TheraCal PT vs. Formocresol in Primary Molar Pulpotomies

Vital pulpotomy is a standard therapeutic intervention in pediatric dentistry aimed at preserving primary molars with carious or mechanical pulp exposure, thereby maintaining tooth function until physiological exfoliation. Traditionally, Formocresol has served as the conventional benchmark medicament; however, concerns regarding its potential systemic toxicity and tissue fixation have prompted the continuous investigation of safer, bioactive alternatives. TheraCal PT is a novel, dual-cured, resin-modified calcium silicate-based material designed to stimulate rapid dentin bridge formation through sustained calcium ion release and alkaline pH maintenance. This randomized controlled trial was established to evaluate and compare the long-term clinical and radiographic efficacy of TheraCal PT against conventional Formocresol in vital primary teeth pulpotomies over a 12-month investigative window.

Study Settings and Population:

This prospective, parallel-group, randomized clinical investigation was conducted at the Postgraduate Clinics of the Department of Pediatric Dentistry, Faculty of Dentistry at Hama University, Syria. The trial protocol was reviewed and formally approved by the Institutional Review Board and the Research Ethics Committee of Hama University. The study population comprised 50 primary molars requiring vital pulp therapy in cooperative pediatric patients aged 5 to 8 years (one molar per child). Legally authorized guardians of all eligible children received a comprehensive presentation regarding the specific trial objectives, risks, and benefits prior to signing a definitive, written informed consent document in compliance with the Declaration of Helsinki.

Eligibility and Screening Criteria:

Strict clinical and radiographic selection criteria were implemented to guarantee sample homogeneity. Eligible pediatric participants were required to exhibit cooperative "positive" or "definitely positive" behavior according to the Frankl Behavior Rating Scale. All participants were systemically healthy, presenting with no conditions that could alter healing mechanisms. Clinically, each target primary molar possessed a restorable coronal tooth architecture. The protocol targeted vital teeth presenting with mechanical or carious pulpal exposure during excavation, with an absolute absence of prior spontaneous or nocturnal pain. Upon controlled surgical excision of the coronal pulp tissue, radicular pulp stumps were required to demonstrate bright red hemorrhage easily controlled via light pressure with a sterile, saline-moistened cotton pellet within 3 to 5 minutes.

Radiographically, all included primary molars exhibited stable root structures with physiological root resorption limited to less than the apical third of the total root length, verified by preoperative periapical radiographs. Target teeth were entirely free from pre-existing radiographic pathosis, explicitly defined by the absence of periapical or inter-radicular furcation radiolucencies, the total absence of pathological internal or external root resorption, and the maintenance of an intact periodontal ligament space. Children exhibiting uncooperative behaviors, or teeth presenting with localized swelling, mobility, fistulous tracts, tenderness to percussion, or uncontrollable radicular hemorrhage were systematically excluded.

Randomization and Allocation Concealment:

The 50 primary teeth were randomly allocated in a strict 1:1 ratio into either the Experimental Group (TheraCal PT) or the Active Control Group (Formocresol), yielding 25 test sites per cohort. The random allocation sequence was computer-generated prior to clinical initiation via an online randomization software package. To prevent selection bias, sequentially numbered, opaque, sealed envelopes (SNOSE) containing the treatment assignments were prepared and maintained by an independent co-investigator. The envelope was exclusively opened by the operational clinician immediately preceding the active pulp management phase, after local anesthesia was established and rubber dam isolation was secured.

Standardized Operative Intervention:

All procedures were executed under rigorous aseptic conditions by a single operator. Local anesthesia was established utilizing 2% lidocaine with 1:100,000 epinephrine, followed by rubber dam application. Access cavity preparation and complete excavation of deep carious dentin were performed. Upon unroofing the pulp chamber, the coronal pulp tissue was amputated at the canal orifices. Local hemostasis was initiated using a sterile cotton pellet moistened with normal saline for up to 5 minutes. Following successful control of hemorrhage, the allocated intervention was performed:

• Formocresol Group: A sterile cotton pellet lightly dampened with a 1:5 dilution of Buckley's Formocresol solution was applied to the radicular pulp stumps for 5 minutes. A sub-base layer of zinc oxide eugenol (ZOE) cement was then placed over the pulp floor.
• TheraCal PT Group: TheraCal PT cement was directly adapted over the radicular pulp stumps and the entire pulpal floor at a uniform thickness of approximately 2 mm. Photo-polymerization was executed using a calibrated LED curing light for a continuous duration of 10 seconds at a stable output of 1100 mW/cm².

Immediately following sub-base applications, all treated primary molars across both cohorts were definitively restored with preformed stainless steel crowns (SSCs) according to the guidelines of the American Academy of Pediatric Dentistry (AAPD).

Success Evaluation and Follow-up Protocol:

Treated subjects were systematically recalled for blinded clinical and radiographic examinations at standardized intervals up to the definitive 12-month endpoint. Clinical success was quantified by the absolute absence of subjective or objective signs or symptoms of pathology (pain, swelling, marginal erythema, fistulous tracts, abnormal mobility, or tenderness to percussion). Radiographic success was evaluated using standardized periapical radiographs achieved via the parallel technique, defined as the total absence of new periapical radiolucencies, inter-radicular furcation radiolucencies, or pathological internal/external root resorption.