The orthodontic appliance: esthetic considerations

The importance of attractive dental and facial appearance is at an all-time high for the American consumer. Because of this emphasis on appearance, the esthetic impact of the orthodontic appliance is a matter of great concern to prospective patients. This article presents an overview of the esthetic features of currently available orthodontic appliances.     

Advanced esthetic laser procedures in orthodontic practice

The use of a soft tissue laser will not only improve the quality and speed of orthodontic treatment, it can dramatically enhance final esthetic results. To optimize the speed of treatment, esthetic considerations should be considered as part of the initial diagnosis. Using a laser allows cleaner finish lines and reduces damage to the gingival crests, with faster healing and less discomfort when compared to more conventional techniques. Even when dealing with complex altered passive eruption cases, soft-tissue laser procedures can provide significant benefits to patients.     

Color stability and fluorescence of different orthodontic esthetic archwires

Objective:To evaluate the color stability of six esthetic archwires at different time periods and their fluorescence.Materials and Methods:Samples were evaluated after 7, 14, and 21 days of immersion in staining solution. Color measurements were performed by means of a spectrophotometer according to the Commission Internationale de I''Eclairage L*a*b* system, and color changes (ΔE*) and National Bureau of Standards units were computed. The fluorescence of as-received samples was evaluated by two observers and compared with that of a bovine central incisor. Statistical differences were investigated using analysis of variance and Tukey''s post hoc test.Results:All brands showed statistically significant color change after 21 days (ΔE* from 1.88 to 12.06). The Optis archwire (fiber-reinforced composite) presented the highest color alteration, although staining was observed only near its ends. The Trianeiro archwire (coated nickel-titanium) and the Ortho Organizers archwire (coated stainless steel) presented with less color change. The Optis archwire was the only one that presented with fluorescence similar to that of bovine teeth.Conclusions:All esthetic archwires assessed showed clinically noticeable color change after 21 days in staining solution. The optical properties of currently available esthetic archwires may not yet be ideal.     

Polymerization color changes of esthetic restoratives

The color changes of three different types of tooth-colored restoratives during polymerization were investigated using colorimetry. L*, a*, b* color parameters of five different shades of Z100 (a mini-filled composite resin), Fuji II LC (a resin-modified glass-ionomer cement), and Dyract (a polyacid-modified composite resin) were taken precure and postcure. The results showed that the restoratives evaluated all underwent color changes during polymerization. The polymerization changes in color parameters were shade and not material dependent. Changes in L* parameter or lightness during polymerization were significant for all material and shade combinations and had the greatest influence on the overall polymerization color change. As the color change was perceivable by the human eye for most shades of materials, the clinical practice of polymerizing some material on, or adjacent to, the undried tooth to confirm shades of esthetic restoratives before restorative procedures is prudent.     

In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires

Objective:To investigate the cytotoxicity of nickel-titanium (NiTi) esthetic orthodontic archwires with different surface coatings.Materials and Methods:Three fully coated, tooth-colored NiTi wires (BioCosmetic, Titanol Cosmetic, EverWhite), two ion-implanted wires (TMA Purple, Sentalloy High Aesthetic), five uncoated NiTi wires (BioStarter, BioTorque, Titanol Superelastic, Memory Wire Superelastic, and Sentalloy), one β-titanium wire (TMA), and one stainless steel wire (Stainless Steel) were considered for this study. The wire samples were placed at 37°C in airtight test tubes containing Dulbecco’s Modified Eagle’s Medium (0.1 mg/mL) for 1, 7, 14, and 30 days. The cell viability of human gingival fibroblasts (HGFs) cultured with this medium was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data were analyzed by a two-way analysis of variance (α  =  .05).Results:The highest cytotoxic effect was reached on day 30 for all samples. The archwires exhibited a cytotoxicity on HGFs ranging from “none” to “slight,” with the exception of the BioTorque, which resulted in moderate cytotoxicity on day 30. Significant differences were found between esthetic archwires and their uncoated pairs only for BioCosmetic (P  =  .001) and EverWhite (P < .001).Conclusions:Under the experimental conditions, all of the NiTi esthetic archwires resulted in slight cytotoxicity, as did the respective uncoated wires. For this reason their clinical use may be considered to have similar risks to the uncoated archwires.     

Shear peel bond strengths of esthetic orthodontic brackets.

