Influence of Preparation Design, Marginal Gingiva Location, and Tooth Morphology on the Accuracy of Digital Impressions for Full-Crown Restorations: An In Vitro Investigation

(1) Background: Intraoral optical scanning (IOS) has gained increased importance in prosthodontics. The aim of this in vitro study was to analyze the IOS accuracy for treatment with full crowns, considering possible influencing factors. (2) Methods: Two tooth morphologies, each with four different finish-line designs for tooth preparation and epi- or supragingival locations, were digitally designed, 3D-printed, and post-processed for 16 sample abutment teeth. Specimens were digitized using a laboratory scanner to generate reference STLs (Standard Tessellation Language), and were secondary-scanned with two IOS systems five times each in a complete-arch model scenario (Trios 3 Pod, Primescan AC). For accuracy, a best-fit algorithm (Final Surface) was used to analyze deviations of the abutment teeth based on 160 IOS-STLs compared to the reference STLs (16 preparations × 2 IOS-systems × 5 scans per tooth). (3) Results: Analysis revealed homogenous findings with high accuracy for intra- and inter-group comparisons for both IOS systems, with mean values of 80% quantiles from 20 ± 2 μm to 50 ± 5 μm. Supragingival finishing lines demonstrated significantly higher accuracy than epigingival margins when comparing each preparation (p < 0.05), whereas tangential preparations exhibited similar results independent of the gingival location. Morphology of anterior versus posterior teeth showed slightly better results in favor of molars in combination with shoulder preparations only. (4) Conclusion: The clinical challenge for the treatment with full crowns following digital impressions is the location of the prospective restoration margin related to the distance to the gingiva. However, the overall accuracy for all abutment teeth was very high; thus, the factors tested are unlikely to have a strong clinical impact.

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Complete-Arch Accuracy of Four Intraoral Scanners: An In Vitro Study

Healthcare ◽

10.3390/healthcare9030246 ◽

2021 ◽

Vol 9 (3) ◽

pp. 246

Author(s):

Giordano Celeghin ◽

Giulio Franceschetti ◽

Nicola Mobilio ◽

Alberto Fasiol ◽

Santo Catapano ◽

...

Keyword(s):

Reference Model ◽

In Vitro Study ◽

Reference Points ◽

Dental Arch ◽

Arch Model ◽

Linear Measurements ◽

Stl File ◽

Digital Reference ◽

Digital Impressions

The purpose of this study is to define the accuracy of four intraoral scanners (IOS) through the analysis of digital impressions of a complete dental arch model. Eight metal inserts were placed on the model as reference points and then it was scanned with a laboratory scanner in order to obtain the reference model. Subsequently, the reference model was scanned with four IOS (Carestream 3600, CEREC Omnicam, True Definition Scanner, Trios 3Shape). Linear measurements were traced on an STL file between the chosen reference points and divided into four categories: three-element mesiodistal, five-element mesiodistal, diagonal, and contralateral measurements. The digital reference values for the measurements were then compared with the values obtained from the scans to analyze the accuracy of the IOS using ANOVA. There were no statistically significant differences between the measurements of the digital scans obtained with the four IOS systems for any of the measurement groups tested.

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Impact of Aging on the Accuracy of 3D-Printed Dental Models: An In Vitro Investigation

Journal of Clinical Medicine ◽

10.3390/jcm9051436 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1436 ◽

Cited By ~ 2

Author(s):

Tim Joda ◽

Lea Matthisson ◽

Nicola U. Zitzmann

Keyword(s):

