Purpose: To evaluate whether a low-dose subperiosteal anaesthesia is effective in minimising risks of inferior alveolar nerve damage at implant placement when compared to high-dose infiltration anaesthesia. Material and methods: One hundred and twenty patients requiring the placement of a single implant in order to replace a missing first mandibular were randomly allocated to two groups: group A (awake hemilip) subperiosteal crestal injection equal to 0.9 ml of articaine with 0.5% epinephrine and group B (numb hemilip) infiltration equal to 7.2 ml of articaine with 0.5% epinephrine in the vestibular fundus. Intraoperative sensory control using sensory tests was carried out in all patients. Outcome measures were neurological complications, intraoperative and postoperative visual analogue scale (VAS) scores for pain and swelling, and a questionnaire evaluating patient satisfaction. Patients were followed for 1 week postoperatively. Results: There were no cases of nerve injury. Seven days after surgery the postoperative VAS score for pain and swelling was lower in group A in a statistically significant manner (difference = -3.41%; 95% CI: -5.57, -1.26; P = 0.002 and difference = -3.33%; 95% CI: -5.41, -1.25; P = 0.002, respectively). Conclusions: No nerve damage occurred using either anaesthesia types, therefore the choice of type of anaesthesia is a subjective clinical decision, however it may be preferable to use a low dose (0.9 ml) of subperiosteal anaesthesia, since it is unnecessary to deliver 7.2 ml of articaine to anaesthetise a single mandibular molar implant site. Keywords: dental implants, inferior alveolar nerve, local anaesthesia