Three-Dimensional Analysis of Dental Models Produced from Intraoral Scanning versus the Conventional Alginate Impression Method

ABSTRACTAims and Objectives:The purpose of this study is to compare digital and conventional impression methods by preclinical students in terms of time and ease and to evaluate their preferences and future expectations.Materials and Methods:Twenty volunteered, 2nd year preclinical students (11 females and 9 males) participated in this study. Students took digital and conventional impressions of the left lower first molar which was made full ceramic crown preparation and opposite full arch from a typodont model (Frasaco, Frasaco GmbH, Tettnang, Germany). They used intraoral scanner (CEREC Omnicam, Sirona Dental GmbH, Bensheim, Germany) for digital impression and also used additional type (Express XT Penta H, 3M ESPE, Seefeld, Germany) and condensation type (Zetaplus, Zhermack SpA, Badia Polesine, Italy) silicones for conventional impression. Their taking impression time was measured. Before taking impression and after taking impression, two kinds of questionnaires were conducted to students about their preference, ease of impression methods, and their future expectations. Statistical analysis was performed by IBM SPSS 23 and Excel 2010 version. Differences between conventional and digital impression in terms of time were analyzed by student’s-t paired test and effect of gender was analyzed by students’s-t independent test.Results:There were statistically significant differences between digital and conventional impression methods in terms of taking impression and total impression time (P < 0.001). But there wasn’t any statistically significant difference between two methods in terms of preparation time. About 85% of students preferred the digital impression method and also 85% of students found that the digital impression method was easy. 95% of students expected to find intraoral scanner in the clinic where working first time.Conclusions:As a result of this study, it has been seen that the students preferred the digital impression method to the conventional impression method and found that the digital impression method was easier.

Conventional impression techniques for complete denture fabrication, although traditional, often pose challenges regarding accuracy and patient comfort. Intraoral scanning offers a digital alternative that promises enhanced precision and patient satisfaction. This study aimed to compare the efficacy, accuracy, and patient outcomes between conventional impression methods and intraoral scanning for the fabrication of complete dentures. A total of 100 edentulous patients were randomly assigned to two groups: one group receiving conventional impressions (n = 50) and the other undergoing intraoral scanning (n = 50). The primary outcome measures included impression accuracy (assessed by comparing final denture fit), time efficiency (total clinical time from impression to denture delivery), and patient satisfaction (evaluated through a standardized questionnaire). Statistical analysis was performed using the Chi-squared test for categorical data and t-tests for continuous variables. The intraoral scanning group demonstrated significantly higher accuracy in denture fit, with 92% of patients reporting excellent fit compared to 74% in the conventional group (P < 0.05). Time efficiency was also enhanced in the intraoral group, with a reduction in total clinical time of 25%. Patient satisfaction scores were notably higher in the intraoral scanning group (8.6 ± 0.5 on a 10-point scale) compared to the conventional group (6.9 ± 1.0). No significant complications were reported in either group. Intraoral scanning proves to be a superior technique for the fabrication of complete dentures compared to conventional methods, offering better denture fit, reduced clinical time, and improved patient satisfaction. These findings suggest that intraoral scanning could replace traditional impression methods in clinical practice for edentulous patients.

Relevance. Early extraction of primary teeth in children aged 4–7 years remains relatively common, with reported rates reaching 43%. Such cases often result in dentoalveolar anomalies and arch deformation. When selecting an impression technique for the fabrication of space maintainers, the priority should be on procedural safety and patient comfort. Digital intraoral scanning offers a modern alternative to traditional impression methods. Materials and methods. A comparative analysis of different impression-taking methods was performed in 90 children aged 4–7 years with early extraction of primary molars. The following were evaluated: fabrication time, risk of complications, and the frequency of adverse sensations during alginate impressions (Hydrocolor 5, Zhermack, Italy), condensation silicone impressions (Zetaplus, Zhermack, Italy), and digital scanning of the dental arches (Runyes IOS-11, China). Statistical analysis was conducted. Results. Digital intraoral scanning shortened fabrication time by 11.5% relative to alginate impressions and by 59.6% relative to condensation silicone. The incidence of gag reflex during scanning was 4 times lower than with alginate impressions and 5.67 times lower than with condensation silicone. Reports of discomfort were 8.67 times less frequent than with alginate impressions and 8 times less frequent than with condensation silicone. All differences were statistically significant for both time efficiency and patient comfort. Conclusion. A comparative analysis of impression techniques for the fabrication of band-and-loop space maintainers after premature loss of primary molars demonstrated the higher efficiency and better patient tolerance of digital intraoral scanning compared with conventional impression methods.

