Quintessence International, 10/1995

In three Scandinavian dental facilities, a series of 334 permanent incisors with fractures of the crown or crown and root was treated by reattachment of the fragment with a resin composite. Two centers (Oslo and Stockholm) employed acid etching of enamel alone for fragment bonding (n=146), while the third center (Copenhagen) used a combination of enamel etching and dentinal bonding (n=188). Although the final retention rate of fragment bonding was similar in the two groups, it took the dentinal bonding group almost three times as long to drop to 50% fragment retention. This difference could be attributed to greater bonding strength in the dentinal bonding group, greater risk of second injury in the younger acid-etching group, or difficulty in maintaining a operative field in the younger age group. The good fragment retention, acceptable esthetics, and pulpal vitality observed in the present series indicate that reattachment of the coronal fragment is a realistic alternative to placement of conventional resin-composite restorations.

Carbamide peroxide dental bleaching has gained much popularity in the past 5 years. Because tooth discoloration caused by dentinogenesis imperfecta involves deep, dark, dentinal stain, practitioners might believe that affected teeth would be resistant to color improvement by bleaching. This article reports the successful use of carbamide peroxide at-home bleaching in a teenager with dentinogenesis imperfecta. Six-month treatment results are shown.

Success in complete-denture treatment is often directly related to the health and condition of the hard and soft tissues that make up the denture-bearing areas. Surgical alteration of the denture-bearing area is frequently necessary to ensure a morphologically corect form capable of providing adequate support for the prosthesis. A number of these anatomic hard and soft tissue obstacles are discussed, and methods for managing these hindrances to complete-denture treatment are suggested.

Many restorative materials are claimed by their manufacturers to match the Vita shade guide. To verify this claim, 40 dental personnel were asked to color match five different restorative materials to their respective Vita shade tabs according to a 5-point scale (1=very poor color match; 5 = excellent color match). Three shades were chosen for each restorative material (a mid-Value shade as well as the highest Value shade and the lowest Value shade present in each system). Pooled scores indicated that the resin composite materials had significantly better overall shade match than did the other materials evaluated and that one resin-modified glass-ionomer cement had significantly better shade match than did the compomer and another resin-modified glass-ionomer cement. Only 11% of the scores for all material and shade combinations were given a good or excellent rating (score greater than 3). Shade match to the Vita shade guide was not material dependent but tended to differ among the different Value shades evaluated.

After maxillary resection, the success of an obturator is often dependent on the neuromuscular skills of the patient and his or her ability to adapt to the shape of the prosthesis. When an obturator has to be replaced, it is desirable to retain the general form of the prosthesis, particularly in an aging patient whose powers of adaptation are reduced. This article describes the use of a copying technique to replace a maxillary obturator. This method facilitated replication of major characteristics of the prosthesis and controlled modification of others, thus minimizing the patient's need to acquire new neuromuscular skills.

A conference concerning the caries-inhibiting efficacy of dentifrices that contain amine and sodium fluorides compared relevant clinical studies and found that both fluoride compounds contribute to the maintenance of dental health. Because of the differing test conditions, the study results cannot, however, be compared. Thus, there is no definite scientific proof of the superiority of one fluoride compound, and no such proof will exist until dentifrices containing amine fluoride and sodium fluoride are tested in a direct clinical comparison.

The case histories of two patients are presented to demonstrate use of soft mouthguard appliances as carries for desensitizing dentifrice when restoration of the teeth or application of densitizing agents is clinically impractical. Potassium nitrate in dentifrice form was a readily available source of potassium ions for altering pulpal nerve sensitivity. Both patients had factitious habits that exacerbated dentinal hypersensitivity and required acute care.

The aim of the present in vitro study was to evaluate the marginal adaptation and seal of direct and indirect (inlay) Class II resin composite restorations made with Z100/Scotchbond MP or Herculite/Optibond. The quality of margins in dentin was assessed for restorations made with or without a lining of glass-ionomer cement or resin-modified glass-ionomer material. The restored teeth were submitted to thermocycling and then to replication for scanning electron microscopic observation and to a dye infiltration test. In the present test conditions, the inlay technique proved its superiority over the direct restorative method. The quality of the dentinal margin of restorations made with Z100/Scotchbond MP appeared also slightly better. Both the glass-ionomer cement and the resin-modified glass-ionomer material, when applied as a lining, increased leakage and downgraded marginal adaptation. The full bonding with modern adhesives appeared to be the most efficient way to enhance the marginal quality of both direct and indirect restorations.

This study examined marginal seal of a visible resin-modified glass-ionomer restorative material. Class V cavity preparations in extracted human premolars were restored with one of four different placement techniques: bulk placement, vertical incremental placement, incremental placement with the gingival increment placed first, or incremental placement with the occlusal increment placed first. Either a cervical former or a hand instrument was used to contour the restorations. Measurement of dye penetration indicated that there was no statistically significant differences in microleakage among the groups, by placement technique or method of contouring. However, two groups contoured with a cervical former were found to be 100% leakage free.

The effects of dentinal surface conditioning with phosphoric acid or with phosphoric acid and subsequent deproteinization by sodium hypochlorite on resin bonding are presented. Bond strengths mediated by the Gluma/Pekafill bonding and estorative system were not affected by the alternative pretreatment methods, while marginal performance of restorations in dentinal cavities was significantly adversely affected by the deproteinization procedure. The resin polymer coupling zine has an important function as a layer that compensates for the curing stresses of the restorative material that act in a wall-to-wall direction.

Sixty non-undercut Class V abrasion lesions in 13 patients were restored with light-cured Type IIa Glass-ionomer cements in accordance with the manufacturer's instructions, 20 each with Fuji II LC, Photac-Fil, and Vitremer. Patients were recalled for examination and photographs 1 week, 6 months, and 1 year posttreatment. Color, marginal discoloration, and retention of the restorations were assessed at each recall period. At 1 year, no loss of restorations was found. Analysis revealed statistically significant darkening in color of the Vitremer restorations, no significant change in color of the Fuji II LC and Photac-Fil restorations, and statistically significant but clinically negligible development of marginal discoloration of all materials.