Reference Model ◽

In Vitro Study ◽

Deviation Analysis ◽

Fixed Dental Prosthesis ◽

In Vitro Investigation ◽

Dental Models ◽

3D Printed ◽

Level Of Significance ◽

The Impact

The aim of this in vitro study was to analyze the impact of model aging on the accuracy of 3D-printed dental models. A maxillary full-arch reference model with prepared teeth for a three-unit fixed dental prosthesis was scanned ten times with an intraoral scanner (3Shape TRIOS Pod) and ten models were 3D printed (Straumann P-Series). All models were stored under constant conditions and digitized with a desktop scanner after 1 day; 1 week; and 2, 3, and 4 weeks. For accuracy, a best-fit algorithm was used to analyze the deviations of the abutment teeth (GFaI e.V Final Surface®). Wilcoxon Rank Sum Tests were used for comparisons with the level of significance set at α = 0.05. Deviation analysis of the tested models showed homogenous intragroup distance calculations at each timepoint. The most accurate result was for 1 day of aging (3.3 ± 1.3 µm). A continuous decrease in accuracy was observed with each aging stage from day 1 to week 4. A time-dependent difference was statistically significant after 3 weeks (p = 0.0008) and 4 weeks (p < 0.0001). Based on these findings, dental models should not be used longer than 3 to 4 weeks after 3D printing for the fabrication of definitive prosthetic reconstructions.

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Evaluation Of The Accuracy Of Digital Impressions Obtained From Intraoral And Extraoral Dental Scanners With Different CAD/CAM Scanning Technologies: An In Vitro Study

Journal of Prosthodontics ◽

10.1111/jopr.13400 ◽

2021 ◽

Author(s):

Passent Ellakany ◽

Maha El Tantawi ◽

Amr A Mahrous ◽

Fahad Al‐Harbi

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

Digital Impressions ◽

Cad Cam

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Accuracy of Guided Implant Surgery in the Edentulous Jaw Using Desktop 3D-Printed Mucosal Supported Guides

Journal of Clinical Medicine ◽

10.3390/jcm10030391 ◽

2021 ◽

Vol 10 (3) ◽

pp. 391

Author(s):

Rani D’haese ◽

Tom Vrombaut ◽

Geert Hommez ◽

Hugo De Bruyn ◽

Stefan Vandeweghe

Keyword(s):

In Vitro Study ◽

Angular Deviation ◽

Implant Surgery ◽

Implant Position ◽

Surgical Guides ◽

Negative Effect ◽

Bone Level ◽

3D Printed ◽

Implant Alignment

Purpose: The aim of this in vitro study is to evaluate the accuracy of implant position using mucosal supported surgical guides, produced by a desktop 3D printer. Methods: Ninety implants (Bone Level Roxolid, 4.1 mm × 10 mm, Straumann, Villerat, Switzerland) were placed in fifteen mandibular casts (Bonemodels, Castellón de la Plana, Spain). A mucosa-supported guide was designed and printed for each of the fifteen casts. After placement of the implants, the location was assessed by scanning the cast and scan bodies with an intra-oral scanner (Primescan®, Dentsply Sirona, York, PA, USA). Two comparisons were performed: one with the mucosa as a reference, and one where only the implants were aligned. Angular, coronal and apical deviations were measured. Results: The mean implant angular deviation for tissue and implant alignment were 3.25° (SD 1.69°) and 2.39° (SD 1.42°) respectively, the coronal deviation 0.82 mm (SD 0.43 mm) and 0.45 mm (SD 0.31 mm) and the apical deviation 0.99 mm (SD 0.45 mm) and 0.71 mm (SD 0.43 mm). All three variables were significantly different between the tissue and implant alignment (p < 0.001). Conclusion: Based on the results of this study, we conclude that guided implant surgery using desktop 3D printed mucosa-supported guides has a clinically acceptable level of accuracy. The resilience of the mucosa has a negative effect on the guide stability and increases the deviation in implant position.

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Accuracy of implant casts generated with conventional and digital impressions - an in vitro study

Clinical Oral Implants Research ◽

10.1111/clr.355_13042 ◽

2017 ◽

Vol 28 ◽

pp. 356-356

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

Digital Impressions

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Biochemical Interactions Between Polymeric Resins Used for Occlusal Splints and Saliva A pilot study comparing the CAD/CAM technology and the conventional approach

Materiale Plastice ◽

10.37358/mp.19.2.5196 ◽

2019 ◽

Vol 56 (2) ◽

pp. 409-412 ◽

Cited By ~ 1

Author(s):

Marina Melescanu-Imre ◽

Mihaela Pantea ◽

Alexandra Totan ◽

Ana Maria Cristina Tancu ◽

Maria Greabu ◽

...