Anecdotal reports of bracket fracture and tooth damage associated with the use of certain esthetic orthodontic brackets have been reported in the literature. With the advent of new esthetic orthodontic brackets, the need has arisen to test the claims of the manufacturers. The objectives of this study were to determine: (1) shear peel bond strengths (SPBS) of various debonded orthodontic brackets, (2) SPBS of these rebonded esthetic brackets with and without use of silane, and (3) fracture sites of all groups examined. Seventy-five noncarious human premolar teeth were randomly divided into five groups (A through E). The teeth were cleaned, stored in 70% ethyl alcohol, and mounted for testing in the Instron machine. The following brackets were bonded to the teeth with Ortho-Concise bonding resin: (A) metal brackets, (B) Silkon brackets, (C) Transcend 2000 brackets, (D) debonded Transcend 2000 brackets, and (E) debonded silanized Transcend 2000 brackets. After wet storage at 37 degrees C for 7 days, the SPBS of brackets were recorded, and fracture sites observed. There were statistically significant differences between the SPBS of metal brackets when compared with the Transcend 2000 and the Silkon brackets. These groups exhibited clinically acceptable SPBS. Debonded silanized Transcend 2000 brackets showed clinically unacceptable SPBS. Fracture sites of metal and Transcend 2000 brackets were resin-bracket, whereas Silkon brackets fracture sites were predominantly resin-enamel.     

Eruptive abnormalities in orthodontic treatment

In the course of orthodontic practice, it is inevitable that one will encounter what is termed here eruptive abnormalities. These abnormalities include teeth that are impacted, ectopically erupting, or transposed. Hyperdontia and hypodontia are also included for consideration. The treatment plans developed to address these anomalies must take into account the space needs of the patient and how one can best gain, maintain, or redistribute that space. Also, soft tissue reactions to the movements also should be considered.     

Conservative adjunct to esthetic orthodontic treatment in young patients

The esthetic effect of orthodontic treatment in young patients may sometimes be incomplete without performing additional procedures related to the form and texture of the anterior teeth. Six young patients, aged 7 to 21 years, presented for orthodontic treatment to improve their dental esthetics. The problems of tooth staining, mutilation, congenitally missing teeth, tooth size/arch length discrepancy, and sequellae of dental trauma neccessitated a combined orthodontic-prosthodontic treatment. Changing morphology and texture by conservative prosthetic procedures proved to be a successful complement to orthodontic treatment.     

Soft- and hard-tissue augmentation by orthodontic treatment in the esthetic zone

A technique that may effectively create a greater volume of available hard and soft tissue in the vertical plane without surgical intervention is reported and explained. Limitations of the forced eruption are also discussed. Creating an esthetic implant-supported restoration is a challenge in patients who have alveolar resorption and/or attachment loss, especially when they present with a high smile line. Many methods to augment this loss of tissue have been proposed; most involve surgical procedures to add bone or bone substitutes to compensate for the loss of alveolar tissue. This case report presents an alternative to bone augmentation procedures with the use of orthodontic tooth movement in the esthetic zone of a 62-year-old woman. The tooth movement facilitated implant placement by increasing soft-tissue volume and facial bony contours.     

Optical properties of esthetic temporary cements and final restoration color

BackgroundOpaque cements can be esthetically unfavorable and alternative translucent materials have been developed. The aim of this study was to evaluate the color interference of a new translucent cement compared with conventional materials, in association with interim restoration with different thickness and shades.MethodsBis-acryl composite disks were prepared in 2 thicknesses (1.2 mm, 0.6 mm) and 3 shades (A3.5, A2, bleached) to simulate the restorations. Cementation over dentin disks was performed with 1 translucent cement (Provicol QM Aesthetic; VOCO), 2 conventional cements (Provicol; VOCO, Temp-Bond NE; Kerr Dental), and 1 transparent liquid (polyethylene glycol 400). The difference between the color of the specimens cemented with the transparent liquid and that of the specimens cemented with each cement was calculated (ΔEab). The data were analyzed using 3-way analysis of variance and Tukey tests (5%).ResultsSignificant differences were observed for all factors and some interactions (P < .05). For Provicol QM Aesthetic, the shade and thickness did not influence the ΔEab. For Provicol and Temp-Bond NE, the lighter and thinner the specimen, the higher the ΔEab. Only Provicol QM Aesthetic had smaller means than the perceptibility threshold. Temp-Bond NE and Provicol had higher values than the acceptability threshold for some combinations.ConclusionsThe highly translucent cement had less color interference than the conventional materials. The thickness and resin shade only affected the results for the opaque cements. The thinner specimens and the lighter shades had higher color interference.Practical ImplicationsThe use of a more translucent cement can produce a smaller color interference on the esthetic outcome of interim restorations.     

Factors affecting the color stability and staining of esthetic restorations

Odontology - This study aimed to assess the color stability of two composite resins, unprotected or protected with a hydrosoluble gel (oxygen inhibitor) during final polymerization, when subjected...     

