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Context: Despite the advances in orthodontic material and treatment mechanics, the placement of fixed appliances increases the risk of enamel demineralization. The development of fluoride release adhesives has attracted considerable interests because the combined use of antimicrobials and fluoride enhances the cariostatic effect.Aim: To compare the shear bond strength (SBS) of fluoride release adhesives with established orthodontic adhesives and assess failure mode using adhesive remnant index (ARI).Settings and Design: The present study included 80 maxillary premolars which were randomly divided into four groups (n = 20) and were further subdivided into two subgroups A - Pumice prophylaxis (PP) and subgroup B - No PP (n = 10).Materials and Methods: Stainless steel brackets were bonded with Transbond XT, Transbond plus (TP) color change adhesive, Light Bond, and Clearfil protect bond. After debonding, the ARI was used to assess the mode of bracket failure.Statistical Analysis: The data were analyzed using two-way analysis of variance, Post-hoc Tukey Honest significant differences test, and Chi-square test.Results: The mean SBS of Group 4 was comparably higher regardless of PP. Brackets bonded with TP showed a comparable SBS to conventional Transbond XT. The ARI scores were predominately 2.Conclusions: Fluoride releasing adhesives combined with antibacterial monomer can play a vital role in reducing white spot lesions by enhancing the cariostatic effect especially in noncompliant\medically compromised patients. [ABSTRACT FROM AUTHOR]

Background: To assess the efficiency and treatment outcome of patients treated with corticotomy-assisted en-masse orthodontic retraction as compared with the en-masse retraction without corticotomy. Materials and Methods: Forty adult patients with bimaxillary protrusion requiring correction of bidental proclination constituted the sample. The study group consisted of 22 patients (male 11, female 11) willing to undergo surgery to reduce the duration of their orthodontic treatment and 18 patients (male 9, female 9) desirous of undergoing conventional orthodontic treatment without surgical intervention constituted the control group. Comparison of rate of retraction and anchor loss between the study and the control group was assessed. Results: Average rate of space closure of 1.8 mm/month in the maxilla and 1.57 mm/month in the mandible was observed in the study group compared to 1.02 mm/month in the maxilla and 0.87 mm/month in the mandible in the control group. The rate of retraction accelerated during the first 2 months of retraction. Molar anchor loss of approximately 0.6 mm occurred in the study group, and 1.8 mm occurred in the control group during the 4 months. Conclusion: The rate of retraction with study group was twice as faster when compared to the control group, accelerating during the first 2 months of retraction. There was better anchorage control with the undecorticated molar segment during the retraction period but was found to increase as time advanced. [ABSTRACT FROM AUTHOR]

Context: Salivary control and maintenance of a dry operating field is a prime requisite of orthodontic bonding. Moisture insensitive primer (MIP) with a clinical significant bond strength values have a better edge over the conventional hydrophobic bonding systems. Aim: The aim of this study is to investigate the effectiveness of two hydrophilic primers with respect to conventional hydrophobic primer by comparing their shear bond strength (SBS) and adhesive-failure locations after contamination with saliva and saliva substitute. Materials and Methods: A total of 150 extracted human premolars were randomly divided into five groups; Group A (Transbond MIP/saliva substitute), Group B (Opal Primo/saliva substitute), Group C (Transbond MIP/natural saliva), Group D (Opal Primo/natural saliva), control group-Group E (Transbond XT/dry), adhesive-Transbond XT used for all five groups and bonded using stainless steel brackets. Shear forces were applied to the samples with a universal testing machine. SBSs was measured in megapascals. The mode of bond failure was determined using the adhesive remnant index (ARI). Results: The mean SBS produced by Transbond MIP was higher than Opal Primo, which was statistically significant according to one-way analysis of variance. Both the tested groups showed lesser bond strength values than Transbond XT (the control). ARI scores revealed that there was no statistically significant difference in the site of bond failure between study groups. ARI scores were found to be lower for study groups suggesting adhesive failure, compared to higher ARI scores for the control group suggesting cohesive failure. Conclusion: Transbond XT adhesive with Transbond MIP or Opal Primo have clinically acceptable bond strength in wet fields. Opal Primo is a viable option to use as a hydrophilic primer clinically. [ABSTRACT FROM AUTHOR]

