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The International Journal of... 2016This pilot study analyzed impression procedures for conventional metal frame removable partial dentures (RPDs). Heads of RPD departments of three dental laboratories...
This pilot study analyzed impression procedures for conventional metal frame removable partial dentures (RPDs). Heads of RPD departments of three dental laboratories were asked to record features of all incoming impressions for RPDs during a 2-month period. Records included: (1) impression procedure, tray type (stock/custom), impression material (elastomer/alginate), use of border-molding material (yes/no); and (2) RPD type requested (distal-extension/tooth-bounded/combination). Of the 132 total RPD impressions, 111 (84%) involved custom trays, of which 73 (55%) were combined with an elastomer. Impression border-molding material was used in 4% of the cases. Associations between impression procedure and RPD type or dentists' year/university of graduation were not found.
Topics: Alginates; Dental Alloys; Dental Impression Materials; Dental Impression Technique; Dentists; Denture Design; Denture, Partial, Removable; Elastomers; General Practice, Dental; Humans; Pilot Projects
PubMed: 26929957
DOI: 10.11607/ijp.4540 -
The European Journal of Prosthodontics... 2001The study investigated the effect of two disinfecting solutions on one brand of alginate impression material and dental stone. Control impressions were immersed in water...
The study investigated the effect of two disinfecting solutions on one brand of alginate impression material and dental stone. Control impressions were immersed in water for equivalent periods and the effect of storage of impressions after disinfection or control immersion in water was also investigated. There were no significant dimensional changes in impressions poured after one hour. All impressions stored for 16 hours before pouring showed significant dimensional changes. Mixing dental stone with one disinfectant caused a significant softening of the cast. It is strongly recommended that all impressions are thoroughly rinsed with water after disinfection to prevent incorporation of disinfectant in the cast.
Topics: Alginates; Calcium Sulfate; Dental Disinfectants; Dental Impression Materials; Drug Storage; Hardness; Materials Testing; Models, Dental; Peroxides; Surface Properties; Triazines; Water
PubMed: 12192949
DOI: No ID Found -
Journal of Oral Rehabilitation Jun 2003The purpose of this study was to inspect visually, the dynamics of the impression flow at seating of the impression tray. The effects of the relief and the escape hole...
The purpose of this study was to inspect visually, the dynamics of the impression flow at seating of the impression tray. The effects of the relief and the escape hole of the impression tray on the impression flow were also examined. Three types of the transparent impression tray (flat tray, relief tray and escape hole tray) were prepared. Transparent silicone polymer was put on the impression tray surface. Four drops of the dark blue silicone impression material was injected into the transparent silicone polymer on the impression tray. The impression tray was seated on the model of the denture-supporting mucosa. The movement of the four drops caused by the impression flow was visually recorded with the video camera and examined. The result for the flat tray showed that the impression material moved from inside to the outside. It was also shown that the speed of the moved impression material increased as the seating of the impression tray advanced. The results for the relief tray and the escape hole tray showed the effect of the relief and the escape hole prepared to the impression tray on the speed and the direction of the flow of the impression material.
Topics: Dental Impression Materials; Dental Impression Technique; Equipment Design; Humans; Materials Testing; Mouth Mucosa; Silicone Elastomers
PubMed: 12787458
DOI: 10.1046/j.1365-2842.2003.01056.x -
The International Journal of Oral &... 2010The aim of this study was to evaluate, using scanning electron microscopy (SEM), the accuracy of four impression techniques for osseointegrated implants (with or without... (Comparative Study)
Comparative Study
PURPOSE
The aim of this study was to evaluate, using scanning electron microscopy (SEM), the accuracy of four impression techniques for osseointegrated implants (with or without acrylic resin splinting and with irreversible hydrocolloid or polyvinyl siloxane [PVS] impression material).
MATERIALS AND METHODS
A metal master model was made with three implant analogs and two prosthetic spaces. This model was used as the standard for all impressions. Two impression materials were used (irreversible hydrocolloid and PVS) and two transfer techniques were used (squared impression copings indexed by the impression material and squared impression copings splinted with acrylic resin). Four groups were therefore analyzed (n = 5): IH = irreversible hydrocolloid only, IHS = irreversible hydrocolloid + splint, P = PVS only, and PS = PVS + splint. A reference framework made with palladium-silver alloy over the UCLA abutment was created on the master model. The fit of this structure to the master model was used as a reference. SEM images of the front and side gaps between the abutments and the implant analogs were created and then measured using image analysis software.
