Impression Technique Research Articles

A Scoping Review of Marginal and Internal Fit Accuracy of Lithium Disilicate Restorations.

To assess and compare the accuracy of the marginal and internal fit of lithium disilicate crowns and onlays fabricated by conventional and digital methods. An electronic search was carried out on MEDLINE, Embase, Web of Science and Cochrane Library between 2010 and 2021. Seventeen studies published between 2014 & 2021 were included, of which thirteen were in vitro laboratory-based studies; three were in vivo clinical studies and one randomised controlled trial. Twelve studies focused on the marginal fit, five focused on the marginal and internal fit. Five studies found that the marginal and internal fit of crowns were more accurate using digital techniques. Five studies noted that there was no difference using either technique and two noted that conventional methods had a more accurate marginal fit. Digital techniques were comparable to conventional methods in terms of accuracy although there was insufficient evidence to indicate that one technique was more accurate than the other with respect to Lithium Disilicate restorations. Digital impressions are reliable and viable alternatives for clinicians compared to conventional impression techniques when restoring teeth with lithium disilicate restorations.

Accuracy of multiple implant impressions using different combinations of impression materials using closed tray technique: An in vitro study.

Decision for precision! The first stage in creating an accurate, passively fitting prosthesis is to replicate the intraoral relationship of implants using impression methods. The technique and the impression material utilized are the key elements that influence the accuracy of the implant imprint. The goal of this study was to assess the accuracy of the described implant impression technique using various impression materials, as well as to look into the clinical aspects that influence implant impression accuracy. Two holes (4.3 mm × 10 mm) were drilled in a U-shaped study plastic model representing the partially edentulous maxilla, and the appropriate Nobel Biocare Replace select implants were implanted. Closed tray copings were placed for the relevant implants, and closed tray impressions were taken with several impression materials (PVS-1) Dentsply, medium-bodied, and 2) Regular setting-Zhermack Elite HD+). To assess passive fit accuracy, a jig trial and RVG IOPA were used. Stereomicroscopy was used to evaluate the precision of the implant and analog interface from two perspectives: buccal and lingual. On the buccal aspect, Group 1 had a mean value of 13703.29, whereas Group 2 had a mean value of 11395.58. On the lingual aspect, Group 1's mean value was 8415.61, whereas Group 2's was 9192.01. In the closed tray technique, no statistically significant differences between different imprint materials were found. There was no significant difference in the accuracy of closed tray implant impression techniques with different impression materials, according to the findings.

Evaluation of accuracy and time taken to make an open tray implant impressions with two techniques.

Implant dentistry's emergence and acceptance have provided physicians with a wide range of new options for fixed and removable rehabilitation. The eventual replacement of the lost tooth is the ultimate success, and this can be accomplished using recognized prosthodontic methods. The present study aims to evaluate the time and dimensional accuracy of implant definitive models with an open tray impression with two different techniques. Impression was made in two different techniques and the cast was poured and checked for the time taken and the accuracy of the impression. In IBM SPSS software version 23.0 all the results were statistically analyzed. An Independent t-test was performed for the parameters. No statistically significant difference was present (P > 0.05) when comparing the accuracy and time taken between the two groups. It is concluded that time taken and the misfit is less for modified open tray impression techniques when compared to the regular open tray impression.

Conventional and digital complete arch implant impression techniques: An in vitro study comparing accuracy

