Dental impression can be contaminated through contact with patient's saliva, blood, or plaque and cross-contamination is avoided by disinfecting impression materials. Nevertheless, the disinfectants may affect the wettability and surface roughness qualities. This study aimed to investigate how the wettability and surface roughness of polyether impression material changed after being immersed in two disinfectants (2% glutaraldehyde for 10 min and 200 ppm hypochlorous acid for 15 min.). 60 polyether dental impression material specimens (Monophase Impregum, 3MESPE, Germany) were randomly categoried into three test groups of ten specimens for each test. A ring mold with a diameter of 30 mm and a thickness of 6 mm was used to prepare the specimens. The specimens were submerged in two disinfection solutions: 2% glutaraldehyde and 200 ppm hypochlorous acid. The control group did not get any disinfection. The wettability of the specimens was determined by measuring the contact angle with a Goniometer, while surface roughness was determined using a digital Profilometer. The data were submitted to a 5% variance significance analysis threshold. The results of this study show that wettability and surface roughness of polyether impression material indicate a non-significant difference as compared with the control group (P>0.05). Within the study's limits, 2% glutaraldehyde showed safe for 10 minutes of immersion disinfection, whereas immersion in 200 ppm hypochlorous acid for 15 minutes shows promise as an efficient disinfectant without compromising the polyether's wettability or surface roughness.

Background and Aims: Making accurate impressions of prepared teeth when they are adjacent to dental implants is of great importance. In these situations, disregarding the selection of appropriate impression material and technique, not only can affect accuracy of transferring of the 3-dimentional spatial status of implant, but also can jeopardize the accurate recording of tooth. In the present study, the accuracy of two impression materials with taper impression copings for recording implant position and surface details was evaluated.Materials and Methods: One metal reference model with 2 implants (Implantium) and a preparation of three grooves on a tooth according to ADA no.19 standard was fabricated. 10 medium- consistency polyEther (PE) impressions using custom trays and 10 polyVinyl Siloxane (PVS) putty wash impressions using prefabricated trays with conical impression coping were made. Impressions were poured with ADA type IV stone. A Coordinate Measuring Machine (CMM) evaluated x, y and angular displacement of the implant analog heads and also accuracy of groove reproduction were measured using a Video Measuring Machine (VMM). These measurements were compared to the ones from reference model. Data were analyzed using one-way ANOVA and T-test.Results: Putty wash PVS had less linear discrepancy compared with reference model (P<0.001). There was no significant difference in the surface detail reproduction (P=0.15).Conclusion: Putty wash PVS had better results for linear displacement compared with medium consistency PE. There was no significant difference in surface detail reproduction between the two impression materials.

Background: To prevent diseases transmission, infection control in dental offices without reducing the accuracy and dimensional stability of impression materials is very important.Objectives: The aim of this study was to evaluate the effects of Sanosil disinfectants on the dimensional stability of some usual impression materials.Materials and Methods: Three types of impression material, namely, alginate, condensational silicone, and polyether, were used in this study. Impressions were obtained from the master steel model. Fifteen impressions of each material (control group) were immersed in water for ten minutes and impressions of study groups were disinfected by immersion in 2% Sanosil for ten minutes. Then impressions were poured by type III gypsum according to the manufacture's instruction. Dimensions of casts in the two anterior dimensions, i.e. interval between the anterior abutments and interval between anterior-posterior abutments, were recorded by a digital caliper with the accuracy of 0.01 mm. Data were analyzed with SPSS through two-way ANOVA test.Results: The results showed that there was no significant difference in the mean dimension of casts prepared by different impression materials in anterior and anterior-posterior dimensions in comparison to the original model after disinfection with Sanosil.Conclusions: The study revealed that disinfection with 2% Sanosil has no significant effect on casts dimensions of alginate, silicone, and polyether impression and dimensional stability is maintained.

