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Alhajj MN, Marquez JR. Simple technique to evaluate denture border extensions using silicone impression material. JOURNAL OF THE IRISH DENTAL ASSOCIATION 2016; 62:213-214. [PMID: 29797830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
INTRODUCTION Extension of denture borders beyond the border line can lead to abnormal movement of the denture and therefore possible loss of retention. Soreness or sore spots that appear in the day(s) after insertion may also result from the overextended borders. OBJECTIVES This article presents a simple technique to evaluate denture border extensions using silicone impression material. MATERIALS AND METHODS One scoop of heavy body silicone is laid on the borders of the denture. The denture is inserted into the mouth and the usual functional movements are performed to investigate any overextensions. - Conclusion: This method is simple, time as well as material saving, and does not need extra instruments or devices.
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Rödiger M, Heinitz A, Bürgers R, Rinke S. Fitting accuracy of zirconia single crowns produced via digital and conventional impressions-a clinical comparative study. Clin Oral Investig 2016; 21:579-587. [PMID: 27469102 DOI: 10.1007/s00784-016-1924-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 07/21/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVES This study focused on the clinical investigation of the internal and marginal fit of CAD/CAM-fabricated zirconia single crowns produced via conventional and digital impression techniques. MATERIALS AND METHODS In a private practice, 20 molar teeth, one from each of 20 patients, were prepared with a circumferential 1.0-mm deep chamfer and an occlusal reduction of 1.5 mm. Conventional impression (CI) taking with a polyvinylsiloxane material (Aquasil Monophase + Aquasil XLV; Dentsply, Konstanz, Germany) and intraoral scanning (IS) (Cara TRIOS; Heraeus, Hanau, Germany) of each of the preparations was performed, and then two respective zirconia copings per tooth were produced (20 crowns per group). The marginal and internal fit of the restorations was evaluated employing a replica technique. For statistical analysis, a pairwise comparison (Wilcoxon rank test) was performed. RESULTS Zirconia single crowns produced with the IS technique revealed a statistically significant better precision of internal fit only in specific areas (chamfer area/occlusal area). The evaluation of marginal fit showed no significant differences between the two groups. All restorations of both groups offered internal and marginal gaps within the postulated clinical tolerance ranges. CONCLUSIONS CAD/CAM-fabricated zirconia single crowns produced with CI and IS techniques offer adequate marginal and internal precision. However, the IS technique provides lower internal gaps in some specific areas. CLINICAL RELEVANCE The clinical precision of fit of restorations produced with a CI and an IS technique appeared to be equivalent. Therefore, the IS technique can be rated as a suitable alternative for the manufacturing of single crowns.
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Gan N, Xiong Y, Jiao T. Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues. PLoS One 2016; 11:e0158800. [PMID: 27383409 PMCID: PMC4934918 DOI: 10.1371/journal.pone.0158800] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 06/22/2016] [Indexed: 11/19/2022] Open
Abstract
Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r = 0.485, p = 0.002 for full dentitions). It was feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Wider dental arch contributed to lower precision of an intraoral digital impression. It should be confirmed in further studies that whether accuracy of digital impressions for whole upper jaws is clinically acceptable.
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Manzella C, Bignardi C, Burello V, Carossa S, Schierano G. Method to improve passive fit of frameworks on implant-supported prostheses: An in vitro study. J Prosthet Dent 2016; 116:52-8. [PMID: 26944406 DOI: 10.1016/j.prosdent.2016.01.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/22/2016] [Accepted: 01/22/2016] [Indexed: 11/16/2022]
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Nasir E, Kamel N, Moussa EH, Hardan L, Zebouni E. [Implications of choice of products and impression technique on the thickness of the dento-prosthetic interface of the CAD-CAM crowns]. ODONTO-STOMATOLOGIE TROPICALE = TROPICAL DENTAL JOURNAL 2016; 39:25-37. [PMID: 30234272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The purpose of this study is to find out what type of impression material is able to achieve a CAD-CAM (Procera) crown with minimal thickness at the dental-prosthetic interface, taking into account the effect of the oversize replica and dimensional variations of the impression materials over time. The accuracy of the marginal adaptation will therefore depend on the oversize replica of clinical preparation controlled by the constant K. Three different types of impression materials: medium viscosity polyether (Impregum 3M-ESPE, Germany), silicones polyvinyl siloxane A (Putty + Very Light) and (Heavy + Light) (Express 3M-ESPE, Germany), were used for making impressions of fifteen initial prototype maxillary teeth made of nickel chrome. The cast of the impressions were poured with plaster type IV (Zhermack, Italy), on which thirty Procera crowns were fabricated. The thickness of the dental-prosthetic interface was then studied at three levels: 0, 1 and 2 mm. The results show that the impression material has a statistically significant impact on the thickness of the dental-prosthetic interface at all three levels. The most compressive impression technique, Putty + Very Light gave the best results at the three levels pre-cited. The results analyzed under optical microscopy show a statistically significant difference between the three impression material products (p-value < 0.05). The calibration constant K, according to each clinical situation, can therefore lead to optimal dental-prosthetic inter-face.
