Abstract: PURPOSE: To evaluate the effect of minimally invasive technique in the treatment of deep caries during pregnancy, and to assess the impact of dental treatment on pain and anxiety among pregnant women. Methods: From January 2017 to November 2017, 60 pregnant women with class I deep caries of the posterior teeth were recruited and divided into experimental group and control group randomly. The third generation chemical decaying technique plus traditional decaying method were used in the experimental group, and traditional decaying method alone was performed in the control group. Pulse and blood pressure during operation, duration of treatment for one tooth, and treatment results and complications at the end of follow-up were measured and recorded. Anxiety was assessed using the general hospital anxiety/depression scale (HAD) during treatment. The data were analyzed with SPSS 22.0 software package for Chi-square test. Results: There was no significant difference in microleakage, secondary caries and shedding rate between the experimental group and control group. However, the experimental group was superior to the control group in terms of treatment time, inhibition of plaque, patients' fear degree, pain sensation and retention of healthy dental tissue. Minimally invasive scavenging technique can effectively relieve pain and anxiety of pregnant women during treatment. Conclusions: Minimally invasive decaying technique is superior to traditional decaying method in the treatment of deep caries in pregnant women and is worth wide application.

Key words: Anxiety, Decaying, Minimally invasive technique, Pregnancy