/min crosshead speed was employed. The resulting data underwent statistical analysis utilizing two-way analysis of variance (ANOVA) and Mann-Whitney U tests.

Results

The analysis revealed no significant difference in fracture strength among the groups (P-value = 0.997). However, the retention strength of the control and IPS groups was significantly higher than that of the other groups.

Conclusion

There were no discernible distinctions among the three study methods regarding fracture strength. Nonetheless, the retention strength of the IPS group resembled that of the control group, surpassing that of the composite and ceramic groups.

Evaluation of the Bond Strength and Fracture Resistance of Different Post Systems

AIM

To compare the bond strength and the fracture resistance of different post systems.

MATERIALS AND METHODS

Endodontically treated 60 mandibular incisor and 60 mandibular premolar teeth were used for the bond strength and fracture resistance test respectively. For each test, three groups (n = 20) were formed according to the posts used zirconia posts (ZR post), individually formed glass fiber reinforced composite posts with an (Interpenetrating Polymer Network-IPN post) and cast metal posts. Then groups were randomly assigned into two subgroups according to the post design: 1-parallel sided and 2-tapered (n = 10/group). All posts were luted with a self-adhesive luting agent. For push-out test two 1 mm thick horizontal root sections were obtained and subjected to push-out test. For fracture resistance test, the specimens were loaded vertically at 1 mm/min crosshead speed. The push out test data were analyzed with Kruskal-Wallis and Dunn's test. Analysis of variance (ANOVA) and Tukey significant difference tests were used to compare the fracture resistance.

RESULTS

Cast metal posts showed the highest retention (p < 0.05); however, IPN and zirconia posts showed similar results. No significant difference was found between parallel sided or tapered designs of post groups in terms of bond strength (p > 0.05). In terms of fracture resistance, IPN post groups showed lowest fracture resistance (p < 0.05). No significant difference was found between parallel sided or tapered posts in terms of fracture resistance, except zirconia post (p > 0.05). There was no relationship between the bond strength and fracture resistance of the post systems (r = - 0.015, p > 0.700).

CONCLUSION

Post type had effect both on the fracture resistance and retention of the posts used. However, post design had effect only on the fracture resistance of the post systems.

CLINICAL SIGNIFICANCE

Superficial treatment of the post used can improve the retention of post systems.

Esthetic and functional consideration in restoring endodontically treated teeth

The selection of the best restoration for an endodontically treated tooth in the aesthetic zone depends on strength and the ability to recreate the form, function, and aesthetics of the natural tooth. The increased use of all-ceramic materials is a result of improved ceramic materials and adhesive systems. However, the advent of the current variety of translucent ceramic systems makes the shade of the abutment important in achieving the desired aesthetic outcome. This article discusses the different types of posts used in the restoration.

Clinical evaluation of pulpless teeth restored with conventionally cemented zirconia posts: a pilot study

STATEMENT OF PROBLEM

Adhesive resin cements are commonly used to lute all-ceramic posts despite limited scientific data on the clinical effectiveness of using bonding agents within prepared root canals.

PURPOSE

The purpose of this study was to retrospectively evaluate the clinical performance of conventionally cemented zirconia posts. Loss of retention, fracture of posts, and fracture of teeth were evaluated.

MATERIAL AND METHODS

Thirty pulpless teeth in 22 patients were treated with zirconia posts. With the exception of 3 situations in which posts were inserted directly and the access openings were closed with composite resin, teeth were restored with indirectly fabricated post-and-core foundations made from zirconia posts (Cerapost or Cosmopost) combined with heat-pressed ceramic cores (IPS Empress Cosmo) and ceramic crowns (IPS Empress II). Restorations (posts and crowns) were cemented with glass-ionomer cement (KetacCem) or resin-modified glass-ionomer cement (ProTec Cem) and reevaluated, retrospectively, for failures such as loss of retention or fractures. Data were reported using descriptive statistics.

RESULTS

The mean observation period was 29 months (range 8-44 months). No loss of retention or fracture of any restoration was observed.

CONCLUSION

Although this study involved a relatively short observation period, there were no signs of failure of conventionally cemented zirconia posts with ceramic crowns.

