To compare the value of periodontal painless anesthesia injection and traditional hand push supraperiosteal infiltration anesthesia in the pulpotomy of children′s primary molars.

Fifty children aged from 5 to 7 years old who had deep caries in the second deciduous molar on both sides of the lower jaw (total 100 teeth) and needed pulpotomy were selected in the department of pediatric dentistry in Qingdao stomatological hospital from January 2018 to July 2019. All the children were divided into painless anesthesia group and traditional anesthesia group, each with 50 teeth. The painless anesthesia group were anesthetized by using a computer-controlled oral local anesthesia system (STA) for periodontal membrane injection on one side of mandibular second molars. The traditional anesthesia group were anesthetized by traditional hand push supraperiosteal infiltration anesthesia on the contralateral mandibular second molars. The pain severity of injection and efficacy of anesthesia during pulpotomy were evaluated using the Wong-Baker FACES Rating Scale (Wong-Baker) . Soft tissue discomfort was evaluated by telephone follow-up 24 hours after the end of treatment. The Chi-square Test was used for statistical analysis of the Wong-Baker scale scores of the two groups during the injection and the pulpotomy.

In the painless anesthesia group, the painless or mild pain rate was 88%, the relatively painful or severe pain rate was 12%. In the traditional anesthesia group, the painless or mild pain rate was 42%, the relatively painful or severe pain rate was 54% during injection. The pain level in the painless anesthesia group was significantly lower than that in the traditional anesthesia group (χ²= 23.502, P<0.001) . During the pulpotomy, the painless or mild pain rate was 98%, and the relatively painful or severe pain rate was 2% in the painless anesthesia group, and in the traditional anesthesia group, the painless or mild pain rate was 96%, and the relatively painful or severe pain rate was 4%. Chi-square Test results showed that the effect of anesthesia in the painless anesthesia group was similar to that in the traditional anesthesia group, with no significant difference (χ²= 0.344, P= 0.57) . The incidence of soft tissue numbness discomfort in the painless anesthesia group (2%) was significantly lower than that in the traditional anesthesia group (100%) , among which 5 children developed self-injury ulcer.

The STA periodontal membrane injection was as effective as traditional hand push suproperiosteal infiltration anesthesia in anesthetizing the primary mandibular molars during pulpotomy, and rates of postoperative complications were lower with STA when compared to traditional hand push supraperiosteal infiltration anesthesia.