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The Journal of Prosthetic Dentistry Oct 2015Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic...
STATEMENT OF PROBLEM
Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic materials have been developed.
PURPOSE
The purpose of this in vitro study was to compare contact angles of water and saliva on 7 unset elastomeric impression materials at 5 time points from the start of mixing.
MATERIAL AND METHODS
Two traditional polyvinyl siloxane (PVS) (Aquasil, Take 1), 2 modified PVS (Imprint 4, Panasil), a polyether (Impregum), and 2 hybrid (Identium, EXA'lence) materials were compared. Each material was flattened to 2 mm and a 5 μL drop of distilled water or saliva was dropped on the surface at 25 seconds (t0) after the start of mix. Contact angle measurements were made with a digital microscope at initial contact (t0), t1=2 seconds, t2=5 seconds, t3=50% working time, and t4=95% working time. Data were analyzed with a generalized linear mixed model analysis, and individual 1-way ANOVA and Tukey HSD post hoc tests (α=.05).
RESULTS
For water, materials grouped into 3 categories at all time-points: the modified PVS and one hybrid material (Identium) produced the lowest contact angles, the polyether material was intermediate, and the traditional PVS materials and the other hybrid (EXA'lence) produced the highest contact angles. For saliva, Identium, Impregum, and Imprint 4 were in the group with the lowest contact angle at most time points.
CONCLUSION
Modified PVS materials and one of the hybrid materials are more hydrophilic than traditional PVS materials when measured with water. Saliva behaves differently than water in contact angle measurement on unset impression material and produces a lower contact angle on polyether based materials.
Topics: Dental Impression Materials; Dental Impression Technique; Elastomers; Humans; Hydrophobic and Hydrophilic Interactions; Materials Testing; Resins, Synthetic; Saliva; Surface Properties; Water; Wettability
PubMed: 26187106
DOI: 10.1016/j.prosdent.2015.05.004 -
The Journal of Prosthetic Dentistry Mar 1987After impression-making procedures, remnants of Xantopren impression material were found in the gingival crevices in eight of 125 patients. In three of the eight...
After impression-making procedures, remnants of Xantopren impression material were found in the gingival crevices in eight of 125 patients. In three of the eight patients, remnants were only discovered subsequent to a systematic exploration with a fine curette. In all eight of the patients in which material was found in the crevice, the location corresponded with defects in the impression itself. Although eight of 125 is not a statistically significant number, it would be nonetheless prudent to consider a routine curettage of abutment sulci after impression-making. This procedure is even more strongly recommended should a defect be detected in the crevicular region of the impression. Impressions should remain in the mouth until full setting and maximum tear strength is reached. Strict adherence to the manufacturers' instructions is necessary.
Topics: Dental Abutments; Dental Impression Materials; Denture, Partial, Fixed; Foreign Bodies; Gingiva; Humans
PubMed: 3553551
DOI: 10.1016/0022-3913(87)90303-9 -
Journal of Oral Rehabilitation Jun 2019The aims of this study were to test the hypotheses that (a) a laserscanner used for measuring maximum depth and volume loss will yield the same results as a surface...
OBJECTIVES
The aims of this study were to test the hypotheses that (a) a laserscanner used for measuring maximum depth and volume loss will yield the same results as a surface profilometer; (b) the surface roughness will affect the maximum depth and volume loss measured with the laserscanner; (c) analytical results using the laserscanner from multiple operators have no more than 10% inter-rater difference and; (d) replicating samples using either stone or impression material is an accurate method for measuring wear using the laserscanner.
MATERIALS AND METHODS
The volume and maximum depth of indentations from fine, medium and rough burs on glass-ceramic disks were measured using two devices, a surface profilometer (Dektak II, Veeco) and a 3D Laserscanner (LAS-20, SD Mechatronik). Replicates of the indentations made from polyvinysiloxane impression material and gypsum were also measured.
RESULTS
Comparison of profilometer and laserscanner readings using ceramic disks demonstrated a mean error of 13.61% for depth and 25.32% for volume. Replication errors were minimal (2.6% for impression, 2.5% for stone). Surface profilometer data for volume measurements revealed a difference of 6.1% for impression and 6.5% for stone compared with ceramics. However, when measurements for replicates were compared between laserscanner and surface profilometer, depth had a mean error of 74% for impression and 51% for stone. Volume differences of 78% for impression and 44% for stone were recorded.
CONCLUSION
This work demonstrated that the laserscanner was a convenient device for measuring wear but there is a need to validate the accuracy of the measurements.
