scholarly journals Accuracy of Impression Material During COVID-19 after Sterilization- In vitro Study

Author(s):  
Abdulrahman Jafar Alhaddad

Aims: The goal of this research is to assess the effect of steam autoclave sterilization due to the impact of Covid-19 on the accuracy of the elastomer impression materials. Study Design: In vitro study. Place and Duration of Study: Department of oral and Maxillofacial Prosthodontics, King Abdul-Aziz University, Jeddah; Saudi Arabia, between June 2021 and November 2021. Methodology: The following materials were used in this study: fully dentate master cast, metal trays, elastomer impression material (addition silicon), type IV stone. Forte impressions made using the metal tray and elastomer impression materials. The impressions were separated equally into two groups: Control group (C.G), untreated impressions. Sterilized group (S.G): Impressions were sterilized by using the steam autoclave. To make stone castings for each group, they were poured with type IV stone. The traveling microscope was used to evaluate the impression material's dimensional accuracy and detail reproduction with and without autoclave sterilization. Results: The cross-arch distance (X) of the master model was measured (41.29 mm), While the cross arch distance (X) in the control group (C.G) of the untreated impressions  had a mean and standard deviation  of 41.492 ± 0.150 mm. In the tested group  (S.G) : the sterilized impression, we found the cross-arch distance (X) had a mean and standard deviation of 41.628 ± 0.223 mm. The master model's Anteroposterior distance (A-P) was measured (21.12 mm). For the control group  (C.G) : we found the mean and standard deviation value reading of the A-P distance were 20.899 ± 0.79 mm. For (S.G) group: we found the mean and standard deviation reading of the A-P distance were 19.992± 0.482 mm. Conclusion: Steam autoclave sterilization of the elastomer impression material should be considered carefully, especially when fabricating fixed partial dentures. If the impression material is to be used in making diagnostic castings, conventional steam autoclave sterilization of the elastomers impression material may be sufficient for patients.

Author(s):  
Salah A. Yousief ◽  
Khames T. Alzahrani ◽  
Suha M. Alhuwairini ◽  
Fai Y. Alharbi ◽  
Dalal A. Eissa ◽  
...  

Introduction: Saliva and blood contaminated impressions are often a source of cross contamination between the clinic and dental laboratory. Explicit communication and observance of an infection control protocol for handling of dental impressions must exist among the office staff as well as between office and dental laboratories. Though disinfection of impression is routinely followed, autoclaving elastomeric impression is an effective method of sterilization them. Objectives: The purpose of this study was to evaluate dimensional stability and detail reproduction of a new addition silicon impression material after disinfection. Methods: In this study, a total of twenty impressions for the master model using heat resistant plastic stock trays. The twenty impressions were divided into two groups according to disinfection technique: (Table 2) Group 1: (n=10) Control group, untreated impressions. (C.G) Group 2: (n=10) Impressions were chemically disinfected. (D.G). after all impressions treatment, they were poured with extra hard stone (type IV) to get stone casts. Dimensional accuracy and detail reproduction of the impression material were evaluated indirectly through the recovered improved stone casts from impressions of the master model using the travelling microscope. Results: Cross arch distance (A): Epoxy resin master model cross arch distance measurement (A) was (41.36 mm). 1.1 Measurements of the cross-arch distance of stone casts Control group (C.G): The mean and standard deviation values of distance (A) in stone models obtained from C.G. were 41.553 ± 0.170 mm. Disinfection group (D.G): The mean and standard deviation values of distance (A) in stone models obtained from D.G were 41.368 ± 0.083 mm. ANOVA test showed that there was a statistically difference shrinkage between the groups (P-value = 0.006). 1.2 Measurement of the dimensional changes in the cross-arch distance of the different groups. The mean and standard deviation values of cross arch distance changes in stone models of C.G. were 0.191 ± 0.170 mm. while dimensional changes in stone models obtained from D.G. were 0.006 ± 0.082 mm. Conclusion: The purpose of this study was to evaluate dimensional stability and detail reproduction of a new addition silicon impression material after disinfection. In this study an epoxy resin master model was duplicated from a modified dentate mandibular model. Within the limitations of this study, it could be concluded that Chemical disinfectant of polyvinyl siloxane impression material can be successfully used in making fixed partial dentures.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3543
Author(s):  
Marco Tallarico ◽  
Aurea Lumbau ◽  
Roberto Scrascia ◽  
Gianluca Demelas ◽  
Franco Sanseverino ◽  
...  

Background: Intraoral scanners (IOSs) in implantology represent a viable approach for single teeth or partial arches. However, when used for complete edentulous arches or long-span edentulous areas, it has been demonstrated that there is a need for improvement of IOS-related techniques. Therefore, the aim of this in vitro study was to assess the trueness and precision of a complete arch digital impression on four and six implants taken with or without a customized, prosthetic-based impression template. Materials and Methods: Two experimental models were prepared, representative of a complete edentulous mandible restored with four and six implants with built-in scan abutments. Models were scanned with (test group, TG) or without (control group, CG) the prosthetic-based impression template. Eight scans were taken for each model. The time needed to take impressions, error, trueness, and precision were evaluated. A statistical analysis was performed. Results: In the case of four implants, the time needed for the impression was 128.7 ± 55.3 s in the TG and 81.0 ± 23.5 s in the CG (p = 0.0416). With six scan abutments, the time was 197.5 ± 26.8 and 110.6 ± 25.2 s in the TG and CG, respectively (p = 0.0000). In the TG, no errors were experienced, while in the CG, 13 impressions were retaken due to incorrect stitching processes. In the four-implant impression, the mean angle deviation was 0.252 ± 0.068° (95% CI 0.021–0.115°) in the CG and 0.134 ± 0.053° (95% CI 0.016–0.090°) in the TG. The difference was statistically significant (p = 0.002). In the six-implant impression, the mean angle deviation was 0.373 ± 0.117° (95% CI 0.036–0.198°) in the CG and 0.100 ± 0.029° (95% CI 0.009–0.049°) in the TG (p = 0.000). In the TG, there were no statistically significant differences in the mean angle deviation within the group (p > 0.05), but there were in the CG. A colorimetric analysis showed higher deviations from the original model for the six-implant impression without a prosthetic template. Conclusions: Although all of the impressions exhibited deviation from the original model in the range of clinical acceptability, the prosthetic-based impression template significantly improved the trueness and precision of complete edentulous arches rehabilitated with four or six implants, making the complete arch digital impression more predictable.


