Comparative evaluation of nickel discharge from brackets in artificial saliva at different time intervals.

OBJECTIVES: To determine and compare the potential difference of nickel release from three different orthodontic brackets, in different artificial pH, in different time intervals. MATERIALS AND METHODS: Twenty-seven samples of three different orthodontic brackets were selected and grouped as 1, 2, and 3. Each group was divided into three subgroups depending on the type of orthodontic brackets, salivary pH and the time interval. The Nickel release from each subgroup were analyzed by using inductively coupled plasma-Atomic Emission Spectrophotometer (Perkin Elmer, Optima 2100 DV, USA) model. Quantitative analysis of nickel was performed three times, and the mean value was used as result. ANOVA (F-test) was used to test the significant difference among the groups at 0.05 level of significance (P < 0.05). The descriptive method of statistics was used to calculate the mean, standard deviation, minimum and maximum. SPSS 18 software ((SPSS.Ltd, Quarry bay, Hong Kong, PASW-statistics 18) was used to analyze the study. RESULT: The analysis shows a significant difference between three groups. The study shows that the nickel releases from the recycled stainless steel brackets have the highest at all 4.2 pH except in 120 h. CONCLUSION: The study result shows that the nickel release from the recycled stainless steel brackets is highest. Metal slot ceramic bracket release significantly less nickel. So, recycled stainless steel brackets should not be used for nickel allergic patients. Metal slot ceramic brackets are advisable.

Influence of erbium, chromium-doped: Yttrium scandium-gallium-garnet laser etching and traditional etching systems on depth of resin penetration in enamel: A confocal laser scanning electron microscope study.

OBJECTIVE: This study was performed to assess the resin tag length penetration in enamel surface after bonding of brackets to identify which system was most efficient. METHODOLOGY: Our study was based on a more robust confocal microscopy for visualizing the resin tags in enamel. Totally, 100 extracted human first and second premolars have been selected for this study and were randomly divided into ten groups of 10 teeth each. In Group 1, the buccal enamel surface was etched with 37% phosphoric acid (3M ESPE), Group 2 with 37% phosphoric (Ultradent). In Groups 5, 6, and 7, erbium, chromium-doped: Yttrium scandium-gallium-garnet (Er, Cr: YSGG) laser (Biolase) was used for etching the using following specifications: Group 5 (1.5 W/20 Hz, 15 s), Group 6 (2 W/10 Hz, 15 s), and Group 7 (2 W/20 Hz, 15 s). In Groups 8, 9, and 10, Er, Cr: YSGG laser (Biolase) using same specifications and additional to this step, conventional etching on the buccal enamel surface was etched with 37% (3M ESPE) after laser etching. In Groups 1, 5, 6, 7, 8, 9, and 10 3M Unitek Transbond XT primer was mixed with Rhodamine B dye (Sigma-Aldrich, Germany) to etched surface and then cured for 20 s. In Group 2, Ultradents bonding agent was mixed with Rhodamine B. In Group 3, 3M Unitek Transbond PLUS, Monrovia, USA, which was mixed with Rhodamine B dye (Sigma-Aldrich, Germany). Group 4, with self-etching primer (Ultradent-Peak SE, USA) was mixed with Rhodamine B dye (Sigma-Aldrich, Germany). Later (3M Unitek, Transbond XT, Monrovia USA) [Figure 1] was used to bond the modified Begg brackets (T. P. Orthodontics) in Groups 1, 3, 5, 6, 7, 8, 9, and 10. In Groups 2, 4 Ultradent-Peak LC Bond was used to bond the modified brackets. After curing brackets were debonded, and enamel depth penetration was assessed using confocal laser scanning microscope. RESULTS: Group J had a mean maximum depth of penetration of 100.876 µm, and Group D was the least having a maximum value of 44.254 µm. CONCLUSIONS: Laser alone groups had comparable depths of penetration to that of self-etching groups but much lower than conventional acid etched groups.

Estimation of alkaline phosphatase in the gingival crevicular fluid during orthodontic tooth movement in premolar extraction cases to predict therapeutic progression.

OBJECTIVES: The objective was to estimate the level of alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) during en-masse retraction stage of orthodontic tooth movement. MATERIALS AND METHODS: 10 patients in the age group of 15-20 years participated in this study. GCF was sampled from the distal surface of the canine and mesial surface of the second premolar on day 0, 1, 7, 14, 21, and 28 postorthodontic treatment. RESULTS: A marked fall in the level of ALP was evident following force application. A progressive decreasing trend in ALP activity on both distal aspect of canine and mesial aspect of the second premolar was observed. The fall in ALP was more on distal aspect canine when compared to the mesial aspect of the second premolar. CONCLUSIONS: Measure of ALP activity in GCF could be an indicator of the biochemical and cellular alterations in bone turnover and hence rate the amount of tooth movement following orthodontic force application.

In vitro assessment of competency for different lingual brackets in sliding mechanics.

