Abstract

Purpose: Computer-aided design/computer-aided manufacturing (CAD/CAM) technology is gaining popularity in dentistry, and more recently, used to fabricate custom post-andcores (PC) for endodontically treated teeth. The purpose of this study was 1) to evaluate the overall retention of conventional cast gold post-and-cores compared to CAD/CAM fabricated printed, milled titanium post-and-core and milled zirconia post-and-cores based on load, time of dislodgement and 2) to evaluate the mode of failure of the post-and-cores.

Materials and Methods: A maxillary central incisor was selected. Root canal treatment was performed, and acrylic resin pattern was used to fabricate post-and-core. A total of 80 post-and-cores (20 conventional and 60 digital) were made and divided into 4 groups based on fabrication method: Group I, conventional method (lost-wax technique) and cast in type IV gold (CCGCP); group II, printed titanium (CPTPC); group III, milled zirconia (CMZPC) and; group IV, milled titanium (CMTPC). Acrylic resin pattern posts were scanned with 3Shape laboratory scanner and exported as STL files. Milled zirconia and milled and printed titanium post-and-cores were fabricated from the digital scans of acrylic resin patterns. The post-and-cores were cemented using Rely X Unicem resin cement after surface treatment. A universal pull out test was used to measure retention at a crosshead speed of .5mm/min. The teeth and posts were evaluated under microscope and with scanning electron microscopy (SEM). The data were statistically analyzed using one-away ANOVA test, Post hoc tests and Tukey adjustment for multiple comparison. Mann- Whitney U test followed by the Bonferroni adjustment were used to compare medians of displacement scores of each group with the gold control group. Statistical analysis was performed using IBM SPSS Statistics (Version 25; IBM Corporation 1989, 2018.) (α = 0.05).

Results: Pull out test revealed higher retention values for (CPTPC) and (CMTPC) among the groups. When compared to (CMZPC), conventional (CCGPC) revealed significantly better retention values (P<0.05) and time to failure. Cohesive failure was observed with groups I, II and IV. However, group III revealed a mixed type of failure.

Conclusions: Within the limitations of this study, although (CCGPC) revealed clinically acceptable values, (CPTPC) and (CMTPC) groups revealed better overall value for retention and time to failure. The titanium seems a promising choice for fabricating dental post-and-core restorations.

LLU Discipline

Prosthodontics

Department

Prosthodontics

School

School of Dentistry

First Advisor

Mathew T. Kattadiyil

Second Advisor

Rami Jekki

Third Advisor

Erik Sahl

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2019

Date (Title Page)

9-2019

Language

English

Library of Congress/MESH Subject Headings

Post and Core Technique -- instrumentation

Type

Thesis

Page Count

xiii, 38 p.

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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