Unit:
Κατεύθυνση Προσθετική (Κλινικές Ειδικεύσεις)Βιβλιοθήκη Οδοντιατρικής
Supervisors info:
Νικήτας Συκαράς, Επίκουρος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Γρηγόρης Πολυζώης, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Νικόλαος Πολυχρονάκης, Επίκουρος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Original Title:
Μελέτη των παραμέτρων που επηρεάζουν την εμφυτευματική συγκράτηση επένθετης οδοντοστοιχίας άνω γνάθου.
Translated title:
Effect of different parameters on maxillary implant overdenture retention.
Summary:
Statement of Problem: The satisfactory performance of an implant overdenture (IOD) relies on the proper treatment planning which is determined by anatomical features. For the construction of a maxillary IOD usually four implants need to be placed. The dispersion of the implants as well as the type of attachment determine the retention and stability of the prosthesis and consequently the level of satisfaction. Moreover, the presence of a “hidden” buccal cantilever in the IOD can alter the effectiveness of the attachment used.
Purpose: The examination of the effect of implant position and dispersion, the type of the attachment and the presence of a cantilever on retention and stability of a maxillary IOD.
Materials and Methods: Eight implant analogs (Straumann) were placed in an epoxy resin cast (#15, 14, 13, 13, 12, 22, 23, 24, and 25) using a surveillor.
A cobalt/chromium cast framework with 3 sets of loops was made. The inner set represents the case where the denture teeth are placed on top of the edentulous ridge while the outer set simulates the existence of a buccal cantilever that is the result of increased resorption.
The testing machine instrumentation was calibrated and balanced using the testing machine’s computer algorithm to account for the weight of the simulated prosthesis and chains. Three chains were attached to the prosthesis and a 3-point vertical pull was used to determine retention against a vertically directed dislodging force parallel to the path of insertion. A 2-point oblique/posterior pull was used to determine stability to determine resistance against para-axial, oblique dislodging forces. Two chains were attached: one in incisor region and alternating chains either on the right or left side molar region. Two types of attachments were evaluated: the Ti egg shaped Dolder bar (Straumann) and the Locator pink (Zest Anchors). The crosshead speed was set at 50.8mm/minute, previously described as the approximate speed of movement of a denture from the ridge during mastication.
Results: The Locator pink exhibits the highest retention and stability values for all the different dispersions except for one (#12, 13, 22, 23). The work obtained is greater when using the Locator and this is due to the longest distance recorded until the complete detachment of the attachment. Finally, the presence of a “hidden” buccal cantilever is associated with greater values of work needed for the complete detachment of the IOD.
Main subject category:
Health Sciences
Keywords:
Implant overdenture, Retention, Maxilla, Parameters
File:
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diplomatiki_theofili.pdf
1 MB
File access is restricted only to the intranet of UoA.
