The effect of different posts on fracture strength of roots with vertical fracture and re-attached fragments

Effect of bone defect width and a ferrule on the fracture characteristics of vertically fractured teeth reattached with adhesive resin cement: An in vitro study

This study aimed to clarify the effects of vertical bone defect width and a ferrule on fracture of the fragments of fractured tooth reattached with adhesive resin cement (reattached tooth). The reattached tooth was built up by a fiber post and composite resin core for abutment and formed to the abutment with or without a ferrule. The vertical bone defect was fabricated with a V-shaped defect in different widths. The fracture load was evaluated using a universal testing machine. The vertical bone defect did not affect the fracture load, but a ferrule increased the root fracture load. For the specimens without a ferrule, debonding between the composite resin core and the root at the coronal loading side and fractures at the apical side of the root were found. In conclusion, the ferrule at abutment could affect fracture load and modes, and the bone defect width did not.

Comparison of Ribbond and Everstick Post in Reinforcing the Re-attached Maxillary Incisors Having Two Oblique Fracture Patterns: An In Vitro Study

Aim and objective

This study aims to compare the resistance to fracture in maxillary incisors which were fractured in two different oblique patterns and then were re-attached and reinforced using anatomic fiber-reinforced composite (FRC) post.

Materials and methods

Sixty extracted and intact human maxillary incisors were obtained and divided into two groups (A and B; n = 30). “Labiopalatal” and “palatolabial” fractures were induced in group A and group B, respectively. These two groups were further subdivided into two subgroups (n = 15). In subgroup I Ribbond fiber (Ribbond Inc., Seattle, WA, USA) and in subgroup II Everstick post (everStick Post™, GC Corporation, Tokyo, Japan) were used. Fractured fragments were re-attached using resin and tested for fracture resistance in universal testing machine. Statistical analysis was done with ANOVA one-way test and post hoc test.

Results

The labiopalatal fracture pattern of group A showed significantly increased resistance to fracture than the palatolabial fracture pattern of group B in both the subgroups. Similarly, subgroup II with Everstick post exhibited significantly higher fracture resistance than subgroup I with Ribbond in both groups A and B (p value < 0.05).

Clinical significance

The study simulates a clinical scenario of coronal fracture of a tooth and focuses on the techniques and materials which can be used for successful management of such cases.

How to cite this article

Khurana D, Prasad AB, Raisingani D, et al. Comparison of Ribbond and Everstick Post in Reinforcing the Re-attached Maxillary Incisors Having Two Oblique Fracture Patterns: An In Vitro Study. Int J Clin Pediatr Dent 2021;14(5):689–692.

A novel insertion design of fiber materials for the adhesive reattachment in vertically fractured teeth

Objective

This ex vivo study aimed to evaluate the strengthening effect of different ferrule and reattachment designs with fiber and adhesive materials on vertically fractured teeth.

Methods

Ninety extracted single-root premolars were instrumented and divided into nine groups (two control groups and seven experimental groups; n = 10). The negative control (NC) group comprised of intact teeth, while the positive control (PC) group comprised of root canal-treated teeth. The roots of the teeth in the experimental groups were vertically fractured into two equal fragments. The fragments were reattached with one of the followings: 4-methacryloxyethyl trimellitate anhydride/methacrylate-tri-n-butyl borane (4-META/MMA-TBB) resin, 4-META/MMA-TBB + quartz fiber post, 4-META/MMA-TBB + glass fiber bundles, 4-META/MMA-TBB + quartz fiber post + 1 mm ferrule, 4-META/MMA-TBB + glass fiber bundles + 1 mm ferrule, 4-META/MMA-TBB + quartz fiber post + 2 mm ferrule, and 4-META/MMA-TBB + glass fiber bundles + 2 mm ferrule. The core build-ups were made with composite resin. The specimens were subjected to compressive loading until failure occurred. Mean load necessary to fracture each sample and the fracture types of these samples were recorded.