The comfortness and effectiveness of digital and conventional impression methods in children have not yet been compared. To assess the digital and conventional impression methods in children in terms of comfort, preference, and the time required to take impressions. Digital impressions were taken by using an intraoral scanner, and conventional impressions were taken by using alginate from 28 patients by the same operator. In each impression-taking-process, comfort was assessed by both the children and the clinician, and the chairside times were written. Student's t tests and Mann-Whitney U tests were used for statistical analyses, and P<.05 was considered to be significant. The digital impression was considered to be more comfortable in the assessments by both the children and the clinician (P<.001). The total time the digital impression took was 465.89±76.71second(s) while that of the conventional impression was 450.25±64.08s when the chairside times of the two impression methods were compared. There was no statistically significant difference (P=.41). The digital impression method compared with the conventional impression method was found to be both more comfortable and preferable by the children, but there was no difference in terms of the time required to take impressions.

Three-dimensional differences between intraoral scans and conventional impressions of edentulous jaws: A clinical study

The accuracy of digital scanners versus conventional impression in patients with cleft lip and palate: A cross-sectional study

This study aimed to quantitatively evaluate the effect of implant-supported provisional restorations (ISPRs) on the accuracy of the intraoral scanned peri-implant soft-tissue profile in the esthetic area. Sixteen patients with a single ISPR in the maxillary central incisor's region were recruited for this study. Three impression methods were sequentially used in each patient: (1) an intraoral scanning (IOS) with the ISPR, (2) a conventional impression using the ISPR as impression coping, and (3) a routine IOS without the ISPR. The stereolithography files of the three impression methods obtained from the same patient were superimposed, and the conventional impression method was used as the reference model. Two-dimensional (2D) and three-dimensional (3D) analyses were performed to measure the peri-implant soft-tissue deviation between the reference models and IOS from the groups with or without the ISPR, respectively. Data were presented as the means±standard deviations. Two-way analyses of variance with post hoc Sidak's multiple comparisons and paired t-tests were performed for 2D and 3D analyses, respectively. The significance level was set at p<.05. The peri-implant mucosa without the ISPR immediately collapsed (<20s), particularly on the palatine side of the labial mucosa and labial side of the palatine mucosa. Consequently, the IOS without the ISPR led to 414.7±116.0μm of overall dimensional deformation in the cuff-like submucosal region, which was significantly larger (p<.0001) than that in the IOS with the ISPR (230.6±85.5μm). Implant-supported provisional restorations are important for accurate replication of the intraorally scanned peri-implant soft-tissue profile.

Evaluating the marginal fit of zirconia copings with digital impressions with an intraoral digital scanner

ObjectivesTo investigate the congruence between the meshes of a combined healing abutment-scan body (CHA-SB) system acquired with four different intraoral scanners and the corresponding library file. Material and methodsA CHA-SB was fixed to an implant at the right first molar position in a dentate mandibular model and digitized by using 4 different intraoral scanners (IOSs) [TRIOS 3 (T3), Omnicam (OC), Primescan (PS), and Virtuo Vivo (VV)] (n = 8) and an industrial grade optical scanner (ATOS Core 80) (n = 1) to generate standard tessellation language (STL) files of the test scans (CHA-SB-STLs) and the master reference model scan (MRM-STL). A reverse engineering software (Studio Geomagic X) was used to superimpose the proprietary library file of the CHA-SB over the generated STL files. Root mean square (RMS) values representing the deviations between the library file and the superimposed STL files were statistically analyzed by using 1-way ANOVA (α=0.05). Qualitative analysis of the deviations was performed by visual inspection. ResultsDifferences between the congruence of the library file and the CHA-SB scans among different IOSs were nonsignificant (F = 1.619, df= 3, P = .207). The single best result was 29 ± 28.9 µm for OC, 30.8 ± 29.6 µm for VV, 35.6 ± 35.5 µm for T3, and 39.5 ± 39.2 µm for PS, which were all above the deviation value of the scan performed by using the industrial-grade scanner (23.2 ± 23.2 µm). ConclusionThe dimensional congruence between the library file and the STL file of the CHA-SB system scans was similar when intraoral scanners with different acquisition technologies were used to scan a model with an implant. Clinical significanceScans of the tested intraoral scanners may result in crowns with similar positional accuracy, given the similarities in congruence of their scans with the library file.

Randomized controlled clinical trial of digital and conventional workflows for the fabrication of zirconia-ceramic fixed partial dentures. Part I: Time efficiency of complete-arch digital scans versus conventional impressions

Trueness of digital implant scans in patients with maxillary defects: An in vitro study.