Statement of problemVarying complete arch digital-implant–scanning techniques have been described, but their accuracy remains uncertain. PurposeThe purpose of this in vitro investigation was to assess the effect of the implant angulation and impression method (conventional, intraoral digital scan, intraoral scan with a splinting framework, and combining cone beam computed tomography [CBCT] and intraoral scan) on the accuracy of complete arch implant recording. Material and methodsThe following 2 casts were obtained: one with 4 parallel (P group) and the other with 4 angled (up to 30 degrees) implant abutment analogs (NP group). Both the casts were digitized (7Series Scanner) (control file). The following 4 subgroups were created: conventional polyether impression with a splinted framework (CNV subgroup), intraoral scan (IOS subgroup), intraoral scan with a splinting framework (S-IOS subgroup), and intraoral scan combined with CBCT scan (CBCT-IOS subgroup) (n=10). For each file, an implant-supported bar was designed and imported into a program (Netfabb) to perform linear and angular interimplant abutment measurements. Two-way ANOVA (Analysis of Variance) and Tukey tests were selected to examine the data (α=.05). ResultsImplant angulation (P=.010) and impression method (P=.003) significantly influenced the linear trueness. The P group (112 μm) obtained better linear trueness than the NP group (144 μm). The CNV subgroup obtained the best linear trueness, while the IOS and CBCT-IOS showed the worst trueness. Group (P<.001) significantly influenced angular trueness. Group (P=.009) and subgroup (P<.001) influenced the linear precision. The P group (72 μm) obtained better linear precision than the NP group (91 μm). The IOS subgroup obtained the best linear precision. Group (P=.034) significantly influenced the angular precision. The P group (0.46 degrees) had higher angular precision compared with the NP group (0.60 degrees). ConclusionsImplant angulation and the impression methods tested, impacted the accuracy of the complete arch implant recording. Parallel implants had better trueness and precision values than nonparallel implants. The conventional impression method showed the best trueness and precision. Among the digital implant scan methods assessed, the S-IOS and CBCT-IOS subgroups acquired significantly better trueness and precision than the IOS subgroup.

Influence of impression technique on the amount of occlusal adjustments of indirect restorations – case report

Influence of impression technique on the amount of occlusal adjustments of indirect restorations – case report

Fabrication of non-replaceable superstructures on conventional and digital impression intraosseous implants

Introduction : Implantology is the fastest growing specialty in dentistry. A key point for the accurate fabrication of fixed prosthetic structures is taking an accurate impression of the prosthetic field. The implant-prosthetic restoration of the masticatory apparatus after the composition of the function and aesthetics of the dentition through digital technology is gaining wider popularity. Aim : The purpose of this article is to address impression materials and compare the two methods of impression taking from implants—conventional and digital—and clarify their advantages and disadvantages. Materials and Methods : After reviewing materials, studies, and publications on the subject, we tried to present and systematize the main methods and techniques for taking an impression of implants in a conventional and digital way, as well as their advantages and disadvantages. The search was conducted using various keywords and combinations: “transfer impression”, “conventional impression”, “intraoral scanner”, “CAD/CAM”, “scan body”. Results : Forty-one original and review articles were reviewed. Impression materials, impression-taking techniques in permanent implant prosthodontics by conventional and digital methods, and types of intraoral scanning systems are discussed. Conclusion: Taking an accurate impression is a key point in implantology. There are differences in the impression taking techniques of implants. Two main impression techniques are used, direct with an open tray and indirect with a closed tray. According to many literature sources, the open-tray impression technique is more precise and produces more accurate results, while others believe that the closed-tray technique is more accurate. More and more often, conventional impressions are being replaced by digital ones. Digital impressions entered dentistry and, in particular, implantology as an alternative to conventional ones for the restoration of small defects such as single crowns and short bridges.

Management of Peri-implant Soft Tissue Emergence Profile and Accurate Transfer Technique

Objectives: Today, the focus of implant dentistry has moved from osseointegration to meeting aesthetic prospects. Aesthetic demands may be satisfied with a suitable emergence profile created in peri-implant healthy soft tissue, this could be a challenging and time-consuming stage. In this article, the one-step formation of a peri-implant emergence profile and an indirect impression technique that preserves the obtained soft-tissue form are described through cases. Methods: In the cases with missing teeth in aesthetic areas, all detailed consent was obtained from the patients. After the placement of the implants, individual temporary crowns were placed immediately and were not removed until the osseointegration was completed in order to create a peri-implant soft tissue profile that would meet the aesthetic and biological requirements. After the healing period, impressions were taken using custom-prepared impression posts by adding resin material to support the formed mucosa. Thus, the soft tissue profiles could be reflected in the models, and the emergence profiles of temporary crowns could be transferred to the final restorations. Results: The aesthetic and biological demands were practically satisfied at the expected level by following the present method. Conclusion: It is possible to manage the soft tissue around the implant in one step and transfer it to the impression easily. An ideal soft-tissue form that meets the aesthetic and biological demands can be obtained, and transferred to the permanent prosthesis, while time saved with this effortless clinical technique.

