Attach drywall to ceiling panels

[Lars48]

Hello
I have mounted the plasterboards on old tekpanels that are 23 mm. I used regular drywall screws (3.9x30). The boards are sitting pretty well on the ceiling. I am wondering if I should use longer screws like 45 so that they go through both the underside and top side of the panels or should I continue with 30 screws?

 

[tergo]

If you use drywall screws for wood, 30mm should be sufficient (provided you screw in as many as there should be in the board)
http://nfgab.se/sv/fastelement/8_tr...gg/803_gipsskruv/1891_gipsskruv-for-traregel/