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Camardella LT, Alencar DS, Breuning H, de Vasconcellos Vilella O. Effect of polyvinylsiloxane material and impression handling on the accuracy of digital models. Am J Orthod Dentofacial Orthop 2016; 149:634-44. [PMID: 27131245 DOI: 10.1016/j.ajodo.2015.10.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 10/01/2015] [Accepted: 10/01/2015] [Indexed: 11/18/2022]
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Iwasaki M, Kawara M, Inoue S, Komiyama O, Iida T, Asano T. Pressure dynamics in the trays caused by differences of the various impression materials and thickness of the relief in the maxillary edentulous model. J Prosthodont Res 2016; 60:123-30. [PMID: 26803561 DOI: 10.1016/j.jpor.2015.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/10/2015] [Accepted: 11/28/2015] [Indexed: 11/18/2022]
Abstract
PURPOSE The purpose of this study is to compare the pressure dynamics in the trays caused by differences in the various impression materials and in the thickness of the relief provided for the trays. METHODS In this study, two types of polyvinylsiloxane elastomers, one type of polyether elastomer and one type of alginate impression material were used. Pressure sensors were embedded at eight locations in a model of an edentulous maxilla, and used a simulation model covered with a pseudomucosa. For each impression material, the measurement was performed five times for each of the three types of trays, and the mean values were determined. Statistical analysis was carried out using one-way analysis of variance and the Tukey's HDS method, and the various pressure sensor values for each of the impression materials were compared 10s and 20s after the start of the measurement. Additionally, we compared differences among the three types of trays after 20s. RESULTS The pressure values for sensors placed in the relief region tended to become uniform. Furthermore, we saw a tendency for the pressure to increase at the alveolar crests of the first molars on the left and right and at the posterior border of the palate, all of which support the denture, when relief was provided. CONCLUSIONS The above results suggest that making the final impression for the denture using the selective pressure technique, with consideration given to the pressure dynamic, may lead to a good outcome in terms of preservation of the alveolar ridge.
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108
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Perez-Davidi M, Levit M, Walter O, Eilat Y, Rosenfeld P. Clinical accuracy outcomes of splinted and nonsplinted implant impression methods in dental residency settings. QUINTESSENCE INTERNATIONAL (BERLIN, GERMANY : 1985) 2016; 47:843-852. [PMID: 27284582 DOI: 10.3290/j.qi.a36323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVE The splint technique of implant-supported restorations is a popular impression method; however, in-vivo studies showing the advantage of this method are scarce. The objective was to compare radiographic fit of the metal frameworks fabricated according to splinted or nonsplinted impression techniques. The null hypothesis was that splinting techniques would result in more accurate impressions. METHOD AND MATERIALS A retrospective analysis was performed on 71 patients who had undergone multi-implant-supported rehabilitation in the years of 2012 to 2013. The treatment was carried out by three senior dentists or by residents in the department of Oral Rehabilitation at the Hebrew University Hadassah Medical Center. Each senior and the residents under his guidance treated patients consistently by only one different impression method: (1) no splint; (2) splinted transfers with pattern resin over dental floss scaffold; (3) splinting of transfers to impression tray with pattern resin. Orthoradial radiographs were used to determine if the metal framework fit the implant abutments. RESULTS In total, 81 impressions and 285 implants were included in the study; 56 impressions were done by seniors and 25 by residents. There was no difference in success between the three methods when done by seniors (P = .76). The fixation to tray method was found to be significantly unsuccessful in the hands of residents (P = .01). CONCLUSION Because the splint methods were not found to be more accurate, splinting the transfers might be an unnecessary step. Splinting of transfers to the impression tray is not recommended for inexperienced dentists.
