Spannungsentwicklung 5-gliedriger Implantatbrücken

Zusammenfassung

Herstellungsweise und Befestigungsmechanismus beeinflussen den Sitz einer implantatgetragenen Suprakonstruktion. Ziel der vorliegenden Studie war es, die Spannungsentwicklung verschiedener zementierbarer und verschraubbarer Implantatbrücken zu quantifizieren.

4 Gruppen 5-gliedriger Brücken auf zementierbaren und verschraubbaren Standardabutments wurden untersucht.

3 ITI-Implantate wurden in Anlehnung an eine reale Patientensituation in ein Messmodell eingearbeitet und Dehnungsmessstreifen mesial und distal der Implantate und an den Brückenzwischengliedern angebracht. Während des Verschraubens respektive Zementierens der Restaurationen wurden die entstehenden Spannungen erfasst. Alle untersuchten Brücken zeigten messbare Dehnungen, wobei kein signifikanter Unterschied zwischen verschraubten und zementierten Brücken nachzuweisen war. Auch zeigten die unterschiedlichen Herstellungsarten für verschraubte Brückenkonstruktionen keinen signifikanten Unterschied. Die geringsten Spannungswerte lagen bei denjenigen Brücken vor, die direkt auf dem Messmodell an vorgefertigte Goldzylinder verklebt wurden.

Summary

Fabrication and retention methods have an influence on the passivity of superstructure fit. The objective of the study presented was to quantify the strain development of various cemented and screw retained FPDs. 4 groups of 5-unit FPDs with 10 samples each, representing the commonly used cemented and screw retained FPD-types, were investigated. 3 ITI implants were anchored in a measurement model according to a real life patient situation. Strain gauges were mounted mesially and distally to the implants and on the bridge pontics. During cement setting and screw fixation, the developing strains were recorded. For statistical analysis, multivariate 2 sample tests were performed setting the level of significance at p = 0.1. All types of FPDs revealed a considerable amount of strain with no significant difference between cement and screw retention. Furthermore, no significant difference was found between the conventional fabrication modes for screw retained FPDs. The lowest strains were found in bridges bonded onto gold cylinders. As bonding of superstructures directly onto implant components compensates impression and laboratory inaccuracies, restorations with best possible passive fit can result. Before recommending this technique, investigations on the long term stability of the adhesive layer should be temporized.

Schlüsselwörter

Adhäsives Befestigen - passive fit - Spannungsentwicklung - Passgenauigkeit - Zementieren - Verschrauben

Key Words

Adhesive Fixation - Passive Fit - Strain Development - Superstructure Accuracy - Cement Retention - Screw Retention

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