Clinical effectiveness of fixed polymer prototype prostheses: a randomized controlled trial

Abstract

Relevance. An analogous recording of occlusal relationships (articulating paper, foil, etc.) is not sufficiently informative for precise determination of occlusal forces and sequence, which is related to the large inaccuracy, labour intensity and lower predictability of prosthetic treatment results. Aim. The study aimed to evaluate the effectiveness of fixed polymer prototype dental bridges in patients with tooth-bounded edentulous spaces and occlusal defects.Material and Methods. The randomized controlled study comprised two study groups: control (n = 21) and main (n = 21), which included the patients with tooth-bounded posterior missing teeth (second premolar and first molar). Prosthetic treatment corresponded to the conventional protocol in the control group. The main group had the missing teeth replaced with prototype prostheses and analogous-digital analysis of occlusal relationships. Intergroup effectiveness comparison rested on the integral occlusal score (IOS) data that considered scores received with T-scan 3 system (TekScan, USA). We also performed an intragroup comparative analysis of the periodontium condition around the abutment teeth using the Doppler ultrasound integral score (DUIS) at the stages before and after the treatment.Results. The study did not reveal statistically significant differences between the values of IOS in the control and main study groups before the treatment (p > 0.05). At the followed treatment stages, control group IOS values significantly differed from those of the main group, namely, by 65.35 % (p < 0.05) just before the replacement of the provisional bridge by the final prosthesis; by 76.19 % (p < 0.05) immediately after the final prosthesis delivery; and by 65.94 % (p < 0.05) one week after the delivery of the final prosthesis. The Doppler ultrasound integral score values reflected the statistically significant positive changes in the study groups (p < 0.05).Conclusion. Fixed polymer prototype prosthesis placement in patients with posterior tooth-bounded edentulous spaces and occlusal defects allowed us to increase prosthetic treatment effectiveness, improve microcirculation around abutment teeth, and harmonize the occlusion, decreasing the risk of possible damage to a ceramic bridge.