A comparative evaluation of frictional resistance and surface roughness of silver coated and uncoated stainless-steel bracket wire assembly- An in-vitro study.

Background: Silver ions act as potent antimicrobial agents. Silver coating of brackets and the archwires can help reduce the formation of white spot lesions and caries which is commonly seen with fixed orthodontic treatment. However, this may affect the friction and surface roughness of the bracket-wire assembly which in turn affects the biological tooth movement. Material and Methods: A total of 60 samples were included in the study which was divided into four groups. Group-1: • 15 silver coated 0.022 x 0.028" slot MBT prescription maxillary central incisor brackets • 15 silver coated 0.019 x 0.025" stainless-steel wires; Group-2: • 15 uncoated 0.022 x 0.028" slot MBT prescription maxillary central incisor brackets • 15 silver coated 0.019 x 0.025" stainless-steel wires; Group-3: • 15 silver coated 0.022 x 0.028" slot MBT prescription maxillary central incisor brackets • 15 uncoated 0.019 x 0.025" stainless-steel wires; Group-4: • 15 uncoated 0.022x0.028" slot MBT prescription maxillary central incisor brackets • 15 uncoated 0.019 x 0.025" stainless-steel wires. All brackets and wires used were of American Orthodontics, St. Paul, USA. Surface modification of wires and brackets was carried out using the Vacuum Coating Unit model by Thermal Vacuum Evaporation method with silver nanoparticles (10 nm size). The frictional resistance of all brackets and wires was checked using Universal Testing Machine. Results: On comparison of maximum load, it was found that friction was highest in group 3, followed by group 1, group 4 and group 2. The mean difference between all groups was found to be statistically significant with a P value < 0.05. The Scanning Electron Microscope studies showed that the surface roughness of silver-coated wires and brackets before the friction test was less compared to uncoated wire-bracket assembly. The surface roughness of the bracket and wire after the friction test was as follows: •Bracket roughness: Group 4> Group 1> Group 2> Group 3 •Wire roughness: Group 4> Group 1> Group 2> Group 3. Conclusions: This study concluded that friction was least when only the wire was coated with silver and the bracket was uncoated and it was the most when the bracket was coated and the wire was uncoated. The surface roughness after the friction test was the least when the wire was uncoated. Key words:Silver nanoparticles, Frictional Resistance, Surface Roughness.

Comparative evaluation of enamel surface roughness after debonding using four finishing and polishing systems for residual resin removal-an in vitro study.

BACKGROUND: Orthodontic bonding and debonding procedures involve risk of damaging the enamel surface and changing its original morphology. The rough surface inhibits proper cleaning, invites plaque deposition, bacterial retention, and stain formation thus dampening the esthetic appearance of the teeth. Restoring the enamel to its original morphology is a challenge. Researches on better adhesive removal methods which can effectively remove the residual resin and restore it best to its original form are continuing till date. No study has compared four contemporary finishing systems for their efficiency on a single platform. AIM: The objective of this study is to evaluate and compare enamel surface roughness after debonding using four different finishing and polishing systems. MATERIAL AND METHODS: Adhesive resin was removed from the buccal surface of 88 premolars after debonding with 4 groups. It included 22 teeth per group: group 1-One gloss system; group 2-Enhance finishing and polishing system; group 3-fiber reinforced stainbuster bur; and group 4-Soflex discs with wheels. Roughness was measured quantitatively and qualitatively with the help of surface roughness tester and scanning electron Microscope (SEM) respectively. RESULTS: No significant difference was found in baseline roughness in four groups. Highest post-polishing roughness was observed in Soflex group (4.62 µm) followed by One gloss system (3.36 µm), Enhance system (3.17 µm), and stainbuster bur (1.99 µm) (p value < 0.01). CONCLUSION: Stainbuster bur created the smoothest enamel surface that was close to the natural enamel followed by Enhance system, One gloss system, and Soflex disc and wheels.

Comparative Evaluation of Frictional Resistance of Silver-Coated Stainless Steel Wires with Uncoated Stainless Steel Wires: An In vitro Study.