Results

The highest mean fracture load was recorded in the NC group (1,036.7 N), which was not significantly higher than the PC group (989.66 N) (p > 0.05). The roots reattached with quartz fiber post demonstrated significantly less fracture strength (871.9 N) as compared to the other test and control groups (p < 0.05). There was no significant difference between the PC group and reattached fragments with different ferrule designs in terms of fracture resistance (p > 0.05).

Conclusions

The customized fiber bundles may be more suitable for reattachment of vertically fractured teeth than the rigid fiber posts. For reattachment procedures, the ferrule design may be preferred to increase the fracture strength of vertically fractured teeth.

Strengthening effect of different fiber placement designs on root canal treated and bleached premolars

To evaluate the strengthening effect of five different fibers with different placement designs in root canal treated and intracoronally bleached premolars. Seventy extracted single-rooted premolars were distributed into 7 groups (G1-G7). Group 1 (G1) included the intact (I) teeth as the negative control. Group 2 (G2) included root canal treated, intra-coronally bleached and composite (C) restored teeth as the positive control. In the other five test groups after root canal treatment the teeth were intra-coronally bleached and fiber materials were placed into standard MOD cavities in the following different designs: an intracanal rigid fiber/Reforpost (G3,RF), an intracanal flexible fiber/ Everstick (G4, FF), four intracanal flexible pin fibers/Dentapreg Pin (G5,PF), an intercuspal flexible fiber /Dentapreg SFU (G6, IF) or an intra-coronal horseshoe-shaped/ Dentapreg SFU (G7,CF). All cavities were filled with a microfilled resin composite. Fracture resistance was tested using a universal testing machine under a crosshead speed of 1 mm/minute. One-way ANOVA and Duncan's Multiple Range tests were used for statistical analysis. Fracture types were recorded. The fracture resistance values in descending order were G1(I): 1190.97 N > G6 (IF): 1138.78 N > G5 (PF): 942.45 N > G3 (RF): 737.40 N > G4 (FF):694.29 N > G2 (C): 611.83 N > G7 (CF): 542.78 N. There were statistically significant differences among the groups (p ≤ 0.05). In all groups, repairable coronal oblique fractures were mostly observed. Flexible fibers placed intercuspally exhibited a significantly better strengthening effect than those of the intracanal flexible and rigid fibers (p < 0.05).

Comparative evaluation of the vertical fracture resistance of endodontically treated roots filled with Gutta-percha and Resilon: a meta-analysis of in vitro studies

Background

Teeth treated endodontically are more susceptible to vertical root fracture (VRF). Some studies have suggested that obturating the root canals with Gutta-percha or Resilon can reinforce endodontically treated teeth, but a few others have presented conflicting results. These inconsistent results cannot guide clinicians in determining clinical approaches. The objective of this meta-analysis is to evaluate and compare the vertical fracture resistance of endodontically treated root canals obturated with Gutta-percha/AH plus and the Resilon system.

Methods

Comprehensive literature searches were performed in the PubMed, Cochrane Library, ScienceDirect, Web of Science and Embase databases. The titles and abstracts of all of the retrieved articles were independently assessed by two authors according to predefined selection criteria. Data in the included articles were independently extracted. Statistical analyses were conducted using Review Manager 5.3 and Stata 12.0 software. The pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated for the outcome indicators. The level of statistical significance was set at p < 0.05. The Cochran Q test (I² test) was used to test for heterogeneity among studies.

Results

Fourteen randomized controlled in vitro trials were included in the meta-analysis. The results demonstrated that the vertical root fracture resistance of unprepared and unfilled roots was significantly higher than that of roots obturated with Gutta-percha/AH plus (SMD = − 0.69, 95% CI = − 1.34 to − 0.04, p = 0.04) or the Resilon system (SMD = − 0.54, 95% CI = − 1.07 to − 0.00, p = 0.05). The differences in fracture resistance between the roots filled with Gutta-percha/AH plus and the prepared unfilled root canals was not significant (SMD = 0.59, 95% CI = − 0.02 to 1.21, p = 0.06). Roots obturated with Resilon had higher fracture resistance than instrumented unfilled roots (SMD = 0.83, 95% CI = 0.44 to 1.22, p < 0.0001) or roots filled with Gutta-percha/AH plus (SMD = 0.62, 95% CI = 0.01 to 1.23, p = 0.05).

