INTRODUCTIONRoot canalobturation is a procedure in which the root canal space is filled withcanal-filling materials at the final stage of root canal treatment, aftercleaning and shaping. The objective of root canal obturation is to prevent ortreat periapical disease by preventing recontamination by bacteria that mayhave remained in the dentinal tubules or that exist in the oral cavity (Kim, etal, 2017).
A threedimensional seal of the root canal system is achieved by proper root canalobturation to prevent the recurrence of bacterial infection. The microleakagebetween the root canal and the periapical tissues is hindered leading to deathof any surviving microorganisms. This prevents the entry of nutrients and toxicbacterial products into the periapical tissues. Various techniques have beendeveloped to achieve the proper obturation of root canal system including thevertical compaction, lateral compaction and carrier based obturation (Gupta, etal, 2015). Rotarynickel-titanium (NiTi) instruments are widely used for root canalinstrumentation.
This widespread use of these instruments has causedmanufacturers to offer corresponding gutta-percha cones that match the taperand diameter of the instruments. It is claimed that these cones will match thetaper and diameter of the canals prepared with the rotary NiTi instruments.Obturation with these cones used as a single-cone technique is alleged toprovide a 3D obturation in less time than traditional obturation techniques andto ensure a high volume of gutta-percha in the canal (Schafer, et al, 2013). The root canalpreparations with NiTi rotary systems are more conical than manualpreparations.
Tapered single cones were introduced in the market in order toimprove the gutta-percha/root canal sealer balance. If the diameter andconicity correspond exactly with the final shaping instrument, the quality ofobturation would be superior to that of the classic single-cone technique(Robberecht, et al, 2012). The advent ofcomputed tomography (CT) has started a revolution of information in healthstudies and has contributed to planning, diagnosis, treatment, and prognosisanalysis of several diseases. Cone-beam computed tomography (CBCT) is arecently developed technology with potential for applications in differentareas of research and clinical dentistry. It designed for imaging hard tissuesof the maxillofacial region, and capable of providing a 3-dimensionalrepresentation of the maxillofacial skeleton with minimal distortion (Decurcio,et al, 2012. Scarfe, et al, 2006).BACKGROUND Complete obturation of the rootcanal with an inert filling material and creation of a hermetic apical seal arethe goals of successful endodontic treatment. Furthermore, the integrity of the rootcanal filling in the apical few millimeters is one of the criteria believed tobe important for achieving successful endodontic treatment.
Mostobturation methods make use of a solid core cemented in the root canal with asealer (Gencoglu, et al,2002).?In manystudies the percentage of gutta-percha filled area (PGP) has been measured. In general,the higher the PGP, the smaller the area of sealer and voids, the better thequality of the root canal filling.
The PGP score may reveal filling problems in theoval canal. When the wings are occupied by debris, the PGP score will be lowerthan in round canals. Because the shape of the wings is irregular, it may bedifficult to place secondary cones into the wings when the root canal is filledusing the cold lateral compaction technique, so here too the PGP score may belower than in the round canals (Sluis, et al, 2005).The Thermafilobturation technique resulted in virtually no gaps and very low amounts ofsealer on the root surface, unlike the lateral condensation technique.
Tubulesealer penetration occurred with both techniques, but was deeper, especially inthe mid and apical zones, with the lateral condensation technique (Guigand, etal, 2005).The quality ofroot fillings of the thermoplasticized gutta-percha in comparison to coldlateral condensation has been evaluated in several studies, with differingconclusions. On radiographs, the Thermafil obturation technique generallyshowed better adaptation than lateral condensation, but in the apical third theresults for both methods were similar. Scanning electron microscopicobservations for Ultrafil, Thermafil and lateral condensation showed betterdentinal wall adaptation in roots obturated with thermoplasticized gutta-perchathan in laterally condensed root canal fillings, regardless of the presence orabsence of a smear layer (Kqiku,et al, 2006).
