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Quintessence International (Berlin,... Mar 2008To investigate the dimensional changes and the surface quality of dental impression materials after disinfection with 3 chemically different agents. (Comparative Study)
Comparative Study
OBJECTIVE
To investigate the dimensional changes and the surface quality of dental impression materials after disinfection with 3 chemically different agents.
METHOD AND MATERIALS
Four alginate impression materials and 1 addition silicone material were selected. The impressions were made from a brass model simulating a 3-unit fixed partial denture. The chemical disinfection was performed with 3 different disinfectants for 10 minutes. Three samples of each impression material and disinfectant agent were investigated. As a control, 3 impressions of each material were made without any disinfection. The casts were made with a type IV dental stone. For each cast, 6 diameters and 3 distances were measured. To evaluate the dimensional stability, measurements were taken at a magnification of 34X with a light microscope. The surface quality was recorded using a profilometer.
RESULTS
The dimensional change and surface quality differed minimally; however, statistically significant differences were found between alginate and addition silicone impression materials (ANOVA, P < .05). Casts from the silicone impressions were more accurate than the casts from alginate impressions.
CONCLUSION
Different impression disinfection methods have only a marginal influence on dimensional stability and surface quality of dental casts. To achieve a higher precision, the use of an addition silicone can be recommended.
Topics: Alginates; Analysis of Variance; Benzalkonium Compounds; Dental Disinfectants; Dental Impression Materials; Disinfection; Glutaral; Models, Dental; Silicone Elastomers; Statistics, Nonparametric; Sulfuric Acids; Surface Properties
PubMed: 18618030
DOI: No ID Found -
Journal of Dentistry Apr 1992Some laboratory tests of impression material accuracy mimic the clinical situation (simulatory) while others attempt to quantify a material's individual properties. This... (Review)
Review
Some laboratory tests of impression material accuracy mimic the clinical situation (simulatory) while others attempt to quantify a material's individual properties. This review concentrates on simulatory testing and aims to give a classification of the numerous tests available. Measurements can be made of the impression itself or the resulting cast. Cast measurements are divided into those made of individual dies and those made of interdie relations. Contact measurement techniques have the advantage of simplicity but are potentially inaccurate because of die abrasion. Non-contact techniques can overcome the abrasion problem but the measurements, especially those made in three dimensions, may be difficult to interpret. Nevertheless, providing that care is taken to avoid parallax error non-contact methods are preferable as experimental variables are easier to control. Where measurements are made of individual dies these should include the die width across the finishing line, as occlusal width measurements provide only limited information. A new concept of 'differential die distortion' (dimensional difference from the master model in one plane minus the dimensional difference in the perpendicular plane) provides a clinically relevant method of interpreting dimensional changes. Where measurements are made between dies movement of the individual dies within the master model must be prevented. Many of the test methods can be criticized as providing clinically unrealistic master models/dies or impression trays. Phantom head typodonts form a useful basis for the morphology of master models providing that undercuts are standardized and the master model temperature adequately controlled.
Topics: Dental Impression Materials; Laboratories, Dental; Materials Testing; Models, Dental; Surface Properties
PubMed: 1564180
DOI: 10.1016/0300-5712(92)90117-u -
Journal of the American Dental... Aug 1996This article reviews the dangers of aspirating foreign bodies of dental origin. Two illustrative cases are presented, including an unusual case involving aspiration of... (Review)
Review
This article reviews the dangers of aspirating foreign bodies of dental origin. Two illustrative cases are presented, including an unusual case involving aspiration of an elastomeric impression material. The authors describe the techniques used to identify the foreign body. A radiodensimetric study of four impression materials demonstrates the difficulty of identifying most impression materials. The authors also present some strategies for reducing the risk of aspiration during dental procedures.
Topics: Adult; Aged; Aged, 80 and over; Alginates; Contrast Media; Dental Amalgam; Dental Impression Materials; Dental Impression Technique; Foreign Bodies; Humans; Inhalation; Lung; Male; Polyvinyls; Radiography; Siloxanes; Sulfides; Viscosity
PubMed: 8803399
DOI: 10.14219/jada.archive.1996.0415 -
Clinical Oral Investigations Sep 2013Digital impression techniques are advertised as an alternative to conventional impressioning. The purpose of this in vitro study was to compare the accuracy of full...