Background and Aims: Accurate recording of implant location is required to achieve passive fit and have the implants without stress concentration. The aim of this in-vitro study was to evaluate the dimensional and angular accuracy of open-tray and closed-tray impression techniques using polyether impression material and also to assess the surface detail reproduction of the tooth while impression making.Materials and Methods: One reference metal model with 2 implants (Implantium) on the position of the maxillary second premolar and first molar and one molar tooth for evaluation of surface details was prepared.27 polyether impressions of these models were made (9 using open-tray, 9 using closed-tray techniques and 9 were made just of the surface of the teeth without any implants). Impressions were poured with ADA type IV stone.Coordinate Measuring Machine was used for measuring the dimensional accuracy and video measuring machine for surface detail reproduction. All of these measurements were compared with the measurements on the reference model. Data were analyzed by and compared by T-test and One-way ANOVA.Results: There was a significant statistical difference between open-tray and closed-tray techniques (P<0.001).There was no significant difference in the surface detail reproduction of open-tray and Closed-tray techniques and impression making with or without the implants (P>0.05).Conclusion: The accuracy of open-tray impression technique was more than closed-tray technique. The surface detail reproduction of the tooth was not affected by impression technique.

Making impression to obtain an accurate working cast needs to use accurate impression materials such as polyether. On the other hand, polyether cannot be used easily in places with undercut such as excessive interproximal spaces and under the pontics of fixed partial dentures as it may be locked in these free spaces. In this article, a method is presented to blockout interproximal spaces in order to minimize distortion and to facilitate impression removal from the mouth.

To improve the toughness of epoxy resin, and clarify the complex interrelationship between the miscibility, morphology, toughness and composition of epoxy resin/graft copolymer blends, amphiphilic polysiloxane graft copolymers (F6-PMSs) with different contents of polyether were synthesized via hydrosilylation between epoxy-immiscible poly(methylhydrosiloxane) and epoxy-miscible allyl polyoxyethylene polyoxypropylene ether (F6) to modify diglycidyl ether of bisphenol A (DGEBA). The miscibility of amphiphilic graft copolymers with epoxy resin was investigated by observing the transparency of the modified epoxies before and after curing and by detecting the glass transition temperature (Tg) of the cured epoxies using differential scanning calorimetry. The morphologies of the cured epoxies were studied by scanning electron microscopy, and the toughness in terms of tensile and impact strength were examined by tensile and impact testing. Results indicated to higher miscibility of polysiloxane with DGEBA by grafting with polyether. Relative to the neat epoxy network, the polysiloxane modified epoxies exhibited lower Tgs and with the increased polyether in graft copolymer, there was a decreasing trend noticed in Tg. The nanostructures were obtained for the modified epoxies with different F6 to PMS ratios (5 wt% of DGEBA). The formation of the nanostructures in the thermosetting composites was judged by following the self-assembly and reaction-induced mechanisms, mainly dependent on the miscibility of graft copolymer with epoxy resin. Moreover, toughness of the epoxy networks was greatly improved by F6-PMS of 100/100 weight ratio at relatively low addition levels.

Objective: The aim of the present study was to evaluate the effect of two impression materials on the shear bond strength of porcelain to immediately sealed dentin.Materials and Methods: Smooth dentin surfaces of 45 extracted premolars were immediately sealed with Adper Single Bond adhesive agent. Forty-five porcelain specimens were also prepared. The teeth were divided into one control and two experimental groups. In control group, an adhesive layer to dentin was applied and feldspathic porcelain specimens were bonded to dentin with Relay X dual-curing cement. In one experimental group, the teeth were embedded in condensational silicon (Speedex) and in the other group in polyether (Impregum Soft) impression materials before bonding the porcelain specimens as in the control group. Shear bond strengths were measured using a universal testing machine. Fracture modes were evaluated under a stereomicroscope. Data was analyzed using oneway ANOVA, Tukey, and chi-square tests (a=0.05).Results: No significant differences existed between bond strength of the control and condensational silicon groups (P=0.31). Bond strength was significantly lower in polyether group in comparison with the control (P<0.0005) and condensational silicon groups (P=0.002).Conclusion: Contamination with polyether impression material adversely affects the shear bond strength of porcelain to immediately sealed dentin.