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Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation.
J Prosthodont. 2019 Feb; 28(2):163-170.JP

Abstract

PURPOSE

This in vitro study evaluated the fracture resistance and clinical prognosis of anterior lithium disilicate crowns (e.max Press and e.max CAD), following endodontic access and repair. The research design simulates intraoral loading conditions to produce clinically applicable results.

MATERIALS AND METHODS

Monolithic anterior crowns, based on #8 anatomy, were fabricated from e.max Press ingots and e.max CAD blocks and adhesively bonded on identical dies milled out of a dentin analog material (NEMA G10). Specimens were divided into 4 groups: intact pressed, repaired pressed, intact milled, and repaired milled (n = 15/group). Repaired pressed and repaired milled were prepared with a standardized endodontic access and repaired using a porcelain repair system and composite resin. All crowns were cyclically loaded under simulated oral conditions and then loaded to failure in water, using a universal testing machine. Data were interpreted using ANOVA/Tukey post-hoc test (α = 0.05).

RESULTS

Mean loads to failure ranged from 758.9 to 931.4 N for the 4 groups, indicating that both fabrication techniques, pressed and milled, yielded restorations that could reasonably withstand maximum masticatory forces. The pressed groups (923.7 N) exhibited significantly higher fracture resistance than the milled groups (797.5 N), p = 0.0002. When milled and pressed groups were categorized into intact and repaired subgroups, no difference was found in fracture resistance between the subgroups. Differences were noted in the modes of fracture, where the milled groups (intact and repaired) exhibited higher frequency of catastrophic fractures than the pressed groups.

CONCLUSIONS

Endodontic access preparation does not appear to affect fracture resistance of an anterior lithium disilicate restoration, suggesting that replacement may not be necessary. Fabrication technique had a significant effect on fracture resistance and fracture mode of lithium disilicate restorations. The pressed fabrication technique resulted in significantly greater crown strength and fracture resistance than the milled technique.

Authors+Show Affiliations

Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX.US Air Force Dental Evaluation & Consultation Service - Dental Materials Research San Antonio, TX.Department of Restorative Dentistry, Oregon Health and Science University School of Dentistry, Portland, OR.Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX.Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX.Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX.Private Practice, Seattle, WA.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

29682833

Citation

Gerogianni, Petrina, et al. "Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation." Journal of Prosthodontics : Official Journal of the American College of Prosthodontists, vol. 28, no. 2, 2019, pp. 163-170.
Gerogianni P, Lien W, Bompolaki D, et al. Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation. J Prosthodont. 2019;28(2):163-170.
Gerogianni, P., Lien, W., Bompolaki, D., Verrett, R., Haney, S., Mattie, P., & Johnson, R. (2019). Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation. Journal of Prosthodontics : Official Journal of the American College of Prosthodontists, 28(2), 163-170. https://doi.org/10.1111/jopr.12798
Gerogianni P, et al. Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation. J Prosthodont. 2019;28(2):163-170. PubMed PMID: 29682833.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation. AU - Gerogianni,Petrina, AU - Lien,Wen, AU - Bompolaki,Despoina, AU - Verrett,Ronald, AU - Haney,Stephan, AU - Mattie,Patrick, AU - Johnson,Russell, Y1 - 2018/04/22/ PY - 2018/02/17/accepted PY - 2018/4/24/pubmed PY - 2019/7/30/medline PY - 2018/4/24/entrez KW - CAD/CAM KW - ceramic crown KW - e.max CAD KW - e.max Press KW - fracture strength KW - incisors KW - monolithic material KW - root canal treatment SP - 163 EP - 170 JF - Journal of prosthodontics : official journal of the American College of Prosthodontists JO - J Prosthodont VL - 28 IS - 2 N2 - PURPOSE: This in vitro study evaluated the fracture resistance and clinical prognosis of anterior lithium disilicate crowns (e.max Press and e.max CAD), following endodontic access and repair. The research design simulates intraoral loading conditions to produce clinically applicable results. MATERIALS AND METHODS: Monolithic anterior crowns, based on #8 anatomy, were fabricated from e.max Press ingots and e.max CAD blocks and adhesively bonded on identical dies milled out of a dentin analog material (NEMA G10). Specimens were divided into 4 groups: intact pressed, repaired pressed, intact milled, and repaired milled (n = 15/group). Repaired pressed and repaired milled were prepared with a standardized endodontic access and repaired using a porcelain repair system and composite resin. All crowns were cyclically loaded under simulated oral conditions and then loaded to failure in water, using a universal testing machine. Data were interpreted using ANOVA/Tukey post-hoc test (α = 0.05). RESULTS: Mean loads to failure ranged from 758.9 to 931.4 N for the 4 groups, indicating that both fabrication techniques, pressed and milled, yielded restorations that could reasonably withstand maximum masticatory forces. The pressed groups (923.7 N) exhibited significantly higher fracture resistance than the milled groups (797.5 N), p = 0.0002. When milled and pressed groups were categorized into intact and repaired subgroups, no difference was found in fracture resistance between the subgroups. Differences were noted in the modes of fracture, where the milled groups (intact and repaired) exhibited higher frequency of catastrophic fractures than the pressed groups. CONCLUSIONS: Endodontic access preparation does not appear to affect fracture resistance of an anterior lithium disilicate restoration, suggesting that replacement may not be necessary. Fabrication technique had a significant effect on fracture resistance and fracture mode of lithium disilicate restorations. The pressed fabrication technique resulted in significantly greater crown strength and fracture resistance than the milled technique. SN - 1532-849X UR - https://www.unboundmedicine.com/medline/citation/29682833/Fracture_Resistance_of_Pressed_and_Milled_Lithium_Disilicate_Anterior_Complete_Coverage_Restorations_Following_Endodontic_Access_Preparation_ DB - PRIME DP - Unbound Medicine ER -