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Purpose: To assess the three-dimensional (3D) accuracy of multi-implant impressions for complete arches obtained using 3D-printing technology, and to determine the clinical feasibility of this approach by comparing the results obtained with those obtained with conventional impression techniques. Materials and Methods: A maxillary model matrix with four implant analogs was used to fabricate 10 stone reference models (control) to simulate edentulous patients. Ten 3D-printed impressions were made using polylactic acid custom open trays with component splinting (3D-printed group). To make 10 conventional impressions of the reference models, the poly(methyl methacrylate) open trays with splinting technique was used (conventional group). Impressions were poured with a type IV dental stone, which had been digitalized utilizing a high-resolution laboratory scanner after connecting the polymer scan bodies. Standard tessellation language (STL) datasets from the two groups of stone models were superimposed with the corresponding reference models. The interimplant distances and interimplant angulations for each implant pair were measured for the reference models and for the two test groups' definitive models, to assess 3D deviations. In addition, the mechanical properties of polylactic acid and poly(methyl methacrylate) tray materials were compared by means of threepoint loading and tensile bond tests. The Student t test was used to compare the differences in implant position and mechanical properties between the two groups, while implant angulations were analyzed with Wilcoxon's rank-sum test, at P = .05. Results: There was less implant-position deviation for the 3D-printed group (mean ± SD: 56.37 ± 12.52 μm) than for the conventional group (71.94 ± 18.86 µm) (P = .014). No significant differences were found in angular deviation between the two groups (P > .05). Flexural strength results suggested that polylactic acid (112.7 ± 1.62 MPa) was stronger than poly(methyl methacrylate) (104.0 ± 2.17 MPa; P < .0001). The tensile bond strength of polylactic acid (0.07 ± 0.005 MPa) was higher than that of poly(methyl methacrylate) (0.03 ± 0.004 MPa; P < .0001). Conclusion: The 3D-printing multi-implant impression technique could be an alternative to conventional impression techniques for complete arches. [ABSTRACT FROM AUTHOR]

Passive fit between prosthesis and implants or abutments is a significant factor in preventing mechanical and biologic failures of implant-supported prostheses. Therefore, impression techniques must transfer the 3D implant position as accurately as possible for a correct superstructure fabrication. A novel impression protocol that uses an individualized open tray design is proposed. It allows the clinician to splint the transfers between the copings, outside the impression area, and to the tray itself to create a rigid monoblock. Thus, distortions produced by the tear of impression material or by transfer abutments’ micromovements during tray retrieval are limited and superstructure misfits are minimized. This technique is specifically recommended for long spanning or completely edentulous patients. [ABSTRACT FROM AUTHOR]

The complexity and labor-intensive nature of making implant-level impressions may inhibit some clinicians from recommending dental implant treatment. This paper describes a simplified impression technique for fabricating anatomical, cement-retained abutments without removing or inserting implant components. Using digitally coded healing abutments, this protocol bridges the gap between traditional impressions and computer-aided abutment manufacturing. Basic logistic considerations are reviewed, as well as other biomechanic and esthetic advantages, that should optimize overall treatment outcomes. [ABSTRACT FROM AUTHOR]

Accurate impression taking for the success of implant prosthesis is a very important process. Methods of taking implant impression include the conventional method using impression coping and impression material, and the digital method using an intraoral scanner and scanbody. However, the impression coping or the scanbody must install after remove healing abutment. Because of this, the dentist must repeat the process of removing and installing the healing abutment, the impression coping or the scanbody several times. In addition, the impression coping or the scanbody rises higher than the occlusal surface, so the patient has the inconvenience of constantly maintaining the open state. Recently, a scannable healing abutment, which can be scanned by a intraoral scanner directly, without the need to remove the healing abutment by applying a scannable part of the scanbody to the healing abutment, was introduced. We present a case of single posterior implant prosthesis using a scannable healing abutment. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to evaluate and to compare the accuracy of implant casts obtained by open tray pick-up impression technique using 2 types of custom-made trays and a specialized aluminum stock impression tray. Materials and Methods: A heat-cure acrylic resin master model was fabricated. Two implants were placed parallel to each other. Ten impressions were made from each group. Polyvinylsiloxane impression material with single step putty wash technique was used for making all the impressions. The resultant casts obtained were compared to the master models with respect to the distances measured between the reference points using a stereomicroscope. The data obtained was statistically analyzed using one-way ANOVA, Tukey's post hoc procedures, and t-test. Results: Mean value obtained was 2.012967 cm (±0.007060) for corimplant stock tray, 2.012627 cm (±0.007945) for autopolymerizing acrylic resin tray, 2.010279 cm (±0.006832) for light-cure hybrid composite tray. P value was calculated to be >0.05; hence, there was nonsignificant deviation of observations from standard value in each group. Conclusion: Statistically insignificant difference was found between the accuracy of casts obtained by the different impression trays. However, light-cure hybrid composite trays showed best results followed by autopolymerizing acrylic resin trays and Corimplant stock tray. [ABSTRACT FROM AUTHOR]

