Statement of problem
Various strategies have been proposed to reduce the cement space of foundation restorations for endodontically treated teeth. However, they may add more operative steps, or the dentist must keep different sizes of drills and posts in stock. A 2-piece universal adjustable post system has been developed to overcome this problem, but whether the system has acceptable fatigue survival performance is unclear.
The purpose of this in vitro study was to evaluate the fatigue survival and stress distribution of endodontically treated teeth without a ferrule and restored with different glass fiber post strategies versus a recently introduced universal 2-piece fiber post system.
Material and methods
Bovine incisor roots were randomly assigned to 3 groups as per the post used (n=13): adapted glass fiber post with post space preparation of the same size, composite resin-custom glass fiber post (CTM), and universal 2-piece glass fiber-reinforced composite resin post (UNI). The posts were adhesively luted, the composite resin core was added, and a composite resin crown was produced with computer-aided design and computer-aided manufacturing (CAD-CAM), and then adhesively luted to each core. A fatigue test was performed with the stepwise stress method (10 000 cycles/step; 20 Hz; load=100 N to 750 N; step=50 N) until fracture, and the failure mode analyzed. The stress distribution was evaluated by finite element analysis with the maximum principal stress criteria by following the parameters of the in vitro test. The solids were considered homogeneous, linear, and isotropic, except for the glass fiber post (orthotropic), and a load of 450 N at 30 degrees was applied. The fatigue failure load and the number of cycles for failure were analyzed with Kaplan-Meier and Mantel-Cox (log rank test) (α=.05). The finite element analysis results were analyzed with colorimetric graphs.
The highest fatigue failure load and the number of cycles for failure were found in the UNI system, whereas the lowest results were found in the CTM group. All groups exhibited repairable failures. The finite element analysis showed the lowest stress in root dentin in the UNI system. The CTM system had the largest stress regions at the dentin and dentin-core interface.
The use of a 2-piece universal glass fiber post system resulted in more fatigue behavior compared with composite resin-custom glass fiber posts.
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- A novel anatomical short glass fiber reinforced post in an endodontically treated premolar mechanical resistance evaluation using acoustic emission under fatigue testing.J Mech Behav Biomed Mater. 2017; 65: 151-159
- Biomechanical considerations for the restoration of endodontically treated teeth: a systematic review of the literature--part 1. Composition and micro- and macrostructure alterations.Quintessence Int. 2007; 38: 733-743
- The effect of the gap between the post restoration and the remaining root canal filling on the periradicular status in a Turkish subpopulation.Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010; 110: 131-135
- Mechanical resistance evaluation of a novel anatomical short glass fiber reinforced post in artificial endodontically treated premolar under rotational/lateral fracture fatigue testing.Dent Mater J. 2016; 35: 233-240
- Are we misusing fiber posts? Guest editorial.Dent Mater. 2016; 32: 125-126
- A structured analysis of in vitro failure loads and failure modes of fiber, metal, and ceramic post-and-core systems.Int J Prosthodont. 2004; 17: 476-482
- Oval fiber posts do not improve adaptation to oval-shaped canal walls.J Endod. 2011; 37: 1386-1389
- Effect of glass-fiber post on the biomechanical behavior of teeth with direct veneers.Braz Dent Sci. 2020; 23: 1-7
- Adhesion of two new glass fiber post systems cemented with self-adhesive resin cements.Dent J (Basel). 2019; 7: 80
- Fracture behaviors of maxillary central incisors with flared root canals restored with CAD/CAM integrated glass fiber post-and-core.Dent Mater J. 2019; 38: 114-119
- Clinical outcomes and success rates of quartz fiber post restorations: a retrospective study.J Prosthet Dent. 2015; 114: 367-372
- Effect of cement type, relining procedure, and length of cementation on pull-out bond strength of fiber posts.J Endod. 2010; 36: 1543-1546
- Fracture resistance of endodontically treated teeth restored with glass fiber reinforced posts and cast gold post and cores cemented with three cements.J Prosthet Dent. 2013; 110: 127-133
- Influence of different post-endodontic restoration on the fatigue survival and biomechanical behavior of central incisors.Am J Dent. 2020; 33: 227-234
- Clinically relevant approach to failure testing of all-ceramic restorations.J Prosthet Dent. 1999; 81: 652-661
- Lithium disilicate glass-ceramic vs translucent zirconia polycrystals bonded to distinct substrates: fatigue failure load, number of cycles for failure, survival rates, and stress distribution.J Mech Behav Biomed Mater. 2019; 91: 122-130
- Influence of remaining coronal thickness and height on biomechanical behavior of endodontically treated teeth: survival rates, load to fracture and finite element analysis.J Appl Oral Sci. 2018; 26: e20170313
- Loading frequencies up to 20 Hz as an alternative to accelerate fatigue strength tests in a Y-TZP ceramic.J Mech Behav Biomed Mater. 2016; 61: 79-86
- Bio-CAD modeling and its applications in computer-aided tissue engineering.Comput Des. 2005; 37: 1097-1114
- A study on stress distribution to cement layer and root dentin for post and cores made of CAD/CAM materials with different elasticity modulus in the absence of ferrule.J Clin Exp Dent. 2019; 11: e1-e8
- 3D FEA of cemented steel, glass and carbon posts in a maxillary incisor.Dent Mater. 2005; 21: 709-715
- Repair of denture base resin using woven metal and glass fiber: effect of methylene chloride pretreatment.J Prosthet Dent. 2001; 85: 496-500
- Evaluation of the biomechanical behavior of maxillary central incisors restored by means of endocrowns compared to a natural tooth: a 3D static linear finite elements analysis.Dent Mater. 2006; 22: 1035-1044
- Mechanical properties, shrinkage stress, cuspal strain and fracture resistance of molars restored with bulk-fill composites and incremental filling technique.J Dent. 2015; 43: 1519-1528
Published online: July 05, 2021
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
© 2021 by the Editorial Council for the Journal of Prosthetic Dentistry.