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Ching K. 3M Intraoral Impression Syringe. HAWAII DENTAL ASSOCIATION JOURNAL 2016:22-23. [PMID: 27265960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Ryniewicz WI, Ryniewicz AM, Wiśniewska G. The evaluation of the accuracy of shape imaging of prosthetic abutment. Acta Bioeng Biomech 2016; 18:43-50. [PMID: 27407015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PURPOSE The aim of the study was the in vitro evaluation of the accuracy of shape imaging of abutment teeth using different impression compounds. METHODS To compare the accuracy of the shape of the numerically imaged real prosthetic abutments with the tested models of abutments obtained with the replica technique, the Geomagic Qualify program was applied. Making use of the licensed program Statistica, statistical analysis of the results obtained was conducted. RESULTS In the research procedures, analyses were conducted for 10 abutment premolars and 10 abutment molars. The tests allowed us to state that the dimensional accuracy of the models of prosthetic abutments obtained with the application of elastic compounds tested ensures comparable shape imaging. CONCLUSIONS The objective method developed and applied here is suitable for controlling the imaging of the abutment teeth. The Geomagic Qualify program that was used during the research is a reliable tool of 3D analysis for the estimation of procedure of abutment tooth preparation and indication of an error of shape of prepared occlusal surface, lateral surface of abutment and errors of shaping the chamfer zone.
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Giménez B, Pradíes G, Martínez-Rus F, Özcan M. Accuracy of two digital implant impression systems based on confocal microscopy with variations in customized software and clinical parameters. Int J Oral Maxillofac Implants 2015; 30:56-64. [PMID: 25615916 DOI: 10.11607/jomi.3689] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To evaluate the accuracy of two digital impression systems based on the same technology but different postprocessing correction modes of customized software, with consideration of several clinical parameters. MATERIALS AND METHODS A maxillary master model with six implants located in the second molar, second premolar, and lateral incisor positions was fitted with six cylindrical scan bodies. Scan bodies were placed at different angulations or depths apical to the gingiva. Two experienced and two inexperienced operators performed scans with either 3D Progress (MHT) or ZFX Intrascan (Zimmer Dental). Five different distances between implants (scan bodies) were measured, yielding five data points per impression and 100 per impression system. Measurements made with a high-accuracy three-dimensional coordinate measuring machine (CMM) of the master model acted as the true values. The values obtained from the digital impressions were subtracted from the CMM values to identify the deviations. The differences between experienced and inexperienced operators and implant angulation and depth were compared statistically. RESULTS Experience of the operator, implant angulation, and implant depth were not associated with significant differences in deviation from the true values with both 3D Progress and ZFX Intrascan. Accuracy in the first scanned quadrant was significantly better with 3D Progress, but ZFX Intrascan presented better accuracy in the full arch. CONCLUSION Neither of the two systems tested would be suitable for digital impression of multiple-implant prostheses. Because of the errors, further development of both systems is required.
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Chen WR, Chang YC, Best CT, Derrick D. Super-imposing maxillary and palatal locations for electroarticulometry: A SIMPLE method. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:EL161-EL166. [PMID: 26328743 DOI: 10.1121/1.4927634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study proposes a method of superimposing a physical palatal profile, extracted from a speaker's maxillary impression, onto real-time mid-sagittal articulatory data. A palatal/dental profile is first obtained by three-dimensional-scanning the maxillary impression of the speaker. Then a high resolution mid-sagittal palatal line, extracted from the profile, is sub-divided into articulatory zones and superimposed, by Iterative Closest Point algorithm, onto reconstructed palatal traces in electromagnetic articulometric (EMA) data. Evaluations were carried out by comparing consonant targets elicited by EMA with the proposed method and by static palatography. The proposed method yields accurate results, as supported by palatography.
