A comparison of the effect of application of sodium ascorbate and amla (Indian gooseberry) extract on the bond strength of brackets bonded to bleached human enamel: An In vitro study.

INTRODUCTION: Whitening of teeth is a popular choice among dental clinicians and patients. However, the changes in enamel structure and composition induced by the bleaching agents cause a decrease in the shear bond strength of brackets leading to premature bracket debonding. Among several methods to overcome this, the most common is delaying bonding by 2-4 weeks. This waiting period can be eliminated by applying an antioxidant (sodium ascorbate) which causes a reversal in the reduction of bond strength. AIM: This study aims to compare the efficacy of a naturally occurring antioxidant (gooseberry) and sodium ascorbate in normalizing the bond strength of enamel to prebleached levels. MATERIALS AND METHODS: Seventy-two extracted premolars were divided into 4 equal groups; 1st group - control group - unbleached teeth, bonded directly, 2nd group - bleached with 16% carbamide peroxide (8 h for 1 week), then bonded. 3rd and 4th group - similarly bleached, followed by application of 10% sodium ascorbate and gooseberry extract (3 h respectively), then bonded. Bond strength was checked using Instron Universal Testing Machine. RESULTS: The bond strength of the control group was the highest and that of the carbamide group was drastically reduced. Considerable increase in the bond strength was seen after treatment with sodium ascorbate with negligible difference between sodium ascorbate and control group (P > 0.05). CONCLUSION: Treatment with gooseberry extract did improve the bond strength but was not as effective as sodium ascorbate postbleaching.

Sella size and jaw bases - Is there a correlation???

INTRODUCTION: Sella turcica is an important cephalometric structure and attempts have been made in the past to correlate its dimensions to the malocclusion. However, no study has so far compared the size of sella to the jaw bases that determine the type of malocclusion. The present study was undertaken to find out any such correlation if it exists. MATERIALS AND METHODS: Lateral cephalograms of 110 adults consisting of 40 Class I, 40 Class II, and 30 Class III patients were assessed for the measurement of sella length, width, height, and area. The maxillary length, mandibular ramus height, and body length were also measured. The sella dimensions were compared among three malocclusion types by one-way ANOVA. Pearson correlation was calculated between the jaw size and sella dimensions. Furthermore, the ratio of jaw base lengths and sella area were calculated. RESULTS AND CONCLUSION: Mean sella length, width and area were found to be greatest in Class III, followed by Class I and least in Class II though the results were not statistically significant. 3 out of 4 measured dimensions of sella, correlated significantly with mandibular ramus and body length each. However, only one dimension of sella showed significant correlation with maxilla. The mandibular ramus and body length show a nearly constant ratio to sella area (0.83-0.85, 0.64-0.65, respectively) in all the three malocclusions. Thus, mandible has a definite and better correlation to the size of sella turcica.

Comparison of Contamination of Low-Frictional Elastomeric Rings with That of Conventional Elastomeric Rings by Streptococcus mutans - An In-vivo Study.

INTRODUCTION: The presence of brackets and ligatures has been shown to be related to an increase in gingival inflammation and increased risk of decalcification. The various measures were taken to reduce the plaque accumulation and also lot of efforts were made by manufacturers that reduced the binding friction between the ligature rings and arch wire that facilitated easy sliding of the tooth through the wire. The low frictional ligatures rings manufactured by different manufacturers presumed to attract fewer bacteria due to greater reduction in surface roughness. Our study aimed to evaluate whether the low frictional elastomeric rings accumulate fewer bacteria than conventional ligature rings. MATERIALS AND METHODS: Thirty patients (15 males and 15 females) who underwent fixed appliance therapy were selected. The study was done using split-mouth design. In each volunteer, synergy low frictional elastomeric rings were tied to brackets bonded to the maxillary premolar on the right side and mandibular premolar on the left side. Conventional elastomeric rings that served as control group were tied to the contralateral teeth, with the same design. Samples were collected after four weeks (28 days) and cultured for bacteria Streptococcus mutans. RESULTS: There was no statistical difference between Streptococcus mutans count in low frictional elastomeric rings with that of conventional rings. CONCLUSION: We concluded that adherence of Streptococcus mutans is similar in both synergy low frictional elastomeric rings and conventional clear elastomeric rings and thus the manufacturer's claim of minimal bacterial adherence was discarded.

Head Strap Double Fluid Level Device: An Innovative and User Friendly Design to Record Natural Head Position (NHP).

Head positions can be oriented in a standardized position when the patient stands upright and focusses his/her eyes into a point in infinity. This is the natural head position. This position offers the maximum reproducibility and correlates well with the clinical picture offered to the diagnostician. This article describes an innovative and user friendly method to record natural head position using the head strap double fluid level device, a design modified from the popular fluid level device by Showfety, Vig and Matteson.

Interdisciplinary Approach for Management of Congenitally Missing Maxillary Lateral Incisors: A Case Report.

Maxillary lateral incisors are frequently found congenitally missing, and their replacement has to be done prosthodontically. However, there are a variety of treatment options; a justified solution after orthodontic correction is the use of Maryland Bridges. Following is a case report of congenitally missing maxillary lateral incisors and an impacted canine and their orthodontic correction followed by prosthetic replacement of the lateral incisors using Maryland bridges.

Evaluation of hyoid bone position and its correlation with pharyngeal airway space in different types of skeletal malocclusion.