The advancement in the field of three-dimensional imaging has overcome the limitations of conventional cephalometry. Presently, only few studies have been carried out to check the reliability and validity of CBCT. Aims: To compare (1) The difference between cephalometric angular and linear measurements in 3D orthogonal (3DO) and 2D perspective (2DP) which were CBCT synthesized cephalograms and (2) to verify the intra- and inter-reliability of the landmarks. Materials and methods: CBCT data of 50 patients was acquired using NEWTOM 3G. The Raw data sets (DICOM) were imported into Dolphin imaging version 10.5. Orthogonal and perspective time points were created and digitized. The results between the two were compared using a customized analysis. Results: Validity of the data was compared using the paired Student's t-test. The level of significance was 5% (p < 0.05). The 2D perspective was significantly different from 3D orthogonal in 21 of 29 parameters. Conclusion: Significant difference was observed between 2D perspective and 3D orthogonal attributing to the effect of magnification and distortion in 2D perspective projection. Intra- and Interoperator reliability of landmark identification in both 2D perspective and 3D orthogonal was in complete agreement with each other showing no significant difference. [ABSTRACT FROM AUTHOR]

Anchorage conservation has always been a challenge in orthodontics especially in cases requiring group movement of teeth. The drawbacks of conventional anchorage conservation methods like headgears and intermaxillary elastics have been overcome with the advent of skeletal anchorage. Mini-implants which have been proved successful in several intraoral locations for anchorage, can also be successfully placed in the maxillary tuberosity region. However, this site is not commonly used due to the fact that the density of bone in this region is comparably low. But with proper case selection and application of sound biomechanical principles, successful treatment results can be achieved with mini-implants placed in this location. The case reports discussed in the article demonstrates the ability of mini-implants when placed in the maxillary tuberosity for en masse distalization of the entire maxillary dentition, its advantages and biomechanics. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of different surface conditioning methods on shear bond strength (SBS) of metal brackets bonded to porcelain surfaces and the influence of silane coupling agent in altering the bond strength. Materials and methods: A total of 80 feldspathic porcelain specimens were used. They were divided into eight different groups based on different surface conditioning methods and combinations: Sandblasting (SAB), hydrofluoric acid (HFA), diamond bur (DB) and air abrasion (AA). Silane coupling agent was used in five groups. Metal brackets were bonded and subjected to SBS testing. The efficiencies between the five individual methods used were analyzed. ARI scoring was done after debonding. Results: The SBS range was between 3.19 and 14.38 (MPa) with a mean of 8.89 ± 3.25 (MPa). The difference between mean SBS between different groups was significant (p < 0.001). As compared to DB-based group (10.46 ± 0.69 MPa) the non-DB based group were lower (8.66 ± 3.40 MPa) but the difference was not significant (p > 0.001). When compared to AA group (9.03 ± 0.59 MPa) the non-AA group were lower (8.87 ± 3.46 MPa) but again the difference was not significant (p > 0.001). ARI score 0 was observed in 47 instances (58.8%), score 1 was observed in 25 instances (31.2%). Conclusion: The results indicated that surface conditioning alone without silanation produced significantly low SBS. Air abrasion followed by silanation produced favorable bond strength and might have the potential to replace alternative methods. [ABSTRACT FROM AUTHOR]

The efficacy of mini-implants has proven itself indispensible in the orthodontic armamentarium and in the last decade the use of miniimplants have become a rule rather than an exception in biomechanically challenging cases. The simplicity of the clinical procedure involved in the placement of the mini-implant has rendered it a popular choice for orthodontists and it does not require extensive training. However, the biomechanical variations associated with its use are quite different and challenging when compared to conventional orthodontics--a fact which cannot be ignored by the clinician. Being an intraoral, extradental device, mini-implants are stationary in nature and this in itself should make one question the considerable variations involved when compared to anchorage using the dentition. The variation in the height of placement of mini-implants, in relation to the center of resistance of the dentition as a whole, and on an individual tooth, is certain to bring about changes in the biomechanical principles. The purpose of this article is to make the clinician cognizant of the biomechanical principles employed when using mini-implants in cases with different growth patterns which may help in improving the overall clinical efficiency. [ABSTRACT FROM AUTHOR]

