Laboratorial argumentation of possibility to use resonance-frequency analysis for the identification of cases with full cement fixation loss among single prosthetic constructions

Abstract

Introduction. According to the previously conducted multifactorial analysis, the loss of retention is the main reason for ascertaining the fact of the failure for single crowns fixed on abutment teeth. The methods described in the literature for assessing the level of retention among single prosthetic constructions are mainly invasive in nature, or are laboratory-oriented, without the prospect of their further implementation within the clinical practice. Objective of the research. To substantiate the possibility of using resonance-frequency analysis in order to differentiate cases with complete cement fixation loss among single prosthetic constructions within laboratory conditions. Materials and methods. Taking into account the fundamental features of conducting relevant measurements during the implementation of resonance-frequency analysis using the Osstell ISQ device, while justifying use of such method in order to differentiate cases with complete cement fixation loss among single prosthetic constructions, it was proposed to use special metal caps that imitate artificial crowns, on the occlusal projection of which an additional microcylindrical groove was modeled; within the latter the standardized SmartPeg transducer should be fixed. After fixing the SmartPeg sensor in the space of the microcylindrical groove on the caps, stability measurements were performed according to the standard method of resonance-frequency analysis on all caps (10 for each group of teeth) before their fixation on glass ionomer cement and 24 hours after fixation. Results and discussions. The stability indicators, expressed in ISQ scores, were distributed among the constructions made for different groups of teeth as follows: the average stability of caps made for molars before their cement fixation was 42,6±11,2 ISQ scores, while 24 hours after cement fixation – 73,8±7,5 ISQ scores; the average stability of caps made for premolars before their cement fixation was 39,2±14,3 ISQ scores, while 24 hours after cement fixation – 71,2±6,8 ISQ scores; the average stability of caps made for canines before their cement fixation was 39,8±12,4 ISQ scores, while 24 hours after cement fixation – 72,5±7,2 ISQ scores; the average stability of caps made for incisors before their cement fixation was 35,6±18,2 ISQ scores, while 24 hours after cement fixation – 70,1±11,3 ISQ scores. Conclusions. In this laboratory study model, the absence of cement fixation among caps simulated the clinical situation of complete retention loss for the prosthetic constructions, and considering that the average ISQ scores were statistically different in all cases before and after cement fixation, it can be concluded that the proposed improved approach of resonance-frequency analysis is sensitive enough to differentiate cases of complete loss of cement fixation among single prosthetic constructions in experimental conditions.