BACKGROUND: Silver is known for its antimicrobial activity. Silver coating effectively reduces Lactobacillus acidophilus and Streptococcus mutans count, thus reducing chances of dental plaque and caries. This silver coating may have effect on frictional property of orthodontic wires. AIM: The aim of this study is to evaluate and compare frictional resistance of silver-coated and uncoated stainless steel (SS) wires. METHODS: Forty SS wires were divided into four groups of 10 each: Group 1 - 0.017 × 0.025 inch SS wires (silver coated), Group 2 - 0.017 × 0.025 inch SS wires (control), Group 3 - 0.019 × 0.025 inch SS wires (silver coated), and Group 4 - 0.019 × 0.025 inch SS wires (control). Surface modification of wires was carried out by the thermal vacuum evaporation method with silver (10 nm size) using vacuum-coating unit model. The frictional resistances of all forty wires were checked on forty 0.022 × 0.028 inch slot central incisor brackets (SS wires and brackets from American Orthodontics, St Paul, USA) mounted on metal plates using universal testing machine. RESULTS: There was no significant difference found in frictional resistance between silver-coated and uncoated 0.017 × 0.025 inch SS wires group (P = 0.854). Statistically significant reduction in frictional resistance was observed in 0.019 × 0.025 inch coated SS wires in comparison to uncoated wires (P = 0.032). CONCLUSION: Overall silver coating either did not affect the frictional resistance (0.017 × 0.025 inch SS wires) or reduced it (0.019 × 0.025 inch coated SS wires) compared to uncoated wires. Findings suggest that the use of silver-coated SS wires in routine orthodontic practice can be implemented after further in vivo human clinical trials.

Comprehensive and Conservative Management of Talon Cusp: A New Technique.

Talon cusp is a common dental anomaly affecting maxillary central incisors. Gradual grinding of this additional cusp is commonly followed now. Advocated below is a new technique explaining the use of air abrasion and putty index during the stepwise reduction of the cusp. The technique is advantageous in preventing patient discomfort and tracking the amount of reduction in a predictable way.

Endodontic treatment of a mandibular first molar with 8 canals: a case report.

Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals.

Age changes of jaws and soft tissue profile.

Age-related changes of jaws and soft tissue profile are important both for orthodontists and general dentists. Mouth profile is the area which is manipulated during dental treatment. These changes should be planned in accordance with other components of facial profile to achieve ultimate aim of structural balance, functional efficacy, and esthetic harmony. Through this paper, the authors wish to discuss age changes of the hard and soft tissues of human face which would help not only the orthodontists but also oral surgeons, prosthodontists, pedodontists, and general dentists.

Technique to incorporate mathematical principles into esthetic dentistry.

Space closure in the maxillary anterior segment using direct composite is one of the most challenging esthetic procedures. The challenge lies in determining and achieving the correct dimensions. Various mathematical principles that have been observed in esthetically pleasing smiles can be applied to simplify the procedure and achieve symmetry while treating spaced dentition. The aim was to devise a technique for simplifying the application of mathematical principles in esthetic dentistry and improve the predictability and accuracy of the procedure of space closure using direct composite.

Dilemmas pertaining to three canals in the mesiobuccal root of a maxillary second molar: a case report.

The mesiobuccal root of the maxillary molars is well known to pose a hindrance during endodontic therapy. Presented here is a case of a maxillary left second molar where three canals were located in its mesiobuccal root with the use of visual and diagnostic aids. Difficulties encountered during the process of unveiling the tooth's internal anatomy were discussed. The dilemmas encountered pertained to the root canal configuration, the nomenclature of the extra canals, and the justification for the presence of a third canal. The root canal configuration of 3-2-1 was confirmed for the mesiobuccal root using information gained from clinical, radiographic, and multi-detector computed tomography (MDCT) scan findings. This case demonstrates the need for efforts to locate extra canals in the mesiobuccal root of the maxillary molars as their internal anatomy remains a mystery.

A comparative evaluation of the retention of metallic brackets bonded with resin-modified glass ionomer cement under different enamel preparations: A pilot study.

