Removal of Intracanal Medicaments by Different Techniques Using Cone Beam Computed Tomography Analysis (Ca(OH)2 - CBCT)

the primary etiological factors for pulpal and periradicular diseases are microorganisms. Therefore, the primary purpose of endodontic treatment is to completely eradicate microorganisms from the root canal. This is achieved through chemo-mechanical preparation of the canal, which includes proper cleaning and shaping by instrumentation and irrigation.

Complexity of the root canal system compromises the eradication of microorganisms completely by traditional methods. The remaining bacteria may multiply between appointments and reach the same previous concentration. Therefore, intracanal medicaments play an important role in canal disinfection.

Intracanal medication becomes more necessary in cases involving bacteria that are resistant to routine treatment, as well as in situations where successful completion of therapy is hindered by persistent pain or continuous exudate.

The concept is to temporarily fill the root canal with a material that would chemically and physically enhance eradication and prevent the proliferation of microorganisms.

The most commonly used intracanal medicament is calcium hydroxide (Ca(OH)2), Through releasing hydroxyl ions disrupts the structural integrity of bacterial cytoplasmic membranes. In addition, Ca(OH)₂ indirectly affects anaerobic microorganisms within the root canal through a reaction between calcium ions and aqueous carbon dioxide, resulting in degradation of bacterial lipopolysaccharides.

Moreover, the biological properties of Ca(OH)₂ as antimicrobial action, induction of hard tissue deposition, and promotion of improved tissue repair all of this make that it considered as the material of choice of intracanal medicament.

However , despite its benefits, Ca (OH)₂ remnants on the canal walls showed multiple disadvantages such as; affecting sealer penetration into dentinal tubules, weakening their final bond to dentin and delaying the setting of some sealers such as zinc oxide eugenol so, Ca (OH)₂ remnants still one of the obstacles during complete the root canal obturation and interference with the physical properties of sealers has been shown to increase apical leakage and eventually compromise the outcome of endodontic treatment.

Additional disadvantages of Ca (OH)₂ include the challenge of removing it from the root canal walls and complete removal of it prior to final obturation is critical. However, manual irrigation alone was unable to completely remove intracanal medicament regardless of the agent use Numerous methods have been suggested for the removal of Ca (OH)₂ from the root canal such as : (1) Manual irrigation with a syringe (2) Manual dynamic agitation (3) Canal brush (4) Passive ultrasonic irrigation (5) Sonic irrigation (6) XP-shaper (7) XP-finisher (8) Rins Endo (9) Endo vac Numerous methods have been used to assess the amount of Ca (OH)₂ remnants within the root canal. These include digital photographs, stereomicroscopy, scanning electron microscopy, and micro-computed tomography.

However, the recent availability of cone beam computed tomography (CBCT) is considered an accurate, noninvasive imaging technique and has been employed to evaluate the quantity of residual intracanal calcium hydroxide. CBCT provides a three-dimensional volume measurement without the need to section the specimens Group assignment

Patients will be randomly divided into three equally treated groups (n=10) According to the type of activation technique as follow:

Group 1: Manual Dynamic Agitation (MDA)* Group 2: Sonic Activation† Group 3: XP-finisher activation‡

After intracanal medicament placement, the volume of the medicament will be measured using CBCT analysis software†††. The patient will then be recalled after one week[19]. At the recall visit, the tooth will be isolated and the intracanal medicament will be removed according to the assigned group:

Group 1: MDA Group 2: Sonic Activation Group3: XP-finisher activation Following intracanal medicament removal according to each group, a second CBCT scan will be taken for evaluation. CBCT interpretation will be used to detect the remnants of intracanal medicament and measure its volume using the cone-beam analysis software After image evaluation, the canal will be dried with sterile paper points, and root canal obturation will be performed using gutta-percha cone* and a resin-based sealer*, employing the cold lateral condensation technique.