Topics: Ceramics; Dental Impression Materials; Materials Testing; Surface Properties
PubMed: 30759313
DOI: 10.1111/joor.12778 -
Journal - Oklahoma Dental Association 1984
Comparative Study
Topics: Dental Impression Materials; Economics, Dental
PubMed: 6595374
DOI: No ID Found -
Dental Update Oct 2000Conventionally, custom trays have been made in the laboratory on casts constructed from preliminary impressions. A spaced tray made in this way allows a uniform...
Conventionally, custom trays have been made in the laboratory on casts constructed from preliminary impressions. A spaced tray made in this way allows a uniform thickness of impression material of approximately 2 mm which is said to enhance the accuracy of the impression-taking procedure. A technique is described to fulfill this criterion without the need for a primary impression, by constructing a spaced putty custom tray inside the mouth.
Topics: Dental Impression Materials; Dental Impression Technique; Equipment Design; Humans; Polyvinyls; Siloxanes; Viscosity; Waxes
PubMed: 11218529
DOI: 10.12968/denu.2000.27.8.376 -
American Journal of Contact Dermatitis... Dec 1999A patient with allergic contact dermatitis caused by benzyl alcohol in a hearing aid impression material and in topical medications is described. In addition, the... (Review)
Review
A patient with allergic contact dermatitis caused by benzyl alcohol in a hearing aid impression material and in topical medications is described. In addition, the patient had topical and probably systemic corticosteroid allergy. Benzyl alcohol allergy is reviewed. allergic contact dermatitis is the most commonly reported allergic reaction to benzyl alcohol. There is also 1 report of contact urticaria. Balsam of Peru patch tests are frequently positive. Reported allergic reactions to injected benzyl alcohol include generalized urticarial reactions, 1 generalized maculopapular reaction and 1 delayed localized reaction.
Topics: Aged; Benzyl Alcohol; Dental Impression Materials; Dermatitis, Allergic Contact; Hearing Aids; Humans; Male; Patch Tests; Polyvinyls; Prosthesis Design; Sensitivity and Specificity; Siloxanes
PubMed: 10594301
DOI: 10.1053/AJCD01000228 -
Swedish Dental Journal 1982In the fabrication of crowns and inlays it is very important that all the details of the impression are exactly reproduced by the cast. These requirements prevail... (Comparative Study)
Comparative Study
In the fabrication of crowns and inlays it is very important that all the details of the impression are exactly reproduced by the cast. These requirements prevail between elastomeric impression materials and dental stones as well as between waxes and investment materials. Inadequate filling of the details of the impression will result in rounded inner corners of the casting, which then may not properly seat on the prepared tooth. Two brands of elastomeric impression material, dental stone, wax, investment material and wetting agent were chosen to study the reproduction of details. A master model of stainless steel, shaped like a truncated cone with a convex top and 60 degrees threads, was used. The shape of this model made it possible to make microscopic measurements of the reproduced detail of the threads. No significant difference, by different prepouring treatment of the impressions was found in reproducing details with elastomeric impression materials and dental stones. All combinations of elastomeric impression materials and dental stones reproduced, however, significantly more details than combinations of waxes and investment materials. The relevance of transferring conclusions from the laboratory investigation to clinical conditions are discussed as well as the clinical value of reproducing details.
Topics: Calcium Sulfate; Dental Casting Investment; Dental Impression Materials; Inlay Casting Wax; Models, Dental; Silicone Elastomers; Surface Properties; Waxes
PubMed: 6963007
DOI: No ID Found -
Vojnosanitetski Pregled Oct 2016Dental impressions present a negative imprint of intraoral tissues of a patient which is, by pouring in gypsum, transferred extraorally on the working cast. Casting an...
BACKGROUND/AIM
Dental impressions present a negative imprint of intraoral tissues of a patient which is, by pouring in gypsum, transferred extraorally on the working cast. Casting an accurate and precise working cast presents the first and very important step, since each of the following stages contributes to the overall error of the production process, which can lead to inadequately fitting dental restorations. The aim of this study was to promote and test a new model and technique for in vitro evaluation of the dental impression accuracy, as well as to asses the dimensional stability of impression material depending on the material bulk, and its effect on the accuracy of working casts.
METHODS
Impressions were made by the monophasic technique using the experimental master model. Custom trays with spacing of 1, 2 and 3 mm were constructed by rapid prototyping. The overall of 10 impressions were made with each custom tray. Working casts were made with gypsum type IV. Measurement of working casts was done 24 h later using a co-ordinate measuring machine.
RESULTS
The obtained results show that the working casts of all the three custom trays were in most cases significantly different in the transversal and sagittal planes in relation to the master model. The height of abutments was mainly unaffected. The degree of convergence showed certain significance in all the three custom trays, most pronounced in the tray with 3 mm spacing.
