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Influence of preparation, fitting, and cementation on the vitro performance and fracture resistance of CAD/CAM crowns.
J Dent. 2017 Oct; 65:70-75.JD

Abstract

OBJECTIVES

To investigate debonding and stability of CAD/CAM composite crowns as a function of (a) preparation design, (b) fitting parameters of the milling process, and (c) type of cementation.

METHODS

Extracted human molars were prepared providing either retentive design (R) or no retention (NR). After digitalization, full-contour crowns were milled using either optimal (OF) or reduced (RF) fitting parameters. A total of 112 crowns were milled from the composite materials Lava Ultimate (L) and Grandio Blocs (G) and a ceramic reference. The crowns were either cemented with self-adhesive cement (SE) or were adhesively bonded (A). After water storage, thermal cycling and mechanical loading was performed. Restorations which failed during storage or TCML were analyzed using scanning electron microscopy and surviving restorations were loaded to fracture.

RESULTS

L crowns survived only with R/OF/A conditions. No debondings were observed for G crowns with OF/A conditions as well as R/OF/SE conditions. Surviving L crowns showed mean fracture values of 1227N (NR/RF/A) and 1534N (R/OF/A), and for surviving G crowns mean fracture values of 2021N (R/OF), 1872N (R/RF), 2242N (NR/OF), and 2070N (NR/RF) were identified.

CONCLUSIONS

Retentive preparation design and/or optimal fitting reduced the number of debondings. For composite restorations, adhesive cementation should be preferred.

CLINICAL SIGNIFICANCE

Preparation design, fitting parameters as well as the type of cementation impact the performance of composite crowns. Retentive preparation design and/or good fitting are mandatory to avoid debonding of composite restorations; adhesive cementation should be preferred in any case.

Authors+Show Affiliations

Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany.Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany.Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany.Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany. Electronic address: sebastian.hahnel@ukr.de.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

28734997

Citation

Rosentritt, Martin, et al. "Influence of Preparation, Fitting, and Cementation On the Vitro Performance and Fracture Resistance of CAD/CAM Crowns." Journal of Dentistry, vol. 65, 2017, pp. 70-75.
Rosentritt M, Preis V, Behr M, et al. Influence of preparation, fitting, and cementation on the vitro performance and fracture resistance of CAD/CAM crowns. J Dent. 2017;65:70-75.
Rosentritt, M., Preis, V., Behr, M., & Hahnel, S. (2017). Influence of preparation, fitting, and cementation on the vitro performance and fracture resistance of CAD/CAM crowns. Journal of Dentistry, 65, 70-75. https://doi.org/10.1016/j.jdent.2017.07.006
Rosentritt M, et al. Influence of Preparation, Fitting, and Cementation On the Vitro Performance and Fracture Resistance of CAD/CAM Crowns. J Dent. 2017;65:70-75. PubMed PMID: 28734997.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Influence of preparation, fitting, and cementation on the vitro performance and fracture resistance of CAD/CAM crowns. AU - Rosentritt,Martin, AU - Preis,Verena, AU - Behr,Michael, AU - Hahnel,Sebastian, Y1 - 2017/07/19/ PY - 2017/05/09/received PY - 2017/06/29/revised PY - 2017/07/08/accepted PY - 2017/7/25/pubmed PY - 2018/7/14/medline PY - 2017/7/24/entrez KW - CAD/CAM KW - Chewing simulation KW - Composite KW - Crown KW - Debonding KW - TCML SP - 70 EP - 75 JF - Journal of dentistry JO - J Dent VL - 65 N2 - OBJECTIVES: To investigate debonding and stability of CAD/CAM composite crowns as a function of (a) preparation design, (b) fitting parameters of the milling process, and (c) type of cementation. METHODS: Extracted human molars were prepared providing either retentive design (R) or no retention (NR). After digitalization, full-contour crowns were milled using either optimal (OF) or reduced (RF) fitting parameters. A total of 112 crowns were milled from the composite materials Lava Ultimate (L) and Grandio Blocs (G) and a ceramic reference. The crowns were either cemented with self-adhesive cement (SE) or were adhesively bonded (A). After water storage, thermal cycling and mechanical loading was performed. Restorations which failed during storage or TCML were analyzed using scanning electron microscopy and surviving restorations were loaded to fracture. RESULTS: L crowns survived only with R/OF/A conditions. No debondings were observed for G crowns with OF/A conditions as well as R/OF/SE conditions. Surviving L crowns showed mean fracture values of 1227N (NR/RF/A) and 1534N (R/OF/A), and for surviving G crowns mean fracture values of 2021N (R/OF), 1872N (R/RF), 2242N (NR/OF), and 2070N (NR/RF) were identified. CONCLUSIONS: Retentive preparation design and/or optimal fitting reduced the number of debondings. For composite restorations, adhesive cementation should be preferred. CLINICAL SIGNIFICANCE: Preparation design, fitting parameters as well as the type of cementation impact the performance of composite crowns. Retentive preparation design and/or good fitting are mandatory to avoid debonding of composite restorations; adhesive cementation should be preferred in any case. SN - 1879-176X UR - https://www.unboundmedicine.com/medline/citation/28734997/Influence_of_preparation_fitting_and_cementation_on_the_vitro_performance_and_fracture_resistance_of_CAD/CAM_crowns_ DB - PRIME DP - Unbound Medicine ER -