This is a study that will be conducted on 6 to 8 years old children to compare the needle-less jet injector with the conventional needle attached syringe in terms of efficiency in controlling pain of local anesthetic infiltration and post-anesthetic pulpotomy of upper first primary molars. The study tests a null hypothesis that states that there is no difference in pain control efficiency of the compared anesthetic techniques when used for the selected treatment procedure in the specified population.

• The conduct of this study is driven by the substantial advantages that are documented to be offered by jet anesthesia over needle injected anesthesia combined with the scarcity, heterogeneity, limitations and contradicting inconclusive results of previously conducted studies assessing the acceptance and anesthetic efficiency of jet injectors against conventional needle attached dental syringes in pediatric patients, particularly for pulpotomy of primary molars. Jet injection offers the opportunity to deliver local anesthesia without using a needle and hence helps to avoid all drawbacks associated with needle injection such as psychological distress; pain; inability to cope with dental treatment; prolonged chair-side time; avoidance of dental care; high clinician skills required for child management and needle-stick injuries. It also allows precise controlled dosing; fast delivery and onset of local anesthesia; absence of post-operative numbness and thus self-inflicted traumatic injuries; reduction of medical waste and cutting down of long-term costs on the clinician. However, the true adequacy of jet anesthesia necessary to complete dental treatment successfully and the acceptance of jet injection in a child patient is yet to be revealed through further research.
• This randomized controlled trial is to be performed on children attending the Diagnosis outpatient clinic in Pediatric Dentistry and Dental Public Health Department, Faculty of Dentistry, Cairo University, Egypt. Children will be screened via personal, medical and dental history taking from them and their parents/caregivers; clinical examination and radiographic examination to identify appropriateness for recruitment in the trial based on the pre-specified eligibility criteria. Legal guardians of eligible children will be informed of the trial aims, conditions and procedures in details and a written informed consent will be obtained from them upon agreement for their children to participate in the trial. A verbal assent will be also obtained from each potential participant following a simple explanation of the trial procedure.
• Based on the sample size to be calculated, a random allocation sequence will be computer generated and will be used to assign participants to the experimental group receiving jet anesthesia (group A) and the control group receiving conventional infiltration anesthesia (group B). The allocation sequence will be enclosed in sequentially numbered, opaque, sealed envelopes and disclosure of the randomization code to the principle investigator will be performed only upon allocation of each corresponding subject throughout the course of the trial.
• For each study group, participants will be introduced to the dental setting and dental instruments to be used and have the anesthetization and dental procedure simply explained while avoiding any anxiety-provoking words. Psychological behavior management techniques such as Tell-Show-Do, voice control, distraction and positive reinforcement will be used similarly for both study groups. Following delivery of anesthesia, pulpotomy of maxillary first primary molars will be performed.
• Throughout the treatment procedure, if rescue anesthesia was needed, it will be delivered by needle infiltration in both study groups and recorded.
• Primary and secondary outcome variables will be measured and recorded via selected tools at pre-specified time points.
• Definitive examination and diagnosis for determination of eligibility, anesthetization, treatment, outcome measurement and data collection procedures will be all performed by the principal investigator.
• The principal investigator will be responsible for managing any intervention-related harms encountered by participants, both medically and financially, following-up the participant whenever necessary and providing post-operative prevention and oral hygiene instructions.
• All examination charts and outcome sheets will be labelled each with a specific code unique to every individual participant. Participant personal information will be kept confidential in a secured limited access area. All data will be electronically backed-up and securely stored by the principal investigator. Statistical analysis and interpretation of the collected results will be performed.
• All study results are planned to be disclosed and communicated to the public via a written thesis that will be orally presented and discussed in a defense that is to be held in Pediatric Dentistry and Dental Public Health Department, Faculty of Dentistry, Cairo University, in the presence of a selected jury. A manuscript of the trial work is planned to be prepared and submitted for publication.

Inclusion Criteria:

• Apparently healthy (Classified as American Society of Anesthesiologists/ ASA I)
• Vital deeply carious maxillary first primary molars indicated for pulpotomy
• No previous dental experience
• Cooperative behavior (rating 3 or 4 on Frankl Category Rating Scale

Exclusion Criteria:

• Refuse to give assent to participate or have parents/caregivers refusing to sign the informed consent form

The duplicate outcome assessor (study director) and the assigned data analyst/ statistician will be blinded.