RESULTS No statistical significant difference in bond strength between both categories was observed in caries-affected dentin at immediate evaluation and in sound dentin after ageing .
Etch- and -rinse adhesives , however , performed better in sound enamel and dentin substrates considering immediate bond strength .
None study assessed the long-term adhesive effectiveness to sound or demineralized enamel .
Although the articles included in this meta- analysis showed high heterogeneity and high risk of bias , the in vitro literature suggests superior performance of etch- and -rinse adhesives in primary teeth in comparison with self-etch systems
AIM To systematic ally review the literature for in vitro studies that evaluated the immediate or after ageing bond strength of  etch- and -rinse and self-etch adhesive systems to enamel and dentin of primary teeth .
Shortening of primary dentin etching time and its implication on bond strength.
OBJECTIVE The aim of this study was to investigate the influence of shortening the etching time on the bond strength of a conventional and a self-etching primer adhesive system used in primary tooth dentin . METHODS Flat dentin surfaces were obtained from 24 primary molars , r and omly assigned to 4 experimental groups . The adhesive systems Single Bond and Clearfil SE Bond were applied in two groups according to the manufacturers ' recommendations . In the other two groups , the adhesives were applied after half-time of acid etching , 7 s for Single Bond and 10 s for Clearfil SE Primer . Resin crowns were built up and after 24 h storage in water at 37 degrees C , the teeth were sectioned to produce beams with cross-sectional area of approximately 0.49 mm2 . Specimens were tested in tension at 0.5 mm/min until failure . Fractured specimens were analyzed to determine the failure mode . RESULTS Tensile bond strengths for Single Bond in primary dentin were higher than for Clearfil SE Bond . Shortening of acid etching time improved bond strength only for Single Bond , while no statistically significant difference was observed for Clearfil SE Bond when both etching times were compared . SIGNIFICANCE No detrimental effect on bond strength was observed when the time of acid etching was shortened in 50 % . Shortening the time for a procedure in a small child without compromising the quality of the work is a very important finding for the practicing pediatric dentist
RESULTS No statistical significant difference in bond strength between both categories was observed in caries-affected dentin at immediate evaluation and in sound dentin after ageing .
Etch- and -rinse adhesives , however , performed better in sound enamel and dentin substrates considering immediate bond strength .
None study assessed the long-term adhesive effectiveness to sound or demineralized enamel .
Although the articles included in this meta- analysis showed high heterogeneity and high risk of bias , the in vitro literature suggests superior performance of etch- and -rinse adhesives in primary teeth in comparison with self-etch systems
AIM To systematic ally review the literature for in vitro studies that evaluated the immediate or after ageing bond strength of  etch- and -rinse and self-etch adhesive systems to enamel and dentin of primary teeth .