Gill, Ashley & Garcia, Mariella & An, Se Won & Scott, JoAnna & Seminario, Ana. (2020). Clinical Comparison of Three Esthetic Full-Coverage Restorations in Primary Maxillary Incisors at 12 Months. Pediatric dentistry. 42. 367-372.

PURPOSE

The purpose of this study was to compare the 12-month clinical outcomes of primary maxillary incisors restored with composite strip crowns (CSCs), NuSmile preveneered stainless steel crowns (PVSSCs), and NuSmile zirconia crowns (ZCs).

METHODS

A total of 135 teeth in 49 two- to four-year-olds with early childhood caries were randomly assigned to crown groups. Demographic and tooth-related variables at baseline and 12 months were assessed by calibrated examiners. Fisher’s exact or chi-square tests were used to test associations (P<0.05). Parental

satisfaction of crown esthetics was evaluated by questionnaire.

RESULTS

Children were, on average, 3.4 years old, female (55 percent), and had a mean decayed, missing, and filled primary teeth (dmft) index score of 10.6. At 12 months, crown retention was significantly lower for CSCs versus PVSSCs or ZCs (79 percent, 100 percent, and 95 percent, respectively; P=0.002). Partial and complete loss of material was significantly higher in CSCs than PVSSCs or ZCs (29 percent, 11 percent, and zero percent, respectively; P<0.001). CSCs presented with increased marginal discrepancies

and color change (P<0.001). Most parents were very satisfied (87 percent); those dissatisfied were concerned with the color of CSCs and PVSSCs (63 percent versus 37 percent; P=0.005).

CONCLUSION

Composite strip crowns showed significantly reduced clinical success in retention, durability, marginal adaptation, and color compared to preveneered stainless steel crowns or zirconia crowns. Parental esthetic satisfaction was highest for NuSmile ZCs.

Johnson-Harris, D. & Chiquet, Brett & Flaitz, Catherine & Badger, Gary & Frey, Gary. (2016). Wear of primary tooth enamel by ceramic materials. Pediatric Dentistry. 38. 519-522.

PURPOSE

The purpose of this study was to document the amount of wear caused by ceramic materials to opposing enamel in primary teeth using an in vitro model.

METHODS

The localized wear by two different ceramic materials (alumina and zirconia) on primary tooth enamel was accomplished using a Leinfelder style in vitro wear test apparatus on 15 samples for 800,000 cycles each. The maximum wear height, width, and depth were measured with a traveling 20X microscope. Descriptive statistics, student’s t test, and Mann-Whitney test were used to analyze enamel wear by the dental ceramics.

RESULTS

The height, width, and depth of the alumina samples were 1186.7 μm, 1097.5 μm, and 123.0 μm, respectively. The height, width, and depth of the zirconia samples were 1113.4 μm, 1082.2 μm, and 192.7 μm, respectively. No statistical difference was observed between the alumina and zirconia in this wear test (P>0.05).

CONCLUSION

Although enamel wear was documented in both groups, the amount of in vitro wear was minimal, suggesting that ceramic crowns can be used without resulting in excess enamel loss to occluding primary teeth.

Donly, Kevin & Cervantes Mendez, Maria Jose & Contreras, Claudia & Liu, Jungyi. (2020). Prospective randomized clinical trial of primary molar crowns: 36-month results. American journal of dentistry. 33. 165-168.

PURPOSE

To clinically evaluate the clinical success of a primary zirconia molar crown, compared with stainless steel crowns (SSCs).

METHODS

This randomized, controlled clinical trial was designed as a split-mouth study. 50 subjects ranging in age from 3-7 years were recruited to provide a total of 50 paired teeth requiring primary molar crowns, each participant receiving a SSC and zirconia crown. Restorations were evaluated at 6-, 12-, 24-, and 36-month recall appointments examining the following criteria: gingival health, estimate of the degree crown was high in occlusion, surface roughness, staining on crown surface, wear of opposing arch tooth, color match, anatomic form, marginal integrity, marginal discoloration, proximal contact area, secondary caries at crown margin and parent/guardian satisfaction with crown appearance.

RESULTS

The 36-month follow up included 23 subjects (46%). 35 crowns (35%) were evaluated; of the 18 zirconia crowns and 17 SSCs, there were no failures at the 36-month evaluation. The only significant differences in the parameters evaluated were parent satisfaction, with the zirconia crown preference (P< 0.05) and gingival health, with the zirconia crowns having healthy adjacent gingiva (P< 0.01). The 36-month results indicated that zirconia primary molar crowns performed similarly to an established SSC for restoration of primary molars.

CONCLUSION

The findings from this study indicated that at 36 months, NuSmile ZR zirconia crowns clinically performed as well as stainless steel crowns.