The use of all-ceramic restorations to splint periodontally compromised teeth: a clinical report

This clinical report describes the use of an all-ceramic system to restore periodontally compromised teeth. A metal-free post-and-core system and all-ceramic crowns were used to splint the teeth and fulfill the esthetic demands.

An alternative method for fabricating a custom-made metal post with a ceramic core

The restoration of anterior non-vital teeth with metal posts and cores and all-ceramic restorations may lead to compromised esthetics because of the semi-translucence of ceramics and the metallic color of the underlying post and cores. This article presents a technique that combines the optical properties of ceramic cores with the mechanical properties of custom-made cast metal posts. The technique involves heat pressing of the core from leucite-enriched glass-ceramic to the underlying custom-made metal post and may provide additional esthetic benefit for anterior teeth especially with little remaining coronal dentin and with small root volume.

Evaluation of fracture resistance of endodontically treated teeth restored with prefabricated posts and composites with varying quantities of remaining coronal tooth structure

OBJECTIVES: The aim of this study was to evaluate the influence of remaining coronal tooth structure on endodontically treated teeth restored with prefabricated posts and two different composites for core build-up: dual-cured resin (Enforce Core) and light-cured resin (Z-250). METHODS: Fourty freshly extracted canines were endodontically treated and divided into four groups: Group I - teeth with 3mm remaining coronal structure, restored with Enforce Core; Group II - teeth with 3mm remaining coronal structure, restored with Z-250; Group III - teeth with no remaining coronal structure, restored with Enforce; Group IV - teeth with no remaining coronal structure, restored with Z-250. After restoration, the teeth were embedded in acrylic resin and the fracture resistance was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. RESULTS: Data were analyzed by two-way analysis of variance, which showed significant differences between groups (p=0.00). The Tukey test did not show significant differences between specimens with and without remaining coronal structure. Conversely, significant difference was observed between groups with different core build-up. The highest values of fracture resistance were found in the group restored with light-cured resin. SIGNIFICANCE: The remaining coronal tooth structure did not influence the resistance of endodontically treated teeth; however, the change of core build-up was able to modify this resistence.

Restoration of endodontically treated teeth

Endodontically treated teeth have lost substantial tooth structure as a result of previous restorations, dental caries, and the access preparation for the endodontic therapy. The topic of restoring these teeth is complex and controversial, and their long-term prognosis is directly connected to the quality of the final restoration. This article describes contemporary knowledge of the biomechanical principles related to the restoration of pulpless teeth and provides a critical review of currently available materials and methods.

The use of chairside silica coating for different dental applications: a clinical report

This article describes an alternative approach to conditioning an alloy surface prior to veneering with composite. The procedure is based on silica coating and silanization of the alloy surface, which can be performed chairside.

Foundation restorations in fixed prosthodontics: current knowledge and future needs

PURPOSE

The Ad Hoc Committee on Research in Fixed Prosthodontics established by the Academy of Fixed Prosthodontics publishes a yearly comprehensive literature review on a selected topic. The subject for this year is foundation restorations.

METHODS

Literature of various in vitro and in vivo investigations that included technical and clinical articles was reviewed to provide clinical guidelines for the dentist when selecting methods and materials for restoration of structurally compromised teeth. Topics discussed and critically reviewed include: (1) desirable features of foundation restorations, (2) foundations for pulpless teeth, (3) historic perspectives, (4) cast posts and cores, (5) role of the ferrule effect, (6) prefabricated posts, (7) direct cores, (8) foundation restorations for severely compromised teeth, (9) problems and limitations, (10) future needs, and (11) directions for future research.

CONCLUSION

This comprehensive review brings together literature from a variety of in vitro and in vivo studies, along with technique articles and clinical reports to provide meaningful guidelines for the dentist when selecting methods and materials for the restoration of structurally compromised teeth.

New all-ceramic indirect post-and-core system

The increasing demand for highly esthetic, biocompatible posts and cores has led to the development of metal-free, post-and-core systems. This article describes and evaluates an indirect method for the fabrication of an all-ceramic post and core.

Direct core buildup using a preformed crown and prefabricated zirconium oxide post

This article describes a procedure that can produce a post and core in a reasonable chair time during a single session. With a preformed crown for core buildup, and being relatively rapid, this is a fairly simple procedure that has good results.