Evaluation of full coronal esthetic restorations in primary incisors: clinical success, parental satisfaction, in vitro fracture resistance and bacterial adhesion

The restoration of severely decayed primary incisors is often a clinical challenge, requirements for an acceptable restoration including; esthetics, durability and biocompatible has been demanded. The aim of this study was to evaluate the clinical performance and the parental satisfaction of three different full coronal esthetic restorations (two zirconia prefabricated crowns and strip crowns), in vitro; evaluation of the fracture resistance of prefabricated crown used in the clinical part, and finally assessment of the initial bacterial adhesion on composite resin and zirconia material surfaces. One hundred and sixty five teeth in 42 children were included. Children were randomly assigned to one of three treatment groups, restorations were placed and evaluated at 3, 6 and 9 months interval. A questionnaire was administered to the parents to evaluate their parental satisfaction. The mean force required to fracture the crowns was determined in MPA, then the fractured specimens were assessed with scanning electronic microscope. Asssessment of the initial bacterial adhesion on composite resin and zirconia material surfaces utilizing hydroxyapatite disc as a tooth enamel surrogate was evaluated with both optical density and colony forming unit methods. Overall clinical success and parental satisfaction was comparable between the restorations. There was no significant difference in the force required to fracture the crowns among the prefabricated crowns. The bacterial adherence to the hydroxyapatite discs shows the highest adherence followed by composite and zirconia discs. Concluding that prefabricated zirconia crowns are likely to be successful and may be indicated as an excellent choice for the treatment of carious primary incisors. Key words: Primary incisors, prefabricated primary zirconia crowns, parental satisfaction, fracture resistance, bacterial adhesion.