Micro-leakage around orthodontic brackets with direct and indirect bonding

At a Glance

Metadata	Details
Publication Date	2016-01-01
Journal	Pakistan orthodontic journal
Authors	Asmi Shaheen, Muhammad Ilyas, Waheed Ul Hamid
Analysis	Full AI Review Included

6CCVD Application Analysis: High-Precision Diamond Sectioning for Orthodontic Microleakage Quantification

This technical analysis connects the material science requirements detailed in “Micro-leakage around orthodontic brackets with direct and indirect bonding” to the specialized chemical vapor deposition (CVD) diamond products and engineering services provided by 6CCVD. The accurate quantification of microleakage at the sub-micrometer scale necessitates highly precise cutting and material preparation, achievable only through advanced diamond tooling.

Executive Summary

This research investigates the critical issue of micro-leakage around orthodontic brackets, validating the need for ultra-high-precision material preparation tools.

Core Finding: The study found no statistically significant difference in mean micro-leakage values under the bracket between Direct (0.0988 mm) and Indirect (0.0915 mm) bonding techniques.
Leakage Location: Micro-leakage depth was consistently higher at the adhesive-bracket interface compared to the enamel-adhesive interface across both groups.
Spatial Variation: Gingival sites exhibited higher micro-leakage scores than incisal (occlusal) sites, validating previous findings related to tooth curvature and composite thickness.
Methodology Focus: Successful analysis relied heavily on the ability to embed the composite/enamel samples in epoxy resin and section them precisely using a low-speed diamond saw (e.g., Struers Auccutom-50).
6CCVD Relevance: Accurate quantification of leakage measured in tens of micrometers (0.01 mm range) requires diamond saw blades manufactured from high-quality Polycrystalline Diamond (PCD) to ensure minimal sample damage, optimal edge quality, and reproducible cuts for subsequent stereomicroscopic analysis (X 40).
Conclusion: This paper highlights the essential role of MPCVD diamond tooling in obtaining reliable cross-sectional data for critical material science applications in biomedical and dental engineering.

Technical Specifications

The following hard data points were extracted relating to the dimensions, measurements, and equipment utilized in the research:

Parameter	Value	Unit	Context
Total Sample Size	60	Premolars	Divided into two groups (30 Direct, 30 Indirect).
Mean Leakage (Direct)	0.0988	mm	Mean micro-leakage under the bracket.
Mean Leakage (Indirect)	0.0915	mm	Mean micro-leakage under the bracket.
P-Value (Direct vs. Indirect)	0.067	N/A	Indicates no statistically significant difference (> 0.05).
Highest Measured Leakage	0.2095 ± 0.02645	mm	Direct Bonding, Gingival, Adhesive-Bracket Interface.
Lowest Measured Leakage	0.1440 ± 0.03499	mm	Direct Bonding, Gingival, Enamel-Adhesive Interface.
Dye Concentration	0.5	%	Basic fuchsine solution for penetration test.
Dye Immersion Time	24	hours	Immersion duration at room temperature.
Curing Light Duration	20	seconds	Applied from all sides for maximum polymerization.
Microscope Magnification	X 40	N/A	Standard magnification used for scoring.
Digital Caliper Resolution	0.5 to 5	mm	Range of measurement recorded (data recorded to nearest value).

Key Methodologies

The experiment relied on specific material preparation and measurement protocols, with diamond tooling being critical for the final precision sectioning stage.

Sample Preparation: Sixty human premolars were cleaned, etched, conditioned, and randomly assigned to Direct or Indirect bonding groups.
Bonding Application: Groups used either Transbond XT (Direct) or Sondhi Rapid Set A/B Primer/Resin (Indirect) composites.
Polymerization: Brackets were cured using an LED light source for 20 seconds from all sides.
Dye Penetration: Teeth were immersed in 0.5% basic fuchsine dye solution for 24 hours to simulate micro-leakage over time.
Sample Embedding: Specimens were embedded in epoxy resin blocks (Heraeus Kulzer) using a polyvinyl siloxane index to maintain accurate orientation.
Precision Sectioning (Diamond Tooling): Four parallel longitudinal sections were cut through the occlusal and gingival surfaces using a low-speed diamond saw (Auccutom-50, Struers) in the bucco-lingual direction.
Analysis: Sections were examined under a stereomicroscope (X 40) and micro-leakage depth (at enamel-adhesive and adhesive-bracket interfaces) was quantified using an electronic digital caliper.

