I don't want to invest a lot of points into constitution so i was thinking: if i put in 15 and then get +3 at ls mastery will i have access to the best implants that req 18 constitution?Never played a sentinel before i don't see the point,they are mediocre at force powers(enemy's save a lot) and they are weak with a lightsaber(i am talking pure damage) sure they got skills,but i only need repair and demolitions,the rest my companions can handle.A couple of examples my latest marauder has 53-112 dmg in the main hand with a double bladed lightsaber ,and the jedi master has 52 wisdom,22 charisma and 54 at def(without any buffs) kreia's lightsabers could not even hit me and i killed them all with force wave(she is immune to statis field and simmilar effects),a sentinel can never achieve that.Nevertheless i will give it a try.

 

Thank you for your time,and sorry for any spelling mistakes,i haven't slept for a wile...

The con score used for implants is the base level-that is the level before any bonuses. Therefore LS mastery as a Sentinal will not, in your case, allow you to use lv 16+ implants if the basic stat is only 15. All mastery will do in your case is give you more hit points.