Evaluation of the effect of chemical disinfection and ultraviolet disinfection on the dimensional stability of polyether impression material: an in-vitro study.

BACKGROUND: Various methods, chemical and physical, disinfect dental impressions. Common chemicals include 1% Sodium Hypochlorite and 2% glutaraldehyde, while UV radiation is a prevalent physical method. Few studies compare their effects on dimensional stability in polyether impressions. This study aims to assess such stability using different disinfection methods. Therefore, this study was planned to evaluate the dimensional stability of polyether impression material using different disinfection methods.

METHODS: This in vitro study compared the effects of chemical disinfectants (1% Sodium Hypochlorite and 2% glutaraldehyde) and UV irradiation on the dimensional stability of polyether impression material. Groups A, B, C, and D, each with ten samples (N = 10), were studied. Group A was untreated (control). Group B was treated with 2% glutaraldehyde for 20 min, Group C with 1% Sodium Hypochlorite for 20 min, and Group D with UV rays for 20 min. A pilot milling machine drill was used to make four parallel holes labeled A, B, C, and D in the anterior and premolar regions from right to left. After sequential drilling, four implant analogs were positioned using a surveyor for accuracy. Ten open-tray polyether impressions were made and treated as described in the groups, followed by pouring the corresponding casts. Distortion values for each disinfection method were measured using a coordinate measuring machine capable of recording on the X- and Y-axes.

RESULTS: A comprehensive analysis was conducted using the one-way ANOVA test for distinct groups labeled A, B, C, and D, revealing significant differences in the mean distances for X1, X2, X4, X5, and X6 among the groups, with p-values ranging from 0.001 to 0.000. However, no significant differences were observed in X3. Notably, mean distances for the Y variables exhibited substantial differences among the groups, emphasizing parameter variations, with p-values ranging from 0.000 to 0.033. The results compared the four groups using the one-way ANOVA test, revealing statistically significant distance differences for most X and Y variables, except for X3 and Y4. Similarly, post-hoc Tukey's tests provided specific pairwise comparisons, underlining the distinctions between group C and the others in the mean and deviation distances for various variables on both the X- and Y-axes.

CONCLUSIONS: This study found that disinfection with 1% sodium hypochlorite or UV rays for 20 min maintained dimensional stability in polyether impressions.