Conclusions

The present study suggests that filling with Gutta-percha/AH plus dose not reinforce endodontically treated roots, whereas obturating with the Resilon system can increase vertical root fracture resistance of prepared roots. As this meta-analysis was based on in vitro studies, it should be careful to extrapolate its conclusion to the clinical context.

Comparative evaluation between glass and polyethylene fiber reinforced composites: A review of the current literature

BACKGROUND

Fiber reinforced composite (FRC) is a promising class of material that gives clinicians alternative treatment options. There are many FRC products available in the market based on either glass or polyethylene fiber type. The aim of this study was to present a comparison between glass and polyethylene fiber reinforced composites based on available literature review.

MATERIAL AND METHODS

A thorough literature search, with no limitation, was done up to June 2017. The range of relevant publications was surveyed using PubMed and Google Scholar. From the search results, articles related to our search terms were only considered. An assessment of these articles was done by two individuals in order to include only articles directly compare between glass and polyethylene FRCs. The search terms used were "fiber reinforced dental composites" and "glass and polyethylene fibers in dentistry".

RESULTS

The search provided 276 titles. Full-text analysis was performed for 29 articles that met the inclusion criteria. Most were laboratory-based research with various test specimen designs prepared according to ISO standard or with extracted teeth and only three articles were clinical studies. Most of studies (n=23) found superior characteristics of glass FRCs over polyethylene FRCs.

CONCLUSIONS

Significant reinforcement differences between commercial glass and polyethylene fiber reinforced composites were found. Key words:Fiber reinforced composite, glass fiber, polyethylene fiber.

Cracked tooth diagnosis and treatment: An alternative paradigm

This article reviews the diagnosis and treatment of cracked teeth, and explores common clinical examples of cracked teeth, such as cusp fractures, fractures into tooth furcations, and root fractures. This article provides alternative definitions of terms such as cracked teeth, complete and incomplete fractures and crack lines, and explores the scientific rationale for dental terminology commonly used to describe cracked teeth, such as cracked tooth syndrome, structural versus nonstructural cracks, and vertical, horizontal, and oblique fractures. The article explains the advantages of high magnification loupes (×6-8 or greater), or the surgical operating microscope, combined with co-axial or head-mounted illumination, when observing teeth for microscopic crack lines or enamel craze lines. The article explores what biomechanical factors help to facilitate the development of cracks in teeth, and under what circumstances a full coverage crown may be indicated for preventing further propagation of a fracture plane. Articles on cracked tooth phenomena were located via a PubMed search using a variety of keywords, and via selective hand-searching of citations contained within located articles.

Fracture resistance of roots filled with three different obturation techniques

Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth—at the cemento-enamel junction and 8 mm apically from the junction—buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was performed; in group 3, the obturation was done with AH 26 + gutta-percha; in group 4, with AH 26 + BeeFill and in group 5, AH 26 + a Thermafil obturator was used. All the roots were mounted vertically in copper rings and filled with acrylic resin, exposing 8 mm of the coronal part. A universal testing machine was used for the strength test. Results: The results were analyzed using the one-way ANOVA test. The significance between the groups was tested with Temhane’s T2 test. The results indicate that instrumentation of root canals had a significant effect on fracture resistance (p<0.05). In addition, there were no differences between the root canal obturation techniques; furthermore, these techniques did not create a statistically important resistance to vertical fracture (p>0.05). Conclusions: The results suggest that instrumentation of root canals significantly weakens the tooth structure to fracture and the root canal obturation techniques that are used are not able to form reinforcement.

Key words:AH 26, obturation technique, vertical fracture.