Digital assessment of the accuracy of implant impression techniques in free end saddle partially edentulous patients. A controlled clinical trial

ObjectivesThis in vivo study aims to assess the accuracy of the digital intraoral implant impression technique, the conventional closed-tray impression technique, and open-tray impression techniques in a standardized method of data segmentation along with the best-fit algorithm to overcome the inconsistency of results of previous studies regarding implant impression techniques.Materials and methodsSixteen implants were placed in eight patients. Each patient has undergone four impression techniques: direct intraoral scanning of the stock abutment, intraoral scanning using a scan body, conventional closed tray impression technique, and the conventional open tray impression technique. The conventional impressions were poured into stone casts with analogues and stock abutments and scanned using a desktop scanner. In intraoral scanning of the scan body, computer-aided design software was used for the replacement of the scan body with a custom-made abutment that is identical to the stock abutment, allowing comparison with the other impression techniques. The deviation in implant position between the groups was measured using special 3D inspection and metrology software. Statistical comparisons were carried out between the studied groups using a one-way analysis of variance (ANOVA) test.ResultsThe total deviation between groups was compared to the reference group represented by the intraoral scanning of the abutment. The total deviation was statistically significantly different (P = 0.000) among the different studied groups. The mean deviation was recorded as 21.45 ± 3.3 μm, 40.04 ± 4.1 μm, and 47.79 ± 4.6 μm for the intraoral scanning of the scan body, the conventional closed, and open tray, respectively.ConclusionFor implant impressions in partially edentulous patients, intraoral oral scanning using a scan body significantly improves scanning and overall accuracy. Regarding conventional impressions, the closed-tray impression techniques showed more accuracy than conventional open-tray impressions.Clinical relevanceIntraoral digital implant impression using scan body offers more accuracy than conventional implant impression techniques for recording posterior implant position in free-end saddle partially edentulous patients.

Evaluation of the accuracy of light polymerizing tray material for splinting in open tray implant impressions: An In-vitro 3D Spatial Analysis.

Aims and objective: Precise reproduction of the intra-oral spatial relationship of implants with an impression becomes the first step in achieving an accurate, passively fitting prosthesis. This in vitro study aims to compare the dimensional accuracy of dental implants in casts obtained from open tray splinted implant impression techniques using two different splinting materials.&#x0D; Methods and Material: A mandibular acrylic model with four implant analogues was used as a reference model. Open tray impression copings were attached to the implant analogues and were splinted using two different materials. Group I-splinted with pattern resin, sectioned and re-joined and Group II- splinted with light cure tray material. Eight polyether impressions were made for each group and poured in type IV dental stone. The casts retrieved from each group were three-dimensionally analysed using coordinate measuring machine with 0.001 mm accuracy. A one-way ANOVA and post hoc test was done to calculate the statistically significant difference between the groups.&#x0D; Results: The present study revealed no significant difference in the inter-implant distances obtained from pattern resin splinted group, whereas, significant difference in z-axis was found in light polymerising tray resin splinted group when compared to the values obtained from the reference model.&#x0D; Conclusions: Casts obtained from splinting the impression copings using pattern resin before making implant impression were found to be more accurate than splinting with light cure tray material.

Effects of Autoclave Sterilization and Multiple Use on Implant Scanbody Deformation In Vitro.

In the intraoral scanner (IOS) impression technique for dental implants, a scanbody (SB) is connected to the implant and scanned. Poly(ether-ether-ketone) (PEEK) is a widely used material for SBs and it is recommended for single use. However, from the perspective of the Sustainable Development Goals, it is desirable to use these products multiple times. As SBs are used in patients' mouths, proper sterilization is necessary for multiple uses. In the present study, the effect of autoclave treatment and connection/disconnection on SB deformation was investigated. The SB was connected to the implant and stereolithography (STL) data were obtained. Then, the SB was disconnected and underwent autoclave treatment, or was connected and disconnected multiple times, or underwent a combination of both processes. The results showed that there were significant differences in the distance and angle when comparing SBs before and after the autoclave treatment, but repeated connections with or without autoclave treatment had no significant impact on the measured values. The surface texture, observed with scanning electron microscopy, showed that a groove was observed on the surface of the SB, but the groove did not show major changes after 10 connection/autoclave processes. These results indicate that autoclave sterilization has some impact on SB deformation but connection/disconnection itself may not have a huge impact on SB deformation.

