Unit:
Κατεύθυνση Προσθετική (Κλινικές Ειδικεύσεις)Βιβλιοθήκη Οδοντιατρικής
Author:
Tsigarou Spyridoula
Supervisors info:
Στέφανος Κούρτης, Αναπληρωτής Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Νικόλαος Πολυχρονάκης, Επίκουρος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Ίλεια Ρούσσου, Λέκτορας, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Original Title:
Σύγκριση της ακρίβειας κατασκευής εκμαγείου εργασίας εμφυτευμάτων με δύο αποτυπωτικά υλικά
Translated title:
Comparison of accuracy of the working cast in implant restorations using two different impression materials
Summary:
Introduction
The use of osseointegrated implants for the restoration of fully or partially edentulous patients has become a widely accepted treatment. The prosthetic superstructures must fit passively on the implants , so as the implant restorations can be successful for a long time. The implant impression, the proper construction of the master cast and the construction of the implant superstructure in the laboratory, may influence the fit of the implant restoration. The most important factors that affect the impression accuracy of implants are the impression technique and the impression material. Most of the existing studies have described various techniques, without a solid conclusion in which technique is preferable.
Aim
The purpose of this study was to compare the effect of two different impression materials on the accuracy of the master cast. The impression materials that were used are medium body polyether and medium body silicone using an open tray.
Materials and methods
A master cast was fabricated in epoxy resin with three dental implants embedded. Five impressions were taken with medium-viscosity polyether and five with medium-viscosity silicone. The technique that was tested was that of open tray.
Two light-cured custom impression trays were fabricated for each impression material and transfer copings were fixed on the implants. Subsequently, the ten impressions were poured with type IV die stone. The first two implants were parallel to each other (Implants A, B) and perpendicular to the horizontal level and the third implant (Implant C) had a 25o inclination to the other two. The metal framework that was constructed in the master cast was fixed to the new specimens and the microgap between this prosthesis and the implant analogs was evaluated. The specimens were observed to an optical microscope from which photos were taken and analyzed using a computer software. The obtained data of the microgap values were statistically evaluated using ANOVA and Categorical Regression analysis.
Results and conclusions
Within the limitations of this study, it can be concluded that:
1)The marginal gap between the implant surface and the prosthesis was affected mainly by the impression material and there were statistical significant differencies.
2)The marginal gaps were increased when medium-viscosity polyether was used compared to medium-viscosity addition type silicone.
3) No statistical difference was found between the impression accuracy of angulated and parallel implants.
4)The impression accuracy of the angulated implants was not affected by the impression material but the impression accuracy of the parallel implants was affected by the impression material. The impression accuracy of the medium-viscosity addition silicone was greater than the impression accuracy of the medium-viscosity polyether.
Main subject category:
Health Sciences
Keywords:
Implants, Impression materials, Marginal gaps, Working cast
