In Clinical Directions (November JADA), Dr. Patrick Carroll shared a time-saving technique using Fugi I Luting Cement (a conventional glass ionomer) for temporizing a broken tooth. Dr. Carroll’s use of a thick mix of Fugi I, rather than IRM, and elimination of mechanical retention is clinically sound.
Certainly, the chemical adhesions of glass ionomer cements, or GICs, to enamel and dentin supports their use as minimal intervention repair materials. While Dr. Carroll was insightful to select the best category of material for quick and easy temporization, the class of GIC he recommends warrants consideration.
Type I (luting) GICs are formulated for optimal film thickness to ensure complete seating of cemented restorations. Fuji I Luting Cement is a Type I GIC. Type II (restorative) GICs are formulated for manageable consistency, strength, wear resistance and esthetic shading. In restorative applications, Type II GICs are superior to Type I GICs, even when the powder-to-liquid ratio of the Type I material is increased as Dr. Carroll suggests.
Conventional GICs harden by a cement-setting (acid/base) reaction. Modification of conventional GICs through the addition of a polymerizable resin results in resin-modified GICs. Several light-cure resin-modified GICs that harden initially by polymerization and complete their setting in the same manner as conventional GICs are classified as Type II GICs. In addition to the advantage of a command set, resin modified GICs offer higher bond strength than conventionals.
Type II materials including Fuji IX GP++, a conventional restorative GIC, and Fuji II LC+++, a resin-modified GIC, represent more durable materials for temporizing broken teeth than luting cement Fuji I. When long-term temporizing requires a highly wear-resistant GIC, Fuji IX GP will outperform Fuji II LC. When maximum adhesion is required, Fuji II LC will outperform Fuji IX GP, but wear may be observed after a few months on contacting surfaces. Based on physical properties, either of the above Type II cements could be expected to outperform Fuji I in restorative applications.
I commend Dr. Carroll’s ingenuity and thank him for his time-saving technique. Clinical results vary according to each practitioner’s ability to manipulate materials beyond the realm of intended use. Generally, however, the best clinical outcomes are the combined result of operator skill, attention to detail, selecting materials that meet ADA/ISO standards and using materials in accordance with their ADA/ISO classification.
