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Marine Drugs Dec 2018Hydrocolloids were the first elastic materials to be used in the dental field. Elastic impression materials include reversible (agar-agar), irreversible (alginate)... (Review)
Review
Hydrocolloids were the first elastic materials to be used in the dental field. Elastic impression materials include reversible (agar-agar), irreversible (alginate) hydrocolloids and synthetic elastomers (polysulfides, polyethers, silicones). They reproduce an imprint faithfully, providing details of a high definition despite the presence of undercuts. With the removal of the impression, being particularly rich in water, the imprints can deform but later adapt to the original shape due to the elastic properties they possess. The advantages of using alginate include the low cost, a better tolerability on the part of the patient, the ease of manipulation, the short time needed for execution, the instrumentation and the very simple execution technique and possibility of detecting a detailed impression (even in the presence of undercuts) in a single step. A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed database. Authors conducted a search of articles in written in English published from 2008 to 2018. All the relevant studies were included in the search with respect to the characteristics and evolution of new marine derived materials. Much progress has been made in the search for new marine derived materials. Conventional impression materials are different, and especially with the advent of digital technology, they have been suffering from a decline in research attention over the last few years. However, this type of impression material, alginates (derived from marine algae), have the advantage of being among the most used in the dental medical field.
Topics: Agar; Alginates; Animals; Colloids; Dental Impression Materials; Dental Impression Technique; Humans; Materials Testing; Surface Properties; Tooth
PubMed: 30597945
DOI: 10.3390/md17010018 -
Nederlands Tijdschrift Voor... Mar 2020Inattention while taking dental impressions of the upper jaw of patients with a palatal defect can lead to dental impression material being left behind. Two patients...
Inattention while taking dental impressions of the upper jaw of patients with a palatal defect can lead to dental impression material being left behind. Two patients with a cheilognathopalatoschisis and a full arch prosthesis in the upper jaw were referred with complaints characteristic of chronic sinusitis and recurrent epistaxis, lasting several years. A facial cone beam computer tomogram revealed dental impression material left behind in the palatal defect and the nasal cavity. In the case of both patients, the foreign bodies were removed under general anaesthesia. One of the patients twice brought up a residual fragment of dental impression material left in the palatal defect after surgery.
Topics: Cleft Lip; Dental Impression Materials; Dental Impression Technique; Humans; Maxilla; Models, Dental
PubMed: 32343274
DOI: 10.5177/ntvt.2020.03.19100 -
Journal of Investigative and Clinical... May 2018The aim of the present study was to assess the accuracy of multi-unit dental implant casts obtained from two elastomeric impression materials, vinyl polyether silicone... (Comparative Study)
Comparative Study
AIM
The aim of the present study was to assess the accuracy of multi-unit dental implant casts obtained from two elastomeric impression materials, vinyl polyether silicone (VPES) and polyether (PE), and to test the effect of splinting of impression copings on the accuracy of implant casts.
METHODS
Forty direct impressions of a mandibular reference model fitted with six dental implants and multibase abutments were made using VPES and PE, and implant casts were poured (N = 20). The VPES and PE groups were split into four subgroups of five each, based on splinting type: (a) no splinting; (b) bite registration polyether; (c) bite registration addition silicone; and (d) autopolymerizing acrylic resin. The accuracy of implant-abutment replica positions was calculated on the experimental casts, in terms of interimplant distances in the x, y, and z-axes, using a coordinate measuring machine; values were compared with those measured on the reference model. Data were analyzed using non-parametrical Kruskal-Wallis and Mann-Whitney tests at α = .05.
RESULTS
The differences between the two impression materials, VPES and PE, regardless of splinting type, were not statistically significant (P>.05). Non-splinting and splinting groups were also not significantly different for both PE and VPES (P>.05).
CONCLUSIONS
The accuracy of VPES impression material seemed comparable with PE for multi-implant abutment-level impressions. Splinting had no effect on the accuracy of implant impressions.
Topics: Dental Implants; Dental Impression Materials; Dental Impression Technique; Dental Prosthesis Design; Elastomers; Humans; Jaw Relation Record; Mandible; Models, Dental; Polymers; Surface Properties
PubMed: 29349910
DOI: 10.1111/jicd.12320 -
Minerva Dental and Oral Science Feb 2023The success in acquiring a precision impression in the dental field is a compromise between the processing time and the setting time of the impression material. A device...
BACKGROUND
The success in acquiring a precision impression in the dental field is a compromise between the processing time and the setting time of the impression material. A device called "Impression Heater" (EU application n° EP20186042.6) has recently been patented, which consists of a self-heating disposable adhesive patch with an exothermic chemical reaction to be placed on the dental impression tray. The aim of the study was to evaluate the effectiveness of a thermal impression accelerator in reducing the setting time of different elastomers.
