Are pediatric preformed zirconia crowns comparable to preformed metal crowns? A real-life retrospective study

OBJECTIVES

Although minimally and noninvasive caries management are advocated in pediatric dentistry, extensive caries progression often requires endodontic treatment followed by crowning of the tooth. Thus, the aim of this study was to evaluate the success of esthetic preformed zirconia crowns (PZCs) compared to the standard preformed metal crowns (PMCs) after pulpotomy in primary molars retrospectively.

METHOD AND MATERIALS

Patients' digital records in a specialized pediatric clinic in Germany were analyzed to include 2- to 9-year-olds, who had received one or more PMCs or PZCs after a pulpotomy between 2016 and 2020. The main outcomes were success, minor failure (restoration loss, wear, or fracture), or major failure (need for extraction or pulpectomy).

RESULTS

In total, 151 patients with 249 teeth (PMC, n = 149; PZC, n = 100) were included. The mean follow-up time was (19.9 months), with 90.4% of the crowns followed for at least 18 months. The majority of the crowns were considered successful (94.4%). The differences in the success rates between PMCs (96%) and PZCs (92%) did not reach the level of statistical significance (P = .182). All minor failures (1.6%) were in the PZC group and located in the maxilla. Independent of crown type, especially first primary molars were prone to failure (7.9%; second primary molars, 3.3%).

CONCLUSION

PMCs and PZCs both show high clinical success rates as restorations of primary teeth after a pulpotomy. However, there was a tendency of greater minor or major failure in the PZC group.

Effects of decontamination protocols on the aesthetic, morphological, and material composition of preformed paediatric crowns

BACKGROUND

Preformed crowns (PCs) are exposed to potentially infectious bodily fluids during the trial fit; however, whether they can be safely re-used remains uncertain. This study determined the effects of decontamination methods on various PCs. The key criteria examined were aesthetic, morphological, and elemental characteristics.

DESIGN

This is a laboratory-based experimental study. Stainless steel, pre-veneered stainless steel, and zirconia PCs underwent either: (a) ultrasonic cleaning with EmPower^® followed by steam sterilisation, (b) thermal disinfection in an instrument washer with Asepti^® Neutraliser/Asepti^® followed by steam sterilisation, or (c) immersion in an ortho-phthalaldehyde (OPA) instrument-level disinfectant. The methods were performed for 1, 5, or 10 cycles, and scanning electron microscopy (SEM); red, green, and blue (RGB) value; and luminosity value were tracked (using a histogram of individual colour reference chips in Adobe Photoshop^® ) to assess colour changes, and energy-dispersive X-ray (EDX) spectroscopy to characterise the material composition.

RESULTS

Pre-veneered stainless steel crowns showed isolated zones of darkening with loss of luminosity and variations in green and blue values after ultrasonic or thermal washer disinfection combined with steam autoclaving at 5 and 10 cycles. No changes occurred with OPA. Both SEM imaging and EDX analysis identified no changes to crown materials from any of the three reprocessing methods.

CONCLUSIONS

Reprocessing protocols need to reflect the differing responses of various types of PCs. Repeated steam sterilisation causes slight aesthetic alterations by way of colour instability and loss of luminosity to pre-veneered stainless steel crowns, but no issues with stainless steel or zirconia PCs.

Long-term Outcomes of Full Pulpotomy in Permanent Molars for Patients Treated in a Single, Short Session under Special Conditions

INTRODUCTION

Endodontic procedures for patients requiring treatment in a single, short session need to be validated. This study aimed at evaluating the long-term outcome of full pulpotomy in permanent molars performed with reinforced zinc oxide-eugenol cement (Intermediate Restorative Material [IRM], Dentsply Sirona, Versailles, France) immediately restored using stainless steel crowns under general anesthesia.

METHODS

The absence of clinical signs and symptoms and the evolution of the periapical index between the treatment date and the longest follow-up time were used to grade the pulpotomy outcome as "effective," "uncertain," or "ineffective." The impact of different criteria on the pulpotomy outcome was tested (ie, the etiology of the lesion, tooth maturity, endodontic difficulty related to the coronal shape and the root canal shape, and endodontic difficulty related to the radiographic root canal appearance).

RESULTS

Among the 608 teeth (338 patients) treated in a single session with IRM full pulpotomy and stainless steel preformed crowns, 263 (143 patients) were evaluated after a median follow-up period of 24 months. Overall, 89% of the pulpotomies were effective, 7.6% were of uncertain outcome, and 3.4% were ineffective. No tested criteria influenced the rate of effectiveness.

CONCLUSIONS

Long-term outcomes of IRM pulpotomy are similar to those of calcium silicate-based cement pulpotomy observed in the literature. This procedure should not be restricted to patients treated under general anesthesia because it is relevant for all special conditions that impose the provision of endodontic treatment in a single, short session, such as dental care emergencies during humanitarian crises or pandemic periods.