Influence of the Angulation and Insertion Depth of Implants on the 3D Trueness of Conventional and Digital Impressions

To study the influence of insertion depth and implant angulation on the 3D trueness of models obtained with different impression techniques. Four different reference models (model 1: parallel, depth of 1.5 mm; model 2: parallel, depth of 4 mm; model 3: 20-degree angle, depth of 1.5 mm; and model 4: 20-degree angle, depth of 4 mm) of partially edentulous maxillae were generated by altering implant angulations and subgingival depths. All scans of reference models were done with a laboratory scanner, and obtained data were exported into standard tessellation language format to be used as virtual reference images. Impressions were obtained from each reference model via three conventional techniques (closed tray [CT], non-hexed open tray [NHOT], and hexed open tray [HOT]) and one digital technique (intraoral scanning [IOS]). A total of 160 impressions were made. The reference and experimental scan data were superimposed by using the best-fit alignment algorithm. Angular (AD), linear (LD), and 3D (RMS) deviations were computed, and obtained data were statistically analyzed. In premolar implant sites, AD and LD values were significantly affected by model type (P ≤ .001 for AD and LD) and impression technique (P = .001 for AD, P = .002 for LD). However, no significant interaction was detected (P = .703 for AD, P = .768 for LD). Model 1 (0.44 ± 0.25 for AD, 7.79 ± 6.29 for LD) and the NHOT technique (0.49 ± 0.43 for AD, 9.04 ± 8.14 for LD) exhibited the lowest mean AD and LD values. In molar implant sites, AD and LD values were significantly affected by model type (P ≤ .001 for AD and LD) and impression technique (P ≤ .001 for AD and LD), as well as by their interaction terms (P = .037 for AD, P = .005 for LD). Considering interaction terms, while the highest and lowest mean AD values were exhibited by IOS-model 4 (1.56 ± 0.25) and NHOTmodel 2 (0.46 ± 0.28), respectively, the highest and lowest mean LD values were exhibited by CT-model 4 (41.40 ± 14.48) and NHOT-model 2 (8.03 ± 4.86), respectively. RMS estimate values were significantly influenced by model type (P ≤ .001) and impression technique (P ≤ .001), as well as by their interaction terms (P = .019). The highest and lowest mean RMS values were exhibited by IOS-model 4 (70.02 ± 4.74) and NHOT-model 2 (25.96 ± 17.67), respectively. In the case of angulated and deeply placed implants, splinted NHOT and HOT techniques can be recommended for better trueness.

Conventional vs. Digital Impression: Comfort Level, Preferences, and Acceptance of Treatment Time among Orthodontic Patients

Background: The escalated technological development and the emergence of computer-aided manufacturing have improved dental restoration accuracy and the accurate manufacturing of prosthetic models. Objective: The study aims to assess patients' comfort level, preferences, and acceptance of treatment time for conventional impression technique vs. digital impression among orthodontic patients treated with clear aligners. Methods: A cross-sectional survey study was conducted between February 2019 and April 2019 by recruiting 50 patients from the orthodontic clinics at multiple centers. A self-administered questionnaire was designed to evaluate patients' perceptions in each impression technique group. Descriptive statistics and paired sample t-test were applied with statistical significance set at P&lt;0.05. Results: The results showed that the impression technique bothered patients as they experienced helplessness during treatment. There was a significant impact on patients' perception of the treatment, whereas there was an insignificant association between comfort level and treatment of the patients. Conclusion: The technicalities of conventional impression were not applied to the intraoral scanners, making these scanners superior and more user-friendly. Digital impression techniques were also preferred by the participants regarding their time, taste/smell, and sensitivity.

