Quintessence International, 08/1998

Objective: The long-term clinical performance of three posterior resin composites and two amalgams was assessed. Method and materials: Thirty Class II restorations each of P-30, Occlusin, Clearfil Posterior (composites), New True Dent alloy, and Solila Nova (amalgams) were placed. Reviews took place at 6 months and at 1, 2, 3, 4, 5, and 10 years. At each visit the gingival condition, the contact point status, and the presence of ledges, gaps, or recurrent caries were assessed. The color match, cavosurface marginal stain, general surface stain, tarnish, and corrosion were also scored where applicable. Epoxy resin replicas were used to measure the maximum depth of wear. Results: After 10 years, there had been corrosion of both the high- and low-copper amalgams and a slight deterioration in color match of a number of composite restorations. Eighteen (of 20) Occlusin restorations had obvious cavosurface marginal stain, attirbuted to staining of the unfilled bonding resin layer. Statistical analysis indicated that New True Dentalloy, Solila Nova, and Clearfil-P exhibited significantly less wear than Occlusin and P-30. None of the restorations examined at the 10-year recall required replacement. Conclusion: The five materials, placed in a dental school environment, provided adequate clinical service for 10 years

Objective: The purpose of this study was to investigate if autoclaving light-curing tips in sterilization packages using a properly maintained autclave filled with distilled water reduced the buildup of boiler scal and allowed the tips eto maintain their ability to transmit energy. Method and Materials: Thirty light-curing tips were divided into groups: control, never autclaved; group 1, no light-curing tip treatment, autclaved only; group 2, autclaved and treated with the Demetron/Kerr Optics Maintenance Kit; group 3, autoclaved and treated with the EFOS Fiberoptic Cleaning Kit; group 4, autoclaved and trated with Shofu Brownie and Greenie polishing points; and group 5, autoclaved and treated with a standard rubber prophylaxis cup. The curing tips were packaged and subjected to 30 autclave cycles in a clinical autoclave with standard loads of clinical instruments. The light transmission was measured with a curing radiometer. Results: Results whoed a 7% decrease in energy transmission for the untreated tips compared to the control. Both polishing system gruops demonstrated a 4% decrease. There was no significant difference between the cont rol and the first three groups. The polishing point and prophylaxis cup groups shoed significantly decreased energy transmission (decreases of 11% and 25%, respectively) Conclusion: Light-curing tips can be autoclaved with routine packaged loads of clinical instruments and retain their ability to transmit light energy, provided that the tips are packaged and the autoclave is properly maintained and filled with distilled water. Commercially available optics maintenance kits are effective in removing deposits and restoring light energy transmission.

A patient presented with a large, multilocular, refractory traumatic bone cyst. The radiolucency had increased in dimension since her last recall. Over 11 years, therapy had included needle aspiration bipsies followed by simple curettage and closure, the most common therapy for traumatic bone cysts. However, all treatment had proved unsuccessful for this patient. It was decided to treat the patient with a slightly unique method. After curettage of the lesion, the traumatic bone cyst was packed with a mixture of autogenous blood, harvested autogenous bone chips, and hydroxyapatite.

Objective: This in vitro study compared the shade changes in extracted teeth during 2 weeks' whitening with 5%, 10%, or 16% carbamide peroxide. Method and materials: After color calibration, the sole examiner selected 110 extracted unrestored, noncarious teeth, shade A3 or darker on a value-oriented guide. The teeth were randomly distributed into equal color groups. The control group (11 teeth) was treated with 0.9% saline, while the experimental groups (33 teeth each) were treated with 5%, 10%, or 16% carbamide peroxide. The solutions remained on the teeth for 8 hours. The teeth and tray were rinsed with tap water for 2 minutes, then rehydrated in 0.9% saline for 16 hours in the humidifier. The shade was asse ssed, and the process was repeated daily for 2 weeks. Results: Repeated-measures analysis of variance indicated a significant difference in overall shade values between the control and all carbamide peroxide-treated groups at days 8 and 15. A Kaplan-Meier Survival Analysis indicated a quicker two-tab color change for the 10% and 16% groups than the 5% group. However, continuation of the 5% treatment to 3 weeks resulted in shades that approached the 2-week 10% and 16% values. Conclusion: Lower concentrations of carbamide peroxide take longer to whiten teeth but eventually achieve the same result as higher concentrations. Higher concentrations may cause increased sensitivity.

