Introduction: Minor rotation of impression coping secured in the impression is an avoidable error that needs to be minimized to ensure precise positioning of implant analog in master cast.
Aim: The aim of the study was to compare the precision in obtaining master casts by improving the stability of impression copings in the impression with the use of tray adhesive along various surface treatments to increase surface area and by mechanical locking.
Materials And Methods: A total of 60 samples were made (15 samples for each group). A total of 15 samples for Group I were prepared with untreated impression copings, 15 samples for Group II with impression copings treated and modified by application of tray adhesive only. Group III includes 15 samples which were fabricated with impression copings modified by making four vertical grooves on surface of impression coping and coated with adhesive. Group IV had 15 samples which were fabricated with impression copings sandblasted with 50 μm aluminum oxide powder and coated with adhesive. Profile projector was used to evaluate the rotational accuracy of the implant analogs by comparing Molar Implant Angle (MIA) and Premolar Implant Angle (PIA) of test samples with reference model. One-way ANOVA and Student t-test were used to analyze the data.
Results: One-way ANOVA didn't show any significant differences for both MIA and PIA between the Groups I, II, III and IV. Student's unpaired t-test revealed no significant difference in the mean MIA and mean PIA. Though results were statistically non-significant, all types of surface treatments of the impression copings showed more accurate transfer than those with no treatment. Sandblasted and adhesive coated impression copings showed minimum amount of rotation followed by those with vertical slots and adhesive coated impression copings.
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http://dx.doi.org/10.7860/JCDR/2017/28372.10501 | DOI Listing |
J Indian Prosthodont Soc
January 2025
Department of Prosthodontics, Chhattisgarh Dental College and Hospital, Rajnandgaon, Chhattishgarh, India.
Aim: The aim of this study was to compare the marginal accuracy of polyetheretherketone (PEEK) and zirconia copings fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and to assess the impact of their material properties on accuracy when produced with a 4-axis milling system under controlled conditions.
Settings And Design: The study employed an in vitro design with a stainless steel die model featuring a 6 mm axial wall height, a 6-degree total occlusal convergence, and a radial shoulder finish line.
Materials And Methods: Thirty stone dies were created from silicone impressions of the metal die and poured using type-IV dental stone.
J Prosthet Dent
October 2024
Distinguished Professor, Advanced Education Program in Implant Dentistry, Loma Linda University School of Dentistry, Loma Linda, Calif.
Fabricating a crown to fit both a tooth and an existing removable partial denture (RPD) using many different techniques has been described. However, in the event of abutment loss, information regarding the clinical and laboratory steps used to fabricate a crown that fits both an implant and an RPD is lacking. This report describes the use of either an impression coping or an interim abutment attached to the implant to which a composite resin interim restoration material is flowed and the RPD then seated to form a resin pattern of the required crown form.
View Article and Find Full Text PDFJ Contemp Dent Pract
June 2024
School of Stomatology, Universidad Privada San Juan Bautista, Lima, Peru, Phone: +5116449131, e-mail: Orcid: https://orcid.org/0000-0003-1678-6282.
Aim: To compare the effect of different ultraviolet-C (UV-C) light exposure times on the dimensional stability of addition silicone dental impressions.
Materials And Methods: The dimensional stability of the addition silicone dental impressions was assessed by measuring specific dimensions on dental casts that were recovered from an upper acrylic resin model of dental implants. The impressions were reproduced using a customized tray adapted in a three-point simplex dental articulator permitting only opening and closing movements.
This paper presents an efficient method for fabricating a full-arch implant prosthesis within one day, using a verification index through a three-dimensional (3D)-printed surgical guide. The technique involves the use of simple impression coping and laboratory analogs to ensure accurate prosthesis placement. Directly using 3D-printed surgical guides as a verification index simplifies and streamlines the procedure, offering a significant clinical advantage.
View Article and Find Full Text PDFPurpose: Anxiety sensitivity (AS) and experiential avoidance (EA) are associated with anxiety in both adults and youths. This study examined the separate contributions of AS and EA in predicting (a) anxiety (symptom severity) and (b) differential treatment outcomes in anxious youth receiving cognitive behavioral therapy (CBT).
Methods: Participants ( = 89; age 10-17 years; 37% male; 78% white) met diagnostic criteria for an anxiety disorder and received CBT ().
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