INTRODUCTION: The hyoid bone and its relation with the pharyngeal space in health and disease has been an intriguing subject for years. AIM: This study attempts to evaluate the hyoid bone position and to ascertain any correlations with pharyngeal airway space in skeletal class I, II, and III malocclusions. MATERIALS AND METHODS: McNamara's airway analysis was carried out to assess the upper and lower airway widths and Hyoid triangle analysis by Bibby and Preston was carried out to determine the position of the hyoid bone. CONCLUSION: A positive correlation was found between the lower airway and horizontal distance from the hyoid bone to the retrognathion in class I skeletal pattern with average growth pattern.

Assessment of clinical outcomes of Roth and MBT bracket prescription using the American Board of Orthodontics Objective Grading System.

BACKGROUND: There is always a need to assess whether small changes in bracket prescription can lead to visually detectable differences in tooth positions. However, with little clinical evidence to show advantages of any of the popularly used bracket systems, orthodontists are forced to make clinical decisions with little scientific guidance. AIM: To compare the orthodontic cases finished with Roth and MBT prescription using American Board of Orthodontics-Objective Grading System (ABO-OGS). SETTINGS AND DESIGN: Department of Orthodontics, Post-graduate dental college, retrospective cross-sectional study. MATERIALS AND METHODS: Forty patients selected were divided into two groups of 20 patients each finished with straight wire appliance using Roth and MBT prescription, respectively. The examiner ability was assessed and calibrated by one of the ABO certified clinician to grade cases using the OGS. STATISTICAL ANALYSIS: Unpaired student t-test was used and P < 0.05 was accepted as significant. RESULTS AND CONCLUSIONS: MBT bracket group had a lower score of 2.60 points in buccolingual inclination and lower score of 1.10 points in occlusal contact category that was statistically significant when compared with Roth group. The difference in total ABO-OGS score was 2.65 points showing that the outcome for the MBT prescription was better than that of the Roth prescription, which is statistically significant, but with little or no clinical significance. It can be concluded that use of either one of the Roth and MBT bracket prescriptions have no impact to the overall clinical outcome and quality of treatment entirely depends on clinician judgment and experience.

The pain management in orthodontics.

Pain and discomfort are the frequent side-effects of the orthodontic therapy with fixed appliances. The people who experience orthodontic pain are likely to self-medicate with nonprescription pain relievers before seeing the dentist. It is imperative for an orthodontist to address questions that might arise in a clinical setting from the viewpoint of the clinicians and the patients/parents. This article will provide an overview of the current management strategies which are employed for alleviating orthodontic pain.

Determination of optimum adhesive thickness using varying degrees of force application with light-cured adhesive and its effect on the shear bond strength of orthodontic brackets: an in vitro study.

AIM: The thickness of the adhesive layer under a bracket may be an important factor that affects the final tooth position and bond strength. With increasing use of preadjusted brackets, it is important to ensure that a consistently even layer of composite is placed under each bracket to take full advantage of bracket design and to avoid the need for compensatory bends to be placed in the archwire. Therefore, the present study is aimed at determining the optimum adhesive thickness by varying the force of application and observing the effect on the shear bond strength of orthodontic brackets. METHODS: Sixty premolars extracted for orthodontic purposes were divided into three groups of 20 samples each. Adhesive thickness was measured by varying the force of application while bonding brackets with light-cured adhesive and tested on a universal testing machine to evaluate the shear bond strength. RESULTS: The study showed that adhesive thickness is inversely proportional to applied force. In addition, the shear bond strength has a tendency to increase with a decrease in adhesive thickness up to a certain extent and then decrease. CONCLUSION: Adhesive thickness between bracket base and tooth surface decreases with an increase in the amount of force application from 1 to 3 oz. Mean shear bond strength increases when adhesive thickness decreases from 0.99 to 0.83 mm, and then it has a tendency to decrease when adhesive thickness decreases to 0.72 mm. Optimum adhesive thickness should be considered to be 0.83 mm, which is the thickness required to achieve sufficient bond strength to prevent chances of bond failure.

Orthodontic management of non-syndromic multiple supernumerary teeth.

Hyperdontia amounts to an odontostomatologic anomaly wherein, there is an increase in tooth number irrespective of the location. This case report represents a form of hyperdontia characterized by bilateral multiple supernumerary teeth in both the jaws without any evident familial history.

Three-dimensional finite element analysis of strength, stability, and stress distribution in orthodontic anchorage: a conical, self-drilling miniscrew implant system.

INTRODUCTION: The aims of this study were to analyze the stress distribution and displacement patterns that develop in an orthodontic miniscrew implant and its surrounding osseous structures for 2 implant materials under horizontal and torsional loading, with no ossseointegration. METHODS: A numeric approach was adopted. The finite element method was used to determine the stress and displacement of the various components at a given time after miniscrew implant application, when, due to viscoelastic relaxation effects, the only remaining stress field was from the application of the orthodontic load. RESULTS: Stress distribution was not significantly different between the 2 types of implant material. Increased stress values were located at the necks of the implants and the surrounding cortical bone. Bending of the titanium miniscrew was observed in the neck region under horizontal traction. CONCLUSIONS: The differences between the values of stress and displacement we obtained for the 2 types of miniscrew were too small to be clinically significant. Optimization of the miniscrew implant composed of the titanium alloy might be achieved by increasing the bulk (quantity) of the material in the neck region. The miniscrew implant can be immediately loaded and used for group movement of teeth.