Evaluation of Accuracy of Casts of Multiple Internal Connection Implant Prosthesis Obtained From Different Impression Materials and Techniques: An In Vitro Study

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 6 (1) ◽  
Author(s):  
Motaz Osman ◽  
Neamat Hassan Abubakr ◽  
Ahmed Suliman ◽  
Hassan Ziada

Abstract Aim This in vitro study aimed to evaluate the effect of implant impression coping geometrical designs on the accuracy of open and closed impression techniques and in the parallel and nonparallel implant positions. Material and methods Three custom-made acrylic resin models of three tested implant systems (Straumann®, SIC Invent®, and Osstem®) with diverse coping geometrical designs were evaluated in simulated cases of two parallel and two nonparallel implants. The horizontal and vertical discrepancies were measured and analyzed. Results No statistically significant differences between the two impression techniques in either parallel or nonparallel implants were observed. The high retentive design of the Osstem system showed a statistically significant difference. Conclusion The geometrical design of the impression copings did not affect the accuracy for either the open and closed tray techniques. However, the high retentive coping design of the Osstem implant affected the accuracy in the open tray technique.


Author(s):  
Dr. Ravi Nag ◽  
Dr. Jagjeet Singh ◽  
Dr. Abhilasha Masih Gottlieb ◽  
Dr. Ponnanna A. A. ◽  
Dr. Nikhil Verma ◽  
...  

Background: Prolonged retention of provisional restoration is depends upon the long term affinity between restoration and teeth structures which depend upon the use of good mechanical characteristics, low solubility, and superior adhesion  quality of luting cement which also resist bacterial and molecular penetration. Hence, assessment of marginal leakage of provisional restorative materials sealed with provisional cements using the standardized procedures is essential. Aim: This study aimed at in vitro study of microleakage of 4 provisional cements, a cavity base compound and a zinc-phosphate luting cement in provisional acrylic resin crowns fixed on extracted human teeth. Material & Methods:  The teeth with acrylic restorations were randomly divided into 6 groups of 6 specimens each. Each group received different types of temporary cement. Acrylic resin crowns were made and fitted on intact human premolars with the 4 cements. All restorations were applied in a standardized manner. Specimen were submerged in a 2% methylene blue solution, then sectioned and observed under a stereomicroscope for the detection of marginal microleakage. Obtained data were subjected to ANNOVA and Chi –square test to know statistical significant difference between different groups.  P value less than 0.05 was considered significant. Results and observation: Mean frequency of microleakage was statistically significant among all the groups under study with Pvalue<0.017. Conclusion: Among all the temporary cement, Zinc-phosphate cements has the best property with reduced microleakage. Even it is used as cavity base but can be used as good temporary cement as far as microleakage is concerned. Key words, Microleakage, provisional cement, restorations, crowns, in vitro


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. 


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Sonam Gupta ◽  
Aparna Ichalangod Narayan ◽  
Dhanasekar Balakrishnan

Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique.Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n=5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA.Results. Statistically significant difference (p<0.05) was found between the two impression materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p>0.05) was observed between varied stock and custom trays.Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials.


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.


2021 ◽  
pp. 232020682110154
Author(s):  
Fahimeh Farzanegan ◽  
Hooman Shafaee ◽  
Majid Darroudi ◽  
Abdolrasoul Rangrazi

Aim: This in vitro study was aimed to evaluate the effect of adding different concentrations of chitosan nanoparticles (NPs) and TiO2 NPs on the shear bond strength (SBS) of an orthodontic adhesive. Materials and Methods: In this in vitro study, 72 extracted human premolars were embedded in an acrylic resin and randomly allocated into four groups of 18 specimens. In group 1 (control), brackets were bonded to the tooth with the Transbond XT orthodontic adhesive. In groups 2, 3, and 4, 0.5% chitosan NPs and 0.5% TiO2 NPs, 1% chitosan NPs and 1% TiO2 NPs, and 1.5% chitosan NPs and 1.5% TiO2 NPs were added to Transbond XT, respectively. Then, the brackets were bonded by the modified adhesive. The SBS and adhesive remnant index (ARI) of each group were assessed with a universal testing machine. The SBS test results were analyzed using one-way analysis of variance followed by the posthoc Tukey’s honestly significant difference (HSD) test. The Kruskal–Wallis test was also applied to evaluate the ARI scores. Results: The results showed no statistically significant difference between groups 1, 2, and 3, but SBS decreased significantly in group 4. With increasing the concentration of NPs up to 1% chitosan NPs and 1% TiO2 NPs, SBS did not change significantly. However, in 1.5% chitosan NPs and 1.5% TiO2 NPs, SBS decreased compared to the other three groups. No significant differences were found between the groups in terms of ARI scores. Conclusion: It is concluded that the orthodontic composite containing 1% chitosan NPs and 1% TiO2 NPs has adequate SBS for use in the clinical setting.


2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.


2015 ◽  
Vol 25 (3) ◽  
pp. 216-223 ◽  
Author(s):  
Helios A. Zeno ◽  
Renan L. Buitrago ◽  
Sidney S. Sternberger ◽  
Marisa E. Patt ◽  
Nick Tovar ◽  
...  

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