2014 ◽  
Vol 40 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Malesh Pujari ◽  
Pooja Garg ◽  
D. R. Prithviraj

Movement of impression copings inside the impression material using a direct (open tray) impression technique during clinical and laboratory phases may cause inaccuracy in transferring the 3-dimensional spatial orientation of implants intraorally to the cast. Consequently, the prosthesis may require corrective procedures. This in vitro study evaluated the accuracy of 3 different impression techniques using polyether and vinyl polysiloxane (VPS) impression material to obtain a precise cast for multiple internal connection implants. A reference acrylic resin model with 4 internal connection implants was fabricated. Impressions of the reference model were made using 3 different techniques and 2 different impression materials. The study consisted of 24 specimens divided into 6 groups of 4 each. Impressions were poured with ADA type IV stone (Kalrock, Kalabhai Karson Pvt Ltd, Mumbai, India). All casts were evaluated for the positional accuracy (mm) of the implant replica heads using a profile projector. These measurements were compared to the measurements calculated on the reference resin model, which served as a control. Data were analyzed with 2-way analysis of variance (ANOVA) followed by Bonferroni multiple comparison procedures to evaluate group means. The results revealed significant difference for anterior implant distance between the 2 impression materials (P < .01) and also among the 3 different techniques (P < .05). The lowest mean variation was found with the polyether impression material and the splinted technique. For posterior implants, the results suggested no significant difference between the 2 impression materials (P ≥ .05). Although results were not statistically significant, the polyether impression material showed the lowest mean variation as compared to the VPS impression material. However, there was a significant difference among the 3 different techniques (P < .05). Among the 3 different techniques, the lowest mean variation between 2 posterior implants was found in the splinted technique. Casts obtained from impression techniques using square impression copings splinted together with autopolymerizing acrylic resin prior to the impression procedure were more accurate than casts obtained from impressions with nonmodified implant impression copings and with airborne particle–abraded, adhesive-coated copings. Casts obtained from polyether impression material were more accurate than casts obtained from vinyl polysiloxane impression material.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jinsa P Devassy ◽  
Nishna Pradeep ◽  
A V Sreekumar ◽  
Jimmy George ◽  
Jittin James ◽  
...  

The retentive strength of the impression material to the impression tray is an important factor that can affect the quality of the final impression. Separation of the impression from the tray or tearing of the impression while removing from the mouth could be one of the reasons for distortion. It is imperative to know the most effective tray adhesive which can be used with different brands of rubber-based impression material. So, this study was directed to compare the different tray adhesives that can be effectively used in our day-to-day clinical practice. 


2019 ◽  
Vol 13 (4) ◽  
pp. 305-310
Author(s):  
Mina Biria ◽  
Sajedeh Namaei Ghasemi ◽  
Seyedeh Mahsa Sheikh-Al-Eslamian ◽  
Narges Panahandeh

Background. This in vitro study aimed to evaluate the microshear bond strength (μSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Methods. Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the μSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene’s and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Results. Significant differences in μSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Conclusion. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.


2018 ◽  
Vol 9 (5) ◽  
pp. 137
Author(s):  
AnujHarish Chandak ◽  
SaeeP Deshmukh ◽  
UshaM Radke ◽  
RajlakshmiS Banerjee ◽  
TusharK Mowade ◽  
...  

2013 ◽  
Vol 14 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Naveen S Yadav ◽  
Teerthesh Jain ◽  
Amrita Pandita ◽  
SMA Feroz ◽  
Pradeep LNU ◽  
...  

ABSTRACT Aim Aim of the present study was to comparatively evaluate dimensional accuracy of newely introduced elastomeric impression material after repeated pours at different time intervals. Materials and methods In the present study a total of 20 (10 + 10) impressions of master model were made from vinyl polyether silicone and vinyl polysiloxane impression material. Each impression was repeatedly poured at 1, 24 hours and 14 days. Therefore, a total of 60 casts were obtained. Casts obtained were scanned with three-dimensional (3D) laser scanner and measurements were done. Results Vinyl polyether silicone produced overall undersized dies, with greatest change being 0.14% only after 14 days. Vinyl polysiloxane produced smaller dies after 1 and 24 hours and larger dies after 14 days, differing from master model by only 0.07% for the smallest die and to 0.02% for the largest die. Conclusion All the deviations measured from the master model with both the impression materials were within a clinically acceptable range. Clinical significance In a typical fixed prosthodontic treatment accuracy of prosthesis is critical as it determines the success, failure and the prognosis of treatment including abutments. This is mainly dependent upon fit of prosthesis which in turn is dependent on dimensional accuracy of dies, poured from elastomeric impressions. How to cite this article Pandita A, Jain T, Yadav NS, Feroz SMA, Pradeep, Diwedi A. Evaluation and Comparison of Dimensional Accuracy of Newly Introduced Elastomeric Impression Material using 3D Laser Scanners: An in vitro Study. J Contemp Dent Pract 2013;14(2):265-268.


Sign in / Sign up

Export Citation Format

Share Document