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Velásquez D, Yaneth JCD, Kaliks JFA. Comparison of Direct and Indirect Techniques to Develop Customized Implant Impression Copings: A Pilot Study. INT J PERIODONT REST 2015; 35:525-31. [PMID: 26133142 DOI: 10.11607/prd.2118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this pilot study was to compare a direct and an indirect technique for fabricating customized impression copings. The accuracy of these techniques to capture the tissue contours that have been developed using implant-supported fixed interim restorations (ISFIRs) in single implants for their esthetic value were evaluated. Five patients presenting with maxillary central incisor ISFIRs were enrolled in the study. Customized impression copings were fabricated using a direct and an indirect technique. Specimens of experimental (direct and indirect technique) and control groups (ISFIR) were compared in terms of linear measurements on their buccolingual (BL) and mesiodistal (MD) dimensions at three different levels: platform, middle, and gingival margin. Statistically significant differences were detected between the control group and the direct technique specimens on both the gingival margin and middle levels (P < .05). Between the direct and indirect techniques, statistically significant differences were found in their MD and BL dimensions at the gingival margin level (G-MD, G-BL) and the buccolingual dimension at the middle level (M-BL) (P < .05). The indirect technique used for the fabrication of customized implant impression copings seems to be more accurate in capturing the profile of the ISFIR at all three levels (platform, middle, and gingival margin). The direct technique is accurate only at the platform level.
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Wilk BL. Intraoral Digital Impressioning for Dental Implant Restorations Versus Traditional Implant Impression Techniques. COMPENDIUM OF CONTINUING EDUCATION IN DENTISTRY (JAMESBURG, N.J. : 1995) 2015; 36:529-533. [PMID: 26247446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Over the course of the past two to three decades, intraoral digital impression systems have gained acceptance due to high accuracy and ease of use as they have been incorporated into the fabrication of dental implant restorations. The use of intraoral digital impressions enables the clinician to produce accurate restorations without the unpleasant aspects of traditional impression materials and techniques. This article discusses the various types of digital impression systems and their accuracy compared to traditional impression techniques. The cost, time, and patient satisfaction components of both techniques will also be reviewed.
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Johnson OR, Lyall M, Johnson CP. The use of dental putty in the assessment of hard surfaces within paved urban areas that may leave defined or patterned marks on bodies. MEDICINE, SCIENCE, AND THE LAW 2015; 55:129-132. [PMID: 24644229 DOI: 10.1177/0025802414527078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The identification of a patterned skin or scalp mark at autopsy can provide key forensic evidence in identifying an injury that may have been left by an assailant's footwear. It is also important to consider whether such a mark could alternatively have been left by the deceased coming into forceful contact with a hard surface at the scene of an incident, for example by falling. This study was designed to demonstrate how variable surfaces are within paved urban areas, including those which might leave marks resembling footwear patterns, and to evaluate whether dental putty impression lifting is a practical and effective adjunct to photography in assessing patterned surfaces. Eighteen 'scenes' of approximately 50 m² were assessed for different hard surfaces by photography and by the production of dental putty impression lifts. The number of hard surfaces varied between 4 and 12 per scene, with 90% (122/135) of all hard surfaces deemed likely to leave distinct marking on skin with forceful contact and 46% (62/135) a defined/regular mark potentially similar to a footwear injury (mean = 3.4 per scene). Dental putty proved to be an excellent tool in characterising hard surfaces, producing firm but slightly flexible lifts that can be used in combination with a commercially available inkless footwear impression kit to generate transparencies that help facilitate detailed comparison work. Whenever a potential footwear mark is identified at autopsy, a systematic examination of all hard surfaces at the scene is mandatory, and this process will be significantly strengthened by the use of dental putty.
