The rationale for full coverage esthetic crowns: a case series

Beyond esthetics: Dr. Patrick Ruck discusses NuSmile^® ZR Anterior Crowns as a long-term solution for complex pediatric dental cases

Background

Several clinical solutions exist for primary anterior teeth with multisurface decay. Full coronal restoration of carious primary incisors may be indicated when caries is present on multiple surfaces, pulpal therapy is indicated, caries may be minor, but oral hygiene is very poor, or in a child with severe early childhood caries or a high caries risk diagnosis.¹ Depending on the clinical scenario, a minimally invasive approach with the utilization of a high viscosity glass ionomer cement (HVGIC), with or without the combination of silver diamine fluoride (SDF) in a strip crown form, may pause the caries progression and provide an adequate clinical solution. Resin composite strip crowns have shown 80% retention rates and adequate parental satisfaction,^1-4 although composite resin strip crowns have shown lower retention rates in teeth with decay involving three or more surfaces and particularly in children with a high caries risk^4-6 (Figure 1). This could be from the continued high caries risk behaviors of the patient, as composite resin strip crowns in this population have shown to have increased inflamed marginal gingiva and gingival bleeding, increased plaque retention along the restoration, and loss of some restorative material.^5,6

Alternatively, a resin-faced stainless steel crown provides a full coverage restoration with excellent retention.⁷ These crowns can serve as a full-coverage restoration with or without the resin facing, but the loss of resin facing can be a major esthetic concern for parents.⁷ Preformed pediatric zirconia crowns address many of the undesirable clinical outcomes of other restorative materials. Their biocompatibility, demonstration of excellent marginal gingival health, low plaque retention, high parental esthetic acceptance, and high survival probabilities make them an excellent clinical choice in the patient with severe early childhood caries.^1,4,5,8-13

With parental interest increasing in esthetic treatment options for complex anterior caries, preformed pediatric zirconia crowns are becoming the treatment of choice for patients with a high caries risk or a severe early childhood caries diagnosis.¹⁴ This review discusses three clinical cases in which NuSmile^® ZR (NuSmile, Houston, Texas) anterior pediatric zirconia crowns were the correct clinical decision in varying clinical scenarios.

Case 1

A 2-year-old male who received full mouth dental rehabilitation (FMDR) under general anesthesia presented for his 6-month recall at 2-year post FMDR. He had significant plaque accumulations with poor oral hygiene along his existing stainless-steel crowns (SSCs) and non-treated teeth. Additionally, the patient had gingival bleeding and gingival inflammation around these clinical sites. His anterior zirconia crowns showed healthy gingival margins with little-to-no plaque accumulations. This positive clinical finding is from the highly polished nature and biocompatibility of pediatric zirconia crowns. These restoration features limit plaque accumulations on the restoration and along the marginal gingiva, providing a localized positive aspect directly related to the choice of restorative material (Figure 2).

“With parental interest increasing in esthetic treatment options for complex anterior caries, preformed pediatric zirconia crowns are becoming the treatment of choice for patients with a high caries risk or a severe early childhood caries diagnosis.”

Case 2

A 3-year-old female presented with pulpal necrosis and abscess on #E and pulpal necrosis on #F. Extraction therapy or pulpectomy was offered. The family was highly motivated to retain #E and #F. The pulpectomy was performed with 0.02 K-Flex hand files, 3% NaOCl with a lateral vented needle, obturated with Vitapex (Neo Dental International Inc., Federal Way, Washington), a premixed paste of calcium hydroxide and iodoform. The access was filled with a HVGIC sealing the pulp therapy and increasing the clinical success by minimizing the potential for bacterial contamination. NuSmile ZR anterior crowns were selected as offering a full-coverage, esthetic, cemented restoration with no polymerization shrinkage when compared to a composite restoration. Crowns were cemented with NuSmile^® BioCem (NuSmile, Houston, Texas). This is clinically beneficial as the provider would want to cement a restoration that provides limited microleakage minimizing the potential for bacterial contamination.^15-17 At 6-month follow up, lesion healing had occurred with healthy gingival margins and no plaque accumulations (Figure 3).

Case 3

A 4-year-old female presented with existing Silver Modified Atraumatic Restorative Technique (SMART) style restorations on #D, #E, #F, #G, and caries on other teeth. These anterior lesions had been previously treated using SDF and covered with a HVGIC in a strip crown form. Though her lesions were stable from the clinical success of the SDF and HVGIC, these restorations were starting to fracture and demonstrate loss of material.  The family wanted a more esthetic treatment option that would have a longer survivability. Additionally due to her high caries risk nature, a full coverage restoration with NuSmile^® ZR anterior crowns were a more ideal solution in stabilizing her extensive decay pattern and covering staining from SDF therapy (Figure 4).

Conclusion

There exist multiple treatment solutions, but NuSmile^® ZR anterior crowns provide a highly biocompatible, long lasting, and esthetically pleasing restoration.  This is an excellent clinical choice for the high caries risk patient with severe early childhood caries.