Stainless Steel Crowns Outperformed Flexible Crowns on Gingival Health at 12 Months

Edited by Dentaltown staff

Stainless steel crowns showed better morphologic stability and gingival health than flexible aesthetic crowns after a year on endodontically treated primary molars, though both performed acceptably on function and radiographic measures, according to a randomized controlled trial published Sept. 4 in BMC Oral Health.

The trial was conducted in the Department of Pediatric and Preventive Dentistry at A.B. Shetty Memorial Institute of Dental Sciences in Mangalore, India. Investigators enrolled 68 endodontically treated mandibular second primary molars in children aged 3 to 8 and randomly allocated them into two groups of 34, one receiving stainless steel crowns and one receiving Bioflx crowns.

Randomization used the sequentially numbered opaque sealed envelopes method. Clinical and radiographic parameters were evaluated at baseline and at three, six, and 12 months.

Both crown types produced satisfactory occlusal harmony, showed no wear on opposing teeth, and were associated with stable temporomandibular joint function throughout the study. Radiographic findings showed no significant differences between the groups.

The difference appeared in the soft tissue and crown form. At 12 months, the stainless steel crowns demonstrated superior morphologic stability and improved gingival health compared with the flexible crowns.

The authors concluded that flexible crowns offer improved aesthetics with acceptable functional and radiographic outcomes and may serve as an aesthetic alternative for restoring primary molars, while stainless steel crowns retain an advantage in long-term morphologic stability and gingival response. They called for further long-term studies to confirm durability.

Nishi Joshi, Kavita Rai, and Manju Raman Nair conducted the trial, which was registered with the Clinical Trial Registry of India in June 2024.

Follow-up ran 12 months at a single institution with a modest sample, which limits what the results say about performance over the remaining years a primary molar restoration is expected to serve.

Sources:
BMC Oral Health, “Clinical performance of Bioflx versus stainless steel crowns in primary mandibular second molars: a randomized controlled trial,” published online Sept. 4, 2026: link.springer.com/10.1186/s12903-026-09717-1