Evaluation of marginal and internal fit of ceramic and metallic crown copings using x-ray microtomography (micro-CT) technology

Pimenta, Manuel Antonio; Frasca, Luís Carlos da Fontoura; Lopes, Ricardo Tadeu; Rivaldo, Elken Gomes

doi:10.1016/j.prosdent.2015.02.002

Cited by 69 publications

(65 citation statements)

References 25 publications

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“…These thick, regular areas may be less vulnerable to microfracture, thus supporting the hypothesis that thin regions are more susceptible to damage during the milling process. Although ZLS presented a greater difference in marginal misfit compared with LDS, this degree of misfit is within the clinically acceptable limits of 120 µm according to most studies 1,3,11-16,21,28 . In addition, the greatest discrepancy did not seem to compromise the mechanical behavior of the material a lot, since moderate negative correlations were observed between fracture load and MG and AMD.…”

Section: Discussionmentioning

confidence: 57%

“…The use of a non-destructive measurement technique, such as μCT, has the great advantage of enabling evaluation of not only the marginal area, but also the intaglio surface, while preserving samples for further analyses (e.g., fracture load) with no effect on the results. It may, however, be considered a costly and slow technique 13,16 .…”

Section: Discussionmentioning

confidence: 99%

“…Gaps >122 µm in axial walls may reduce the fracture strength of a crown 16,17,25,27 . In the present study, AG values for both materials were <122 µm, and AG was not correlated with fracture load.…”

Section: Discussionmentioning

confidence: 99%

“…In the present study, AG values for both materials were <122 µm, and AG was not correlated with fracture load. Another area of internal analysis is the occlusal wall, where misfit exceeding 450 µm may compromise cementation due to polymerization shrinkage 16 . In this study, OG values were <450 µm, within the clinically acceptable range for general internal misfit, and did not differ between materials 12 .…”

Section: Discussionmentioning

confidence: 99%

“…Although the use of this technique has widely spread, misfit values can differ among restorations made with the same system and impression technique due to material composition 1,12,14,16 . Material hardness can interfere with fit results, as harder materials can make the milling process difficult, leaving crowns susceptible to small fractures in very thin regions, such as cervical areas 14,17,25,27 ; thick and irregular cement lines can also compromise fit 11,28 .…”

Section: Introductionmentioning

confidence: 99%

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Misfit and fracture load of implant-supported monolithic crowns in zirconia-reinforced lithium silicate

et al. 2017

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Zirconia-reinforced lithium silicate (ZLS) is a ceramic that promises to have better mechanical properties than other materials with the same indications as well as improved adaptation and fracture strength. Objective In this study, marginal and internal misfit and fracture load with and without thermal-mechanical aging (TMA) of monolithic ZLS and lithium disilicate (LDS) crowns were evaluated.Material and methods Crowns were milled using a computer-aided design/computer-aided manufacturing system. Marginal gaps (MGs), absolute marginal discrepancy (AMD), axial gaps, and occlusal gaps were measured by X-ray microtomography (n=8). For fracture load testing, crowns were cemented in a universal abutment, and divided into four groups: ZLS without TMA, ZLS with TMA, LDS without TMA, and LDS with TMA (n=10). TMA groups were subjected to 10,000 thermal cycles (5-55°C) and 1,000,000 mechanical cycles (200 N, 3.8 Hz). All groups were subjected to compressive strength testing in a universal testing machine at a crosshead speed of 1 mm/min until failure. Student’s t-test was used to examine misfit, two-way analysis of variance was used to analyze fracture load, and Pearson’s correlation coefficients for misfit and fracture load were calculated (α=0.05). The materials were analyzed according to Weibull distribution, with 95% confidence intervals.Results Average MG (p<0.001) and AMD (p=0.003) values were greater in ZLS than in LDS crowns. TMA did not affect the fracture load of either material. However, fracture loads of ZLS crowns were lower than those of LDS crowns (p<0.001). Fracture load was moderately correlated with MG (r=-0.553) and AMD (r=-0.497). ZLS with TMA was least reliable, according to Weibull probability.Conclusion Within the limitations of this study, ZLS crowns had lower fracture load values and greater marginal misfit than did LDS crowns, although these values were within acceptable limits.

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Section: Discussionmentioning

confidence: 57%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Misfit and fracture load of implant-supported monolithic crowns in zirconia-reinforced lithium silicate

et al. 2017

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Fit of tooth‐supported zirconia single crowns—A systematic review of the literature

Ahmed

Shariati

Gazzaz

et al. 2020

Clinical & Exp Dental Res

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Purpose The purpose of this study is to systematically map all the factors that influence the fit and adaptation of zirconia crowns and/or copings. Materials and methods The investigational strategy involved carrying out an electronic search between December 1, 2009 and September 1, 2019 through the Embase and Medline databases using Boolean operators to locate appropriate articles. Results A total of 637 articles were discovered after the removal of duplicates, and 46 of these were selected for evaluation. Further, a quality assessment was performed using GRADE evaluation criteria. Conclusions Shoulder finish line preparations had slightly better marginal fit compared to chamfer finish lines. Crowns obtained from digital impressions had comparable to superior marginal adaptation compared to conventional impressions. Increasing cement space showed to improve zirconia crown adaptation. Cementation and veneering zirconia frameworks found to increase the marginal and internal gaps. Limited information is available on the effect of the alteration of sintering time/Temperature and/or sintering techniques on the adaptation of zirconia crowns. Most of the selected studies had a moderate quality assessment evaluation. Future studies could investigate the chair‐side, ultra‐fast sintering effect on the marginal gap of zirconia crowns.

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Chairside measurement of the marginal and internal fit of crowns: a new intraoral scan–based approach

et al. 2019

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Evaluation of marginal and internal fit of ceramic and metallic crown copings using x-ray microtomography (micro-CT) technology

Cited by 69 publications

References 25 publications

Misfit and fracture load of implant-supported monolithic crowns in zirconia-reinforced lithium silicate

Misfit and fracture load of implant-supported monolithic crowns in zirconia-reinforced lithium silicate

Fit of tooth‐supported zirconia single crowns—A systematic review of the literature

Chairside measurement of the marginal and internal fit of crowns: a new intraoral scan–based approach

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