Comparison of Cleaning Efficacy and Instrumentation Time in Primary Molars: Mtwo Rotary Instruments vs. Hand K-Files

Introduction: Pulpectomy is the preferred treatment for restorable primary teeth with symptomatic irreversible pulpitis or periradicular lesion. Considering the rather new application of rotary files for pulpectomy of primary teeth, the aim of this study was to compare the cleaning efficacy and instrumentation time of hand K-files and Mtwo rotary system for preparation of human primary molars. Methods and Materials: This experimental study was conducted on 100 extracted primary maxillary and mandibular intact molars with no resorption. Access cavities were prepared and India ink was injected into the root canal on a vibrator using an insulin syringe. Canals were then divided into 5 groups (n=20): in group I, canals were instrumented using K-files up to #25 for mesial and buccal canals and #30 for palatal and distal canals. In group II, canals were prepared using Mtwo rotary files (15/0.05, 20/0.06 and 25/0.06 for mesial and buccal canals and 15/0.05, 20/0.06, 25/0.06 and finally 30/0.05 for distal and palatal canals). In group III, root canals were only irrigated with saline. Groups IV and V were the positive and negative control groups, respectively. The time required for cleaning and preparation of the canals for each of the specimens in groups I, II and III was recorded. Results: The mean score of cleanliness of Mtwo was not significantly different from K-file group (P>0.05). However the mean instrumentation time in Mtwo group was significantly shorter (P<0.001). Conclusion: Although there were no differences regarding the cleaning efficacy of either system, Mtwo rotary files were far more time efficient.Keywords: Deciduous Tooth; Hand K-files; Mtwo; Primary Molars; Pulpectomy; Root Canal Preparation; Root Canal Therap

Comparison of Apical Transportation with the Use of Rotary System and Reciprocating Handpiece with Precurved Hand Files: An In Vitro Study

Introduction: Success of root canal treatment depends on several factors; among which, maintaining the original canal path during mechanical preparation is extremely important. This in vitro study aimed to compare apical transportation using RaCe NiTi rotary system and precurved stainless steel (SS) hand files in a reciprocating handpiece. Methods and Materials: Mesiobuccal canals of 40 extracted human mandibular first and second molars with 20 to 45° curvatures and 3 to 7 mm curve radius were chosen for this study. After working length determination, the teeth were divided into two groups (n=20). Root canals were prepared with RaCe in group 1 and NSK handpiece and precurved SS hand files in group 2 up to #30 with 2% taper in both groups. Radiographs were taken of teeth before and after instrumentation from buccolingual and mesiodistal directions. The images were superimposed using Adobe Photoshop CS3 software. Degree of straightening and amount of apical transportation at 0, 0.5, 1, 2, 3, 4 and 5 mm levels short of the working length were determined using digital subtraction radiography. The student’s t test was used to compare the degree of straightening and Mann Whitney test was applied to compare apical transportation (millimeters) between the two groups. Results: No significant difference was noted between the two groups on buccolingual or mesiodistal views in degree of straightening and apical transportation on buccolingual view (P>0.05). However, on mesiodistal view, NSK reciprocating handpiece caused greater apical transportation at 0. 0.5 and 1 mm levels (P<0.05). Conclusion: The RaCe system and precurved SS files in reciprocating handpiece were highly similar in terms of degree of straightening and apical transportation. Thus, engine-driven NSK reciprocating handpiece can be used as an efficient adjunct for root canal preparation.Keywords: Canal Transportation; RaCe Instruments; Reciprocating Handpiec

The Effect of BC Sealer, AH-Plus and Dorifill on Push-out Bond Strength of Fiber Post

