achment ▁of ▁the ▁period ont al ▁lig ament ▁( P DL ). ▁The ▁P DL ▁is ▁a ▁lig ament ▁that ▁attach es ▁the ▁root ▁of ▁the ▁to oth ▁to ▁the ▁supporting ▁al ve olar ▁b one . ▁This ▁lig ament ▁allows ▁for ▁occ lus al ▁force ▁absor ption . ▁Pla que ▁accum ul ates ▁within ▁the ▁pocket ▁initi ating ▁an ▁infl am mat ory ▁response ▁due ▁to ▁an ▁increased ▁number ▁of ▁sp iro ch etes . ▁There ▁are ▁different ▁types ▁of ▁b acter ia ▁that ▁make ▁up ▁dent al ▁pla que . ▁In ▁cases ▁of ▁ag gress ive ▁period ont itis ▁three ▁major ▁species ▁of ▁b acter ia ▁have ▁been ▁identified ▁within ▁the ▁period ont al ▁pocket . ▁These ▁b acter ia ▁include ▁P orph y rom onas ▁ging ival is , ▁Pre v ot ella ▁inter media , ▁and ▁Act in ob ac ill us ▁act in om yc et em com it ans . ▁Health y ▁ging iva ▁consists ▁of ▁few ▁micro organ isms , ▁mostly ▁c oc co id ▁cells ▁and ▁straight ▁ro ds . ▁D ise ased ▁ging iva ▁consists ▁of ▁increased ▁numbers ▁of ▁sp iro ch etes ▁and ▁mobile ▁ro ds . Inter actions ▁between ▁pla que ▁and ▁host ▁infl am mat ory ▁response ▁determine ▁the ▁alter ations ▁in ▁pocket ▁depth s . ▁B acter ial ▁pla que ▁initi ates ▁a ▁n ons pec ific ▁host ▁infl am mat ory ▁response ▁with ▁the ▁intention ▁of ▁elimin ating ▁ne c rot ic ▁cells ▁and ▁harm ful ▁b acter ia