The final objective of endodonticprocedures should be the total obturation of the root canal space. Many rootcanal filling techniques have been developed in the hope of achieving totalroot canal obturation. Most of the currently employed techniques use either asolid core and a cementing substance, or a plastic material which can beadapted more or less to the shape of the root canal system (Schilder,2006).Gutta-perchaexhibited the lowest percentage of voids and gaps in the root sections exceptat the apical third where GuttaFlow showed the lowest gaps and voids. This alsocan be attributed to the filling technique, because the manufacturers ofGuttaFlow recommend that it is dispensed first in the apical part of the rootcanal, and then a master gutta-percha cone is placed. This ensures the leastamount of voids and gaps in the apical third (Hammad, et al, 2009).
Numerousmaterials and techniques have been developed for filling root canals. It hasbeen reported that the quality of adaptation between the surface of the rootcanal and the gutta-percha is uncertain in fillings created by the lateralcondensation technique, even though this method has the advantage of creating atight apical seal through compression of several gutta-percha cones withspreaders. However, canal curvature and other anatomic features may preventachievement of this tight seal.6 In addition, metal spreaders must be placed inthe canal several times during the filling process for lateral compaction ofthe gutta-percha, but practitioners may have difficulty achieving the requiredbalance between optimal compression of the gutta-percha and avoidance of rootfracture through application of too much pressure (Tasdemir, et al,2009). On a study ofusing micro-CT-based quantitative three-dimensional method for analysis of rootcanal filling adaptation to the canal walls was presented.
It may serve as auseful tool to study and compare the quality of root canal fillings. Within thelimitations of the present study, the self-adjusting files allowed bettercleaning and shaping and better adaptation of the root canal filling than thoseallowed by rotary files (Metzger, et al, 2010). Shapingfacilitates three-dimensional cleaning by removing restrictive dentin, allowinga more effective volume of irrigant to penetrate, circulate, and potentiallyclean into all aspects of the root canal system. Well-shaped canals result in atapered preparation that serves to control and limit the movement of warm guttapercha during obturation procedures. Importantly, shaping also facilitates 3Dobturation by allowing pre-fit pluggers to work deep and unrestricted bydentinal walls and move thermosoftened obturation materials into all aspects ofthe root canal system.
Improvement in obturation potential is largelyattributable to the extraordinary technological advancements in shaping canalsand cleaning and filling root canal systems (Ruddle, 2010).A correlationwas found between root canal morphology and the master cone adjustmentvariables in the “Single-cone” group. When the morphology was oval, we observedbetter gutta-percha adjustment. This could be explained by the smaller amountof friction between the master-cone and the root canal walls in an oval canalcompared with a circular canal. This correlation was not found in the “Combinedsystem” group. This was to be expected, because if the gutta-percha is heatedand condensed, the root canal morphology no longer matters (Robberecht, et al,2012).To cope withsuch different obturation difficulties many root obturating techniques havebeen evaluated over the years and the filling materials from simple pastemixtures to silver points with sealing cements. To obturate root canal system theideal obturating material chosen should be non-irritating, non-toxic,radiopaque, easily manipulated, insoluble in tissue fluids and able to adapt tocanal walls.
Gutta-perchais currently the material of choice due to its inertness, biocompatibility,dimensional stability and plasticity (Qureshi, et al, 2012). Three-dimensionalobturation of the prepared root canals is essential to long- term clinicalsuccess of root canal therapy. The root canal system should be sealed apically,coronally, and laterally and the obturation material should be of uniformdensity.
