Evaluation of the relationship between the cost and properties of glass ionomer cements indicated for atraumatic restorative treatment.

The aim of this study was to evaluate microshear bond strength (µSBS), water sorption and solubility of glass ionomer cements (GIC) indicated for atraumatic restorative treatment (ART). Cylindrical specimens (6 x 2.4 mm) were used to test the sorption and solubility of each GIC (n = 5). The specimens were weighed before and after immersion in water and desiccation. For the µSBS test, 60 primary molars were ground to obtain flat surfaces from both enamel and dentin. The teeth were then assigned to the tested GIC (n = 10) groups, namely Fuji IX - FIX, Ketac Molar - KM and Maxxion R - MX. The exposed surfaces were pre-treated with GIC liquid. Polyethylene tubes were placed on the pre-treated surface and filled with one of the GIC. After 24 h, the specimens were submitted to the µSBS test. The failure mode was assessed using a stereomicroscope (400 x magnification). The powder to liquid ratio and cost of material were also determined (n = 3). The data were analyzed by ANOVA and Tukey's post hoc test. Linear regression was used to determine the relation between cost and the other variables. Overall, MX showed lower µSBS values (enamel: 3.93 ± 0.38; dentin: 5.04 ± 0.70) than FIX (enamel: 5.95 ± 0.85; dentin: 7.01 ± 1.06) and KM (enamel: 5.91 ± 0.78; dentin: 6.88 ± 1.35), as well as higher sorption and solubility. The regression analyses showed a significant and positive correlation between cost and µSBS in enamel (R2 = 0.62; p < 0.001) and dentin (R2 = 0.43; p < 0.001); and a negative correlation between cost and water sorption (R2 = 0.93; p < 0.001) and solubility (R2 = 0.79; p < 0.001). In conclusion, the materials indicated for ART exhibit distinct physical and mechanical properties; in addition, low-priced materials may interfere with GIC properties.

Evaluation of the relationship between the cost and properties of glass ionomer cements indicated for atraumatic restorative treatment

The aim of this study was to evaluate microshear bond strength (μSBS), water sorption and solubility of glass ionomer cements (GIC) indicated for atraumatic restorative treatment (ART). Cylindrical specimens (6x2.4 mm) were used to test the sorption and solubility of each GIC (n = 5). The specimens were weighed before and after immersion in water and desiccation. For the μSBS test, 60 primary molars were ground to obtain flat surfaces from both enamel and dentin. The teeth were then assigned to the tested GIC (n = 10) groups, namely Fuji IX - FIX, Ketac Molar - KM and Maxxion R – MX. The exposed surfaces were pre-treated with GIC liquid. Polyethylene tubes were placed on the pre-treated surface and filled with one of the GIC. After 24 h, the specimens were submitted to the μSBS test. The failure mode was assessed using a stereomicroscope (400x magnification). The powder to liquid ratio and cost of material were also determined (n = 3). The data were analyzed by ANOVA and Tukey's post hoc test. Linear regression was used to determine the relation between cost and the other variables. Overall, MX showed lower μSBS values (enamel: 3.93 ± 0.38; dentin: 5.04 ± 0.70) than FIX (enamel: 5.95 ± 0.85; dentin: 7.01 ± 1.06) and KM (enamel: 5.91 ± 0.78; dentin: 6.88 ± 1.35), as well as higher sorption and solubility. The regression analyses showed a significant and positive correlation between cost and μSBS in enamel (R2 = 0.62; p < 0.001) and dentin (R2 = 0.43; p < 0.001); and a negative correlation between cost and water sorption (R2 = 0.93; p < 0.001) and solubility (R2 = 0.79; p < 0.001). In conclusion, the materials indicated for ART exhibit distinct physical and mechanical properties; in addition, low-priced materials may interfere with GIC properties.

Methods and preliminary findings of a cost-effectiveness study of glass-ionomer-based and composite resin sealant materials after 2 yr.

