The study is designed as a randomized controlled trial with two parallel groups. Children aged 5-9 years with primary molars from suffered symptomatic signs of irreversible pulpitis will be randomly assigned into two groups. The first group (experimental group) will be injected with 4% articaine 1:100.000 epinephrine (inferior alveolar nerve block). For the second group, the mandibular second primary molars will be anesthetized using 4% articaine 1:100.000 epinephrine using inferior alveolar nerve block.

Inclusion Criteria:

• Healthy children are classified as I or II according to ASA
• Presence of at least one mandibular primary molar with symptomatic signs of irreversible pulpitis
• Presence of at least two-thirds of the root length in periapical radiograph

Exclusion Criteria:

• Unrestorable crowns
• Children with systemic, severe behavior or emotional problems
• Presence of gingival redness, swellings, fistulous of sinus tract
• Radiographic evidence of internal root resorption, pulp stones or calcifications, and/or bone radiolucency