Comparing Two Anesthetic Techniques for Implant Placement

To evaluate in a comparative way the patient's perception in implant surgery in the posterior mandibular quadrants depending on whether the operation is performed under trunk anaesthesia or infiltrative anaesthesia, in both cases with Articaine.

Randomized and multicenter prospective study to be developed in eight centers with similar socio-professional characteristics, with the same operative protocol.

A significant sample of patients will be randomized to undergo the same intervention (surgery to place implants in the posterior mandible) under one or another type of anesthesia (inferior alveolar block nerve or infiltrative) and data will be collected using a Numerical Rate scale on four occasions (after the incision, after drilling, after suturing and after 12h).

The optimal anesthesia for posterior mandibular implant surgery remains controversial and dependent on operator's preferences. Although not evidence-based, most operators usually avoid infiltration anesthesia in the posterior mandible due to its uncertain efficacy. However, various comparative studies with articaine 4% have not found differences between infiltration (INF) and inferior alveolar nerve block (IANB) but current research is still conflicting.

Infiltration anesthesia is easier for the operator and more tolerable for the patient. Should it were sufficient for surgical procedures in the posterior mandible it could become the first option in routine surgeries.

The purpose of this prospective, randomized and multicenter study is to clarify the efficacy of infiltration anesthesia for placing implants in the posterior mandible.

The study will take place in eight centers with similar socio-professional characteristics and the same operative protocol. The study has been approved by the Ethical Research Committee of the University Hospital of San Juan (Alicante, Spain).

On a significant sample of patients (96n) that meet the in-exclusion criteria, the same intervention (implant placement surgery in posterior area of the mandible) has been carried out randomly (List Randomizer, www.random.org/lists) with one or another type of anesthesia (group A: IANB or group B: INF).

Data of pain perception from patients were collected intraoperatively, by means of a Numerical Rating Scale, in three moments (after incision, after drilling, after suturing) and global satisfaction one week post surgery.

Five confounding variables were also recorded, gender, use of release incision, number of implants placed, wether or not Guided Bone Regeneration (GBR) was applied and the distance from the implant apex to the mandibular canal. A non-parametric statistical analysis was applied.

Eligibility Criteria:
Inclusion Criteria:

* Patient in health status American Society of Anesthesiologists (ASA) I and ASA II
* Any age and gender
* Unitary or multiple posterior mandibular edentulism.
* Need to replace at least one implant and at least 2mm distal to mental foramen
* Absence of orofacial neurological symptoms

Exclusion Criteria:

* Any contraindication for implant surgery.
* Hypersensitivity to any of the products used in the study
* ASA patients ≦ II
* Pharmacological allergies that contraindicate the intervention
* Patients medicated with sedatives or analgesics up to 24h before the intervention
* Psychotropic drug abuse or medication that may alter painful perception 15 days before the intervention
* Pregnant or nursing women
* Interventions with conscious sedation
* Women on contraceptive treatment
* Bisphosphonate-treated patients
* Pathological mental state (dementia, psychosis)
* Severe dental anxiety
* Lack of collaboration
* Signs of infection in the area to be operated
* Unconventional surgical requirements (split crest, vertical regeneration, block graft, etc.)