Κατεύθυνση Προσθετική (Κλινικές Ειδικεύσεις)
Βιβλιοθήκη Οδοντιατρικής

2021-04-15

2020

Palantza Eirini

Κούρτης Στέφανος, Αναπληρωτής Καθηγητής, Τμήμα Οδοντιατρικής,Σχολή Επιστημών Υγείας, ΕΚΠΑ
Ρούσσου Ίλεια, Επίκουρη Καθηγήτρια, Τμήμα Οδοντιατρικής,Σχολή Επιστημών Υγείας, ΕΚΠΑ
Χαλαζωνίτης Δημήτρης, Καθηγητής, Τμήμα Οδοντιατρικής,Σχολή Επιστημών Υγείας, ΕΚΠΑ

Σύγκριση της ακρίβειας αποτύπωσης εμφυτευμάτων με συμβατική και ψηφιακή τεχνική σε ολική νωδότητα.

Greek

Accuracy of digital vs conventional full mouth implant impressions.

Introduction
The use of osseointegrated implants consists a well-documented and frequently used treatment modality for the rehabilitation of edentulous patients. The passive fit of prosthodontic frameworks is critical to achieve long-term survival and success, free of mechanical and biological complications in multiple implant rehabilitations. An accurate implant impression is an integral prerequisite for obtaining a precise master cast, which is the key for the fabrication of an accurately fitting prosthesis. There are various implant impression techniques and materials that have been utilized for full-mouth implant impression, though to date there is no commonly accepted method for the production of accurate and repeatable implant impressions.
Aim
The aim of the present study was to compare the accuracy (i.e., precision and trueness) of full-arch conventional implant impressions using two different materials (silicone and polyether) to that of full-arch digital implant impressions produced from two different digital intraoral impression systems.
Materials and Methods
A master model was fabricated representing an edentulous mandible with 4 implants with internal hexagon connection placed at the sites of canines and first molars. The two anterior implants were parallel to the residual ridge, while the two posterior implants had an angulation of 15o to the distal and 15o to the lingual respectively. For the conventional impression groups, two custom trays were fabricated from light-curing acrylic resin. The technique applied was the open-tray impression technique with non-splinted impression copings. Two different impression materials were utilized, an additive silicone and a polyether, at monophase medium body consistencies. A silicone would was used for pouring of the dental stone at universal shape and dimensions. The digital impressions were obtained with the use of two different intraoral scanners, after the connection of titanium scan bodies. A total of 10 impressions were produced for each of the 4 experimental groups.
The conventional models as well as the master model were digitized with the use of a high-resolution laboratory reference scanner and the STL files were extracted. The STL files of the models and of the intraoral impressions were imported in powerful superimposition software, for the conduction of measurements in pairs of files. The software calculated the 3D deviations, as well as the linear and angular displacements among scan bodies at the digital files. For trueness measurements every STL file of each experimental group was superimposed to the digital master model, while for precision measurements all the STL files of each experimental group were superimposed to each other. Additionally, the scanning reliability of the two intraoral scanners in comparison with the reference scanner was estimated.
Results and Conclusions
IBM-SPSS 26 was used for data processing. The data were subjected to a regularity test and then to a Variance Analysis (ANOVA one-way with Levene’s test for the use of LSD or Tamhane for Post-hoc testing). The general minimum desired level of statistical significance was set at p = 0.05.
The three different parameters that were analyzed included trueness, precision and scanning reliability.
Within the limitations of this study, it can be concluded that:
The accuracy of full mouth mandibular implant impressions was influenced by both the impression technique used (conventional vs. digital) and the impression material used (silicone vs. polyether) or the intraoral scanner used (Trios vs. Heron).
1. In terms of trueness, silicone had the highest impression accuracy with the lowest deviation values, followed by polyether and Trios, but the differences between these three groups were not statistically significant in the majority. Heron showed statistically lower accuracy results in all measurements compared to the other groups.
2. In the detailed measurements, the distance deviation measurements generally showed lower values than the angle deviation measurements. Silicone showed more accurate results in distance measurements, in the majority of them. In the angle measurements, no material or scanner was consistently superior to the rest.
3. In terms of precision, conventional impressions with the use of silicone or polyether were statistically significantly superior to digital impressions with either scanner. Silicone and polyether showed no statistically significant difference between each other.
4. In terms of scanning reliability, the deviation of the implants can adversely affect the reliability of the scanner.

Health Sciences

Impressions, Implants, Digital Impressions, Full Mouth Restorations, Intraoral Scanners

No

0

Yes

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https://pergamos.lib.uoa.gr/uoa/dl/object/2943340