Comparison of mineral trioxide aggregate and diluted formocresol in pulpotomized human primary molars: 42-month follow-up and survival analysis

Abstract

Purpose: The purpose of this study was to test the hypothesis that there is no significant difference in the clinical and radiographic outcomes of diluted formocresol (DFC) compared to gray mineral trioxide aggregate (GMTA) pulpotomy in human primary molars.

Methods: A total of 152 children with 252 primary molars met selection criteria. Of those, 119 and 133 teeth were randomly assigned to the GMTA and DFC groups, respectively. Periapical radiographs, taken pre- and/or postoperatively and at each 6-month follow-up, were digitized and evaluated by three blinded and calibrated examiners.

Results: Over a 42-month period, a total of 865 clinical and radiographic evaluations were conducted. There was no significant difference in clinical success, with the cumulative proportion of GMTA-treated teeth surviving at 0.98 vs DFC-treated teeth at 0.95 (P>.05). Radiographic success, however, was significantly greater for GMTA vs DFC, with the cumulative proportion of GMTA-treated teeth surviving at 0.90 vs DFC-treated teeth at 0.47 (P<.001). Overall, DFC-treated teeth were 5.1 times more likely to fail than GMTA-treated teeth. Radiographic pathologies were observed more frequently in the DFC-treated teeth (P<.05).

Conclusion: Gray mineral trioxide aggregate can be considered an acceptable replacement for diluted formocresol when used as a medicament for primary molar pulpotomies.

Figure 1

Flowcharts demonstrate the number of teeth recruited, treated and recalled at each follow up time point at either the UMOPD or MCHC test site.

Figure 1

Flowcharts demonstrate the number of teeth recruited, treated and recalled at each follow up time point at either the UMOPD or MCHC test site.

Figure 2

Kaplan-Meier plot of clinical survival, in months, by material. DFC=diluted formocresol; MTA=mineral trioxide aggregate; cum survival= cumulative proportion of survival.

Figure 3

Kaplan-Meier plot of radiographic survival in months by material. DFC=diluted formocresol; MTA=mineral trioxide aggregate; cum survival= cumulative proportion of survival.

Figure 4

Histologic findings of diluted formocresol-treated teeth. (A) Partial dentin bridge formation with ectopic tertiary dentin (TD) formation present in the pulpal space. Tertiary dentin, with odontoblasts trapped within, is evident lining the radicular walls. Chronic inflammation of pulp cells (CI) with lymphocyte infiltration can be observed. (B) Radicular pulp obliteration with hyalinization of the pulpal tissue. Chronic inflammatory cells are aggregated at the orifice of the pulp canal. (C) Dentin bridge formation (DB) successfully walling off chronic inflammatory and necrosis45 pulp tissue in direct contact with the pulpal medicament. (D) Healthy pulp tissue with some signs of red blood cell aggregation in the blood vessels and partial DB. (E) Reparative dentin formation along the walls of the pulpal canal resulting in pulp canal obliteration. Excessive connective tissue is present in the radicular pulp tissue; however, no signs of inflammation can be noted in this sample. (R) Internal root resorption with osteoclastic activity noted in numerous resorption lacuni of the radicular dentin wall (white arrows).

Figure 5

Histologic findings of mineral trioxide aggregate (MTA)-treated teeth. (A) MTA material in direct contact with pulpal tissue. Pulpal tissue exhibited a small degree of blood vessel enlargement with aggregation of red blood cells (blue arrow). No odontoblasts were evident in this sample; however, some tertiary dentin was noted adjacent to the MTA material (white arrow). (B) Tertiary dentin formation was highly irregular at the orifice of the pulp canal. No residual pulpal tissue was evident in this sample. (C) Radicular pulp canal obliteration with irregular connective tissue repair. No signs of viable pulp cells. (D) Dentin bridge formation adjacent to residual healthy pulpal tissue.