Comparison of the Dimensional Changes of Ariadent and Bayer Alginate Impression Materials (Invitro)

  Abstract:

  Background and Aim: : Dimensional changes of impression materials cause distortion of the cast with negative impact on the outcomes of prosthodontics treatments. There is less evidence about accuracy of the domestic alginate impression materials.The aim of this study was to compare the dimensional changes of Ariadent and Bayer alginate impression materials.

  Materials and Methods In this experimental study, seventeen casts were made from master model by a cast metallic special tray, using Ariadent (case) and Bayer (control) alginates. Small and large diameter, height and distance of two dies were measured by a digital measuring instruments. Data were collected and analyzed by Paired T –Test, and MannWhittney for the two groups and master model.

  Results: The difference between the size of small and large diameter, height, and distance of centers of two dies made from Bayer alginate was 209.2 ± 185.6, 345.5 ± 230.7, 219.9 ± 213.1. and 328± 478.7 and for the Ariadent alginate was 198.3 ± 215.5, 342.8± 227.3, 336.7± 280.9, and 281.9± 336.7 microns respectively. These differences were significant with respect to master model (P<0.0005).

  The changes of measured dimensions within two groups were not significant statistically (P <0.5).

  Conclusion: Both impression materials have significant dimensional changes which can not be used in fixed prosthodontics however they can be used in removable prosthodontics with adherence to the principles of standard guidelines.

  Key word:Dental Impression materials, Irreversible hydrocolloids, Dimensional changes 

ABSTRACT

Background and Aim: Dimensional changes of the impression materials after disinfection is a serious problem in dentistry which could fail the treatment. The aim of this study is to determine the effect of three disinfectants:2% Deconex,5.25% sodium hypochlorite and Nanosil D2 ,on dimensional changes of Bayer Alginate.

Materials and Methods: This experimental study was conducted on 32 impressions were taken from one model. The impressions were divided in to four groups: one group was consireded as the control and the other three case groups were disinfected with the mentioned materials .After disinfection and pouring the casts, measurement was done in different dimensions using Electronic Digital Caliper. The acquired data were analyzed with One Way ANOVA test.

Results: Dimensional changes of Bayer Alginate after disinfection with two mentioned disinfectants 5.25%Sodium Hypochlorite and Nanosil D2 was significant but they were within standard limit .(P.value<0.05)but about 2%Deconex, P.value was not significant.(P.value>0.05)

Conclusions: Evaluating the results showed that 2%Deconex caused less dimensional changes in comparision to 5.25%Sodium Hypochlorite and Nanosil D2 statistically .However percentage dimensional changes of three materials were in standard limit of alginate dimensional changes. Each of them can be used to disinfecting alginate by immersion technique .