6CCVD Solutions & Capabilities

The requirement for producing ultra-smooth, dimensionally accurate cross-sections of highly complex, multi-material dental specimens (enamel, composite, epoxy resin) highlights a critical need for high-quality MPCVD diamond cutting tools. 6CCVD provides the core materials necessary to manufacture the advanced diamond saws used in this precision application.

Applicable Materials

To replicate or extend the precise sectioning methodology employed (using a low-speed diamond saw on abrasive composite/epoxy/enamel blocks), 6CCVD recommends:

Polycrystalline Diamond (PCD) Plates/Wafers: Ideal for manufacturing durable, wear-resistant abrasive cutting discs. Our PCD material provides superior uniformity required for precise, low-damage cuts necessary for microscopic measurement (down to the 0.01 mm scale).
Optical Grade SCD Substrates: While typically used for optical windows, ultra-thin Single Crystal Diamond (SCD) wafers (0.1 µm to 500 µm thickness) could be utilized for specialty microtome blades where unparalleled sharpness and geometric precision are required for highly detailed, damage-free surface preparation (Ra < 1 nm polishing capability).

Customization Potential

The experimental use of a low-speed diamond saw (Struers Auccutom-50) implies the need for specific, high-tolerance diamond blades. 6CCVD excels in meeting these engineering demands:

Capability	6CCVD Service Offering	Relevance to Research Replication
Custom Dimensions	Plates/wafers up to 125 mm (PCD).	Enables the manufacture of custom diameter, highly stable cutting discs for industrial saw equipment.
Thickness Control	SCD/PCD thickness controlled from 0.1 µm to 500 µm.	Critical for controlling blade kerf width and maximizing section yield without sacrificing mechanical stability.
Surface Finish	Polishing standard Ra < 5 nm (Inch-size PCD).	Ensures the cut face is smooth and featureless, eliminating cutting artifacts that could interfere with micrometer-scale leakage measurement under the stereomicroscope.
Custom Shaping/Dicing	In-house laser cutting and shaping services.	Allows rapid production of bespoke diamond tooling geometries tailored to specific saw interfaces or mounting requirements.

Engineering Support

The challenges in material processing for orthodontic research—specifically dealing with the complex interfaces between enamel, adhesive, and bracket—require specialized expertise.

6CCVD’s in-house PhD team can assist researchers and engineers with material selection and optimization for similar biomedical and high-abrasive cutting projects, ensuring the diamond material specified (PCD grade, grain size, and polishing standard) maximizes sample integrity and analytical accuracy.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Introduction: It is essential to obtain a reliable adhesive bond between an orthodontic attachment and tooth enamel. All brackets exhibit micro leakage and its in the best interest of the patient to have minimal iatrogenic effects of this micro-leakage. Hence the objective of this study was to compare the microleakage under and around orthodontic brackets bonded with direct and indirect bonding technique. Material and Methods : Sixty human premolars were collected. Microleakage scores were directly recorded, using an electronic digital caliper (Guang Lu,China). For each section, there were two sides to be evaluated (incisal-gingival or mesial-distal) and each side had two interfaces to the score (enamel-adhesive and adhesive-bracket). Four parallel longitudinal sections were taken through the occlusal and gingival surfaces with a low-speed diamond saw in the bucco-lingual direction Results : This study showed that although microleakage values are slightly different (0.0988mm and 0.0916mm in direct and indirect bonding respectively) between the two bonding techniques, but this was insignificant. Similarly, the bracket to adhesive interface showed higher microleakage depth in both groups as compared to adhesive enamel interface. The gingival sites of all the tooth sections showed higher microleakage as compared to the incisal sites. Conclusions: No significant difference of micro-leakage existed around and under bracket when bonded with different techniques.

Tech Support

Original Source

DOI: None