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Journal of Healthcare Engineering 2017To overcome difficulties associated with conventional techniques, impressions with IOS (intraoral scanner) and CAD/CAM (computer-aided design and manufacturing)... (Review)
Review
To overcome difficulties associated with conventional techniques, impressions with IOS (intraoral scanner) and CAD/CAM (computer-aided design and manufacturing) technologies were developed for dental practice. The last decade has seen an increasing number of optical IOS devices, and these are based on different technologies; the choice of which may impact on clinical use. To allow informed choice before purchasing or renewing an IOS, this article summarizes first the technologies currently used (light projection, distance object determination, and reconstruction). In the second section, the clinical considerations of each strategy such as handling, learning curve, powdering, scanning paths, tracking, and mesh quality are discussed. The last section is dedicated to the accuracy of files and of the intermaxillary relationship registered with IOS as the rendering of files in the graphical user interface is often misleading. This overview leads to the conclusion that the current IOS is adapted for a common practice, although differences exist between the technologies employed. An important aspect highlighted in this review is the reduction in the volume of hardware which has led to an increase in the importance of software-based technologies.
Topics: Computer-Aided Design; Dental Enamel; Dental Impression Materials; Dental Impression Technique; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Light; Maxilla; Models, Dental; Reproducibility of Results; Software; Technology
PubMed: 29065652
DOI: 10.1155/2017/8427595 -
International Journal of Computerized... 2019Intraoral scanners (IOSs) are widely used for obtaining digital dental models directly from the patient. Additionally, improvements in IOSs are made from generation to...
OBJECTIVE
Intraoral scanners (IOSs) are widely used for obtaining digital dental models directly from the patient. Additionally, improvements in IOSs are made from generation to generation. The aim of this study was to evaluate the accuracy of new and actual IOS devices for complete- and partial-arch dental impressions in an in vitro setup.
MATERIALS AND METHODS
A custom maxillary complete-arch cast with teeth made from feldspar ceramic material was used as the reference cast and digitized with a reference scanner (ATOS III Triple Scan MV60). One conventional impression technique using polyvinylsiloxane (PVS) material (President) served as the control (CO), and eight different IOS devices comprising different hardware and software configurations (TRn: Trios 3; TRi: Trios 3 insane; CS: Carestream Dental CS 3600; MD: Medit i500; iT: iTero Element 2; OC4: Cerec Omnicam 4.6.1; OC5: Cerec Omnicam 5.0.0; PS: Primescan) were used to take complete-arch impressions from the reference cast. The impressions were repeated 10 times (n = 10) for each group. Conventional impressions were poured with type IV gypsum and digitized with a laboratory scanner (inEos X5). All datasets were obtained in standard tessellation language (STL) file format and cut to either complete-arch, anterior segment, or posterior segment areas for respective analysis. Values for trueness and precision for the respective areas were evaluated using a three-dimensional (3D) superimposition method with special 3D difference analysis software (GOM Inspect) using (90-10)/2 percentile values. Statistical analysis was performed using either one-way analysis of variance (ANOVA) or Kruskal-Wallis test (α = 0.05). Results are given as median and interquartile range [IQR] values in µm.
RESULTS
Statistically significant differences were found between test groups for complete- and partial-arch impression methods in vitro (p < 0.05). Values ranged from 16.3 [2.8] µm (CO) up to 89.8 [26.1] µm (OC4) for in vitro trueness, and from 10.6 [3.8] µm (CO) up to 58.6 [38.4] µm (iT) for in vitro precision for the complete-arch methods. The best values for trueness of partial-arch impressions were found for the posterior segment, with 9.7 [1.2] µm for the conventional impression method (CO), and 21.9 [1.5] µm (PS) for the digital impression method.
CONCLUSION
Within the limitations of this study, digital impressions obtained from specific IOSs are a valid alternative to conventional impressions for partial-arch segments. Complete-arch impressions are still challenging for IOS devices; however, certain devices were shown to be well within the required range for clinical quality. Further in vivo studies are needed to support these results.
Topics: Computer-Aided Design; Dental Arch; Dental Impression Technique; Humans; Imaging, Three-Dimensional; Models, Dental
PubMed: 30848250
DOI: No ID Found -
Journal of Clinical and Experimental... Sep 2020Biologically oriented preparation technique (BOPT) is a vertical preparation technique without a finish line to create a new anatomic crown with a prosthetic emergence...