Purpose To compare the accuracy of digital and conventional impression techniques for completely edentulous patients and to determine the effect of different variables on the accuracy outcomes. Materials and methods A stone cast of an edentulous mandible with five implants was fabricated to serve as master cast (control) for both implant- and abutment-level impressions. Digital impressions ( n = 10) were taken with an intraoral optical scanner ( TRIOS, 3shape, Denmark) after connecting polymer scan bodies. For the conventional polyether impressions of the master cast, a splinted and a non-splinted technique were used for implant-level and abutment-level impressions (4 cast groups, n = 10 each). Master casts and conventional impression casts were digitized with an extraoral high-resolution scanner ( IScan D103i, Imetric, Courgenay, Switzerland) to obtain digital volumes. Standard tessellation language ( STL) datasets from the five groups of digital and conventional impressions were superimposed with the STL dataset from the master cast to assess the 3D (global) deviations. To compare the master cast with digital and conventional impressions at the implant level, analysis of variance ( ANOVA) and Scheffe's post hoc test was used, while Wilcoxon's rank-sum test was used for testing the difference between abutment-level conventional impressions. Results Significant 3D deviations ( P < 0.001) were found between Group II (non-splinted, implant level) and control. No significant differences were found between Groups I (splinted, implant level), III (digital, implant level), IV (splinted, abutment level), and V (non-splinted, abutment level) compared with the control. Implant angulation up to 15° did not affect the 3D accuracy of implant impressions ( P > 0.001). Conclusion Digital implant impressions are as accurate as conventional implant impressions. The splinted, implant-level impression technique is more accurate than the non-splinted one for completely edentulous patients, whereas there was no difference in the accuracy at the abutment level. The implant angulation up to 15° did not affect the accuracy of implant impressions. [ABSTRACT FROM AUTHOR]

Purpose The study aims to evaluate three-dimensionally (3 D) the accuracy of implant impressions using a new resin splinting material, 'Smart Dentin Replacement' ( SDR). Materials and Methods A titanium model of an edentulous mandible with six implant analogues was used as a master model and its dimensions measured with a coordinate measuring machine. Before the total 60 impressions were taken (open tray, screw-retained abutments, vinyl polysiloxane), they were divided in four groups: A (test): copings pick-up splinted with dental floss and fotopolymerizing SDR; B (test): see A, additionally sectioned and splinted again with SDR; C (control): copings pick-up splinted with dental floss and autopolymerizing Duralay® (Reliance Dental Mfg. Co., Alsip, IL, USA) acrylic resin; and D (control): see C, additionally sectioned and splinted again with Duralay. The impressions were measured directly with an optomechanical coordinate measuring machine and analyzed with a computer-aided design ( CAD) geometric modeling software. The Wilcoxon matched-pair signed-rank test was used to compare groups. Results While there was no difference ( p = .430) between the mean 3 D deviations of the test groups A (17.5 μm) and B (17.4 μm), they both showed statistically significant differences ( p < .003) compared with both control groups ( C 25.0 μm, D 19.1 μm). Conclusions Conventional impression techniques for edentulous jaws with multiple implants are highly accurate using the new fotopolymerizing splinting material SDR. Sectioning and rejoining of the SDR splinting had no impact on the impression accuracy. [ABSTRACT FROM AUTHOR]