Introduction: Dentinal canal walls are in direct contact with endodontic sealers prior to post space preparation and luting cements after post space preparation. This direct contact may affect the bond strength of intraradicular posts to root dentin. This study aimed to assess the effect of three different sealers on the bond strength of fiber posts to root dentin. Methods and Materials: The canals of 56 extracted single-rooted human premolars after selection and decoronation were prepared. For obturation of the canals, specimens were randomly divided into four groups (n=14) according to the type of sealer used in conjunction with gutta-percha: group 1 (control) without any sealer; group 2 with AH-Plus sealer (resin based); group 3 with Dorifill sealer (ZOE-based); and group 4 with BC Sealer (calcium silicate-based). Nine mm-deep post space was prepared in the canal of each specimen. Intraradicular fiber posts were cemented using dual-cure resin cement (Panavia F2.0). Sections of 1 mm thickness were made at the coronal, middle and apical thirds of the post space of each specimen. The push-out bond strength of post to root dentin was measured in a universal testing machine. The data were analyzed using one-way ANOVA and post-hoc Tukey’s test. Results: The mean push-out bond strength in the coronal third was significantly lower in Dorifill group compared to AH-Plus (P=0.004). This value was significantly lower in BC Sealer group than AH-Plus (P=0.000) and control group (P=0.03). In middle and apical thirds, the mean push-out bond strength was not significantly different among the four groups (P=0.407, P=0.065, respectively). The mean push-out bond strength was significantly lower in apical than coronal third in AH-Plus group (P=0.001). Conclusion: Application of BC Sealer and Dorifill decreased the mean push-out bond strength of intracanal post to root dentin in the coronal third in comparison to AH-Plus.Keywords: Bond Strength; Endodontic Sealer; Fiber Post; Resin Cemen

Dentists’ attitude and perceived educational barriers to oral health promotion among patients with disabilities

BACKGROUND AND AIM: Individuals with disability usually suffer from complex oral problems and marked physical limitations, and therefore need special dental care. The dentists’ attitude and perceived educational barriers for oral health promotion among the individuals with disabilities were evaluated in the present study. METHODS: In this cross-sectional study, 193 dentists participating in the 54th International Congress and Exhibition of Iranian Dental Association in 2014 were invited to complete a valid and reliable questionnaire. The questionnaire included questions on attitude, satisfaction with training courses, perceived barriers to learn about oral health of patients with disabilities, age, gender, office location (city), and experience of treating patients with disabilities. The results were analyzed in SPSS software using linear regression analysis. RESULTS: A total of 177 questionnaires were collected. The mean age of the participants was 35.5 (10.1) years, and 53.8% of the participants were men. The mean score of attitude and perceived barriers was 27 out of 52, and 13.6 out of 24, respectively. Dentists were not satisfied with education they had received. The most important barrier was the shortage of experts for training (52.1%). The linear regression model controlling the confounders revealed a better attitude among dentists with higher satisfaction with their academic education and among those perceiving less barriers in receiving the related academic educations. CONCLUSION: The dentists’ attitude towards the oral health promotion of patients with disabilities was not in a desirable level. The dentists satisfied with their training during academic education had a better attitude towards treating these patients, indicating the need for more extensive interactive training programs. KEYWORDS: Dentistry for Disabled; Attitude; Barrier; Dentist; Oral Healt

Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Nano-filled Composites

Objectives: The purpose of this study was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite. Materials and Methods: Sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. In group I, a conventional orthodontic composite (Transbond XT) was used to bond the brackets, while two nano-composites (Filtek TM Supreme XT and AELITE Aesthetic Enamel) were used in groups II and III respectively. The teeth were stored in distilled water at 37°C for 24 hours, thermocycled in distilled water and debonded with a universal testing machine at a crosshead speed of 1 mm/min. The adhesive remnant index (ARI) was also evaluated using a stereomicroscope. Results: AELITE Aesthetic Enamel nano-composite revealed a SBS value of 8.44±2.09 MPa, which was higher than Transbond XT (6.91± 2.13) and Filtek TM Supreme XT (6.04± 2.01). Statistical analysis revealed a significant difference between groups II and III (P < 0.05). No significant difference was found between groups I and III, and between groups I and II (P > 0.05). Evaluation of ARI showed that Transbond XT left fewer adhesive remains on teeth after debonding. Conclusion: Results of this study indicate that the aforementioned nano-composites can be successfully used for bonding orthodontic brackets

Effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin.

