title: Application times for the single-step/double-mix technique for impression materials in clinical practice.
abstract: Hydrophilicity of unset impression materials underlies changes occurring during working time. Hence, the clinical application time when impression materials contact oral tissues after mixing may play a critical role in successful impressions. The aim of this study was to analyze the clinical time course of impression taking applying the single-step/double-mix technique. Application times of 86 impressions, comprising 265 prepared teeth and 46 implants, taken by 14 different clinicians at a university dental clinic were analyzed. The mean time from loading the impression tray until its final position in the patient's mouth (total application time) was 51.2 seconds; confidence intervals were 46.9 (lower limit) and 55.5 (upper limit). The number of registered teeth and implants did not influence the duration of impression taking. Related to wettability data, several polyvinyl siloxane impression materials show decreased hydrophilicity with respect to estimated application times. The authors suggest considering clinically relevant application times for impression taking in future in vitro studies on physicochemical characteristics of impression materials.
authors.affiliation: Section Medical Materials and Technology, Department of Prosthodontics, University Hospital Tuebingen, Germany. frank.rupp@med.uni-tuebingen.de
authors.forename: Frank
authors.initials: F
authors.lastname: Rupp
authors.forename: Odie
authors.initials: O
authors.lastname: Saker
authors.forename: Detlef
authors.initials: D
authors.lastname: Axmann
authors.forename: Jurgen
authors.initials: J
authors.lastname: Geis-Gerstorfer
authors.forename: Eva
authors.initials: E
authors.lastname: Engel
mesh_terms: D060326:Chemistry Techniques, Synthetic; D003760:Dental Impression Materials / Q000138:chemical synthesis* / Q000737:chemistry; D003761:Dental Impression Technique; D004987:Ethers; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D011145:Polyvinyls; D012117:Resins, Synthetic; D012833:Siloxanes; D018709:Statistics, Nonparametric; D013997:Time Factors; D017155:Wettability
chemical_list: D003760:Dental Impression Materials; D004987:Ethers; C022821:Impregum; C495448:Permadyne garant; D011145:Polyvinyls; D012117:Resins, Synthetic; D012833:Siloxanes; C034183:vinyl polysiloxane