An Overview of Systematic Reviews and Meta-analyses Evaluating Different Impression Techniques for Implant-Supported Prostheses in Partially and Completely Edentulous Arches.

To summarize the evidence and determine the most effective impression technique for implant-supported prostheses in terms of accuracy, time efficiency, and patient preference in partially and completely edentulous arches. The searches were performed independently up to April 30, 2021 by two review authors through the Cochrane Oral Health Review, MEDLINE/PubMed, LILACS, and Science Direct databases. Moreover, manual and gray literature searches were performed to identify further potential reviews. Only English language-based systematic reviews with and without meta-analyses evaluating the different dental implant impression techniques were included. The outcomes assessed were accuracy, time efficiency, and patient preference. The methodologic quality of the included reviews was investigated by using the R-AMSTAR tool, and the degree of overlap of primary studies was assessed by calculating the percentage of corrected covered area (CCA) as proposed by Pieper et al.64 Results: The qualitative analysis included a total of 28 reviews, 8 of which included meta-analyses, published between 2008 and 2021, involving a total of 42 clinical trials and 203 laboratory studies. Digital vs conventional implant impression techniques were compared in 17 reviews, different digital impressions in 3 reviews, and different conventional impression techniques in the remaining reviews. Overall, the methodologic quality assessed by using the R-AMSTAR tool was moderate (mean: 26.7 ± 5.5) with slight overlap of primary studies (CCA; 5.23%). Within an overall moderate methodologic quality, the digital implant impressions showed favorable outcomes in terms of accuracy, time efficiency, and patient preference in partially edentulous arches involving three or fewer implants. However, the accuracy of full-arch digital impressions involving multiple implants is not satisfactory and needs significant improvements. Hence, future studies following stringent guidelines and robust methodology are recommended to substantiate the findings of this overview and provide a high level of evidence.

Procedure Time and Students' Perception Comparing Full Arch Digital Scans with Conventional Impressions: A Cross-Over Randomized Experimental Trial.

Methods Ninety-six dental students each prepared tooth #36 for an all-ceramic crown on typodont models and were then randomly assigned into either group A: performed digital scan first, or Group B: performed conventional impression first. Procedure time was recorded for both. Immediately following each procedure, students indicated their perceived procedure difficulty. After exposure to both techniques, they selected their preferred one. Results There was a statistically significant difference between the mean procedure time of both techniques (P < 0.0001), where students spent 663.76 ± 442.50 seconds to complete the conventional impression and 293.32 ± 181.49 seconds to complete the digital scan. Females were significantly faster in completing the conventional impression compared to males. On the contrary, male students were faster in digital scanning than female students. There were no carryover effects in the duration and the initially performed procedure. 76% (73 of 96) of participants preferred digital scanning with no statistical significance shown between the preferred and initially performed procedure. Participants perceived conventional impressions to be more difficult than digital scans. There was a weak positive correlation between the VAS score and the procedure time for the digital technique (R = 0.25) and a moderate positive correlation for the conventional technique (R = 0.45). Conclusions The digital technique was preferred and perceived as easier than the conventional among undergraduate dental students with no impression-making experience, suggesting their readiness for new technology uptake. However, no significant correlation was found between the initially performed procedure and preference.

Evaluation of the effect of different complete denture impression techniques on dental anxiety levels

Background: There are several different impression materials and techniques utilized in the fabrication of complete dentures.&#x0D; Aim of the study: To determine the anxiety levels and the clinical procedure time for maxillary completely edentulous patients by the use of two different impression techniques; the use of a low-fusing green stick compound along with zinc oxide eugenol impression paste and addition silicone (polyvinyl siloxane) along with light body material.&#x0D; Materials and Methods: Twelve maxillary edentulous subjects aged between 44 and 68 were randomly recruited for the study. After having the primary impression two special trays were fabricated for each patient; the first tray for the sectional border moulding group using impression compound along with ZOE final impression material (Group Z), and the second tray for the single-step border moulding technique using additional polyvinyl siloxane impression along with light body final impression materials (Group P). Comparisons between the two groups' procedure time and patients' visual analog scale (VAS) levels were made.&#x0D; Results: The results showed that group P had significantly reduced the VAS compared to group Z 17.5±12.88 and 57.5±16.03, respectively (P=0.000). The mean total procedure times for single-step border moulding and sectional border moulding impression techniques were 12.25±5.16 and 27.5±4.00, respectively (P=0.000). Also, a significant association between the treatment groups and VAS scores was observed by the multiple regression analysis model (P=0.000).&#x0D; Conclusion: As a result of the better patients' perceptions and reduced clinical time, the study findings suggested using a single-step border moulding technique in the upper arch together with additional vinyl silicon material.

