Quintessence International, 10/1997

It is just 20 years since glass-ionomer cements were introduced to the profession as a restorative material capable of an ion exchange adhesion to tooth structure as well as a continuing fluoride release. At the time of presentation there was considerable publicity, but, in retrospect, it is likely that the materials were marketed prematurely, before there had been a great deal of clinical investigation. The clinical short-term results were rather disappointing, particularly in relation to esthetics, because the original version lacked translucency. In the next few years, some manufacturers worked to refine the product and improve the properties and achieved reasonable results. In the early 1980s, it was shown that the main problem with both esthetics and physical properties was the need to maintain a proepr water balance in the material during the early setting phase. Once this problem was identified and overcome, it became possible to achieve excellent results, but these have not been reported frequently. This article discusses a method of placement that will lead to acceptable glass-ionomer restorations and shows a series of restorations that are up to 15 years old.

Amalgambond Plus with a high-performance additive was evaluated for its ability to bond a resin composite or an amalgm alloy to deep dentin in primary teeth with nonretentive cavity preparations. The clinical performance of amalgam and resin composite mesio-occlusalodistal restorations bonded with Amalgambond Plus was evaluated at 15 months and 2 and 3 years. There was no statistically significant difference in the retention, marginal adaptation, secondary caries, and postoperative sensitivity over the times of the evlaution or between amalgam and resin composite restorations. After 3 years, most of the teeth were extracted because it was their exfoliation time, and 29 restorations limited within buccal and lingual cusps were evaluated for marginal leakage. There were no significant differences in microleakage between amalgam and resin composite restorations lined with Amalgambond Plus. Amalgambond Plus has the potential for serving successfully as a cavity liner with either amalgam or resin composite restorations.

The dentition of a patient with ectodermal dysplasia was restored with a modifed hollowed maxillary overdenture opposing a conventional mandibular overdenture. Lingualized occlusion was used because it was the ideal occlusal scheme for this patient to achieve denture stability. The lingual cusps of the maxillary posterior teeth contacted the fossae of the mandibular teeth to create freedom of movement and to prevent lateral interference.

Glass-ionomer cements offer advantages in the treatment of the primary dentition. New, colored, highly viscous glass-ionomer cements hold the promise of better abrasion properties. Owing to their high viscosity, their handling characteristics are similar to those of amalgam. Examination of their properties demonstrated increased resistance to abrasion in comparison to amalgam, although no improvement in fatigue or flexural resistance was found. Clinical experience extending over 2.5 years confirmed these results.

This report describes a young patient with fusion of a maxillary central incisor to a supernumerary tooth. Treatment involved extraction of the fused tooth and orthodontic movement of the lateral incisor to occupy the position of the extracted tooth. A resin composite lmainate veneer was placed on the lateral incisor to simulate the appearance of a central incisor. Five years of follow-up revelaed that treatment had successfully restored esthetics and function.

Death of the dental pulp before completion of root development results in a tooth with an open apex. During endodontic treatment, the open apex makes obturation difficult, because there is no apical stop against which the filling can be packed and condensed. For many years, open apices have been treated by root canal fillings or by periapical surgery with or without a reverse seal. Currently, the conservative appraoch is preferred over surgical management, to avoid the physical and psychological trauma of surgery to a young patient. Two patients were treated by calcium hydroxide-sterile water paste to promote the apexification of the nonvital teeth with an imcompletely formed apex. Normal endodontic preparation of the canal had been carried out in the immature tooth. Radiologic examination after 6 to 9 months showed that the apex of the maxillary incisors was completed by newly formed tissue.

The effect of an adhesive bonding system on wear of posterior resin composite restorations was investigated using an in vitro three-body wear test. Resin composite restorations were placed with an adhesive system (Syntac) in Class I cavities on occlusally flattened extracted molars. Control restorations were prepared with the same resin composites but without etching or bonding. The surface of each restoration was replicated with poly(vinyl siloxane) for epoxy dies at baseline and after every 100,000 cycles until the completion of 400,000 wear cycles. The generalized wear (contact-free wear) of the composite restorations was scanned and traced at the same stag e of replication with a profilometer. The use of an adhes ive system significantly reduced the wear rate of the resin composites used in this study.