NCT00972556.

Trial name or title	Comparison of Mineral Trioxide Aggregate (MTA) and 20% formocresol in Pulpotomized Human Primary Molars
Methods	Background: Formocresol is the most widely used pulpotomy medicament in the primary dentition. There are concerns associated with this medicament, primarily the carcinogenicity of the chemical and internal resorption of the treated tooth. Recently, MTA has been suggested with preliminary studies showing promising results. Study design: This is a prospective clinical randomised controlled trial (RCT), which will be performed at Department of Dentistry, National Taiwan University Hospital, to compare the treatment outcomes between MTA and formocresol in pulpotomised human primary molars and to evaluate whether GMTA is a viable alternative to DFC in pulpotomies treatment of human primary molars. Hypotheses: null hypotheses: there is no clinical, radiographic, or histological difference between GMTA and DFC at six, 12, 18, 24 month post‐treatment when used as a pulp dressing agent in pulpotomised primary molars. Alternative hypotheses: there is a statistically significant difference between GMTA and DFC as a pulpotomy agent. GMTA shows clinical and/or radiographic and/or histological success as a dressing material following pulpotomy in primary human molars and may be a suitable replacement for DFC in primary molar pulpotomy. Specific aims: the primary aims of this investigation are: compare the clinical and radiographic results of GMTA with DFC pulpotomies on vital human primary molars at six, 12, 18, and 24 months post‐operatively. Assess intraradicular histological changes of the pulpal tissue and root dentin following pulpotomy treatment with GMTA or DFC. The secondary aims of this investigation are: assess the outcome of GMTA by multiple operators that have been calibrated to the methods of mixing and placing the material. Assess whether sex, tooth type, arch, and child's age at time of treatment influence the overall success rate of GMTA pulpotomies. Compare the radiographic success of the two materials based on both the traditional radiographic assessment criteria adopted by the American Academy of Pediatric Dentistry (AAPD) and the alternative radiographic success criteria adopted by Zurn et al. 2000.To serve as a basis for future research in the comparison of GMTA and DFC pulpotomies. This will include larger sample size, longer follow‐up periods, and a collaborative study with UM group (Prof. Jan C. Hu).
Participants	Inclusion criteria Primary first or second molars with normal pulp, reversible, or irreversible pulpitis, that have vital carious pulp exposures due to caries and whose pulp bled upon entering the pulp chamber. Teeth in which haemostasis could be achieved with pressure of a saline dampened sterile cotton pellet prior to medicament/material placement. No clinical symptoms or evidence of pulp degeneration, such as excessive bleeding from the root canal, history of swelling, mobility, or sinus tracts. Children with percussion sensitivity or spontaneous and persistent pain but where haemostasis could be achieved with pressure of sterile cotton pellet. No radiographic signs of internal or external root resorption, inter‐radicular and/or periapical bone destruction, or furcation radiolucency. No more than one‐third physiologic root resorption has occurred. Teeth had not previously been pulpally treated. Teeth deemed to be restorable with posterior stainless steel crowns. 30 months to 10 years (child) Exclusion criteria Not present
Interventions	Drug: Gray Mineral Trioxide Aggregate (GMTA) Once haemorrhage from the pulp chamber is under control using direct pressure of a sterile cotton pellet, pulp stumps are covered with a MTA paste, obtained by mixing 0.2g GMTA powder with sterile water in a powder to liquid ratio of 3:1 in weight. The GMTA will be then immediately covered with a zinc‐oxide eugenol base (IRM) material. Other Name: ProRoot MTA Drug: Diluted (20%) formocresol (DFC). After the pulp haemostasis is achieved with direct pressure of a sterile cotton pellet, a sterile cotton pellet dampened with 20% DFC will be placed in contact with the pulp for 5 minutes, followed by the immediate placement of a zinc‐oxide eugenol base (IRM) material. Other Name: Buckley's Formo Cresol
Outcomes	Primary: clinically and radiographically outcomes (time frame: six, 12, 18, and 24 months); Secondary: histological outcome (time frame: when the subjective tooth physically exfoliates from oral cavity)
Starting date	September 2009
Contact information	Contact: Yuan‐Ling Lee, PhD, Contact: Hsiao‐Hua Chang, MS
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