OBJECTIVES
Digital impression techniques are advertised as an alternative to conventional impressioning. The purpose of this in vitro study was to compare the accuracy of full ceramic crowns obtained from intraoral scans with Lava C.O.S. (3M ESPE), CEREC (Sirona), and iTero (Straumann) with conventional impression techniques.
MATERIALS AND METHODS
A model of a simplified molar was fabricated. Ten 2-step and 10 single-step putty-wash impressions were taken using silicone impression material and poured with type IV plaster. For both techniques 10 crowns were made of two materials (Lava zirconia, Cera E cast crowns). Then, 10 digital impressions (Lava C.O.S.) were taken and Lava zirconia crowns manufactured, 10 full ceramic crowns were fabricated with CEREC (Empress CAD) and 10 full ceramic crowns were made with iTero (Copran Zr-i). The accessible marginal inaccuracy (AMI) and the internal fit (IF) were measured.
RESULTS
For AMI, the following results were obtained (mean ± SD): overall groups, 44 ± 26 μm; single-step putty-wash impression (Lava zirconia), 33 ± 19 μm; single-step putty-wash impression (Cera-E), 38 ± 25 μm; two-step putty-wash impression (Lava zirconia), 60 ± 30 μm; two-step putty-wash impression (Cera-E), 68 ± 29 μm; Lava C.O.S., 48 ± 25 μm; CEREC, 30 ± 17 μm; and iTero, 41 ± 16 μm. With regard to IF, errors were assessed as follows (mean ± SD): overall groups, 49 ± 25 μm; single-step putty-wash impression (Lava zirconia), 36 ± 5 μm; single-step putty-wash impression (Cera-E), 44 ± 22 μm; two-step putty-wash impression (Lava zirconia), 35 ± 7 μm; two-step putty-wash impression (Cera-E), 56 ± 36 μm; Lava C.O.S., 29 ± 7 μm; CEREC, 88 ± 20 μm; and iTero, 50 ± 2 μm.
CONCLUSIONS
Within the limitations of this in vitro study, it can be stated that digital impression systems allow the fabrication of fixed prosthetic restorations with similar accuracy as conventional impression methods.
CLINICAL RELEVANCE
Digital impression techniques can be regarded as a clinical alternative to conventional impressions for fixed dental restorations.
Topics: Computer-Aided Design; Crowns; Dental Impression Materials; Dental Impression Technique; Dental Marginal Adaptation; Dental Prosthesis Design; Humans; Materials Testing; Silicones; Surface Properties; Workflow; Zirconium
PubMed: 23086333
DOI: 10.1007/s00784-012-0864-4 -
A self-disinfecting irreversible hydrocolloid impression material mixed with chlorhexidine solution.The Angle Orthodontist Sep 2007To examine the antibacterial effect and several physical properties of an irreversible hydrocolloid impression material mixed with chlorhexidine solution.
OBJECTIVE
To examine the antibacterial effect and several physical properties of an irreversible hydrocolloid impression material mixed with chlorhexidine solution.
MATERIALS AND METHODS
The experimental irreversible hydrocolloid specimens were prepared and allocated into four groups (Group0.1 g/L, Group0.2 g/L, Group0.5 g/L, Group1.0 g/L) according to the concentrations of chlorhexidine solution used as the mixing liquid. Specimens mixed with distilled water served as a control. The antibacterial effect, three-dimensional accuracy, flowability, and setting time were tested. Statistical analysis was performed using a one-way analysis of variance and a Tukey test, which was used for multiple comparisons (alpha=.05).
RESULTS
Zones of growth inhibition were observed around the test specimens, but not around the control specimens, and there were significant intergroup differences in the diameters of the inhibition zones. In the accuracy test, no significant differences (P>.05) were detected among all the measurements for all groups, and the accuracy was clinically acceptable. Also, no significant differences in the flowability (P=.987) and setting time (P=.103) were detected.
