Evaluation of the balanced force concept for instrumentation of curved canals in vivo study

In the presented study, 40 clinical cases having canal curvatures that rangedfrom 30-80 degrees was prepared by the balanced force technique. In half ofthe cases, modified tip k-files were used and in the other half, k-reamerswere used in canal preparation. Curved canals were enlarged 5-6 sizes largerthan the initial files. Degrees of canal curvature were measured by Shnider'smethod before instrumentation and after filling. The following conclusionsare drawn: 1] Modified tip k-files produced a preparation with nearly notransportation in the range of curvature 30-44 degrees. 2] K- reamer'spreparation showed a very small transportation of six degrees in the samerange of curvature. 3] Canal transportation using either type of instrumentsincreased slowly as the preinstrumentation curvature degree increased. 4]Enlargement of severely curved canals up to six sizes larger than the initialfile can be easily performed using the balanced force concept

Root canal morphology of mandibular second molars in Egyptian inhabitants

In the present investigation, 60 mandibular second molars from Egyptianpatients were cleared for the study of root canal morphology. The aim was tostudy root canal pattern of such teeth to reveal if there is any specificracial characteristics in Egyptian population. This study concluded that Egyptian mandibular second molars had two separate roots in 96.7%of the teeth examined. Mesial roots were found to have four canal types;namely; type II, type VI, type III and type I in a decreasing order. Distalroots had two canal types in equal percentages, which are type I and type IV. Results of the present study showed that race might have an influence on themorphologic pattern of root canals in permanent dentition. A wider scale ofmorphologic study concerning permanent teeth from Egyptian people isrecommended

Frequency of root canal types in mandibular first molar: a clinical-roentgenographic study

A clinical investigation was performed concerning the frequency of canal typesin mandibular first molars. Mesial roots specially were studied in thepresent work in view of the recognized discrepancies in the literatureconcerning canal type of this tooth. Diagnosis of the canal type was based onradiographic interpretation using the shift technique. The followingconclusions are then drawn. Mesial roots were found to have two canal typesin all cases studied. The two mesial canals were found to unite at or nearthe apex to form one single apical foramen in 48% of the cases. However, theyremain separate in 52% of the cases. For those cases diagnosed as having typeII canal configuration, a method for preserving the integrity of apicalforamen was supposed and presented. The use of the shift radiographictechnique during endodontic treatment is mandatory to help in diagnosis ofroot canal type

Comparative study of the sealing ability of retrofilling techniques as correlated to marginal adaptation

This investigation was undertaken to compare the sealing ability andadaptation of four retrofilling materials, and five retrofilling techniques,namely; amalgam with and without varnish, composite, cavit W and heat sealedgutta percha. Electrochemical sealability study showed that all testedretrofilling materials leaked. However, leakage varied greatly betweendifferent tested materials. The smallest amount of leakage was detected withheat sealed gutta percha, followed by cavit W. amalgam without varnish gave thehighest leakage score. On the other hand, amalgam with varnish and compositetook an intermediary position. These results correlated completely with theresults of marginal adaptation concerned with cavit W, composite and amalgamwithout varnish. However, negative correlation was found in case of heatsealed gutta percha and amalgam with varnish

Root canal morphology of mandibular third molar and its endodontic significance

Ninety recently extracted mandibular third molar teeth were examined for root canal morphology. The studied parameters included tooth length, roots curvatures and patterns. Tooth length averaged 20.65 mms. Mesial roots were found straight in 23.3% of the cases examined. They were distally curved in about half of the cases. About two thirds of the distal roots were equally distributed as straight and distally curved. Three canal patterns were found namely, one canal with one apical foramen, two canals with one apical foramen and two canals with two apical foramina. The study revealed that all canals were easily explored, patent and generally without obstructions. The results of this study encouraged the endodontic practitioner for treating this tooth with equal frequency as any other tooth in the dental arch

Radioisotope determination of apical seal following dowel preparation

Fifty freshly extracted anterior teeth were obturated with gutta percha and sealer using lateral condensation methods. The teeth were divided into five groups according to the method of gutta percha removal. Group A, posts spaces were prepared using hot root canal pluggers. Group B and C two types of drills, group D reamers while group E was used as a control group. The specimens were then submerged in solution 137 Cs chloride for 48 hours. The result showed that the mean leakage was greater with group B and C, while the least leakage was demonstrated with group A. Group D showed more leakage than group A. The study concluded that the suitable methods for dowel space preparation was recorded with hot pluggers. Radioactive isotopes tracer technique seemed to be satisfactory for leakage determination. The maximum leakage pattern was recorded when using rotary instruments