Epley et al and Schilder suggested that the ideal root canal obturatingmaterial should be well-adapted to the canal walls and its irregularities andthe entire length of the canal be densely compacted with homogenous mass ofgutta-percha. Several materials and techniques have been developed forachieving a successful obturation, gutta-percha is the most commonly used rootcanal obturation material and its physical properties have made it possible touse it in several different techniques (Mustafa, 2013). Lateralconsideration of gutta-percha has been proven to be a very popular andclinically effective filling technique. However, Schilder reported that finalfilling by lateral consideration resulted in a non-homogeneous mass of manyseparate gutta-percha cones pressed together and joined only by friction andthe cementing substance. Warm gutta-percha best fulfills the requirements of aroot canal filling because homogeneity is provided throughout the entire lengthof filling (Samson, et al,2013). To achievelong-term stability, the filling should be well adapted to the canal walls, andits irregularities and the entire length of the canal should be denselycompacted with a homogeneous mass of gutta-percha (Wolf, et al, 2014).The maximumamount of obturating material was observed in Calamus group followed byThermafil and lateral compaction. Minimum voids were seen in obturation byCalamus technique (Gupta, et al, 2015).
In a studythat concluded the carrier-based gutta-percha obturation systems revealed significantlyhigher percentage of gutta-percha-filled area in comparison to single-cone andlateral condensation techniques (Yilmaz, et al, 2016). In all thepervious study showing that different obturation method can get differentresult which will affect in the quality of the root canal filling. Usingguttaflow and carrier-based gutta-percha obturation systems show the leastamount of voids and also the highest in filled area in comparing to the otherstechnique. RESEARCH DESIGN AND METHODSSubject: This is an experimental study which will beconducted at the UQUDENT hospital of umm al-qura university Makkah, KSA. Thetotal number of extracted teeth will be 30.Ethical approval: Ethical approval frominstitutional reviewing board will be obtained before starting this study.The Inclusion criteria for the study samplesis as follows:§ Extracted teeth with singlecanal and closed apex.
The exclusion criteria for the study samplesis as follows:§ Tooth with multi-canal.§ Tooth with crack or fractures. § Tooth with open apex.§ Tooth with sever curvature.Thirty extracted human teeth were collectedand cleaned from any debris then stored first with 10% of sodium hypochlorite forone day and then stored in saline.
Teeth then decoronated with a diamond wheeland achieve working length about 16 mm using K-type file number 10 insertedinto the canal until it visible from the apical foramen, working length was set1mm short of the length. Teeth divided randomly into three group (n=10) andmounted in transparent acrylic resin. For the cleaning and shaping start withK-type file number 15 to establish apical patency and followed with K-type filenumber 20 and 25, irrigation with 2 ml of 2.5% sodium hypochlorite between eachfile.
The root canal then instrumented using ProTaper Next rotary systemaccording to the manufacturers’ instructions, three file used X1-yellow, X2-redand X3-blue. Irrigation with 2 ml of 2.5% sodium hypochlorite between each fileduring instrumentation followed by 17% of EDTA aqueous solution. EDTA 17% usedfor final rinse. Dryness with paper point. According to the groups we havethree obturation techniques. Thefirst group will receive a root canal filling by using System-B withgutta-percha cartridges, master gutta-percha cone inserted to the canal andcoated with resin based to the full working length, pack the filling material andplace within 5 mm to the canal terminus, then flow the gutta-percha materialinto the canal and compact the canal with plugger until the desire level.
The second group will receive a root canalfilling by lateral condensation technique, master gutta-percha cone coated withresin based sealer and inserted to the full working length, accessorygutta-percha cone coated with the same sealer and inserted to the canal andlateral condensation performed until the canal filled and can’t introduce moreaccessory gutta-percha cone. The third group will receive a root canalfilling by using single cone technique, F3 ProTaper gutta-percha cone selectedand coated with resin based sealer and inserted to the full working length.All the three group will place at thecomputed tomography machine; three horizontal section will be analysed (apicalthird, middle third and coronal third).
Validity and Reliability of thetest: The intra examiner consistency will bemaintained through training and repeat examination until satisfaction resultobtain. replication of statistically significant results, under the same conditions andgenerate the same results. Statisticalanalysis: Datawill be collected and tabulated and statistically evaluated by StatisticalPackage for Social Science (SPSS) Version 22 for mac.