Heat-curing autopolymerizing (self-cure or cold-cure), thermoplastic, and light-curing acrylic resin are the most commonly used orthodontic baseplate materials. While cured acrylic resins present few problems to the patient, in the laboratory acrylic resin has to be sprayed, mixed, or packed in a fume-extraction unit because of the harmful fumes emitted by the raw inflammable chemicals. Light-curing material, on the other hand, is virtually nonflammable and has virtually no aroma. A light-cure technique for the construction of orthodontic baseplates is described. While buildup of the baseplate is slightly slower than for self-cured material, the shorter time involved in trimming and polishing means that overall construction is faster. It is easier to obtain a uniform thickness with light-cured material, and it provides superior fit. These results, however, are subject to more extensive clinical trials. The only apparent disadvantage is the fine powder produced during trimming. Even with a bench equipped with an extraction unit, it is advisable to use a face mask to prevent the inhalation of dust.

Severe mandibular alveolar ridge resorption is usually observed in patients with long-term edentulism and/or ill-fitting dentures. In some of these patients, the genial tubercles project into the floor of the mouth as a high point in the anterior area of the mandibular residual ridge. The lingual flanges of mandibular stock imperssion trays usually impinge on the most prominent areas of the resorbed mandibular edentulous ridge (ie, internal oblique lines and genial tubercles). It is suggested that a preliminary custom tray be made in such cases to pour an initi al impression so that individual custom trays can be fabricated. An efficient method for constructing such a custom impression tray from readily available materials is described.

Objective: The color stability of laboratory-made composite veneers was compared to that of artificial resin teeth under in vivo conditions. Method and materials: Veneers and resin teeth of removable partial dentures were measured colorimetrically with reflection spectrophotometry; the color changes were characterized in the Commission Internationale d'Eclairage L*a*b* color space. The color was first determined 24 hours after manufacture and again after 6, 12, and 18 months at incisal, cervical, and centrofacial tooth positions. The denture teeth and veneers were measured, cleaned to eliminate the influence of surface discoloration, and measured again at every recall. The food consumption and tooth cleaning habits of the patients were taken into account. Results: In all groups the maximum color changes from the baseline measurement were AL* = 2.1, Aa* = 0.4, and Ab* = 1.8. The changes in the AE* values were between 1.0 and 2.5 units. Despite polishing, the AE* values increased by approximately 0.2 to 0.3 units in relation to the previous measurement with increased wearing time. External discolorations were eliminated by polishing, depending on the type of material; the maximum color change because of polishing was between 0.8 and 2.0 units for AE*. The resin teeth showed no significant changes in the AE* values. Conclusion: After a wearing period of 18 months, the discolorations of the tested materials were clinically acceptable. The artificial resin teeth showed statistically smaller color changes than did the veneering materials

Oral ulcerations can be both a localized disease entity and a manifestation of an underlying systemic condition. In individuals infected with the human immunodeficiency virus, oral ulceration may serve as a marker for a specific systemic illness, early immunosuppression, and disease progression. This article reviews clinical manifestations, diagnosis, and management of oral ulcerations in individuals with the human immunodeficiency virus.

Objective: This study evaluated the biocompatibility of a resin-modified glass-ionomer material on monkey pulps. Method and materials: Standardized Class V cavities were prepared in 112 teeth distributed in six healthy adult monkeys. The resin-modified glass-ionomer cement was placed in 24 nonexposed and 36 exposed pulps according to manufacturer's instructions. ZOE was used as a control in nonexposed pulps, while calcium hydroxide was used as a control for exposed pulps. Tissues were collected at 6 to 7, 21 to 27, and 90 to 97 days. After demineralization, the teeth were serially sectioned, stained, and observed by light microscopy. Results: Except for one resin-modified glass-ionomer pulp at 6 days, there were no differences between the responses of nonexposed pulps to resin-modified glass-ionomer specimens and ZOE controls. In exposed pulps, eight of 36 resin-modified glass-ionomer pulps showed various grades of inflammatory response, all associated with stained bacteria. Pulpal healing was similar in both resin-modified glass-ionomer and calcium hydroxide direct-capped exposures. Twenty-two of 26 exposed pulps restored with the resin-modified glass-ionomer cement showed dentin bridge formation at 21 and 97 days. Conclusion: The resin-modified glass-ionomer material exhibited acceptable biologic compatibility in exposed and nonexposed cavities.