Comparison of Anesthetic Efficacy and Safety Between Inferior Alveolar Nerve Block and the Infiltrative Technique for the Treatment of Peri-implant Diseases in Posterior Mandibular Implants

This triple-blind randomized clinical trial aims to compare the anesthetic efficacy and safety of two local anesthesia techniques for the surgical treatment of peri-implantitis in posterior mandibular implants: inferior alveolar nerve block (IANB) and infiltrative anesthesia with 4% articaine and epinephrine 1:100,000.

Peri-implantitis is an inflammatory disease affecting the tissues around dental implants, characterized by progressive bone loss and clinical signs of inflammation. When non-surgical therapy is insufficient, surgical treatment is required, usually involving flap elevation, debridement of granulation tissue, implant surface decontamination, and, depending on the defect, resective, regenerative, or combined surgery.

Effective local anesthesia is essential in these procedures, especially in the posterior mandible, where dense bone may limit anesthetic diffusion. IANB is the conventional technique for achieving profound mandibular anesthesia, but it may fail due to anatomical variations, accessory innervation, or technical difficulty. Infiltrative anesthesia has been proposed as an alternative, particularly with articaine because of its high diffusion capacity, although its predictability in complex mandibular surgery remains uncertain.

The main objective is to compare the efficacy of IANB and infiltrative anesthesia, measured by the need for re-anesthesia during surgery. Secondary objectives include assessing safety, intraoperative discomfort, postoperative pain, duration of anesthesia, patient satisfaction, and adverse events.

Adult patients requiring surgical treatment for peri-implantitis in posterior mandibular implants at the Dental Hospital of the University of Barcelona will be included. Eligible participants must be ≥18 years old, medically fit for surgery, and able to understand the study and complete the questionnaires. Exclusion criteria include pregnancy, allergy to articaine or epinephrine, uncontrolled systemic disease, coagulation disorders or anticoagulant medication, ASA III or higher status, and contraindications to conventional analgesic or anti-inflammatory medication.

Participants will be randomly assigned to either the IANB group or the infiltrative anesthesia group. Randomization will be performed using a computer-generated sequence placed in opaque, sequentially numbered envelopes. The patient, surgeon, outcome assessor, and statistician will remain blinded to group allocation.

The study includes three visits. At the first visit, eligibility will be assessed and informed consent obtained. At the second visit, surgery will be performed after the assigned anesthetic technique. Patients will record pain using visual analogue scales at injection, during surgery, 2 h, 6 h, 12 h, 24 h, and daily until day 7, as well as rescue medication use and sick leave. At the third visit, 7-9 days after surgery, postoperative healing, complications, adverse events, pain diary, and patient satisfaction will be assessed.

The primary outcome is anesthetic efficacy, defined as absence of need for re-anesthesia. Secondary variables include demographic factors, systemic disease, medication, smoking, dental anxiety, type and duration of surgery, surgeon experience, number and position of implants, intraoperative and postoperative pain, duration of anesthesia, adverse events, complications, and patient-reported experience measures.

Data will be analyzed using Stata/IC 15.1. Quantitative variables will be described using means and standard deviations or medians and interquartile ranges, depending on normality. Qualitative variables will be presented as frequencies and percentages. Group comparisons will use appropriate statistical tests, with significance set at p \< 0.05.

As a pilot exploratory trial, the study will include 30 patients, 15 per group. Its aim is to assess feasibility, estimate preliminary event rates, and generate data for future confirmatory trials. The study will follow the Declaration of Helsinki and applicable data protection regulations. Participation will be voluntary, anonymous, and based on written informed consent.