The cost-effectiveness of glass-carbomer, conventional high-viscosity glass-ionomer cement (HVGIC) [without or with heat (light-emitting diode (LED) thermocuring) application], and composite resin sealants were compared after 2 yr in function. Estimated net costs per sealant were obtained from data on personnel time (measured with activity sampling), transportation, materials, instruments and equipment, and restoration costs for replacing failed sealants from a community trial involving 7- to 9-yr-old Chinese children. Cost data were standardized to reflect the placement of 1,000 sealants per group. Outcomes were the differences in the number of dentine caries lesions that developed between groups. The average sealant application time ranged from 5.40 min (for composite resin) to 8.09 min (for LED thermocured HVGIC), and the average cost per sealant for 1,000 performed per group (simulation sample) ranged from $US3.73 (for composite resin) to $US7.50 (for glass-carbomer). The incremental cost-effectiveness of LED thermocured HVGIC to prevent one additional caries lesion per 1,000 sealants performed was $US1,106 compared with composite resin. Sensitivity analyses showed that differences in the cost of materials across groups had minimal impact on the overall cost. Cost and effectiveness data enhance policymakers' ability to address issues of availability, access, and compliance associated with poor oral-health outcomes, particularly when large numbers of children are excluded from care, in economies where oral health services are still developing.

Bleaching and bonding for the older patient.

UNLABELLED: Older people who remain reasonably well may wish to maintain or enhance their dental and oral appearance, preferably at minimal biologic and financial costs. Bleaching and bonding represents a very good treatment option and a sensible strategy for this group. Bleaching addresses the discoloration, while direct composite bonding can improve the shape of worn, or otherwise unaesthetic, teeth without damaging the structure or health of the residual tooth tissue. This pragmatic treatment is well tolerated by older patients. The visual and functional improvements are greatly appreciated by this group, partly because of the non-destructive and affordable nature of the benefits. CLINICAL RELEVANCE: Bleaching and bonding represents a proven, sensible, pragmatic, affordable and practical approach to managing the aesthetic problems of older patients, and the benefits are achievable without destroying their residual sound tooth tissue.

Comparison of bonding time and shear bond strength between a conventional and a new integrated bonding system.

Conventional adhesive systems use 3 different agents, an enamel conditioner, a primer solution, and an adhesive resin during the bonding of orthodontic brackets to enamel. A characteristic of some new bonding systems is that they combine the conditioning and priming agents into a single application as well as precoat the bracket with the adhesive in an attempt to save time during the bonding procedure. This study compared the total bonding time and shear bond strength (SBS) of 2 bracket-bonding systems: (1) an integrated system that incorporates a self-etching primer and precoated brackets and (2) a conventional system in which the etchant and primer are applied separately and the adhesive applied to the bracket by the clinician. The results of the SBS and the total bonding time comparisons (t = 3.451) of the 2 adhesive systems showed a significant difference (P = .0001). The mean SBS was 9.4+/-3.7 MPa for the new bonding system and 6.2+/-4.4 MPa for the conventional system. The mean total bonding time was 36.5 s/tooth for the new system and 46.7 s/tooth for the conventional system. The clinician has to decide whether the increase in bond strength, the decrease in the total bonding time, and the steps saved during the bonding procedure with the new bonding system balance the increased cost incurred.

The Burton approach to indirect bonding.

There has been a resurgence of interest in the indirect bonding technique for orthodontics. The procedure is not often used in the UK and the reasons for this, as well as the renewal of interest, are explored. A costing exercise suggests that the cost-effectiveness of the technique may be improved by the described Burton technique and, in the light of current manpower considerations, the implications for its use in the future are also discussed.

Bond strengths of two dental bonding systems.

A new bonding system named Kevloc has been introduced. It is based on acrylization of the metal surface with the goal of preventing the occurrence of a marginal gap between the metal and the resin. The purpose of this investigation was to determine the values of the shear bond strength achieved using the Kevloc technique on Ag-Pd (Auropal SE) and Co-Cr (Basil S) alloys and to compare them with those obtained with the OVS technique. The shear bond strengths were measured with the Smitz-Schulmayer shear test in a universal testing machine for polymer materials. A microscope image analyzer was used to measure the thickness of bonding layers and to reveal the possible occurrence of the marginal gap with both techniques. No marginal gap was detected with either technique. Kevloc provided better results than OVS only in a group of specimens tested after polymerization. Immersion in water and thermocycling reduced the initially high bond strength values of Kevloc specimens, whereas the bond strength values of OVS specimens remained unchanged regardless of which aging treatment was used. Microscopic examination did not reveal the existence of the marginal gap for either bonding system. According to the results obtained, it can be concluded that the Kevloc bonding system does not provide better shearing bond strength than the OVS bonding system.