Accuracy is the most important thing in implant prosthesis, for this reason it is essential procedure to check the accuracy of impression taking. However, impression material has its own error and the error occurs in model-making procedure. As an alternative way to this, using intraoral scanner can be suggested and many studies were issued reporting that there’s no statistically significant difference in accuracy between intraoral scanner and conventional impression. Therefore, the purpose of this study is to report the process of making of implant prosthesis using intraoral scanner, which is more convenient, fast, accurate compared with conventional method. [ABSTRACT FROM AUTHOR]

Objectives: Precise implant-supported prosthodontics requires accurate impressions. Many in vitro studies comparing different implant impression techniques were performed. The purpose of this in vivo study was to compare the discrepancy of two different impression techniques of implants clinically. Material and methods: Four implants were inserted nearly bilateral in ten edentulous jaws. From each jaw, two different impressions (A, transfer; B, splinted pick-up) were taken. Respectively two stone casts of each jaw were produced and scan bodies were mounted on the lab analogues to digitize the casts. One scan body of the digitized casts was each superimposed and the deviations of the remaining three scan bodies were measured three dimensionally. The fit of the suprareconstructions was evaluated clinically on both casts and in the mouth. Results: The mean discrepancy of scan body 2 was 192 μm (±96), 282 μm (±97) for scan body 3, and 366 μm (±114) for scan body 4. The discrepancies between two scan bodies were statistically significant ( p ≤ 0.010; ANOVA test). Comparing the data with the span between the scan bodies, a linear regression line could be drawn to show the dependency between the misfit and the length of the span. Clinically, the fit on the cast produced by the splinted pick-up technique was favorable. Conclusions: The discrepancy between the splinted pick-up impression technique and the transfer technique were in a range with clinical influence. Clinical relevance: For better accuracy of implant-supported prosthodontics, the splinted pick-up technique should be used for impressions of four implants evenly spread in edentulous jaws. [ABSTRACT FROM AUTHOR]

Implant-supported prosthodontics requires precise impressions to achieve a passive fit. Since the early 1990s, in vitro studies comparing different implant impression techniques were performed, capturing the data mostly mechanically. The purpose of this study was to evaluate the accuracy of three different impression techniques digitally. Dental implants were inserted bilaterally in ten polymer lower-arch models at the positions of the first molars and canines. From each original model, three different impressions (A, transfer; B, pick-up; and C, splinted pick-up) were taken. Scan-bodies were mounted on the implants of the polymer and on the lab analogues of the stone models and digitized. The scan-body in position 36 (FDI) of the digitized original and master casts were each superimposed, and the deviations of the remaining three scan-bodies were measured three-dimensionally. The systematic error of digitizing the models was 13 μm for the polymer and 5 μm for the stone model. The mean discrepancies of the original model to the stone casts were 124 μm (±34) μm for the transfer technique, 116 (±46) μm for the pick-up technique, and 80 (±25) μm for the splinted pick-up technique. There were statistically significant discrepancies between the evaluated impression techniques ( p ≤ 0.025; ANOVA test). The splinted pick-up impression showed the least deviation between original and stone model; transfer and pick-up techniques showed similar results. For better accuracy of implant-supported prosthodontics, the splinted pick-up technique should be used for impressions of four implants evenly spread in edentulous jaws. [ABSTRACT FROM AUTHOR]

Aim: This in vitro study aimed to evaluate the effect of implant impression coping geometrical designs on the accuracy of open and closed impression techniques and in the parallel and nonparallel implant positions. Material and methods: Three custom-made acrylic resin models of three tested implant systems (Straumann®, SIC Invent®, and Osstem®) with diverse coping geometrical designs were evaluated in simulated cases of two parallel and two nonparallel implants. The horizontal and vertical discrepancies were measured and analyzed. Results: No statistically significant differences between the two impression techniques in either parallel or nonparallel implants were observed. The high retentive design of the Osstem system showed a statistically significant difference. Conclusion: The geometrical design of the impression copings did not affect the accuracy for either the open and closed tray techniques. However, the high retentive coping design of the Osstem implant affected the accuracy in the open tray technique. [ABSTRACT FROM AUTHOR]