RESULTS
IH presented the largest misfit. The splinted impression copings generated a smaller marginal gap than the indexed material technique, irrespective of the impression material used. There was no significant difference between IHS, P, PS, and the reference (multivariate test, Wilks criteria). However, PS presented a standard deviation that was three times lower than those of the other groups, and its mean was closer to the reference.
CONCLUSIONS
The IH impression technique was the least accurate technique. There was no difference between IHS, P, and PS techniques with regard to the reference constant. The impression techniques that used splinted impression copings generated more accurate casts, irrespective of the impression material.
Topics: Dental Implantation, Endosseous; Dental Impression Materials; Dental Impression Technique; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Humans; Microscopy, Electron, Scanning; Patient Care Planning; Reproducibility of Results; Splints
PubMed: 21197487
DOI: No ID Found -
Journal of Radiation Research Sep 2022We evaluated the basic characteristics and efficacy of our newly developed patient fixation system for head and neck radiotherapy that uses a dedicated mouthpiece and...
We evaluated the basic characteristics and efficacy of our newly developed patient fixation system for head and neck radiotherapy that uses a dedicated mouthpiece and dental impression materials. The present investigation demonstrated that with this system, the changes in the absorbed dose to water depending on the material of the mouthpiece were small, with a maximum of 0.32% for a 10-MV photon beam. For the dental impression material, we selected a silicone material with the lowest Hounsfield unit (HU) value that had little effect on the generation of artifacts and the quality of the X-ray beam. Multiphase magnetic resonance imaging (MRI) revealed that the head-up and -down motions in the thermoplastic shell without the mouthpiece were 5.76 ± 1.54 mm, whereas the motion with the mouthpiece decreased significantly to 1.72 ± 0.92 mm (P = 0.006). Similarly, the head-left and -right motion displacement decreased from 6.32 ± 1.86 mm without the mouthpiece to 1.80 ± 0.42 mm with the mouthpiece (P = 0.003). Regarding the tongue depressor function of the mouthpiece, the median distance from the hard palate to the surface of the tongue was 28.42 mm. The present results indicate that the new immobilization device developed herein that uses a mouthpiece and a thermoplastic shell is useful for suppressing patients' head motions and tongue positions.
Topics: Dental Impression Materials; Head and Neck Neoplasms; Humans; Neck; Radiotherapy Planning, Computer-Assisted; Silicones; Water
PubMed: 35818301
DOI: 10.1093/jrr/rrac044 -
Journal of the American Dental... Jun 1967
Topics: American Dental Association; Dental Impression Materials; Humans; United States; Zinc Phosphate Cement
PubMed: 5228842
DOI: 10.14219/jada.archive.1967.0412 -
Dental Materials : Official Publication... Apr 2014Thiol- and allyl-functionalized siloxane oligomers are synthesized and evaluated for use as a radical-mediated, rapid set elastomeric dental impression material....
OBJECTIVES
Thiol- and allyl-functionalized siloxane oligomers are synthesized and evaluated for use as a radical-mediated, rapid set elastomeric dental impression material. Thiol-ene siloxane formulations are crosslinked using a redox-initiated polymerization scheme, and the mechanical properties of the thiol-ene network are manipulated through the incorporation of varying degrees of plasticizer and kaolin filler. Formulations with medium and light body consistencies are further evaluated for their ability to accurately replicate features on both the gross and microscopic levels. We hypothesize that thiol-ene functionalized siloxane systems will exhibit faster setting times and greater detail reproduction than commercially available polyvinylsiloxane (PVS) materials of comparable consistencies.
METHODS
Thiol-ene functionalized siloxane mixtures formulated with varying levels of redox initiators, plasticizer, and kaolin filler are made and evaluated for their polymerization speed (FTIR), consistency (ISO4823.9.2), and surface energy (goniometer). Feature replication is evaluated quantitatively by SEM. The Tg, storage modulus, and creep behavior are determined by DMA.