METHODS
Three samples of 5 different elastomeric materials (width 6 mm x length 50 mm x depth 3-5-7 mm) the hardening of the material was evaluated at intervals of 15 seconds using an ASTM 2240 Shore-A durometer at 20 °C. The same procedure was replicated 3 times after positioning on a Impression Heater at temperatures of 35 °C, 50 °C and 65 °C, for each material.
RESULTS
An increase in the impression material temperature from 35 °C to 50 °C reduces the setting time of an amount between 38.1% and 45.8%. Increasing the temperature from 35 °C to 65 °C results in a reduction of the setting time between 52.4% and 66.9%. At higher temperatures, the greater thickness of the impression material requires longer hardening times.
CONCLUSIONS
The tests carried out confirm the validity of the patented idea which reduces the time of impression taking while keeping the working time sufficiently long for the operator to manoeuvre.
Topics: Dental Impression Technique; Dental Impression Materials; Elastomers; Elasticity; Time Factors
PubMed: 36197277
DOI: 10.23736/S2724-6329.22.04676-9 -
Clinical Oral Investigations Aug 2012Polyether impression materials have been used in dentistry for more than 40 years. Allergic reactions to these materials such as reported in the 1970s ceased after... (Comparative Study)
Comparative Study
Polyether impression materials have been used in dentistry for more than 40 years. Allergic reactions to these materials such as reported in the 1970s ceased after replacement of a catalyst. Very recently, however, patients have started to report symptoms that suggest a new allergic reaction from polyether impression materials. Here, we report on the results of allergy testing with polyether impression materials as well as with its components. Eight patients with clinical symptoms of a contact allergy (swelling, redness or blisters) after exposure to a polyether impression material were subjected to patch tests, two of them additionally to a prick test. A further patient with atypical symptoms of an allergy (nausea and vomiting after contact with a polyether impression material in the oral cavity) but with a history of other allergic reaction was also patch tested. The prick tests showed no immediate reactions in the two patients tested. In the patch tests, all eight patients with typical clinical symptoms showed positive reactions to the mixed polyether impression materials, to the base paste or to a base paste component. The patient with the atypical clinical symptoms did not show any positive patch test reactions. Polyether impression materials may evoke type IV allergic reactions. The causative agent was a component of the base paste. In consideration of the widespread use of this impression material (millions of applications per year) and in comparison to the number of adverse reactions from other dental materials, the number of such allergic reactions is very low. In very scarce cases, positive allergic reactions to polyether impression materials are possible.
Topics: Adult; Aged; Blister; Dental Impression Materials; Dermatitis, Allergic Contact; Edema; Erythema; Ethers; Female; Humans; Hypersensitivity, Delayed; Intradermal Tests; Middle Aged; Mouth Diseases; Nausea; Patch Tests; Resins, Synthetic; Retrospective Studies; Vomiting; Young Adult
PubMed: 21947905
DOI: 10.1007/s00784-011-0618-8 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Dec 2022This work aimed to synthesize a novel injectable alginate impression material and evaluate its accuracy.
OBJECTIVES
This work aimed to synthesize a novel injectable alginate impression material and evaluate its accuracy.
METHODS
Certain proportions of sodium alginate, trisodium phosphate dodecahydrate, potassium fluorotitanate, diatomaceous earth, and other ingredients were dissolved in water and mixed evenly with a planetary centrifugal mixer to obtain a certain viscosity base paste. Certain proportions of calcium sulfate hemihydrate, magnesium oxide, glycerin, and polyethylene glycol (PEG) 400 were mixed evenly with a planetary centrifugal mixer to obtain the reactor paste with the same viscosity as the base paste. The base and reactor pastes were poured into a two-cylinder cartridge at a 2∶1 volume ratio. A gun device was used to accomplish mixing by compressing materials into a mixing tip. The samples were divided into three groups: injectable alginate impression materials (IA group) as the experimental group, and Jeltrate alginate impression materials (JA group) and Silagum-putty/light addition silicone rubber impression materials (SI group) as the two control groups.
RESULTS
Scanning electron microscopy (SEM) showed that the injectable alginate impression materials had a denser structure and fewer bubbles than the commercial alginate impression material. The accuracy of the three kinds of impression materials was evaluated by 3D image superposition. The deviations between the three test group models and the standard model (trueness) were 49.58 μm±1.453 μm (IA group), 54.75 μm±7.264 μm (JA group), and 30.92 μm±1.013 μm (SI group). The deviations of the models within each test group (precision) were 85.79 μm±8.191 μm (IA group), 97.65 μm±11.060 μm (JA group), and 56.51 μm±4.995 μm (SI group). Significant differences in trueness and precision were found among the three kinds of impression materials (<0.05).