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Yang X, Sun YF, Tian L, Si WJ, Feng HL, Liu YH. [Precision of digital impressions with TRIOS under simulated intraoral impression taking conditions]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2015; 47:85-89. [PMID: 25686335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To evaluate the precision of digital impressions taken under simulated clinical impression taking conditions with TRIOS and to compare with the precision of extraoral digitalizations. METHODS Six #14-#17 epoxy resin dentitions with extracted #16 tooth preparations embedded were made. For each artificial dentition, (1)a silicone rubber impression was taken with individual tray, poured with type IV plaster,and digitalized with 3Shape D700 model scanner for 10 times; (2) fastened to a dental simulator, 10 digital impressions for each were taken with 3Shape TRIOS intraoral scanner. To assess the precision, best-fit algorithm and 3D comparison were conducted between repeated scan models pairwise by Geomagic Qualify 12.0, exported as averaged errors (AE) and color-coded diagrams. Non-parametric analysis was performed to compare the precisions of digital impressions and model images. The color-coded diagrams were used to show the deviations distributions. RESULTS The mean of AE for digital impressions was 7.058 281 μm, which was greater than that of 4.092 363 μm for the model images (P<0.05). However, the means and medians of AE for digital impressions were no more than 10 μm, which meant that the consistency between the digital impressions was good. The deviations distribution was uniform in the model images,while nonuniform in the digital impressions with greater deviations lay mainly around the shoulders and interproximal surfaces. CONCLUSION Digital impressions with TRIOS are of good precision and up to the clinical standard. Shoulders and interproximal surfaces scanning are more difficult.
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Vohra F, Rashid H, Hanif A, Ghani SMA, Najeeb S. TRENDS IN COMPLETE DENTURE IMPRESSIONS IN PAKISTAN. J Ayub Med Coll Abbottabad 2015; 27:108-112. [PMID: 26182752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND Multiple materials and techniques have been reported for complete denture impressions in literature. The aim of the study was to assess the trends in complete denture impression materials and techniques among general dental practitioners (GDP) and specialists (SP) in Pakistan. METHODS In this cross-sectional study, self-designed-structured questionnaires were distributed among 500 dentists in Pakistan. The three-part questionnaire enquired about the demographic features, preferred impression materials, impression techniques and related procedures commonly used in their clinical practice. A comparison between the responses of SP and GDP was also drawn. Frequency distribution and Chi-square test were performed to compare the responses. RESULTS A total of 294 questionnaires were completed at a response rate of 58.8%. 75% of GDP used alginate for primary impressions and 66% of SP preferred impression compound for the same. A majority of both SP and GDP favoured the used of custom trays (SP 81%, GDP 85%) and selective pressure technique (SP 84%, GDP 53%) for final impression. However, 85% of GDP used zinc-oxide eugenol and 62% of SP favoured elastomeric materials for the same. Most of the SP and GDP used chemical cured resin custom trays (SP 54%, GDP 75%), however, 86% of SP used spaced trays and almost 60% of GDP preferred close-fitting trays. CONCLUSIONS The practice of GDP and SP with regards to CD impression materials and techniques differed significantly. Continued education and training for GDP and SP with respect to procedures and techniques related to CD is recommended.
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Akpinar YZ, Yilmaz B, Tatar N, Demirtag Z. Changing the bonding force of impression tray to edentulous maxillary jaw simulator with impression valve system: in vitro study. Niger J Clin Pract 2015; 18:115-119. [PMID: 25511355 DOI: 10.4103/1119-3077.146992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE The aim of this study was to evaluate the effect of an impression valve system (IVS) on the bonding force between an impression tray and an edentulous maxillary jaw. MATERIALS AND METHODS In this in vitro study, a polyether-coated maxillary jaw simulator (PM) was used to model an edentulous maxillary jaw. The IVS was placed into individual impression trays. An irreversible hydrocolloid impression was taken of the PM when the IVS was open and closed. The impression tray bonding force was measured using a digital dynamometer. Student's t-test was used to determine the significance of the difference between these two groups. RESULTS The impression tray was more easily separated from the PM when the IVS was open (108 ± 3.9 N). The separation was more difficult when the IVS was closed (153.7 ± 14.2 N). The difference between these two findings (P = 0.000) was significant. CONCLUSION The use of an IVS facilitates the removal of the impression tray from the mouth when taking impressions from an edentulous maxillary jaw.