RESULTS
Increasing redox initiation rate increases the polymerization rate but at high levels also limits working time. Combining 0.86 wt% oxidizing agent with up to 5 wt% plasticizer gave a working time of 3 min and a setting time of 2 min. The selected medium and light body thiol-ene formulations also achieved greater qualitative detail reproduction than the commercial material and reproduced micrometer patterns with 98% accuracy.
SIGNIFICANCE
Improving detail reproduction and setting speed is a primary focus of dental impression material design and synthesis. Radical-mediated polymerizations, particularly thiol-ene reactions, are recognized for their speed, reduced shrinkage, and 'click' nature.
Topics: Allyl Compounds; Cross-Linking Reagents; Dental Impression Materials; Elastomers; Kaolin; Materials Testing; Polymerization; Polymers; Siloxanes; Sulfhydryl Reagents
PubMed: 24553250
DOI: 10.1016/j.dental.2014.01.011 -
International Dental Journal Dec 2011To evaluate the handling of a new impression mixing device and the associated impression material by general dental practitioner members of the PREP Panel.
AIMS
To evaluate the handling of a new impression mixing device and the associated impression material by general dental practitioner members of the PREP Panel.
DESIGN
By means of a questionnaire, the participating practitioners recorded their views on the mixing machine and impression materials, having used these for ten weeks.
SETTING
UK general dental practices.
PARTICIPANTS
General dental practitioner members of a UK practice-based research group.
METHODS
A questionnaire was designed to elicit views on the performance of the mixing device and impression material under test. This was distributed to the practitioners who had used the test materials for 10 weeks and the data thereby obtained collated and presented, principally in the form of VAS scales.
OUTCOME MEASURES
Rating of various parameters of the mixing device and impression materials on VAS scales.
RESULTS
The Pentamix 3 machine scored well for ease of initial use [4.8 on a visual analogue scale (VAS) where 1 = very difficult to use and 5 = very easy to use]. In a range of criteria (including cleanliness, easy handling, time to fill the tray and overall convenience) the Pentamix scored highly on VAS scales. A maximum score of 5 (on a VAS where 1 = very dissatisfied and 5 = very satisfied) was achieved for reproducible mixing quality. The appreciation of the Pentamix 3 mixing machine was demonstrated by the fact that 85% (n = 11) of evaluators stated that they would recommend it to colleagues. Regarding the impression material under evaluation, 85% (n = 11) of the evaluators stated that they would recommend Impregum Quick impression materials to their colleagues.
CONCLUSIONS
Within the limitations of this study, the Pentamix 3 automatic impression mixing device scored highly in this assessment, together with the impression materials assessed.
Topics: Attitude of Health Personnel; Chemical Phenomena; Community-Based Participatory Research; Dental Impression Materials; Dental Impression Technique; Dentists; Disinfection; Equipment Design; General Practice, Dental; Humans; Reproducibility of Results; Resins, Synthetic; Surface Properties; Time Factors; United Kingdom
PubMed: 22117789
DOI: 10.1111/j.1875-595X.2011.00079.x -
Oral Surgery, Oral Medicine, and Oral... Oct 1990
Topics: Dental Impression Materials; Female; Foreign Bodies; Gingiva; Humans; Mandible; Middle Aged; Molar; Radiography; Rubber
PubMed: 2216391
DOI: 10.1016/0030-4220(90)90221-d -
Minerva Stomatologica Apr 2020Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of... (Review)
Review
Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of prostheses and in the production of positives for small-scale casting. It is also used in the pharmaceutical, cosmetic and food industries for various uses. The purpose of our study is to assess whether the chemical and physical characteristics of water can influence the characteristics and performance of these materials. These impression materials are often marketed as a powder to be mixed with water, but water is not included during the purchase. We have considered different articles, but unfortunately the results that speak of this topic are few and contain little information. We have therefore carried out a review of the present literature on Pubmed and Embase search engine. The same product used by two people with two different waters will have different characteristics. The possibility of knowing these effects could allow for more performing materials and above all for identical and reproducible materials. In conclusions, the results indicate to follow the manufacturer's instructions, and eventually turn to the use of automatic devices.
Topics: Alginates; Dental Impression Materials; Materials Testing; Powders
PubMed: 32489090
DOI: 10.23736/S0026-4970.19.04293-6