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Effect of Post Material and Length on Fracture Resistance of Endodontically Treated Premolars: An In-Vitro Study.

Amarnath GS, Swetha MU, Muddugangadhar BC, Sonika R, Garg A, Rao TR - J Int Oral Health (2015)

Bottom Line: Analysis indicated significant differences (P < 0.001) among the groups.Among the SS posts, SS/7 (246 N) exhibited the highest failure load and SS/4 (122 N) the lowest.FP/10 (140.5 N) exhibited the highest failure load among the FP and FP/4 (68.5 N) the lowest.

View Article: PubMed Central - PubMed

Affiliation: Head, Department of Prosthodontics including Crown and Bridge and Implantology, M R Ambedkar Dental College and Hospital, Bengaluru, Karnataka, India.

ABSTRACT

Background: Endodontically treated teeth with posts are more prone to fracture. Hence, the purpose of this study was to investigate the in-vitro fracture resistance of devitalized teeth and mode of failure restored with posts of different materials and different lengths.

Materials and methods: Sixty freshly extracted human mandibular premolars were endodontically treated and then restored with 1 of 2 prefabricated posts: Stainless-steel (SS) and glass-fiber (fiber posts [FP]) with intraradicular lengths of 4, 5 or 10 mm (n = 10). Following core restoration, a static compressive load was applied perpendicular to the long-axis of the teeth. Initial failure of each specimen was recorded in Newton. The mode of failure was also determined radiographically. The data were analyzed using two-way ANOVA and Tukey's post-hoc analysis with Bonferroni adjustment.

Results: Analysis indicated significant differences (P < 0.001) among the groups. Among the SS posts, SS/7 (246 N) exhibited the highest failure load and SS/4 (122 N) the lowest. FP/10 (140.5 N) exhibited the highest failure load among the FP and FP/4 (68.5 N) the lowest. SS posts showed post pull out, followed by core fracture while FP showed core debonding, followed by core fracture as the primary mode of failure.

Conclusion: Fracture resistance of the teeth proportionately increased with increase in the length of FP while it decreased with that of metal post. SS posts showed greater fracture resistance than FP when 90° load was applied.

No MeSH data available.


Related in: MedlinePlus

Loading specimens at 90° to the long axis of the tooth at 3 mm from the tooth-core interface.
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Figure 5: Loading specimens at 90° to the long axis of the tooth at 3 mm from the tooth-core interface.

Mentions: Manufacturer supplied parapost drills were used for post space preparation. An additional 3 mm of post length was allowed to extend coronal to the CEJ. The post space and posts were etched, bonded and light cured. Posts were cemented with Paracore dual cure resin cement, Coltene Whaledent, USA (Figure 2). Core formers were used for core build-up up to 4 mm from the coronal tooth floor (Figures 3 and 4). Each sample was mounted and positioned in an acrylic block with their longitudinal axis perpendicular to the load direction. A universal testing machine with a custom made loading plunger was used to load the specimens at 90° to the long axis and 3 mm from the tooth-core interface with a crosshead speed of 0.5 mm/min until primary failure occurred (Figure 5). The failure load was recorded. In addition, the mode of failure was also recorded as root fracture, core fracture, post fracture or any interface de-bonding. Teeth were radiographed by using radiographic film to determine the mode of failure (Figure 6).


Effect of Post Material and Length on Fracture Resistance of Endodontically Treated Premolars: An In-Vitro Study.

Amarnath GS, Swetha MU, Muddugangadhar BC, Sonika R, Garg A, Rao TR - J Int Oral Health (2015)

Loading specimens at 90° to the long axis of the tooth at 3 mm from the tooth-core interface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4513771&req=5

Figure 5: Loading specimens at 90° to the long axis of the tooth at 3 mm from the tooth-core interface.
Mentions: Manufacturer supplied parapost drills were used for post space preparation. An additional 3 mm of post length was allowed to extend coronal to the CEJ. The post space and posts were etched, bonded and light cured. Posts were cemented with Paracore dual cure resin cement, Coltene Whaledent, USA (Figure 2). Core formers were used for core build-up up to 4 mm from the coronal tooth floor (Figures 3 and 4). Each sample was mounted and positioned in an acrylic block with their longitudinal axis perpendicular to the load direction. A universal testing machine with a custom made loading plunger was used to load the specimens at 90° to the long axis and 3 mm from the tooth-core interface with a crosshead speed of 0.5 mm/min until primary failure occurred (Figure 5). The failure load was recorded. In addition, the mode of failure was also recorded as root fracture, core fracture, post fracture or any interface de-bonding. Teeth were radiographed by using radiographic film to determine the mode of failure (Figure 6).

Bottom Line: Analysis indicated significant differences (P < 0.001) among the groups.Among the SS posts, SS/7 (246 N) exhibited the highest failure load and SS/4 (122 N) the lowest.FP/10 (140.5 N) exhibited the highest failure load among the FP and FP/4 (68.5 N) the lowest.

View Article: PubMed Central - PubMed

Affiliation: Head, Department of Prosthodontics including Crown and Bridge and Implantology, M R Ambedkar Dental College and Hospital, Bengaluru, Karnataka, India.

ABSTRACT

Background: Endodontically treated teeth with posts are more prone to fracture. Hence, the purpose of this study was to investigate the in-vitro fracture resistance of devitalized teeth and mode of failure restored with posts of different materials and different lengths.

Materials and methods: Sixty freshly extracted human mandibular premolars were endodontically treated and then restored with 1 of 2 prefabricated posts: Stainless-steel (SS) and glass-fiber (fiber posts [FP]) with intraradicular lengths of 4, 5 or 10 mm (n = 10). Following core restoration, a static compressive load was applied perpendicular to the long-axis of the teeth. Initial failure of each specimen was recorded in Newton. The mode of failure was also determined radiographically. The data were analyzed using two-way ANOVA and Tukey's post-hoc analysis with Bonferroni adjustment.

Results: Analysis indicated significant differences (P < 0.001) among the groups. Among the SS posts, SS/7 (246 N) exhibited the highest failure load and SS/4 (122 N) the lowest. FP/10 (140.5 N) exhibited the highest failure load among the FP and FP/4 (68.5 N) the lowest. SS posts showed post pull out, followed by core fracture while FP showed core debonding, followed by core fracture as the primary mode of failure.

Conclusion: Fracture resistance of the teeth proportionately increased with increase in the length of FP while it decreased with that of metal post. SS posts showed greater fracture resistance than FP when 90° load was applied.

No MeSH data available.


Related in: MedlinePlus