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Light energy attenuation through orthodontic ceramic brackets at different irradiation times

Santini A, Tiu SH, McGuinness NJ, Aldossary MS

J Orthod, 2016 Sep;43(3):193-201.
PMID: 27487476 DOI: 10.1080/14653125.2016.1205310

OBJECTIVE: To evaluate the total light energy (TLE) transmission through three types of ceramic brackets with, bracket alone and with the addition of orthodontic adhesive, at different exposure durations, and to compare the microhardness of the cured adhesive.
MATERIALS AND METHODS: Three different makes of ceramic brackets, Pure Sapphire(M), Clarity™ ADVANCED(P) and Dual Ceramic(P) were used. Eighteen specimens of each make were prepared and allocated to three groups (n = 6). MARC(®)-resin calibrator was used to determine the light curing unit (LCU) tip irradiance (mW/cm(2)) and TLE (J/cm(2)) transmitted through the ceramic brackets, and through ceramic bracket plus Transbond™ XT Light Cure Adhesive, for 5, 10 and 20 s. Vickers-hardness values at the bottom of the cured adhesive were determined. Statistical analysis used one-way analysis of variance (ANOVA); P = 0.05.
RESULTS: TLE transmission rose significantly among all samples with increasing exposure durations. TLE reaching the adhesive- enamel interface was less than 10 J/cm(2), and through monocrystalline and polycrystalline ceramic brackets was significantly different (P

Matched MeSH terms: Curing Lights, Dental*
Fulltext Light Curing Units: Tips For Orthodontists

Radzi, Z., Yahya, N.A., Zamzam, N., Wood, D.J.

Ann Dent, 2004;11(1):-.
MyJurnal

Choosing the right light-curing unit can be a very difficult task for some orthodontists. Currently, there are various types of light curing units available in the market with various trade names and specifications. Most of the time information regarding light curing units is obtained from advertisements, websites or manufacturers’ catalogues. Sometimes such information can be misleading. This article attempts to provide several tips for orthodontists in selecting light curing units.

Matched MeSH terms: Curing Lights, Dental
Fulltext Relationship of the light intensity of selected light curing units with varying distance and angulation of the light curing tip and lightmeter

Radzi, Z., Abu Kasim, N.H., Yahya, N.A., Abu Osman, N.A., Kassim, N.L.

Ann Dent, 2008;15(1):33-39.
MyJurnal

The purpose of this study was to investigate the light intensity of selected light curing units with varying distance and angulation of the light curing tip and lightmeter. Materials and method: Four types of light units; Spectrum 800 (Dentsply), Coltulux 3 (Coltene), Elipar FreeLight 2 (3M Espe) and Starlight Pro (Mectron) were evaluated for light intensity at various distances between the light curing tip and the radiometer Cure Rite Denstply (0,1,3,5,10 and 15 mm). The light curing units were tested at right angles to the aperture of the light meter and at the angles of 45°, 60° to it at a standardized 5 mm distance. Results: The highest light intensity was obtained when the tip of light curing unit was in contact with the lightmeter aperture. The light intensity decreased significantly when the light tip was placed 5mm, 10mm and 15mm away from the lightmeter aperture. However, no significant differences (p> .05) were detected between Omm, Imm and 3mm. There was a decrease in light intensity when light~·tip was angulated at 45° and 60° except for Coltolux 3. Conclusions: The intensity of the curing light was affected by the distance between the light curing tip and the lightmeter. However, the decrease in light intensity of the light curing unit was found not to obey the inverse square law for the distances 0 to 15 mm. The study found that there was no significant difference between 45° and 60° angulation between the light curing tip and the lightmeter. However, the decrease in light intensity was significant when compared to the light tip placed perpendicular (90°) to the aperture of the light meter.

Matched MeSH terms: Curing Lights, Dental
Fulltext Depth of polymerization of a new nanocomposite according to different exposure times and shades

Lui, J.L., Chan, C.L., Yap, K.T.

Ann Dent, 2006;13(1):6-11.
MyJurnal

The aim of the study was to determine the depth of cure of a new nanocomposite when exposed to different curing times and also when different shades were polymerized. The nanocomposite, Filtek Supreme (3M ESPE), was packed into 96 plastic cylindrical moulds measuring 4 mm in internal diameter and 8 mm in length and then polymerized using a conventional quartz-tungsten-halogen light curing unit. The first part of the study involved curing 16 samples each of A2 shade of the nanocomposite at exposure times of 20s, 40s, 60s and 120s. For the second part, a similar number of samples of the dentinal opacity shades of A2, B3 and A4 of the nanocomposite were polymerized at a constant exposure time of 40s. The depth of polymerization of the nanocomposite in each sample was measured using a digimatic indicator. Curing depths were found to increase significantly (P < 0.05) with longer exposure time (20s < 40s < 60s < 120s) and decrease significantly with darker shades (A2 > B3 > A4).

