Issues‎ > ‎vol2n2‎ > ‎

sdj-10043

Influence of prefabricated post screw head design on the stress pattern in the core and crown. Finite element stress analysis study

Abdulsalam R Al-Zahawi

College of Dentistry, University of Sulaimani

DOI: https://doi.org/10.17656/sdj.10043

Abstract


Objectives: 
This study evaluated the influence of dental post head design on the stress distribution in the core and crown structure as an in vitro study.

Materials and Methods:
3D finite element model prepared for three different stainless steel post head designs (rectangular with sharp line angle (A), rectangular with fillet line angle (B), and post with round head (C), inserted in single rooted tooth and retained the composite core and zircon crown.  Two configurations of load (100) Newten were applied vertically (V) and lateral oblique (LO) on the occlusal surface of the crown. The results were analyzed and the maximum Von Mises stress option of the stress analysis, at the core and crown parts were compared.

Results
: The results shown that the Maximum Von Mises stresses value in design A (45.58, 186.16) MPa, design B (44.48, 183.71) MPa and design C (29.31, 12984) under V load and LO load in sequence.  The maximum Von Mises stress location was at the cervical margin of the crown,  in design A and B, while located at the top surface of the core for design C under both load configurations. The stresses were concentrated at the top surface of the core in designs A and B, whereas, the stress pattern distributed uniformly in the core structure for design C.

Conclusions
: The round post screw head design produces more benign stress distribution under different occlusal load compared with rectangular shape particularly at the crown margin.

Keywords: Post head, finite element, core and crown, stress patter, stress analysis.



References:

1.       Kokane VB, Patil SN. Post Endodontic Restoration: Are You Serious? Journal of Dental and Medical Sciences Nov.- Dec. 2012; 3  (1):04-7.

2.       Shillingburg HT, Sather DA, Wilson EL, Cain JR, Mitchell DL, Blanco LJ, et al. Fundamentals of fixed prosthodontics Fourth edition ed. edition F, editor. USA: Quintessence Publishing Co.Inc; 2012.

3.       Kokane VB, Patil SN. Post Endodontic Restoration: Are You Serious? Journal of Dental and Medical Sciences. Nov.- Dec. 2012;3 (1):04-7.

4.       Chang W-C, Millstein PL. Effect of design of prefabricated post heads on core materials. The Journal of Prosthetic Dentistry. 1993;69(5):475-82.

5.       Peroz I, Blankenstein F, Lange K-P, Naumann M. Restoring endodontically treated teeth with posts and cores—a review. Quintessence Int. 2005;36(9):737-46.

6.       Pereira JR, Mendonça Neto Td, Porto VdC, Pegoraro LF, Valle ALd. Influence of the remaining coronal structure on the resistance of teeth with intraradicular retainer. Brazilian dental journal. 2005;16(3):197-201.

7.       Guzy GE, Nicholls JI. In vitro comparison of intact endodntically treated teeth with and without endo-post reinforcement. The Journal of Prosthetic Dentistry. 1979;42(1):39-44.

8.       Trope M, Maltz DO, Tronstad L. Resistance to fracture of restored endodontically treated teeth. Dental Traumatology. 1985;1(3):108-11.

9.       Morgano SM. Restoration of pulpless teeth: application of traditional principles in present and future contexts. The Journal of Prosthetic Dentistry. 1996;75(4):375-80.

10.     Heydecke G, Butz F, Strub JR. Fracture strength and survival rate of endodontically treated maxillary incisors with approximal cavities after restoration with different post and core systems: an in-vitro study. Journal of Dentistry. 2001;29(6):427-33.

11.     Kovarik RE, Breeding LC, Caughman WF. Fatigue life of three core materials under simulated chewing conditions. The Journal of Prosthetic Dentistry. 1992;68(4):584-90.

12.     Zalkind M, Shkury S, Stern N, Heling I. Effect of prefabricated metal post-head design on the retention of various core materials. Journal of Oral

Rehabilitation. 2000;27(6):483-7.

13.     Cohen BI, Pagnillo MK, Newman I, Musikant BL, Deutsch AS. Retention of a core material supported by three post head designs. The Journal of Prosthetic Dentistry. 2000;83(6):624-8.

14.     Nelson SJ. Wheeler's dental anatomy, physiology and occlusion: Elsevier Health Sciences; 2009.

15.     Pérez-González A, González-Lluch C, Sancho-Bru JL, Rodríguez-Cervantes PJ, Iserte-Vilar JL. Biomechanical Models of Endodontic Restorations. 2011.

16.     Christensen GJ. Amalgam vs. composite resin: 1998. J Am Dent Assoc. 1998;129(12):1757-9.

17.     van Noort. Introduction to Dental Materials. Mosby El Siver. 2007;Third Edition:88,118.

18.     Tjan A, Dunn JR, Lee J. Fracture resistance of amalgam and composite resin cores retained by various intradentinal retentive features. Quintessence international (Berlin, Germany: 1985). 1993;24(3): 211-7.

19.     Callister WD, Rethwisch DG. Materials science and engineering: an introduction: Wiley New York; 2007.