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Giménez B, Özcan M, Martínez-Rus F, Pradíes G. Accuracy of a digital impression system based on parallel confocal laser technology for implants with consideration of operator experience and implant angulation and depth. Int J Oral Maxillofac Implants 2014; 29:853-62. [PMID: 25032765 DOI: 10.11607/jomi.3343] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To evaluate the accuracy of a digital impression system based on parallel confocal red laser technology, taking into consideration clinical parameters such as operator experience and angulation and depth of implants. MATERIALS AND METHODS A maxillary master model with six implants (located bilaterally in the second molar, second premolar, and lateral incisor positions) was fitted with six polyether ether ketone scan bodies. One second premolar implant was placed with 30 degrees of mesial angulation; the opposite implant was positioned with 30 degrees of distal angulation. The lateral incisor implants were placed 2 or 4 mm subgingivally. Two experienced and two inexperienced operators performed intraoral scanning. Five different interimplant distances were then measured. The files obtained from the scans were imported with reverse-engineering software. Measurements were then made with a coordinate measurement machine, with values from the master model used as reference values. The deviations from the actual values were then calculated. The differences between experienced and inexperienced operators and the effects of different implant angulations and depths were compared statistically. RESULTS Overall, operator 3 obtained significantly less accurate results. The angulated implants did not significantly influence accuracy compared to the parallel implants. Differences were found in the amount of error in the different quadrants. The second scanned quadrant had significantly worse results than the first scanned quadrant. Impressions of the implants placed at the tissue level were less accurate than implants placed 2 and 4 mm subgingivally. CONCLUSIONS The operator affected the accuracy of measurements, but the performance of the operator was not necessarily dependent on experience. Angulated implants did not decrease the accuracy of the digital impression system tested. The scanned distance affected the predictability of the accuracy of the scanner, and the error increased with the increased length of the scanned section.
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Mi H, Wu Y, Zheng G. [Application study of optical method in measuring wall thickness of dental impression]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2014; 31:1229-1232. [PMID: 25868235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Dental impressions are widely used in the field of oral restoration. The materials are used for making impression in oral cavity. In order to measure the thickness of impression for reference in clinic, the real impressions are taken as the object for studying. Through optical method, charge-coupled device (CCD) is used for collecting the grey image of cutting section of the impressions which are located in the same plane with steel dividing ruler. According to convert relationship between dividing ruler and pixels collecting grey image, the thickness of impression specimens can be obtained. The results show that the optical method used for measuring thickness is feasible to the task and the precision can reach micro dimension. The experiment method and technique can also be provided for measuring thickness of similar tissue engineering materials.
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Lin YH, Lin MY. Ear mold impression material as an aural foreign body. EAR, NOSE & THROAT JOURNAL 2014; 93:382-383. [PMID: 25255342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
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[Comparative evaluation of physical-mechanical properties and surface morphology of the samples of base self cured acrylic resin "Redont-kolir" polymerized in the silicone and alginate matrixes]. GEORGIAN MEDICAL NEWS 2014:33-37. [PMID: 25214268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Determination of advantages of using silicone or alginate impression material as a matrix is decisive for quality of immediate and transitional dentures manufactured by the direct method using self-cured acrylic resins. The aim of this study was a comparative evaluation of physical-mechanical properties and surface morphology of the samples of base self-cured acrylic resin "Redont-kolir" polymerized in the silicone and alginate matrix. The samples were polymerized in the C-silicone - "Zeta plus-putty" ("Zhermack", Italy) and alginate -"Ypeen" ("Spofa Dental", Czech Republic) matrixes under different regimes: 1) in the pneumopolymerizer "Averon" at an air pressure of 3 atm., a temperature of 450C for 15 minutes, and 2) polymerization in water at 450C for 15 minutes. We determined the following physical and mechanical properties: bending load, toughness, bending stress at break, hardness by Heppler, conical point of fluidity and water absorption. Electron microscopy studies of the samples have been conducted on electronic raster microscope JSM-840 ("Jeol", Japan). As a result of studies, it was found that the optimum regime of polymerization for acrylate "Redont-kolir" is in the pneumopolymerizer "Averon" at an air pressure of 3 atm., a temperature of 450 C for 15 minutes. By the results of studying the surface morphology of the samples we can draw a conclusion that the use of an alginate impression material as matrix allows to obtain a qualitatively better surface of denture. But taking into account the technological properties of the alginate impression materials, namely an expressed shrinkage, their use for this purpose must be limited by the time during which the impression matrix remain stable in size, which is specified by manufacturer's recommendations.