Biologically oriented preparation technique (BOPT) is a vertical preparation technique without a finish line to create a new anatomic crown with a prosthetic emergence profile. This case report describe the protocol realized digitally in a patient who required a new fixed partial denture (FPD) in the anterior esthetic zone. After time of temporary restoration, definitive conventional (CI) (double-cord retraction and vinyl polysiloxane material), and digital impression (DI) with three different intraoral scanner (IOS) (Trios®, True Definition® and iTero®) were taken. All digital impression were obtained through three different scans: temporary restoration in the mouth after healing period, prepared teeth, and temporary restoration out of the mouth. To establish which of the IOS was the most accurate, it was necessary to compare the STL files obtained from each of the IOS with the STL file of the conventional impression, which was digitized with a laboratory scanner (3Shape D800). All these STL were imported to a software (ExoCAD 2.4 Plovdiv®), and they were superimposed. To establish the difference in trueness with SC, 6 points were chosen, 3 points in teeth, and another 3 points in soft tissue. The mean measurement in terms of trueness in teeth were: STS (0,039 mm), SI (0,054 mm), STD (0,067 mm); and in soft tissue were: STS (0,051 mm), SI (0,09 mm), STD [0,236 mm]. The IOSs showed differences between them in terms of trueness, being the Trios the most accuracy IOS. Final restoration was fabricated and cemented. The patient was examined at 3, 6 and 12 months, without any type of biological or mechanical complications. Digital impression with an IOS seems to be a viable alternative to perform zirconia FPD in the BOPT tecbique. Intraoral scanners, accuracy, vertical preparation, precision, CAD-CAM, prosthodontics.
PubMed: 32994882
DOI: 10.4317/jced.56967 -
Journal of Pharmacy & Bioallied Sciences Feb 2024Smart materials encompass a variety of substances, including smart antimicrobial peptides, pit and fissure sealants, impression materials, cement, and sutures. These... (Review)
Review
Smart materials encompass a variety of substances, including smart antimicrobial peptides, pit and fissure sealants, impression materials, cement, and sutures. These materials can change properties under specific stimuli such as temperature, stress, moisture, pH, or electric and magnetic fields. These constituents signify the commencement of a novel era or epoch in the field of smart dentistry and exhibit the potential for enhanced efficacy in the future.
PubMed: 38595377
DOI: 10.4103/jpbs.jpbs_550_23 -
Journal of Medicine and Life May 2023This study aimed to examine the effect of inter-dental abutment distance on the accuracy of digital and conventional impression methods. Five maxillary and mandibular...
This study aimed to examine the effect of inter-dental abutment distance on the accuracy of digital and conventional impression methods. Five maxillary and mandibular models were prepared with different inter-dental abutment distances. Digital scans were obtained using an extraoral laboratory scanner as reference data. Each group was scanned 8 times using the intra-oral scanner for the digital method. For the conventional impression method, 8 additional silicone impression material was used to generate the stone casts from each group. Then casts were scanned. In the next step, stereolithography (STL) data was exported from the scans. The STL files were super-imposed on the reference scans using 3shape dental designer software to make the measurement. Kolmogorov-Smirnoff was used to determine if the data were normally distributed. In the digital impression method, as the abutment distance increased, the accuracy decreased. Various inter-dental abutment distances in digital groups showed significant differences (p=0.016) in impression accuracy, while the difference among conventional groups was not statistically significant (p=0.822). In the digital method, the mean inter-dental abutment between the 4-5 and 3-7 groups, 4-6 and 3-7 groups had a significant difference (p<0.05). However, the conventional method revealed no significant differences (p>0.05) between groups. In conclusion, when the inter-dental abutment distance exists and is surrounded by soft tissue, the possibility of error in the digital impression method is higher than in the conventional impression method.
Topics: Humans; Dental Abutments; Models, Dental; Computer-Aided Design; Mandible; Maxilla; Imaging, Three-Dimensional; Dental Impression Technique
PubMed: 37520485
DOI: 10.25122/jml-2023-0103 -
Dentistry Journal Aug 2022Over the past 20 years, there have been many innovations in orthodontic diagnosis and therapy. Among the innovations, there is the taking of dental impressions (DIs)....
Over the past 20 years, there have been many innovations in orthodontic diagnosis and therapy. Among the innovations, there is the taking of dental impressions (DIs). Dental impressions are the negative imprint of hard and soft tissues of one or both arches, and they allow a plaster model to be formed, i.e., a positive reproduction. Traditional dental impressions can be made of different materials, such as alginate, while digital impression is captured by an intra-oral scanner. Digital impression, despite the evident advantages, has not yet replaced the conventional impression. The aim of this study is to evaluate which dental impressions are the most used by dentists. For this purpose, we considered 120 questionnaires sent electronically to patients of different dental private practices from different countries, where the dentists can use both techniques. The results highlighted that the kind of impression adopted is very much influenced by the type of therapy and orthodontic devices used in the treatment. We can conclude that, despite the advent of digital technology, conventional impressions are still used for fixed devices, while digital impressions are more adopted for orthodontic customized devices and therapies with clear aligners, that are very widespread among adult patients.