Keyword(s):

Oxidative Stress ◽

Uric Acid ◽

In Vitro Study ◽

Acrylic Resin ◽

Occlusal Splints ◽

Oral Environment ◽

Cad Cam ◽

3D Printed ◽

Polymeric Resins

The CAD/CAM technology has been successfully integrated in clinical and laboratory aspects of dental medicine. The present in vitro study focuses on the biochemical interactions between saliva and three types of polymeric resins for occlusal splints. Dental material samples were produced from 3D printed, milled and self-cured resins and were incubated with saliva samples from 20 healthy volunteers. The results showed that the 3D printed and milled polymeric resins did not produce any significant changes in oxidative stress parameters (uric acid, TAC, GGT, OXSR-1) or inflammatory markers (IL-2, IL-6). On the other hand, the self-cured acrylic resin produced a significant decrease in the salivary TAC and uric acid, the most important antioxidants in saliva, affecting the capacity of saliva to protect the oral environment against oxidative stress.

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Evaluation of Sealing Materials Adhesion to Enamel An in vitro study

Materiale Plastice ◽

10.37358/mp.17.1.4801 ◽

2017 ◽

Vol 54 (1) ◽

pp. 129-132

Author(s):

Andreea Simona Pop ◽

Radu Septimiu Campian ◽

Mariana Pacurar ◽

Elina Teodorescu ◽

Olimpia Bunta ◽

...

Keyword(s):

In Vitro Study ◽

Specific Method ◽

High Concentration ◽

Posterior Teeth ◽

Inorganic Particles ◽

Material Homogeneity ◽

Materials Used ◽

High Degree ◽

Pits And Fissures

Sealing the pits and fissures of posterior teeth represents a local and specific method of caries prevention. The aim of this study was to evaluate the adhesion of two materials used in sealing pits and fissures: Pitt and Fisure and Fissurit FX (Voco), with the help of the scanning electronic microscope (SEM). The results of the study revealed a much higher quality of the Fissurit FX (Voco) product both in terms of adhesion to the enamel and material homogeneity. The Pitt and Fisure product showed a high degree of detachment from the enamel, marginal infiltration, large particles and a high concentration of inorganic particles.

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An In-Vitro Investigation into the Cement Pressurization Achieved During Insertion of Four Different Femoral Stems

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/095441105x34400 ◽

2005 ◽

Vol 219 (6) ◽

pp. 407-413 ◽

Cited By ~ 5

Author(s):

C Gozzard ◽

S Gheduzzi ◽

A W Miles ◽

I D Learmonth

Keyword(s):

Revision Surgery ◽

In Vitro Study ◽

The Other ◽

Stem Volume ◽

Factors Associated ◽

In Vitro Investigation ◽

Femoral Stems ◽

Stem Shape ◽

Distal Stem

Adequate cement pressurization during stem insertion improves the interdigitation of cement into bone. This increases the strength of the cement-bone interface, thus contributing to the reduction of the incidence of aseptic loosening, the commonest cause of revision surgery. This in-vitro study compared the cement pressurization achieved during insertion of four different stems of equivalent sizes: the Elite Plus (DePuy, UK), C-Stem (DePuy, UK), Exeter (Stryker, USA), and CPS-Plus (Plus Orthopedics, Switzerland). The maximum pressures attained at the time of stem insertion were recorded at proximal, mid and distal stem levels. The Elite Plus generated significantly higher distal pressures than the other stems. The CPS-Plus generated significantly greater proximal cement pressures than the Elite Plus, C-Stem, and Exeter prostheses. The triple taper of the C-Stem increased the cement pressurization medial to the stem. The stem shape and the presence or absence of a proximal stem centralizer affect cement pressurization. The presence of a proximal stem centralizer, a large stem volume, and a lateral-medial taper are all factors associated with increased cement pressurization during stem insertion.

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