CONCLUSIONS
The accuracy of the new injectable alginate impression material was better than that of the traditional powder-type alginate impression material but worse than that of the addition silicone rubber impression materials. The novel injec-table alginate impression material demonstrated good operation performance and impression accuracy, showing broad application prospect.
Topics: Alginates; Silicone Elastomers; Dental Impression Materials; Powders
PubMed: 36416318
DOI: 10.7518/hxkq.2022.06.006 -
Compendium of Continuing Education in... Mar 2022Conventional impressions are the benchmark for any new replication technique due to the demonstrated accuracy of PVS and polyether impression materials.1 However, it is...
Conventional impressions are the benchmark for any new replication technique due to the demonstrated accuracy of PVS and polyether impression materials.1 However, it is well known that throughout the impression process there are potential risks to final accuracy, including setting of the impression material, removal of the impression, and fabrication of the stone model.2-4 Despite the documented accuracy of PVS and polyether impressions, studies have repeatedly shown that most impressions sent to dental laboratories have some sort of deficiency. One study evaluated 193 FPD impressions made by 41 dentists immediately after they arrived at 11 dental laboratories and reported that 50.7 percent of all the impressions had voids or tears in the finish line area, 40.4 percent had air bubbles at the margin line, and 26.9 percent had both.5 Thus, although impression material has documented accuracy, making an accurate impression involves more than just the precision of the material.
Topics: Dental Impression Materials; Dental Impression Technique
PubMed: 35272463
DOI: No ID Found -
The Journal of Prosthetic Dentistry Mar 2023Ingestion or aspiration of foreign objects may present as a significant complication with various common dental procedures. The most reported ingested or aspirated...
Ingestion or aspiration of foreign objects may present as a significant complication with various common dental procedures. The most reported ingested or aspirated dental materials have included endodontic instruments and metal restorative and prosthetic materials, which can often be identified clinically and radiographically from their relative radiodensities. The authors present an unusual report of lodged impression material in the hypopharynx, which was not detectable radiographically.
Topics: Humans; Hypopharynx; Dental Impression Materials; Foreign Bodies
PubMed: 34284870
DOI: 10.1016/j.prosdent.2021.06.020 -
Compendium of Continuing Education in... Jun 2017Alginate impression (irreversible hydrocolloid) material is commonly used in dental practice because it is easy to mix, low in cost, and well tolerated by patients. The...
Alginate impression (irreversible hydrocolloid) material is commonly used in dental practice because it is easy to mix, low in cost, and well tolerated by patients. The material is not dimensionally stable, however; thus, it is necessary to pour the impression immediately after the molding is accomplished, or within 60 minutes if the impression is kept in 100% humidity. Excessive contact of the alginate impression with the cast model over time may affect the model's properties. In this study, the authors tested the effect of contact time between an alginate impression and type III dental stone on cast model properties. Sixty-seven cast models were obtained from a stainless steel cylinder by using irreversible hydrocolloid impression material and type III dental stone. Thirty-seven cast models were separated from the impression after 1 hour (control group) and 30 cast models were separated after 6 hours (study group). The samples were evaluated under light microscope for surface details and measured by digital caliper for dimensional stability. An indentation on the cast was made and the depth of the indentation was then measured with a digital caliper to measure hardness. The dimensional stability of the cast models was not affected when contact time was increased from 1 hour to 6 hours (P = .507). Surface details did not deteriorate when contact time was increased, as all of the samples could reproduce all details after the 1-hour and 6-hour interval periods. However, hardness was greater after 1 hour of contact time (P = .001) than after 6 hours of contact time. In conclusion, contact between alginate impression material and type III dental stone up to 6 hours did not affect the dimensional stability and richness of the surface; hardness, though, was significantly affected.
Topics: Alginates; Calcium Sulfate; Dental Impression Materials; Dental Impression Technique; Dental Materials; Hardness Tests; Humidity; Materials Testing; Microscopy; Models, Dental; Stainless Steel; Surface Properties; Time Factors
PubMed: 28586232
DOI: No ID Found -
British Dental Journal Oct 2006The object of making an impression in implant dentistry is to accurately relate an analogue of the implant or implant abutment to the other structures in the dental... (Review)
Review
The object of making an impression in implant dentistry is to accurately relate an analogue of the implant or implant abutment to the other structures in the dental arch. This is affected by use of an impression coping which is attached to the implant or implant abutment. This impression coping is incorporated in an impression - much as a metal framework is 'picked up' in a remount impression for fixed prosthodontics. With implant copings the coping is usually attached to the implant or abutment with screws. The impression material used is usually an elastomeric impression material; the two types most widely used and shown to be the most appropriate are polyether and polyvinyl siloxane impression materials.
Topics: Dental Abutments; Dental Implants; Dental Impression Materials; Dental Impression Technique; Humans
PubMed: 17031344
DOI: 10.1038/sj.bdj.4814118