Matched MeSH terms: Curing Lights, Dental
Fulltext Shear bond strength of orthodontic adhesives on different tooth types : an in vitro study

Radzi, Z., Yahya, N.A., Kasim, N.H.A., Ismail, N.H., Ismail, N.A., Zamzam, N

Ann Dent, 2006;13(1):18-23.
MyJurnal

Introduction: Owing to the variety of materials and methods employed, comparison of the results and findings from bonding studies is difficult. Until recently, several types of teeth have been used in published research papers as a substrate in orthodontic bonding research including bovine incisors, fresh and rebonded human premolars. Objectives: The purpose of this study was to compare the shear bond strength of an adhesive bonded to different tooth surfaces (human premolar, bovine incisor and rebonded human premolar). Methods: Two groups of thirty premolar teeth and one group of bovine incisors had brackets attached in a standardized manner using Transbond XT (3M Unitek). The adhesive was cured using conventional halogen light and a specially designed tool to standardize the distance between the light curing tip and the adhesive. The debonding force was measured using Instron universal testing machine. ANOVA and Post Hoc Dunnett C test were performed to determine any significant difference among groups (p

Matched MeSH terms: Curing Lights, Dental
Fulltext A survey on light intensity outputs of QTH, cabled and cordless LED light curing units

Athirah Ab Rahman, Adam Husein, Hany Mohamed Aly Ahmed, Dasmawati Mohamad, Wan Zaripah Wan Bakar, Manal Farea, et al.

Archives of Orofacial Sciences, 2014;9(2):85-90.
MyJurnal

Light intensity output is one of the determinants for adequate curing of visible light-cured materials. The aim of this survey was to evaluate the light intensity outputs (LIOs) of light curing units (LCUs) in dental clinics of Hospital Universiti Sains Malaysia (HUSM) and School of Dental Sciences, Universiti Sains Malaysia (USM). The respective LIOs of all functioning Quartz Tungsten Halogen (QTH) and Light Emitting Diode (LED) LCUs were tested using two light radiometers. For cordless LED LCUs, the testing procedure was done in situ and after being fully charged. Statistical analysis using Kruskal Wallis and Wilcoxon signed ranks tests were performed to compare the LIOs between groups and between the LIOs of in situ and post-charged cordless LED LCUs, respectively. The level of significance was set at 0.05 (p

Matched MeSH terms: Curing Lights, Dental
Light energy transmission through six different makes of ceramic orthodontic brackets

Aldossary MS, Abu Hajia SS, Santini A

Int Orthod, 2018 12;16(4):638-651.
PMID: 30385291 DOI: 10.1016/j.ortho.2018.09.005

OBJECTIVE: To measure Total Light Energy (TLE) Transmission through six makes of ceramic orthodontic brackets alone and bracket-plus-adhesive samples, using the MARC™-Resin Calibrator (RC).
METHODS: Six makes, three each monocrystalline (M) and polycrystalline (P) were used; PureSapphire (M), SPA Aesthetic (M), Ghost (M), Mist (P), Reflections (P), and Dual Ceramic (P). The Ortholux™ Light Curing Unit (LCU) was used to cure the orthodontic adhesive Transbond™XT. The LCU's tip irradiance was measured and TLE transmitted through the ceramic bracket was obtained, then adhesive added to the bracket, and transmitted TLE measured through bracket-plus-adhesive samples. The LCU was set at five seconds as recommended for curing adhesive through ceramic brackets.
RESULTS: Mean tip irradiance was 1859.2±16.2mW/cm2. The TLE transmitted through brackets alone ranged 1.7 to 3.9J/cm2, in the descending order: Ghost>Pure Sapphire>Reflections>Mist>SPA Aesthetics>Dual Ceramic. The TLE transmitted through bracket-plus-adhesive samples ranged 1.6 to 3.7J/cm2, in the descending order: Ghost>Mist>Reflections>Pure Sapphire>SPA Aesthetics>Dual Ceramic. TLE was reduced with the addition of adhesive (range -0.1 to -0.7J/cm2). There was a significant difference for Pure Sapphire, Reflections, and Mist (P<0.05), but not for SPA Aesthetics, Ghost, and Dual Ceramic. There was no overall significant difference between the monocrystalline and polycrystalline makes. The two best makes were of the monocrystalline type, concerning TLE transmission, but with the exception of polycrystalline Dual Ceramic; the next worst make was a monocrystalline bracket, SPA Aesthetics.
CONCLUSION: Light energy attenuation through ceramic orthodontic brackets is make-dependent, with no overall difference between monocrystalline and polycrystalline brackets. Light energy is further attenuated with the addition of resin-based orthodontic adhesive.

Matched MeSH terms: Curing Lights, Dental*
Microleakage assessment of a repaired, nano-filled, resin-based fissure sealant

Qadri GW, Noor SN, Mohamad D

Pediatr Dent, 2009 Sep-Oct;31(5):389-94.
PMID: 19947133

The purpose of this study was to evaluate the effects of different repairing techniques of a fractured sealant on microleakage in vitro.

Matched MeSH terms: Curing Lights, Dental