Comparative analysis of efficacy and cleaning ability of hand and rotary devices for gutta-percha removal in root canal retreatment: an in vitro study.

AIM OF THE STUDY: To evaluate the efficacy and cleaning ability of Hedstrom files, and ProTaper retreatment instruments in removing gutta-percha from root canals with and without xylene as solvent. MATERIALS AND METHODS: Sixty extracted single rooted human teeth were selected and decoronated, straight access established working length determined 1 mm short of canal, chemomechanical preparation done and obturated with guttapercha and AH plus sealer. Samples were stored for 1 week in humidifier divided into four groups of 15 teeth each. • Group I: Hedstrom files without xylene. • Group II: Hedstrom files with xylene. • Group III: ProTaper retreatment instruments without xylene. • Group IV: ProTaper retreatment instruments with xylene. and the following criteria were assessed - Time taken for initial plunge of instrument into guttapercha. - Time taken for complete removal of gutta-percha to reach working length - Ability of H files and ProTaper retreatment files with/ without xylene to remove gutta-percha in coronal, middle and apical 1/3 of canal. The teeth were grooved in labiolingual cross section, observed under a steromicroscope and scored according to gutta-percha debris left in the canal. Results were evaluated using ANOVA test and multiple comparisons done using Scheffe test. RESULTS: The least time to reach working length was found with group IV followed by groups III, II and group I respectively. Also the fastest way to remove maximum gutta-percha was group IV followed by groups III, II, and I respectively with a statistically significant difference among all groups. Apical 1/3 has more amount of remaining gutta-percha debris than middle and coronal 1/3 in all groups. The amount of gutta-percha debris in apical 1/3 was least in group IV followed by groups III, II and I respectively. DISCUSSION: The better performance of ProTaper rotary instruments has been attributed to their special flute design which tends to pull gutta-percha coronally directing it toward orifice. Also the movements of engine driven instruments produce frictional heat which plasticises gutta-percha and aids in easy removal. Apical third of root canals showed more guttapercha debris compared to coronal and middle 1/3 and has been attributed to the greater anatomic variability and difficulty of instrumentation in the apical area. The existence of deep groves and depressions on dentine walls in this apical 1/3 make them less instrumented areas as it did be difficult to direct the file against the extreme root canal wall. CONCLUSION: The fastest technique to remove gutta-percha and the shortest time to reach working length was observed with ProTaper retreatment instruments with xylene followed by ProTaper retreatment files without xylene and Hedstrom files without xylene. After instrumentation for removal of gutta-percha, apical third was found to have more debris compared to coronal and middle 1/3 of the root canal.

Cleaning efficiency of anatomic endodontic technology, ProFile System and Manual Instrumentation in oval-shaped root canals: an in vitro study.

AIM: This in vitro study is an attempt to compare the effectiveness in cleaning oval shaped root canals using Anatomic Endodontic Technology (AET®), ProFile system® and Manual Instrumentation with K-files. METHODOLOGY: Sixty oval shaped single rooted maxillary and mandibular premolars with straight canals were divided in to three groups. The root canals were, confirmed as being oval shape by means of radiographs made in a buccolingual and mesiodistal direction. Automated canal preparation was performed using Anatomic Endodontic Technology (group 1) and the ProFile system® (group 2). Manual instrumentation (group 3) was performed with k-files. Irrigation was performed using alternatively 3% NaOCl and 17% EDTA, followed by rinsing with normal saline. The roots were split longitudinally into two halves and examined under a scanning electron microscope. The presence of debris and smear layer was recorded at distances 1, 5 and 10 mm from the working length using a three step scoring scale. Mean scores for debris and smear layer was calculated and statistically analyzed for between and within groups significance, using the Kruskal-Wallis nonparametric ANOVA test and Bonferroni's multiple comparison test. RESULTS: At 1, 5 and 10 mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls as compared to canals prepared with ProFile system® or manual instrumentation. For all three groups significantly lower mean smear layer scores (p < 0.05) were recorded at 5 and 10 mm levels compared with the 1 mm level. Significantly lower mean debris scores (p < 0.05) were also recorded at 5 and 10 mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile system® and manual instrumentation groups. CONCLUSION: Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved with any of the techniques and instruments investigated.

Accuracy of electronic apex locator in enlarged root canals with different root canal irrigants: an in vitro study.

AIM: To evaluate the accuracy of Root ZX-II (J Morita Corp) apex locator in enlarged root canals with different root canal irrigants. MATERIALS AND METHODS: 48 freshly extracted single rooted mandibular premolar teeth were used. The apical enlargement was done up to #45 K-file as the master apical file (MAF). The teeth were randomly divided into 4 groups and mounted in an experimental apparatus. The following irrigants were used during electronic canal measurements: group 1: saline; group 2: 3% NaOCl; group 3: 2% chlorhexidine; group 4: 17% EDTA. The canal measurement was done with Root ZX-II apex locator using #10 and #45 K-file. Data were analyzed by two way ANOVA and Bonferroni multiple comparison test. RESULTS: Statistical analysis showed that there was statistically significant difference between #10 and #45 K-file for group 1 (p < 0.01). CONCLUSION: Root ZX-II was accurate in the presence of 3% NaOCl and 17% EDTA when measured with smaller and larger files. However, it was accurate in the presence of saline and 2% CHX when larger files were used.

Role of ozone therapy in minimal intervention dentistry and endodontics - a review.

Ozone has been successfully used in medical field since many years owing to its oxidizing property making it an excellent antimicrobial agent. Moreover its potent anti-inflammatory property along with favorable cellular and humoral immune response made ozone an effective therapeutic agent. Also its ability to arrest and reverse carious lesions in a predictable way opened up a new chapter in minimal intervention dentistry. Furthermore its efficacy in curbing resistant poly microbial root canal flora appears very promising. This article is based on information through valid textbooks, peer reviews, journals and medline/pubmed search. How to cite this article: Reddy S A, Reddy N, Dinapadu S, Reddy M, Pasari S. Role of Ozone Therapy in Minimal Intervention Dentistry and Endodontics - A Review. J Int Oral Health 2013; 5(3):102-108.

A rare presentation of bilateral maxillary dens invaginatus diagnosed using cone beam computed tomography.

Dens invaginatus is a developmental variation in the formation of a tooth that causes changes in the internal anatomy of the tooth. The presence of double dens invaginatus is extremely rare. Understanding the type, extension, and complex morphology of dens invaginatus is essential. Diagnosis of this condition using conventional radiographic techniques is not easy. Advanced imaging techniques, such as cone beam computed tomography (CBCT) are very helpful in diagnosis of these complex anatomic variations. In the present case report, we demonstrate the use of CBCT in the evaluation and treatment planning of bilateral maxillary dens invaginatus, of which one presented as a case of double dens.

Maxillary molar with two palatal roots: Two case reports.

An awareness and understanding of the presence of an additional root and unusual root canal morphology is essential as it determines the successful outcome of endodontic treatment. Aberrations in root canal anatomy are commonly occurring phenomena. A thorough knowledge of basic root canal anatomy and its variation is necessary for successful completion of endodontic treatment. This report points to the importance of looking for additional roots and canals because knowledge of their existence would enable clinician to treat a case successfully that otherwise might end in failure.