Mechanical properties of different esthetic and conventional orthodontic wires in bending tests

Aims

The goal of this study was to determine the mechanical properties of different esthetic and conventional orthodontic wires in three-point and four-point bending tests, and in a biomechanical test employing three bracket systems.

Methods

The behavior of round wires with a diameter of 0.46 mm (0.018″) were investigated: uncoated nickel titanium (NiTi) wires, surface modified NiTi wires; FLI^® Orthonol Wire^® and glass fiber reinforced plastic wires. The biomechanical bending test was performed using the following bracket types: metal brackets (Discovery^®, Dentaurum), ceramic brackets (Fascination^®, Dentaurum), and plastic brackets (Elegance^®, Dentaurum). All bending tests were performed in the orthodontic measurement and simulation system (OMSS) at a temperature of 37 °C. The classical three-point bending test was performed according to an ISO standard (DIN EN ISO 15841:2007) using the appropriate thrust die and supports with a predefined span of 10 mm. In the other tests the supports or interbracket distances were chosen such that the free wire length was also 10 mm (5 mm between adjacent brackets). All wires were loaded centrally to a maximum of 3.1 and 3.3 mm in the biomechanical test, respectively. The force was measured upon unloading with a loading velocity of 1 mm/min. Each specimen was loaded twice and a total of 10 specimens tested for each product. Weighted means and the error of the weighted mean were calculated for each product.

Results

Fiber reinforced wires displayed lowest forces in three-point bending with values of 0.4 N at a displacement of 1 mm and 0.7 N at a 2 mm displacement. In four-point bending the forces were 0.9 N and 1.4 N, respectively, at the same displacements. Almost all of the translucent wires showed fracture upon bending at displacements greater than 3 mm, independent of the bending test and bracket type. The different investigated NiTi wires, surface modified or conventional, only showed minor variation, e.g., 2.2 N for rematitan^® Lite White and 2.0 N for rematitan^®, 2.1 N for FLI^® Coated Orthonol^® and 1.7 N for Orthonol^® in four-point bending. The rhodinized wire generated forces between these values (2.1 N).

Conclusion

The translucent wires had the lowest forces in all three bending tests; however, displacements above 3 mm resulted in increased risk of fracture. Forces of investigated NiTi wires were very high and in part above clinically recommended values.

     

Retention capacity of the bracket bases of new esthetic orthodontic brackets

Tensile bond strength and bond failure locations were evaluated in vitro for three types of direct bonding cements (self-cured diacrylate, dual-cured diacrylate, and dual-cured glass ionomer) with four types of brackets (stainless steel, polycarbonate, ceramic, and ceramic-polycarbonate) by using a plastic cylinder as the substrate. A highly filled, self-cured diacrylate cement gave the highest bond strength values with the polycarbonate, stainless steel, and ceramic-polycarbonate brackets. A dual-cured diacrylate cement gave the highest bond strength with a mechanically retained ceramic bracket. The dual-cured glass ionomer cement gave the highest bond strength values with a silanated ceramic bracket. All bond failures occurred at the bracket/cement interface with the stainless steel bracket, whereas failure locations were at the bracket/cement interface and within the cement with the polycarbonate bracket. Bond failures occurred between bracket and cement, within the cement, and within the bracket with the ceramic brackets. (AM J ORTHOD DENTOFAC ORTHOP 1995;107:596-603.)     

Dental esthetic self-perception in young adults with and without previous orthodontic treatment

The aim of this study was to determine which dental esthetic self-perception evaluation tool discriminated better between orthodontically treated or untreated Peruvian young adults. A total of 630 students were randomly chosen from the 2000 admitted in 2002 to a private university in Peru. Students undergoing active orthodontic treatment at the time of examination were excluded. Self-perceived dental esthetic appearance was evaluated through Standardized Continuum of Aesthetic Need, Oral Aesthetic Subjective Index Scale, and Visual Analogue Scale (VAS). A stepwise multivariate discriminant analysis was developed to classify orthodontic treatment according to the three evaluation tools. A total of 199 students (31.6%) reported a history of orthodontic treatment. Differences between orthodontically treated and untreated groups were found only for the mean VAS score (P < .001). Although three different approaches were used to evaluate dental esthetic self-perception, only VAS allowed the discrimination of the self-perceived dental appearance between orthodontically treated and untreated Peruvian university young adults. Similarities in the self-perceived dental appearance of treated and untreated groups reported in previous epidemiological studies could be explained because different evaluation instruments were used. Further studies are required to support current findings.