Primary and Supplementary Anesthetic Efficacy of Modified Infiltration Technique with 4% Articaine versus Inferior Alveolar Nerve Block with 2% lidocaine in Mandibular molars with Irreversible Pulpitis: A Randomized Clinical Trial

To study the efficacy of primary and supplementary injection with modified infiltration technique using Articaine 4% in mandibular molars diagnosed with irreversible pulpitis, and to compare it with inferior alveolar nerve block using lidocaine 2%.

A concealed, randomized, parallel-designed, phase III clinical trial on 108 patients in three groups.

This study will be done in the Endodontic Department and subordinate clinics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. The statistician will be blinded to the aims and methods of the injection. Also, the investigator will be unaware of the randomization table, and the allocated injection for each patient. The nurse and the practitioner will not be involved in any other steps of this study.

Healthy patients with an age between 18 and 65, and with a first or second mandibular molar diagnosed with irreversible pulpitis will include in this study. Pregnant or nursing females will be excluded from this study.

In the primary modified infiltration technique group, a two-step subperiosteal injection using articaine 4% with 1:100.000 epinephrine, will be performed in the middle point of the line between the most apical part of the buccal scalloped gingiva of the target tooth and its nearby tooth. This injection will be performed twice; first, distally, and second, mesially. In the Inferior alveolar nerve block group, a conventional Inferior alveolar nerve (IANB) block will be performed, using lidocaine 2% with 1:100.000 epinephrine. In the supplemental group, after using an IANB, another subperiosteal injection will be done.

The target tooth's response to electric pulp test. The patient's pain score while injection, access cavity preparation, and initial filing on 170 mm visual analog scale.

Since the subperiosteal nature of the injections cannot be assured, the "Modified infiltration technique" was used instead of the subperiosteal technique.

The randomization table will be provided by the statistician. The permuted block randomization method will be used for randomizing the participants. In each block, randomization sequences will be generated using Microsoft Excel software. The statistician will be blinded to the study's aims and methods of injections.

The investigator will leave the treatment room after evaluating the inclusion and exclusion criteria. Then, the practitioner will carry out the injection after opening the allocated opaque and sealed envelope just before the injection. afterward, the practitioner will use a rubber dam to blind the investigator and tell the investigator to come back to the treatment room and collect the required information. The code on the envelopes, that distinguishes the type of injection using the randomization sequence, will be recorded in the patients' profiles. The investigator will be blinded to the type of injection. Due to the different methods of the two injections, completely blinding the practitioner and patients will not be applicable. The statistician will be blinded to the aims and steps of the present study.