[Study on the effect of alginate impression spray disinfection process on model accuracy].

Purpose: To investigate the effect of a new cleaning and disinfection process of oral impressions on the accuracy of alginate dental impression.

Methods: Sixteen young volunteers were selected to make alginate oral impression (2 times for each upper and lower jaw) and oral scandata acquisition (1 time for each upper and lower jaw) to obtain STL data. The 2 pairs of alginate impressions of each subject were numbered group 1, group 2, inwhich group 1 was not sterilized and the oral impression film in group 2 was treated with the method and steps of new oral impression cleaning and disinfection. All the oral impressions of the subjects were perfused with plaster models in the same standard way and demoulded. The obtained plaster models were examined and scanned after appropriate trimming and grinding. The plaster model data obtained from each group of each patient after warehouse scanning were compared with the orally scanned model data for alignment analysis, and root mean square(RMS) was used as a parameter to evaluate the deviation between the test model and the standard model. The chromatograms of the deviations were saved for visualization and analysis to observe the differences in model accuracy from several dimensions. Statistical analysis was performed with SPSS 23.0 software package.

Results: The differences in RMS of model accuracy of maxillary dental series of alginate impressions were statistically significant, in which the RMS of the group disinfecting the maxillary oral impression film with a new oral impression cleaning and disinfection process was significantly higher than that of the nonsterilized group (P=0.006), while the difference between model accuracy RMS of the mandibular disinfection group and non-disinfection group was not statistically significant(P=0.874).

Conclusions: The new technical specifications for cleaning and disinfection of dental impressions recommended by the Chinese Stomatological Association have certain effects on the accuracy of dental impressions made of alginate material,and the details in its process should be further improved.