PubMed: 36005245
DOI: 10.3390/dj10080147 -
Cureus Aug 2023Addition silicones have revolutionized the field of fixed prosthodontics because of their dimensional stability, sufficient tear strength and excellent detail... (Review)
Review
Addition silicones have revolutionized the field of fixed prosthodontics because of their dimensional stability, sufficient tear strength and excellent detail reproduction. This review study aims to provide a detailed description of the essential variables to be taken into account during the process of making addition silicone impressions in fixed prosthodontics. These variables include the selection of appropriate tray type, size, and fabrication; the use of tray adhesive; gingival displacement techniques; manipulation of the impression material; the choice of the impression material's viscosity; impression techniques; and the proper insertion, removal, disinfection, and pouring of the cast. Additionally, this review aims to help doctors produce high-quality impressions by empowering them to critically assess the impressions to spot mistakes and motivating them to redo impressions that have serious problems before submitting them to the laboratory.
PubMed: 37746395
DOI: 10.7759/cureus.44014 -
Cureus Oct 2022Controlling the cross-contamination between the dental clinic and laboratory is of utmost importance to maintain the health of dental healthcare personnel (DHCP) and... (Review)
Review
INTRODUCTION
Controlling the cross-contamination between the dental clinic and laboratory is of utmost importance to maintain the health of dental healthcare personnel (DHCP) and patients. The aim of this paper was to review the current literature with regard to the use of chlorhexidine as a prosthetic disinfectant in prosthodontic practice.
MATERIALS AND METHODS
A scoping review of the literature was performed in Medline/PubMed, Ovid Embase, and the Cochrane Library. A search for all literature published from 1980 to 2021 was based on the following keywords: ['Chlorhexidine/gluconate' OR 'chlorhexidine', OR 'gluconate', OR 'denture disinfectants', OR 'antimicrobial', OR 'disinfectant', OR 'impression disinfectants, OR prosthesis' OR 'biofilm, microbiology'] OR [teeth]. We reviewed the disinfectant in terms of its mechanism of action, antimicrobial effectiveness, disinfection techniques, clinical applications, corrosiveness/damage to the structure of prostheses, and reasonable shelf life.
RESULTS
Chlorhexidine was tested under different concentrations ranging from 0.2 to 5%. It provided a significant reduction in biofilm viability but had a minimum effect on with a variable effect result that showed no significant differences in the dimensional changes by immersion of alginate dental impressions for no more than 10 minutes and no clinically significant dimensional differences on aluwax, polyether, condensation siloxane, and polyvinyl siloxane were noticed. Nonetheless, chlorhexidine altered the surface of the silicone and acrylic resins and affected the long-term hardness of the relining material.
CONCLUSION
Within the limitations of this review, the use of chlorhexidine disinfectant demonstrates a good measure in the reduction of contamination and cross-infection and has a minimal effect on the dimensional stability of most impression materials. Further studies with in-vitro testing are required to confirm these findings.
PubMed: 36415428
DOI: 10.7759/cureus.30566 -
Clinical and Experimental Dental... Jun 2023To compare the accuracy of five different tooth-implant impression techniques. (Review)
Review
PURPOSE
To compare the accuracy of five different tooth-implant impression techniques.
MATERIALS AND METHODS
In this in vitro, experimental study, an acrylic model containing one bone-level Straumann dental implant at the site of maxillary first molar and an adjacent second premolar prepared for a porcelain fused to metal restoration was used. Impressions were made from the model using five different one-step tooth-implant impression techniques including scanning with an intraoral scanner, occlusal matrix, wax relief, closed-tray, and open-tray techniques. Each technique was repeated 15 times. The impressions were poured with dental stone, and the obtained casts were scanned by a laboratory scanner. The scan file of each technique was compared with the scan file of the original acrylic model by Geomagic Design X software. Data were analyzed by one-way analysis of variance, and Tamhane's post-hoc test (α = 0.05).
RESULTS
For dental implant, intraoral scanning had the highest accuracy (0.1004 mm ) followed by open-tray (0.1914 mm ), occlusal matrix (0.2101 mm ), closed-tray (0.2422 mm ), and wax relief (0.2585 mm ) techniques (p < 0.05). For the prepared tooth, wax relief (0.0988 mm ) had the highest accuracy followed by occlusal matrix (0.1211 mm ), open-tray (0.1663 mm ), closed-tray (0.1737 mm ), and intraoral scanning (0.4903 mm ) technique (p < 0.05). For both dental implant and prepared tooth, occlusal matrix (0.2431 mm ) had the highest accuracy followed by open-tray (0.2574 mm ), wax relief (0.2693 mm ), closed-tray (0.2862 mm ), and intraoral scanning (0.3192 mm ) technique (p > 0.05).
CONCLUSION
The compared simultaneous tooth-implant impression techniques had comparable accuracy with no significant difference.
Topics: Humans; Dental Implants; Dental Impression Technique; Dental Impression Materials; Dimensional Measurement Accuracy; Models, Dental
PubMed: 37042090
DOI: 10.1002/cre2.737