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Ehsani S, Siadat H, Alikhasi M. The effect of implant connection length on the dimensional impression accuracy of inclined implants. Int J Oral Maxillofac Implants 2014; 28:e315-20. [PMID: 24278936 DOI: 10.11607/jomi.3153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Accurate recording of implant locations is essential for precise passively fitting prostheses with proper support. This in vitro study evaluated the accuracy of impressions made of parallel and nonparallel implants with different lengths of impression coping connections. MATERIALS AND METHODS A reference model containing four internal-connection implant analogs (two at 0 degrees and two at 30 degrees in relation to the perpendicular line) was fabricated. Thirty medium-consistency silicon impressions of this model were made using the open-tray impression technique. Three groups of 10 specimens each were made with different impression coping connection lengths (2, 1.5, or 1 mm). Impressions were poured with type IV stone. The positional accuracy of the implant replica heads in the x-, y-, and z-axes was evaluated using a coordinate measuring machine, and measurements were compared with the obtained dimensions from the reference model. Data were analyzed with two-way analysis of variance (α = .05). RESULTS There was no significant difference in impression accuracy, regardless of the lengths of the impression connections. Additionally, there was no significant difference between the impression accuracy of inclined and straight implants, except in the y-axis (P = .006). CONCLUSIONS Within the limitations of this study, the accuracy of implant impressions did not differ for different lengths of transfer coping connections of inclined and straight implants.
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Baba NZ, Goodacre CJ, Jekki R, Won J. Gingival displacement for impression making in fixed prosthodontics: contemporary principles, materials, and techniques. Dent Clin North Am 2014; 58:45-68. [PMID: 24286645 DOI: 10.1016/j.cden.2013.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The clinical success and longevity of indirect restorations depend on the careful and accurate completion of several procedures. One of the challenging procedures is management of the gingival tissues and gingival esthetics. The goal for management of gingival tissues and gingival esthetics is to maintain the normal appearance of healthy gingival. Achieving this goal requires optimal health before treatment and minimal trauma during treatment. The best way of optimizing health and minimizing trauma is to avoid contacting the gingiva with restorative materials.
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Marques J, Musse J, Caetano C, Corte-Real F, Corte-Real AT. Analysis of bite marks in foodstuffs by computer tomography (cone beam CT)--3D reconstruction. THE JOURNAL OF FORENSIC ODONTO-STOMATOLOGY 2013; 31:1-7. [PMID: 24776435 PMCID: PMC5734833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The use of three-dimensional (3D) analysis of forensic evidence is highlighted in comparison with traditional methods. This three-dimensional analysis is based on the registration of the surface from a bitten object. The authors propose to use Cone Beam Computed Tomography (CBCT), which is used in dental practice, in order to study the surface and interior of bitten objects and dental casts of suspects. In this study, CBCT is applied to the analysis of bite marks in foodstuffs, which may be found in a forensic case scenario. 6 different types of foodstuffs were used: chocolate, cheese, apple, chewing gum, pizza and tart (flaky pastry and custard). The food was bitten into and dental casts of the possible suspects were made. The dental casts and bitten objects were registered using an x-ray source and the CBCT equipment iCAT® (Pennsylvania, EUA). The software InVivo5® (Anatomage Inc, EUA) was used to visualize and analyze the tomographic slices and 3D reconstructions of the objects. For each material an estimate of its density was assessed by two methods: HU values and specific gravity. All the used materials were successfully reconstructed as good quality 3D images. The relative densities of the materials in study were compared. Amongst the foodstuffs, the chocolate had the highest density (median value 100.5 HU and 1,36 g/cm(3)), while the pizza showed to have the lowest (median value -775 HU and 0,39 g/cm(3)), on both scales. Through tomographic slices and three-dimensional reconstructions it was possible to perform the metric analysis of the bite marks in all the foodstuffs, except for the pizza. These measurements could also be obtained from the dental casts. The depth of the bite mark was also successfully determined in all the foodstuffs except for the pizza. Cone Beam Computed Tomography has the potential to become an important tool for forensic sciences, namely for the registration and analysis of bite marks in foodstuffs that may be found in a crime scene.
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