Comparison of Five Anesthetic Delivery Systems for Palatal Infiltration

Sercan Küçükkurt200 enrolled

Overview

This study is a randomized clinical trial evaluating five different anesthetic delivery systems for palatal infiltration in adults undergoing maxillary molar extraction. A total of 200 healthy volunteers were enrolled and randomly assigned to receive anesthesia using one of the following devices: conventional dental syringe, manual pressure syringe, spring-activated syringe, needle-free jet injector, or computer-controlled local anesthetic delivery system. The purpose of the study is to compare patient-reported pain, dental fear, and physiological responses (pulse rate and oxygen saturation) associated with each system. The results are expected to provide evidence on which devices may improve patient comfort and cooperation during palatal infiltration procedures.

This randomized, parallel-arm superiority trial was conducted at Istanbul Aydın University, Faculty of Dentistry, between September 2023 and March 2025. Two hundred healthy adults (≥18 years) requiring maxillary molar extraction under palatal infiltration anesthesia were equally randomized into five groups (n=40). All participants received 0.4 mL of 4% articaine with 1:100,000 epinephrine, delivered with one of the five systems. The primary outcome was pain perception measured immediately after injection using a visual analog scale (VAS). Secondary outcomes included changes in dental fear, pulse rate, oxygen saturation, and any adverse events. The study was approved by the Istanbul Aydın University Ethics Committee. Written informed consent was obtained from all participants.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

200

Conditions

Interventions

Conventional Dental SyringeDEVICE

Palatal infiltration anesthesia using a conventional dental syringe with a 27G needle. A total of 0.4 mL of articaine 4% with epinephrine 1:100,000 was administered manually over 15-20 seconds following aspiration.

Spring-Activated Syringe (PCJ, PAROJECT™)DEVICE

Palatal infiltration using a spring-activated push-button syringe (PAROJECT™). Two calibrated 0.2 mL doses of articaine 4% with epinephrine 1:100,000 were administered following aspiration.

Needle-Free Jet Injector (NFI, Comfort-in™)DEVICE

Palatal infiltration using a needle-free jet injector (Comfort-in™). A total of 0.4 mL of articaine 4% with epinephrine 1:100,000 was delivered in less than one second at 4-5 bar pressure. Aspiration not applicable.

Computer-Controlled Local Anesthetic Delivery (CCLAD, CALAJECT™)DEVICE

Palatal infiltration using a computer-controlled local anesthetic delivery system (CALAJECT™, Program I) with a 30G, 16 mm needle. AutoFlow rate 0.006-0.009 mL/s, with automatic aspiration after 5 seconds and constant microprocessor-controlled pressure. A total of 0.4 mL of articaine 4% with epinephrine 1:100,000 was administered.

Manual Pressure Syringe (MCJ, ASPIJECT™)DEVICE

Palatal infiltration using a manual pressure-controlled syringe (ASPIJECT™) with a 30G, 16 mm needle. A total of 0.4 mL of articaine 4% with epinephrine 1:100,000 was administered manually over 15-20 seconds with aspiration.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age ≥ 18 years * ASA physical status I or II * No systemic conditions affecting anesthetic metabolism * No known allergy to local anesthetics or vasoconstrictors * No psychiatric disorders or anxiolytic medication * Ability to provide written informed consent Exclusion Criteria: * Pregnancy or lactation * Active infection at the injection site * Diagnosed needle phobia * Prior exposure to any of the tested injection systems * Use of premedication, sedatives, or topical anesthetics on the day of the procedure

Outcomes

Primary Outcomes

Pain during injection (VAS, 0-10 cm)

Pain perception recorded immediately after palatal infiltration using a 10-cm visual analog scale (VAS; 0 = no pain, 10 = worst imaginable pain).

Time frame: Immediately after injection

Secondary Outcomes

Change in dental fear (VAS, 0-10 cm)

Fear measured on a 10-cm VAS before and after injection; difference (ΔVAS) represents fear reduction.

Time frame: Baseline (before injection) and immediately after injection

Pulse rate (bpm)

Pulse rate measured with fingertip oximeter at three time points: baseline (before injection), peri-procedural (during injection), and 3 minutes after injection.

Time frame: Baseline (before injection), peri-procedural (during injection), and 3 minutes post-injection

Oxygen saturation (SpO₂, %)

Oxygen saturation measured with fingertip oximeter at three time points: baseline (before injection), peri-procedural (during injection), and 3 minutes after injection.

Time frame: Baseline (before injection), peri-procedural (during injection), and 3 minutes post-injection

Adverse events

Recording of any immediate or delayed adverse events associated with anesthetic delivery (pain, swelling, bleeding, syncope, allergic reactions).

Time frame: From the time of injection through study completion (average of 1 week follow-up)