Primary molars with necrotic pulp or abscess are common unfortunate event faced in pediatric dentistry .The traditional treatment is either pulpectomy or extraction. ٍuccess of pulpectomy treatment is about 85% in abscessed primary teeth.

The aim of pulpectomy is to preserve teeth in a symptom free state until they are replaced by their successor naturally during the transition from primary to permanent dentition, thus avoiding extraction. The adequate restoration of the involved teeth may preserve the arch length reestablish the masticatory function and esthetics and prevent harmful tongue habits and speech alterations due to anterior teeth decay.

The techniques available for management of necrotic primary molars are either pulpectomy or extraction, but according to guidelines American Academy of Pediatric Dentistry, extraction and space maintainer is a viable option but a successfully restored tooth is far superior space maintainer than an appliance. So preservation of primary molars is not only important for masticatory function but also for preservation of developing occlusion.

The rationale includes the chemical and mechanical removal of irreversibly inflamed or necrotic radicular pulp tissue, followed by root canal filling with a material that can resorb at the same rate as the primary tooth and be eliminated rapidly if accidentally extruded through the apex and have the ability for disinfection of pulpal and periapical lesion.

In this study 2 medications will be used as root canal filling. First is the mixture of zinc oxide eugenol based sealer (ZicalR) and 3mixtatin which is composed of 3 antibiotics (ciprofloxacin, cefixime, metronidazole), simvastatin, and zinc oxide the term 3mix-tatin as an acronym for the mixture of triple mixture antibiotics and simvastatin. Statin components are emerging material in regenerative endodontics. Clinical and experimental trials proved the pleiotropic effect of statin, as it increases the osteoblastic function and suppresses the osteoclastic function. In addition to that, evidence proved that it is a potent anti -inflammatory as it reduce the CRP and pro-inflammatory cytokines. Second medication will be Zical which is a zinc oxide eugenol based sealer composed of Zinc Oxide, Bismuth Sub-carbonate, Barium Sulphate, Sodium Borate, Iodoform, and Hydrogenated Resin. Liquid contains: Eugenol.

Inclusion Criteria

1. Children age range from 5-7 years.
2. Children free from any systemic diseases or genetic disorders.
3. Primary molar with necrotic pulp, with pain, gingival abscess, sinus openings.
4. Clinical mobility not exceeding grade two.
5. Radiographic evidence of non-perforating internal resorption, external resorption not exceeding 1\3 of the root
6. Furcation or periapical radiolucency.

Exclusion Criteria:

1. Non-restorable molars or beyond repair, for example: decay reaches to bifurcation, a hard gingival margin cannot be established or infection cannot be eradicated by other mean (Balaji, 2007).
2. Patient with known allergy to any type of antibiotics or anti-hyperlipidemia drugs.
3. Patient with facial cellulitis or lymphadenopathy
4. Lack of patient/parent compliance and cooperation.
5. Refusal of participation or failure to obtain an informed consent.