INTRODUCTION: For orthodontists, the ideal bonding material should be less moisture-sensitive and should release fluoride, thereby reducing unfavorable iatrogenic decalcification. Resin-Modified Glass Ionomer Cements (RMGICs), due to their ability to bond in the presence of saliva and blood can be a very good bonding agent for orthodontic attachments especially in the areas of mouth, which are difficult to access. Moreover, their fluoride releasing property makes them an ideal bonding agent for patients with poor oral hygiene. However, their immediate bond strength is said to be too low to immediately ligate the initial wire, which could increase the total number of appointments. The effect of sandblasting and the use of sodium hypochlorite (NaOCL) on the immediate bond failure of RMGIC clinically have not been reported in the literature until the date. This investigation intended to assess the effect of sandblasting (of the bracket base and enamel) and NaOCL on the rate of bond failure (with immediate ligation at 30 min) of Fuji Ortho LC and its comparison with that of conventional light cured composite resin over a period of 1 year. MATERIALS AND METHODS: 400 sample teeth were further divided into 4 groups of 100 each and bonded as follows: (1) Group 1: Normal metallic brackets bonded with Fuji Ortho LC. (2) Group 2: Sandblasted bracket base and enamel surface, brackets bonded with Fuji Ortho LC. (3) Group 3: Deproteinized enamel surface using sodium hypochlorite and brackets bonded with Fuji Ortho LC. (4) Group 4: Normal metallic bracket bonded with Transbond XT after etching enamel with 37% phosphoric acid. This group served as control group. RESULTS AND CONCLUSION: Results showed that sandblasting the bracket base and enamel, can significantly reduce the bond failure rate of RMGIC.

A self-designed instrument to evaluate cavosurface angle for class I amalgam cavity preparation: A learning aid.

Fighting the controversies, amalgam, as a posterior restorative material has survived till date. The fate of amalgam restoration is determined by geometry of the cavity preparation and cavosurface angle is one integral part of the cavity, which decides the marginal characteristics of the restoration and health of the tooth. Low edge strength of amalgam highlights the importance of cavosurface angle. However, at the same time conservation of the tooth also should be considered. This article presents a self-designed instrument to evaluate and obtain a cavosurface angle close to 110°. The design of the instrument also helps in evaluating parameters, such as depth of the cavity, undercut angle, and allows finishing of the buccal or lingual walls.

Multiple idiopathic cervical resorption: a diagnostic dilemma.

Multiple idiopathic cervical resorption is an uncommon condition, the etiology of which remains unknown. The case of a 36-year-old woman with idiopathic resorption in the cervical areas of multiple teeth is presented. Her medical history was noncontributory, but her dental history was valuable in reaching a diagnosis. Hematologic and endocrinal investigations were unremarkable, but a computed tomography scan revealed relevant information. The progression of the lesion and involvement of multiple teeth without any pattern or chronology are challenges faced when diagnosing and treating this condition.

A comparative evaluation of dentinal hypersensitivity and microleakage associated with composite restorations in cavities preconditioned with air abrasion - An ex vivo study.

BACKGROUND AND OBJECTIVE: Enormous advances have been made in adhesives; however, the problem of post-operative sensitivity has dragged along. Enough literature exists on the effect of air abrasion over bond strength of composites. However, not much is reported on its relation with microleakage and post operative sensitivity. Therefore, the aim of the study was to compare and evaluate dentinal hypersensitivity and microleakage associated with composite restorations in cavities preconditioned with air abrasion. STUDY DESIGN: Fifteen patients were selected for the study who had to undergo extractions of both maxillary first premolars. On each patient, occlusally placed Class V cavities were made using rotary burs on both the premolars. On the right side premolar, restoration was done using total etch technique. On the left side premolar, restoration was done in similar way after preconditioning of the cavity with air abrasion. Sensitivity levels were recorded on a modified visual analogue scale preoperatively and post operatively at 1 week and one month time period. Following extraction, dye penetration test was done and 1 sample each from one group was subjected to Scanning Electron Microscope for evaluation of tooth restoration interface. RESULTS: Clinically significant difference was there in post operative sensitivity levels after one month between the two groups. Increase in sensitivity was less in teeth restored after preconditioning with air abrasion. Dye penetration was also less in teeth restored after preconditioning with air abrasion. However, penetration at the gingival wall was more than the occlusal wall in both the groups. CONCLUSION: The study consolidates the fact that microleakage and post operative sensitivity are linked directly. It also proves that air abrasion can help in reducing the post operative sensitivity to a level; however, a larger sample size would be needed to obtain more robust results with stronger validation.