CONCLUSION
Chlorhexidine self-disinfecting irreversible hydrocolloid impression material can exhibit varying degrees of antibacterial activity without influencing the three-dimensional accuracy, flowability, and setting time.
Topics: Bacteria; Biocompatible Materials; Chlorhexidine; Dental Impression Materials; Disinfectants; Time Factors
PubMed: 17902233
DOI: 10.2319/070606-277 -
Stomatologiia 2005Results of the profound study of influence of the type of impression material, impression tray and making impression technology upon main quality characteristics of the... (Comparative Study)
Comparative Study
[Influence of the type of impression material, impression tray and making impression technology on the dimensional accuracy and depth of impression material penetration into "gingival sulcus". In vitro study].
Results of the profound study of influence of the type of impression material, impression tray and making impression technology upon main quality characteristics of the precise impression (dimensional accuracy and depth of impression material penetration into gingival sulcus) are reviewed. Original method to investigate depth of impression material penetration into gingival sulcus on experimental model is described. The impression technology exercises more influence on quality characteristics of the precise impression than type of the used material and impression tray. Optimal combination of different viscosity impression materials with technology of making impression has been defined.
Topics: Dental Impression Materials; Dental Impression Technique; Gingiva; In Vitro Techniques; Models, Dental
PubMed: 16091710
DOI: No ID Found -
International Dental Journal Sep 1965
Topics: Agar; Dental Impression Materials; International Cooperation
PubMed: 5214044
DOI: No ID Found -
Dental Materials Journal May 2007The aim of this study was to investigate how to achieve sufficient and stable adhesive strength between impression material and tray. Impression materials were molded...
The aim of this study was to investigate how to achieve sufficient and stable adhesive strength between impression material and tray. Impression materials were molded between autopolymerizing resin columns, and tensile strength was measured as a function of these factors: tray storage time (1, 2, 4, 7, and 10 days), adhesive drying time (0, 1, 5, 10, and 15 minutes), and tray surface roughness (air abrasion, bur-produced roughness, and no treatment). Tensile bond strength was not affected by tray storage time throughout the entire evaluation period of 10 days. As for tray adhesive drying time, Reprosil and Exaimplant yielded extremely low values for drying times of 10 minutes or less (P<0.05), while Imprint II and Impregum were not influenced by drying time. Vinyl polysiloxane achieved the highest adhesive strength with bur-produced roughness, which was significantly higher than with air abrasion or no treatment (P<0.05), whereas polyether achieved the lowest value with bur-produced roughness (P<0.05). It was concluded that surface treatment of custom tray should be adapted to the type of impression material used to achieve optimum bond strength.
Topics: Dental Impression Materials; Dental Impression Technique; Elastomers; Surface Properties; Tensile Strength; Time Factors
PubMed: 17694739
DOI: 10.4012/dmj.26.323 -
Dental Update 2004Thirty years ago the author set out the logical sequence of dimensional changes that could occur in the impression materials of the 1970s. In the 21st Century, it...
Thirty years ago the author set out the logical sequence of dimensional changes that could occur in the impression materials of the 1970s. In the 21st Century, it appears that little has changed and that what the dental practitioner requires today is the same as it always was--a forgiving material that produces perfect impressions with a minimum of trauma to the patient, dentist and technician.
Topics: Alginates; Dental Impression Materials; Dental Impression Technique; Elasticity; Elastomers; Humans; Viscosity; Wettability
PubMed: 15000008
DOI: 10.12968/denu.2004.31.1.40 -
Dental Update Apr 2005Approximately 20,000 impressions are made with alginate annually at the University Dental Hospital of Manchester alone, and countless more wherever clinical dentistry is...
Approximately 20,000 impressions are made with alginate annually at the University Dental Hospital of Manchester alone, and countless more wherever clinical dentistry is practised. A proportion of these are considered unsatisfactory for clinical use. The reason for these 'failures' is often poor operator technique, rather than an inherent problem of the material. With improved handling of the material and better clinical technique, failures can be avoided. This paper provides an overview of the use of alginate impression material in clinical dentistry.
Topics: Alginates; Dental Impression Materials; Dental Impression Technique; Disinfection; Humans
PubMed: 15881512
DOI: 10.12968/denu.2005.32.3.169