CONCLUSION
The impression material bulk of 1–3 mm could provide accurate working casts when using the monophasic impression technique. The increase of the distance between abutment teeth influences the accuracy of working casts depending on the material bulk. [Projekat Ministarstva nauke Republike Srbije, br. TR 35020: Research and development of modelling methods and approaches in manufacturing of dental recoveries with the application of modern technologies and computer aided systems]
Topics: Calcium Sulfate; Computer-Aided Design; Dental Casting Technique; Dental Impression Materials; Dental Impression Technique; Denture Bases; Denture Design; Humans; Models, Dental; Reproducibility of Results; Resins, Synthetic
PubMed: 29327892
DOI: 10.2298/VSP150105089P -
Clinical Oral Investigations Apr 2018The objective of this study was to evaluate the accuracy of different impression techniques on multiple implants. (Comparative Study)
Comparative Study
OBJECTIVES
The objective of this study was to evaluate the accuracy of different impression techniques on multiple implants.
MATERIAL AND METHODS
A master cast simulating a jaw with four implants was used. Eight impression techniques were tested: open tray-polyether#1, open tray plus splint of impression copings with acrylic resin-polyether#1, closed tray-polyether#1, open tray-polyether#2, open tray-splint-polyether#2, closed tray-polyether#2, open tray-impression plaster, and digital impression (DI). Five impressions of the master cast were taken with each traditional impression (TI) technique, pouring 35 sample casts. Three different clinicians took 5 DI each (n = 15). A three-dimensional coordinate measurement machine (CMM) was used to measure implant angulation and inter-implant distances on TI casts. TI data and DI Standard Tessellation Language datasets were compared with the master cast. The best and the worst impressions made with TI and DI were selected to fabricate four milled titanium frameworks. Passive fit was evaluated through Sheffield test, screwing each framework on the master cast. Gaps between framework-implant analogs were measured through a stereomicroscope (×40 magnification).
RESULTS
Statistically significant differences in accuracy were found comparing the different impression techniques by CMM (p < 0.01). DI performed the best, while TI techniques revealed a greater variability in the results. Sheffield test revealed a mean gap of 0.022 ± 0.023 mm (the best TI), 0.063 ± 0.059 mm (the worst TI), 0.015 ± 0.011 mm (the best DI), and 0.019 ± 0.015 mm (the worst DI).
CONCLUSIONS
Within the limits of this in vitro study, the digital impression showed better accuracy compared to conventional impressioning.
CLINICAL RELEVANCE
The digital impression might offer a viable alternative to traditional impressions for fabrication of full-arch implant-supported prostheses with satisfactory passive fit.
Topics: Dental Implants; Dental Impression Materials; Dental Impression Technique; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Humans; In Vitro Techniques; Models, Dental; Video Recording
PubMed: 28965251
DOI: 10.1007/s00784-017-2217-9 -
Dental Materials : Official Publication... Jul 2018The main objective of the present in vitro study is to evaluate the antimicrobial activity and properties of irreversible hydrocolloid impression material incorporated...
Does the size matter? Evaluation of effect of incorporation of silver nanoparticles of varying particle size on the antimicrobial activity and properties of irreversible hydrocolloid impression material.
OBJECTIVES
The main objective of the present in vitro study is to evaluate the antimicrobial activity and properties of irreversible hydrocolloid impression material incorporated with silver nanoparticles of varying size at different concentrations.
METHODS
Silver nanoparticles of 80-100, 50-80, 30-50 and 10-20nm size were added to irreversible hydrocolloid impression material at 0.5, 1.0, 2.0 and 5.0wt%. Antimicrobial activity of the silver nanoparticle incorporated irreversible hydrocolloid was measured using disk diffusion method. The gel strength, flow, gelation time and permanent deformation were measured according to American Dental Association specification #18. Data were analyzed using analysis of variation at a confidence interval of 95% (α=0.05).
RESULTS
Silver nanoparticles of 80-100nm size have imparted superior antimicrobial activity to the irreversible hydrocolloid in a dose-dependent manner whereas finer nanoparticle size did not exhibit any antimicrobial activity. The addition of silver nanoparticles did not alter the properties of irreversible hydrocolloid at 0.5 and 1.0wt% whereas at higher concentrations significant differences in flow, gelation time and strength were observed.
SIGNIFICANCE
The results of the present study indicate that silver nanoparticles of size range 80-100nm are superior in imparting antimicrobial activity to irreversible hydrocolloid compared to finer particle size range.
Topics: Anti-Infective Agents; Colloids; Dental Impression Materials; In Vitro Techniques; Materials Testing; Metal Nanoparticles; Particle Size; Silver
PubMed: 29706228
DOI: 10.1016/j.dental.2018.03.016