Effect of Thickness Variation in Coronal Plug on Root Maturation and Periapical Healing

d. Second visit: After 3 weeks the patients will be randomly divided into 2 groups: Group A: Patients will be anesthetized 1 carpule of mepivacaine without vasoconstrictor (Mepivacaine HCl 3%), the access will be reopened under rubber dam isolation and the canal will be irrigated with a total of 20 ml of 1.5-2.5% sodium hypochlorite solution. The canal will then be dried with sterile paper points; a sterile sharp needle will be used to irritate the apical tissue until bleeding occurred apically in the root canal space so as to create a biological scaffold for the regenerative process. Over a 15-minute time period, the blood will be allowed to clot to a level of 3 mm below the cemento-enamel junction. A resorbable matrix such as CollaPlug™, Collacote™, CollaTape™ will be placed over the blood clot if necessary. Then 3 mm of MTA will be placed using a suitable size amalgam carrier. A damped cotton pellet on a tweezer placed above the unset MTA and large condenser will be used to seal the canal orifice completely. The access cavity will be sealed with Fuji IX glass ionomer filling material and acid etched composite resin bonded filling material. Group B: The same procedures that will be followed in group A will be also done in group B, except for the thickness of MTA coronal plug which will be 5mm in its thickness e. Follow-up: The patients will be recalled after 1, 6 and 12 months for follow up. The post-treatment follow-up examination will be accomplished as follows: * CBCT scan will be done at 6 and 12 months follow up appointments. * An evaluation was performed on each patient to assess presence of any signs and symptoms clinically by inspection, percussion, palpation, or biting on the treated tooth.