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Summary

Prosthetic treatment frequently involves the restoration of endodontically treated teeth (ETT), which in turn implies that there has been a reduction of the crown due to previous restorative treatment, trauma and/or endodontic manipulations. The prognosis of a restored ETT is very much dependent on pre-endodontic status of the tooth, the quality of the endodontic treatment, the amount remaining tooth structure and the bone support.

The aim of this study is to measure fracture resistance of extracted premolar teeth restored with 2 different diameter posts.

Extracted premolars were collected and stored in physiologic solution at 5°C. The teeth were examined for fractures by direct and transillumination observation and 40 premolars were accepted for the study. The PC were modelled using the appropriate diameter plastic pattern for the post and Pattern Resin (GC) was used to model the core part of the PC. The PC patterns were invested and cast in cobalt chromium alloy and then cemented using zinc phosphate cement. Fracture resistances of the samples were tested in an "Instron 4301" (Instron Series IX Automated Material Testing System Version 5) with a loading speed of 0.5 mm/min.

The data for each sample was recorded graphically. Both groups were analyzed using the t-test (p<0.01) in relationship to the mean value of that group.

Post and cores significantly reduce the fracture resistance of the tooth and should be used only to secure retention and resistance form for full coverage crowns. Teeth with a larger diameter post have a reduced fracture resistance than teeth with a smaller diameter.

Key words: post and core, endodontically treated teeth, Material Testing System.

Received: 15 12 2005

Accepted for publishing: 24 03 2006

*Department of Prosthodontics, Riga Stradins University, Latvia.

Linards Grieznis* - D.D.S., PhD student.

Peteris Apse - D.D.S., MSc (Toronto), prof., Dr. Habil. Med.

Una Soboleva* - D.D.S., Assistant professor, Head of the Department of Prosthodontics, Institute of Stomatology, Riga Stradins University.

Address correspondence to Department of Prosthodontics, Institute of Stomatology, 20 Dzirciema str., Riga LV 1007, Latvia.

E-mail: apse@ark.lv



	Baltic Dental and Maxillofacial Journal

March, 2006, Vol. 8, No. 1 CONTENTS SCIENTIFIC ARTICLES Assessment Of Skeletal And Dental Pattern Of Class II Division 1 Malocclusion With Relevance To Clinical Practice 3-8 Comparison between Scanora® panoramic radiography and bitewing radiography in the assessment of marginal bone tissue 9-15 The Craniofacial Morphology of the Parents of Children with Cleft Lip and/or Palate: A Review of cephalometric studies 16-20 Mutation analysis of the MSX1 gene exons and intron in patients with nonsyndromic cleft lip and palate 21-24 Influence of premolar extractions on tooth size discrepancy. Part Two: Analysis of Bolton values 25-29 The effect of 2 different diameter cast posts on tooth root fracture resistance in vitro 30-32 © 2006 Stomatologija		Stomatologija 2006; 8 (1): 30-2 273 KB The effect of 2 different diameter cast posts on tooth root fracture resistance in vitro Linards Grieznis, Peteris Apse, Una Soboleva Summary Prosthetic treatment frequently involves the restoration of endodontically treated teeth (ETT), which in turn implies that there has been a reduction of the crown due to previous restorative treatment, trauma and/or endodontic manipulations. The prognosis of a restored ETT is very much dependent on pre-endodontic status of the tooth, the quality of the endodontic treatment, the amount remaining tooth structure and the bone support. The aim of this study is to measure fracture resistance of extracted premolar teeth restored with 2 different diameter posts. Extracted premolars were collected and stored in physiologic solution at 5°C. The teeth were examined for fractures by direct and transillumination observation and 40 premolars were accepted for the study. The PC were modelled using the appropriate diameter plastic pattern for the post and Pattern Resin (GC) was used to model the core part of the PC. The PC patterns were invested and cast in cobalt chromium alloy and then cemented using zinc phosphate cement. Fracture resistances of the samples were tested in an "Instron 4301" (Instron Series IX Automated Material Testing System Version 5) with a loading speed of 0.5 mm/min. The data for each sample was recorded graphically. Both groups were analyzed using the t-test (p<0.01) in relationship to the mean value of that group. Post and cores significantly reduce the fracture resistance of the tooth and should be used only to secure retention and resistance form for full coverage crowns. Teeth with a larger diameter post have a reduced fracture resistance than teeth with a smaller diameter. Key words: post and core, endodontically treated teeth, Material Testing System. Received: 15 12 2005 Accepted for publishing: 24 03 2006 Department of Prosthodontics, Riga Stradins University, Latvia. Linards Grieznis - D.D.S., PhD student. Peteris Apse - D.D.S., MSc (Toronto), prof., Dr. Habil. Med. Una Soboleva* - D.D.S., Assistant professor, Head of the Department of Prosthodontics, Institute of Stomatology, Riga Stradins University. Address correspondence to Department of Prosthodontics, Institute of Stomatology, 20 Dzirciema str., Riga LV 1007, Latvia. E-mail: apse@ark.lv