Marginal and Internal Fit of Cobalt-Chromium Fixed Dental Prostheses Generated from Digital and Conventional Impressions

Svanborg, Per; Skjerven, Henrik; Carlsson, Pablo; Eliasson, Alf; Karlsson, Stig; Örtorp, Anders

doi:10.1155/2014/534382

Cited by 58 publications

(48 citation statements)

References 23 publications

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“…Regarding the marginal fit, the results of the current study agree with the study of Svanborg et al, who found no significant difference for the absolute marginal gap of 3‐unit bridges fabricated using direct and indirect digitalisation techniques and pre‐defined marginal cement gap of 30 μm . Nevertheless, in the current study, the mean difference between the measured absolute marginal discrepancy and the pre‐defined marginal cement gap is higher than in the study of Svanborg et al . While the literature suggests the clinically acceptable marginal gap to vary from 50 to 200 μm, 120 μm is often referred to as the maximum clinically tolerable marginal cement gap .…”

Section: Discussionsupporting

confidence: 86%

“…Internal and marginal fit are two factors thought to be of high clinical importance for the long‐term survival and success of fixed dental prostheses (FDP) . Two different methods have been used for assessing the fit of reconstructions in vivo: (a) the replica method, which uses impression material to replicate the cement film, and (b) the triple scan technique, which uses digital technology to assess the cement gap by superimposing the preparation with both the internal and external surfaces of the reconstruction . However, these methods are mainly used in laboratory research as they are impractical in the clinic and very time consuming.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of marginal and internal fit of acrylic bridges using optical coherence tomography

Al-Imam

Michou

Benetti

et al. 2018

J of Oral Rehabilitation

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Summary Background The potential of non‐invasive optical coherence tomography (OCT) as a tool for assessment of fit of indirect reconstructions is not fully explored. Objectives The objectives were to investigate the feasibility and validity of OCT, and to measure the internal and marginal fit of acrylic bridges fabricated using direct and indirect digitalisation. Methods The accuracy of the employed swept source OCT (wavelength: 1310 nm) was assessed by comparing with an object with known dimensions. Validity was assessed by measuring an OCT measurements on replica, mimicking the cement film thickness, with stereomicroscopic measurements. The reconstructions were placed on the abutments without cementation. The internal and marginal fit of acrylic bridges from direct and indirect digitalisation techniques were then assessed by obtaining 5 OCT B‐scans per abutment tooth at pre‐defined positions located 250 μm apart. The marginal and internal cement gaps were measured using image‐processing software (ImageJ). Mean and standard deviation were calculated for both groups and t test assuming unequal variances was carried out. The level of significance was defined at 0.05. Results A strong linear correlation (r = 0.865) between OCT and stereomicroscopy was found. T test showed significantly (P < 0.01) better internal fit of bridges made from indirect digitalisation, but no difference in marginal fit. Conclusion OCT is a feasible and valid tool for investigating internal and marginal fit of acrylic dental reconstructions. Better internal fit was observed in bridges fabricated using the direct digitalisation technique. No difference in marginal fit was found between the two fabrication methods.

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Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Evaluation of marginal and internal fit of acrylic bridges using optical coherence tomography

Al-Imam

Michou

Benetti

et al. 2018

J of Oral Rehabilitation

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“…In that case, no significant differences were seen between the investigated systems (iTero mean, 142 μm; Straumann CARES mean, 147 μm) [23]. Keul et al [12] investigated the marginal opening of 4-unit CoCr and zirconia frameworks also using the iTero and Straumann CARES system: CoCr frameworks from digital impressions showed significantly lower mean values for marginal fit than ones from conventional impressions (digital impression mean, 56.90 μm; conventional impression mean, 90.64 μm; p < 0.001).…”

Section: Discussionmentioning

confidence: 74%

Fit of 4-unit FDPs from CoCr and zirconia after conventional and digital impressions

et al. 2015

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“…A recent study reported that most of the newer intraoral scanners showed better precision than the older ones. 15 Optical impression systems will continue to improve, resulting in a more reliable complete arch impression for different treatment indications.…”

Section: Discussionmentioning

confidence: 99%

Accuracy evaluation of intraoral optical impressions: A clinical study using a reference appliance

Atieh

Ritter

et al. 2017

The Journal of Prosthetic Dentistry

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Statement of problem Trueness and precision are used to evaluate the accuracy of intraoral optical impressions. Although the in vivo precision of intraoral optical impressions has been reported, in vivo trueness has not been evaluated because of limitations in the available protocols. Purpose The purpose of this clinical study was to compare the accuracy (trueness and precision) of optical and conventional impressions by using a novel study design. Material and methods Five study participants consented and were enrolled. For each participant, optical and conventional (vinylsiloxanether) impressions of a custom-made intraoral Co-Cr alloy reference appliance fitted to the mandibular arch were obtained by 1 operator. Three-dimensional (3D) digital models were created for stone casts obtained from the conventional impression group and for the reference appliances by using a validated high-accuracy reference scanner. For the optical impression group, 3D digital models were obtained directly from the intraoral scans. The total mean trueness of each impression system was calculated by averaging the mean absolute deviations of the impression replicates from their 3D reference model for each participant, followed by averaging the obtained values across all participants. The total mean precision for each impression system was calculated by averaging the mean absolute deviations between all the impression replicas for each participant (10 pairs), followed by averaging the obtained values across all participants. Data were analyzed using repeated measures ANOVA (α=.05), first to assess whether a systematic difference in trueness or precision of replicate impressions could be found among participants and second to assess whether the mean trueness and precision values differed between the 2 impression systems. Results Statistically significant differences were found between the 2 impression systems for both mean trueness (P=.010) and mean precision (P=.007). Conventional impressions had higher accuracy with a mean trueness of 17.0 ±6.6 µm and mean precision of 16.9 ±5.8 µm than optical impressions with a mean trueness of 46.2 ±11.4 µm and mean precision of 61.1 ±4.9 µm. Conclusions Complete arch (first molar-to-first molar) optical impressions were less accurate than conventional impressions but may be adequate for quadrant impressions.

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Marginal and Internal Fit of Cobalt-Chromium Fixed Dental Prostheses Generated from Digital and Conventional Impressions

Cited by 58 publications

References 23 publications

Evaluation of marginal and internal fit of acrylic bridges using optical coherence tomography

Evaluation of marginal and internal fit of acrylic bridges using optical coherence tomography

Fit of 4-unit FDPs from CoCr and zirconia after conventional and digital impressions

Accuracy evaluation of intraoral optical impressions: A clinical study using a reference appliance

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