AIM: To determine the static frictional resistance of different lingual brackets at different second order angulations when coupled with stainless steel (SS) archwire in dry and wet conditions. MATERIALS AND METHODS: Using a modified jig, frictional resistance was evaluated under different conditions for a total of 270 upper premolar lingual brackets (0.018″ × 0.025″ - conventional - 7(th) generation and STb, self-ligating - evolution) with no in-built tip or torque together with 0.016″ × 0.022″ straight length SS archwires. For conventional brackets, the archwire was secured with 0.008″ preformed SS short ligature ties. STATISTICAL ANALYSIS: One way analysis of variance with Tukey HSD as post-hoc test was applied for degree wise and bracket wise comparison within dry condition and wet condition. For pair wise comparison Student's t-test was used. RESULTS: Under both conditions the static frictional resistance is significantly higher for self-ligating brackets at 0°, while at 5° and 10° it is higher for 7(th) generation brackets. Statistically, significant difference does not exist at 0° between conventional brackets and the same was found at 5° and 10° between STb and self-ligating brackets. With an increase in second order angulations, all the evaluated samples exhibited an increased frictional value. Wet condition samples obtained a higher value than their corresponding dry condition. CONCLUSION: The self-ligating bracket evaluated in this in vitro study is not beneficial in reducing friction during en-mass retraction due to its interactive clip type.

Evaluation of tensile strength and surface topography of orthodontic wires after infection control procedures: An in vitro study.

AIM: The aim of this study is to evaluate, the influence of four types of sterilization/disinfection procedures (autoclave, hot air oven, glutaraldehyde, and ultraviolet [UV] light) on the tensile strength and surface topography of three orthodontic wires (stainless steel (SS), titanium - molybdenum alloy [TMA], and cobalt chromium (CoCr)). MATERIALS AND METHODS: Sample comprised of three types of 8 inches straight length segments of orthodontic wires. They were divided into three groups according to wire composition comprising of 50 samples each. Totally 50 samples of each group were then equally divided into five subgroups according to sterilization method. After sterilization and disinfection of the experimental group, surface topography was examined with scanning electron microscope (SEM) and tensile strength was tested using universal testing machine. RESULT: The results of this study show that the mean ultimate tensile strength (UTS) of SS wire after four sterilization procedures were similar to the control group (1845.815 ± 142.29 MPa). The mean UTS of TMA wire increases after four sterilization procedures when compared with the control group (874.107 ± 275.939 MPa). The mean UTS of CoCr wire remains same after UV light disinfection, but increases after other three sterilization procedures when compared with the control group (1449.759 ± 156.586 MPa). SEM photographs of the present study shows gross increase in pitting roughness of the surface topography of all the three types of wires after four types of sterilization. CONCLUSION: Orthodontists who want to offer maximum safety for their patients can sterilize orthodontic wires before placement, as it does not deteriorate the tensile strength and surface roughness of the alloys.

Speedy orthodontics: a case report.

Management of severe rotation poses a great challenge for the orthodontist, especially when cortical anchorage occurs. The conventional methods require excessive treatment time, rely on patient compliance, and can cause root resorption. A groundbreaking new procedure developed by Wilcko et al, which is actually a modification of the conventional corticotomy procedure, amalgamates the orthodontic mechanics, alveolar decortications, and augmentation procedure to make treatment time three to four times faster than conventional orthodontic techniques. This procedure uses the dynamics of bone physiology and redirects the emphasis in tooth movement to the manner in which supporting bone responds to orthodontic forces applied to the tooth. This article includes a case report in which the technique is used on a patient who has a severely rotated mandibular left canine.

Accidental ingestion of molar band and its management: maintenance is better than management.

Ingestion of a broken part of fixed orthodontic appliance is a potential complication during orthodontic treatment. We report a case of accidental ingestion of molar band and its subsequent diagnosis followed by endoscopic retrieval method. Although prevention of such incidence is the best method at the same time management of such an event is also crucial. The objective of this paper is to draw attention to the potentially serious complications that can occur if preventive techniques are not practiced and also the management of such event.

Comparison and measurement of the amount of anchorage loss of the molars with and without the use of implant anchorage during canine retraction.

INTRODUCTION: The purpose of this study was to compare and measure the amount of anchorage loss with titanium microimplants and conventional molar anchorage during canine retraction. METHODS: Subjects for this study comprised 10 orthodontic patients (7 women, 3 men) with a mean age of 19.6 years (range, 18 to 25 years), who had therapeutic extraction of all first premolars. After leveling and aligning, titanium microimplants 1.3 mm in diameter and 9 mm in length were placed between the roots of the second premolars and the first molars. Implants were placed in the maxillary and mandibular arches on 1 side in 8 patients and in the maxilla only in 2 patients. A brass wire guide and an intraoral periapical radiograph were used to determine the implant positions. After 15 days, the implants and the molars were loaded with closed-coil springs for canine retraction. Lateral cephalograms were taken before and after retraction, and the tracings were superimposed to assess anchorage loss. The amount of molar anchorage loss was measured from pterygoid vertical in the maxilla and sella-nasion perpendicular in the mandible. RESULTS: Mean anchorage losses were 1.60 mm in the maxilla and 1.70 mm in the mandible on the molar anchorage side; no anchorage loss occurred on the implant side. CONCLUSIONS: Titanium microimplants can function as simple and efficient anchors for canine retraction when maximum anchorage is desired.