Context: Variations in palatal bone thickness (PBT) at various locations have caused considerable problems when using these sites for anchorage purposes. Aims: To find the comparative thickness of the palatal bone at different locations and to validate its morphology for anchorage purposes using mini-implants (MI). Settings and Design: This investigation was undertaken to compare the mean PBT and level of significance of differences between male and female subjects and between two different age-groups. Materials and Methods: The computed tomography (CT) data for 60 patients (30 males and 30 females) in two different age-groups (group A: 15-24 years; group B: 25-35 years) were imported into CAD-based medical software, (MIMICS®; Materialise, Belgium) for multiplanar reconstruction. The measurements were made in two planes- transverse and sagittal-and at different positions in each of the planes. Statistical Analysis: The mean and standard deviations of the PBT at different points were calculated. The Student's t-test and Mann-Whitney U test were used for comparisons between the groups. Results: Significant variations were observed in the thickness of the palatal bone for both groups tested, with the anterior region at 4 mm behind the incisive papilla showing the maximum thickness. Conclusions: Despite the palatal bone being thickest in the mid-palatal suture (MPS) region, this is not the ideal site for anchorage purposes due to inadequate calcification and interposition of connective tissue, especially in young growing children. So, the alternate optimum position is the paramedian region, 3 mm lateral to the MPS and 4 mm from the incisive foramen (IF). [ABSTRACT FROM AUTHOR]

Purpose: To document a clinically relevant position of the inferior alveolar nerve (IAN) in complete dentate south Indian patients in the age group of 20-29 years using cone beam computerized tomograms. Materials and Methods: The investigators used a cross-sectional study design and a study sample of subjects who had a radiographically identifiable IAN canal with complete set of 28 permanent teeth excluding 3rd molars. Predictor variables were age, tooth position, and side. Outcome variables were the linear distances between the buccal and lingual aspect of the IAN canal, buccal and lingual cortical thickness, IAN canal diameter, and the superior aspect of the IAN canal from the periapex of first and second mandibular molar. Descriptive statistics and Mann-Whitney U test were performed. P value of ≤ 0.05 was taken as significant. Results: The study sample was composed of 10 male and 10 female patients with a mean age of 24.2 ± 3.00 years. On average, the lingual cortical thickness was 1.68 mm at 1st molar and 1.44 at 2nd molar level. Gender and side influenced the outcome with varying statistical significance. Conclusions: The range of linear dimension of mandibular canal, cortical bone thickness, and distance between tooth apex and IAN canal have been presented for the South Indian population in the age group of 20-29 years. The implications of the findings will influence on the course of surgery. Further large-scale studies are needed to validate the findings of this study. [ABSTRACT FROM AUTHOR]

The article presents a case study of an 18-year-old female with chief complaint of proclined upper incisors, protrusive lips and spacing in the lower arch. It was reported that the patient has undergone orthodontic treatment with fixed appliances after an upper and lower premolar extraction. Moreover, miniscrews were placed four months after the extraction of the third molar coinciding with the end of the leveling and alignment phase on the treatment process of the patient.

This paper studies the advantages of geocell reinforcement on the performance of earth embankments constructed over weak foundation soil through laboratory model tests and proposes a simple method for the design of geocell-supported embankments. Model embankments were constructed above a layer of geocells formed using geogrids on top of a soft clay bed prepared in a steel test tank. Uniform surcharge pressure was applied on the crest and pressure-deformation behavior of the embankment and strains in the walls of geocells were monitored continuously until the failure was reached. The influence on the behavior of the embankment of various parameters—like tensile stiffness of geocell material, height and length of geocell layer, pocket-size of the cell, pattern of formation of geocells, and type of fill material inside the cells—was studied. Geocell reinforcement was found to be advantageous in increasing the load-bearing capacity and reducing the deformations of the embankments. The experimental results were validated using a general purpose slope-stability program and a design procedure useful for the preliminary design of geocell-supported embankments is illustrated. [ABSTRACT FROM AUTHOR]