The goal of this clinical trial is to evaluate the outcomes of different medications used for pulpotomies (baby root canal) in children. The main question it aims to answer is: • what are the long-term clinical and radiographic success of pulpotomies in baby teeth using two different medications (NeoMTA and NeoPUTTY) over a 24-month follow-up period? Healthy children aged between 3 and 10 years undergoing dental treatment under general anesthesia who have deep caries lesions approximating or reaching the nerve will be invited to participate in this study. Pulpotomies (baby root canal) will be performed by trained dentists following a protocol. Children will receive pulpotomies either with NeoMTA or NeoPUTTY, two medications indicated for the procedure. Participants will be asked to come for an appointment at 1, 6, 12 and 24 months after the procedure. Researcher will compare the clinical and radiographic performance of pulpotomies (baby root canal) done with both medications.

This single-site, double-blinded (participants and evaluators) randomized clinical trial with parallel groups will be conducted at the Division of Dentistry, Montreal Children's Hospital. Healthy children aged between 3 and 10 years undergoing dental rehabilitation under general anesthesia who have deep caries lesions approximating or reaching the pulp without any signs or symptoms of pulpal degeneration in one or more primary molars will be invited to participate in this study. All participants will be randomly assigned (1:1 ratio) into two groups: i) pulpotomy with NeoMTA; and ii) pulpotomy with NeoPutty. Follow-up visits at 1, 6, 12 and 24 months will be conducted to assess the clinical and radiographic outcomes.

The sample size calculation was done using G*Power 3.1.9.4 software (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany). In a recent study conducted by our research team, the 24-month success rates of NeoMTA pulpotomy in primary molars was 98% (manuscript in preparation for submission). To account for a desired accuracy of 20%, a significance level of 5%, and a safety margin of 20% to compensate for patient dropouts, a minimum sample size of 47 teeth in each group will be required.

Trained clinical staff f will perform all primary molar pulpotomies following a standardized protocol doe each pulp medication used (NeoMTA or NeoPUTTY).

A baseline questionnaire will be filled by caregivers to assess children's sociodemographic characteristics. At each follow-up visit, standardized clinical and radiographic will be performed by trained dentists.

The post-operative clinical success will be considered as a retained tooth that is void of signs and symptoms of infection such as pain on percussion, mobility, presence of a fistula, or an abscess. Radiographic success will be determined by the lack of pathologic changes such as internal or external root resorption, or a periradicular pathosis. The extraction of the tooth due to signs and symptoms of infection will be considered as a failure.

Inclusion Criteria:

• Healthy children aged between 3 and 10 years
• Primary molars with no history of spontaneous or persistent pain
• Restorable primary molars with deep carious lesions approximating or reaching the pulp
• Primary molars with at least 2/3rd of the root length present
• Radiographically, the inclusion criteria were as follows: deep dentin caries approximating or reaching the pulp; no more than one-third of physiologic root resorption; no widening of the periodontal ligament (PDL) space; no pathologic internal or external root resorption; and no apical or furcal radiolucency.
• Children who can understand and speak French or English.

Exclusion Criteria:

• Primary molars with pathological mobility, tenderness to percussion, swelling, or sinus tract
• Primary molars without hemostasis after coronal pulp amputation within five minutes.
• Primary molars with widening of the periodontal ligament (PDL) space; pathologic internal or external root resorption; and apical or furcal radiolucency