This research aimed to evaluate the marginal and internal gaps of crowns, which were produced using both digital and conventional impression techniques and cemented with various types of cement. For the full ceramic crown restoration, an anatomically prepared acrylic first molar phantom tooth (Frasaco GmbH, Germany) was scanned with Scanner S600 ARTI (Zirkonzahn). 160 PMMA analogues produced from the milling unit. Two impression methods were used: digital impressions by intraoral scanner (Aadva Intra Oral 3D Scanner, GC) and PVS impression. Cerasmart, Initial LRF Block, Zirconia Prettau and ICE Zircon monolithic blocks milled with M1 Milling Unit (Zirkonzahn). Restorations cemented with light-cured and dual-cured cements. (n = 10) Pre and post-cementation 3D images overlap was performed using Geomagic Control X (3D Systems, NC, USA). Data were analysed by using SPSS 25.0. p<0.05 difference was considered significant. Digital impressions were significantly higher than PVS impressions in all groups (p<0.05). A significant difference was found between the materials (p<0.05). Cerasmart showed a significantly more marginal gap than the other groups. Prettau and ICE Zircon crowns with the conventional impression group showed a significantly smaller marginal gap than the others. Monolithic crowns fabricated by CAD-CAM using the digital and conventional impression methods had clinically acceptable marginal and internal gaps. Crowns cemented with dual-cured cements showed significantly more marginal gap than light-cure groups. Key words:3D scanning, Marginal accuracy, Marginal fit, Monolithic crown.

Orthodontists use various dental records such as dental models or casts for diagnosis and treatment planning which includes making of dental impressions and study casts. Conventional alginate impressions are challenging for the patients with extreme gag reflex, irritation &amp; discomfort. Recently 3D technology has led to development of scanning and digital models, but one major concern has been the accuracy. So this study was done to compare the accuracy, time and patient acceptance between intraoral scanner and conventional alginate impression technique. 15 patients were selected. Alginate impressions were made using zhermack neocolloid. The patients were subjected to digital scanning with Medit i500 intraoral scanner. Procedures were timed. After the impressions, each patient was asked to complete survey. Tooth width measurements were made using digital vernier caliper from stone models. In the second method digital images were measured using medit link software. Anterior and overall Bolton ratio was calculated to determine accuracy. Digital impressions are accurate and comparable to conventional impressions as tooth width measurements did not differ significantly. Conventional impression consumed more time. Patients preferred digital impressions.Intraoral scanners are accepted by patients and they have comparable accuracy and time efficient compared to conventional impression.

Background: Most of the treatment modalities in dentistry are based on obtaining study models. The study models are of two types, namely, conventional study models made of gypsum products and digital models Aim: To evaluate patient’s perception on intra-oral scanning and alginate impression in Chennai population. Methodology: 20 subjects were selected from the Department of Orthodontics, Saveetha Dental College and Hospital, Chennai. Conventional impression was made using alginate and intra-oral scanning was done for the same patient after 5 days. The patients were asked to fill a questionnaire comprising of 12 questions. Results: Majority of the participants reported that alginate impression had more gag reflex and made the mouth dry. Participants preferred alginate impressions in terms of maximum mouth opening. The overall discomfort was equal for both techniques. Intra-oral scanning consumed more time than alginate impressions. Thus the overall preference rate was equal for both intra-oral scan and alginate impression. Conclusion: Orthodontic patients in Chennai reported equal preference for intra-oral scan and alginate impression.

PURPOSERemovable partial dentures (RPDs) require metal frameworks for support, stability, and retention. Conventional impression methods are time-consuming and may introduce inaccuracies that affect framework fit. Intraoral scanning (IOS) offers a digital alternative that may improve accuracy and efficiency; however, few studies have quantitatively compared frameworks fabricated using IOS data with those fabricated using conventional methods. This study aimed to compare the accuracy of RPD frameworks fabricated using conventional and IOS-based methods.MATERIALS AND METHODSThis study included 15 arches from 13 patients requiring RPDs. Each arch received two metal frameworks, one fabricated using the conventional impression method (CON group) and the other using IOS (IOS group). Qualitative evaluations included visual inspection and pressing with a plugger, whereas quantitative evaluations were performed using three-dimensional superimposition and gap measurements at the rest-seat areas. Paired t-tests were used to compare the accuracy, and two-way analysis of variance was used to evaluate the interaction between the fabrication method and tooth position.RESULTSAll frameworks met the qualitative evaluation criteria. In the quantitative evaluation, the IOS group exhibited a significantly smaller mean gap (201 ± 78 µm) than the CON group (239 ± 83 µm) (P = .015). Furthermore, the IOS group demonstrated significantly greater accuracy, particularly at the terminal abutments of distal-extension RPDs.CONCLUSIONClinically acceptable RPD framework accuracy was achieved in both groups. However, accuracy was significantly better in the IOS group, especially at the terminal abutments of distal-extension RPDs.