Table 3 Summarized data of the 5 included studies

Karamouzos 2010 [25]

Prospective split-mouth design

26 patients (13 girls, 13 boys) a mean age of 13 years 7 months (SD, 2.9 years)

Adhesives—chemically cured (System 11, Ormco, Glendora, CA, USA) and light-cured (Transbond XT, 3 M Unitek, Monrovia, CA, USA)

The resultant color differences (DE) between the interval groups were calculated

Chemically cured resin was associated with greater color changes than light-cured composite

The reflectance spectrophotometer SpectroShade (LUA005, MHT Optic Research AG, Zurich, Switzerland; software version, 2.20)

End point: end of active treatment

Eliades 2001 [23]

Prospective split-mouth design

Group I:15

No-mix adhesive resin (Unite, 3 M, Monrovia, CA, USA) chemically cured (GC Fuji Ortho, GC Corp., Tokyo, Japan)

The resultant color differences (DE) between the interval groups were calculated

The highest differences were recorded for the baseline-debonding interval for both adhesives used. No difference was found with respect to E between adhesive materials.

Artificial accelerated photo-ageing

Group II:15

Trakyali 2009 [26]

RCT

Group 1:15

Transbond XT Light cure adhesive 3 M Unitek,

The resultant color differences (DE) between the interval groups were calculated

Color changes of orthodontic bonding systems induced by photoageing cannot be clinically observed.

Artificial accelerated photoageing

Group 2:15

Group 3:15

Monrovia, CA, USA

Group 4:15

Eagle Bond American Orthodontics, Sheboygan, Wisconsin, USA

Group 5:15

Polishing with Stainbuster eliminates enamel surface roughness, which may improve light reflection.

Blugloo Ormco, Scafati, Italy

Light bond Reliance Orthodontic Products Inc., Itasca, Illinois, USA

Unite 3 M Unitek

Boncuk 2014 [22]

RCT

Of the 175 teeth, 25 served as control specimens.

Group 1 (control). untreated

CIE (Commission Internationale de l’Eclairage) L*a*b* color system

Orthodontic treatment alters the original color of enamel, and both the adhesive system and the resin-removal methods are responsible for this change. When brackets are bonded with the etch-and-rinse system or the SEP, cleaning the adhesive residuals with Stainbuster burs is recommended for minimal change.

handheld spectrophotometer (SpectroShade

Group 2. Enamel was etched with 37% orthophosphoric acid ,Transbond XT Adhesive Primer (3 M Unitek, Monrovia, CA, USA)

Group 3. A self-etch adhesive system (Transbond Self-Etching Primer [SEP]; 3 M Unitek) was used in conjunction with Transbond XT Adhesive Resin as with group 2.

Group 4.

20% polyacrylic acid, the brackets were bonded with light-cured resin-modified glass ionomer cement (RMGIC; Fuji Ortho LC; GC Corp, Tokyo, Japan).

The remaining were randomly assigned to three experimental groups (n = 150 each) with respect to the adhesive tested

Micro;

MHT, Verona, Italy

Joo 2011 [24]

RCT

Teeth specimens were randomly divided into 9 groups of 15 teeth

Group 1: Control

CIE (Commission Internationale de

The self-etching primers system would show less stain

reflection spectrophotometer (CM- 3500d, Minolta, Osaka, Japan)

Group 2: Transbond-F (3 M Unitek)

Group 3: Transbond-FP (3 M Unitek)

l’Eclairage) L*a*b* color system

susceptibility if the thin residual adhesive resin layer after debonding is removed by polishing

Group 4: Ortho Solo-F (Ormco Corp, Glendora, CA)

Group 5: Ortho Solo-FP (Ormco Corp, Glendora, CA)

Group 6: Transbond Plus-F (3 M Unitek)

Group 7: Transbond Plus-FP (3 M Unitek)

Group 8: Prompt L-Pop-F (3 M ESPE, Seefeld, Germany)

Group 9: Prompt L-Pop-FP (3 M ESPE, Seefeld, Germany)