Accuracy of Conventional Versus Digital Impression Techniques in Construction of Digitally Printed Surgical Guide "In Vitro Study"

Accuracy of Conventional Versus Digital Impression Techniques in Construction of Digitally Printed Surgical Guide "In Vitro Study"

Prosthodontic management of Atwood's order V and VI mandibular ridge with cocktail impression technique

Residual ridge resorption is the reduction in size of the bony ridge under the mucoperiosteum. The resorption occurs faster in the mandibular arch as compared to the maxillary arch. Fabrication of any dental prosthesis over a compromised residual alveolar ridge is really a challenge for prosthodontists. The pattern of bone resorption observed in Atwood's Orders V and VI causes difficulty in providing successful dentures, especially lower denture where stability of denture may get compromised. This clinical case report elicits a combination of different impression techniques to improve mandibular denture stability in severely resorbed ridges preventing their further resorption.

Patient Satisfaction with Complete Denture Constructed Using Modified Windows Impression Technique with Custom Dual Tray for hypermobile Maxillary Residual Ridge

Patient Satisfaction with Complete Denture Constructed Using Modified Windows Impression Technique with Custom Dual Tray for hypermobile Maxillary Residual Ridge

Comparison of the accuracy between conventional and various digital implant impressions for an implant-supported mandibular complete arch-fixed prosthesis: An in vitro study.

This in vitro study compared the accuracy between conventional and different intraoral scanner impression methods and stereophotogrammetry term of 3D deviation for a complete mandibular edentulous arch with 5 placed implants. An edentulous mandibular model was prepared with three straight and two 17° angled screw-retained abutments screwed on implants. Different impression techniques were compared: one conventional impression, CO (open-tray splint impression coping, Polyether), three groups of intraoral scanners, TS (Trios 4), IT (iTero Element 2), and PS (Primescan), and one stereophotogrammetry, PIC (Precise Implants Capture). An extraoral scanner (E4 scanner) was used to digitize the reference model as a control group. Scan body positions were compared with 3D deviation by using a 3D analysis software program (Geomagic ControlX 2020.1.1) with the best-fit alignment technique. The accuracy of the scan bodies' position of each impression technique between each group area was analyzed using one-way ANOVA followed by Scheffé's comparison test for trueness and precision. (α = 0.05). Statistical 3D deviations of the whole scan body were found among the CO, TS, PS, IT, and PIC groups for both trueness (p < 0.05) and precision (p < 0.05). PIC showed the least 3D deviation of trueness (48.74 ± 1.80µm) and precision (5.46 ± 1.10µm), followed by TS, PS, IT, and CO. CO had the highest 3D deviation of trueness (141 ± 5.58µm) and precision (40.4 ± 1.3.39µm), which was significantly different from PIC, TS, and PS. For completed-arch digital implant impressions, stereophotogrammetry has shown better accuracy than other digital and conventional impression techniques, especially in terms of precision. The highest 3D deviation was found in the conventional splint open-tray impression technique.

Unexpected configurations for the optical solitons propagation in lossy fiber system with dispersion terms effect

In this work, we will design unexpected configurations for the optical soliton propagation in lossy fiber system in the presence of the dispersion term solitons via two distinct and impressive techniques. The first one is the (G′/G)‐expansion method, while the second is solitary wave ansatze method. The two methods are implemented in the same vein and parallel. The obtained perceptions are new and were not achieved before. The comparison between our achieved visions and that achieved by other authors who used different schemas has been documented.