This study aimed to assess the effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin.Sixty-eight single-rooted single-canal extracted human premolar teeth were used. Tooth crowns were separated from the roots at the cementoenamel junction (CEJ). Roots were buccolingually sectioned into mesial and distal halves. Specimens were randomly divided into 5 groups, with 20 teeth in each solvent group and 4 teeth in each control group. Primary microhardness of specimens was measured using Vickers microhardness tester. Specimens were exposed to solvents for 15 minutes and were subjected to microhardness testing again. Data were recorded and analyzed using repeated measure ANOVA.No significant difference was found in dentin microhardness before and after exposure to solvents in any of the orange oil, eucalyptol, chloroform or saline groups (P=0.727). None of the experimental groups showed any significant difference in terms of dentin microhardness reduction (P=0.99) and had no significant difference with the negative control group.This study showed that chloroform, eucalyptol and orange oil as gutta percha solvents did not decrease the microhardness of root dentin. Thus, none of the mentioned solvents has any superiority over the others in terms of affecting dentin properties

Treatment of Symptomatic Geographic Tongue with Triamcinolone Acetonide Alone and in Combination with Retinoic Acid: A Randomized Clinical Trial

Objectives: Geographic tongue or migratory glossitis is an inflammatory disorder with unknown etiology. Considering the accompanied burning pain, taste dysfunction, and lack of definite cure, it is important to treat this condition symptomatically. The objective of the current study was to compare the efficacy of a combination of 0.05% retinoic acid and 0.1% triamcinolone acetonide with that of triamcinolone acetonide alone for treatment of symptomatic geographic tongue. Materials and Methods: This randomized controlled double-blind clinical trial was performed on 28 patients with symptomatic geographic tongue, who were referred to two dental clinics. Participants were randomly divided into two groups and treated with triamcinolone alone or retinoic acid plus triamcinolone for 10 days. Patients were assessed for the level of pain, burning sensation and size of lesion at the beginning and at the end of the study. Participants were followed up for two months after cessation of treatment (at the end of each month). SPSS 11 was applied to compare the two therapeutic modalities. Results: Twenty-eight participants with a mean age of 40 years were evaluated including Seven (25%) males and 21(75%) females. There was a positive family history of geographic tongue in 21 patients. Despite the diminished pain and burning sensation as well as smaller size of lesions following treatment (P 0.05). No side effect was reported.  Conclusion: The combination of triamcinolone and retinoic acid was not more effective than triamcinolone alone for symptomatic treatment of geographic tongue

Longevity of Amalgam Build-Up Restorations in Endodontically Treated Teeth

Background and Aim: Restoration of endodontically treated teeth is one of the most important and challenging topics in restorative dentistry. Longevity of such restorations is an essential factor in treatment planning. Amalgam build-up is a conservative method for restoration of endodontically treated teeth. Therefore, this study aimed to assess the longevity of this type of restoration in endodontically treated molar teeth. Materials and Methods: In this retrospective study, 110 endodontically treated molar teeth of 98 patients that had received amalgam build-up restorations with at least one cusp coverage with 3-10 years of longevity were evaluated. The restorations included mesio-occluso-distal (MOD;40%), disto-occlusal (DO;23%), mesio-occlusal (MO;17%) and complex amalgam restorations (20%). Binary logistic regression and Kaplan-Meier tests were used for statistical analysis. Results: Of all restorations, cracks were observed in 22.7% of restorative materials and 10.9% of teeth. Secondary caries was found in 29% of the teeth. Based on binary lo-gistic regression, MOD restorations had significantly higher rate of marginal fracture and recurrent caries (P<0.05). Teeth with one or four built-up cusps were significantly more resistant to fracture compared to other groups. Patients, who regularly used dental floss had significantly lower rate of secondary caries and restoration fracture (P=0.032). Conclusion: The average longevity of amalgam build-up restorations was 8.45 years, which is comparable to minimum longevity of casting restorations. Thus, amalgam restorations seem to be an acceptable conservative method for restoration of endodontically treated teeth

Effect of acidic environment on the push-out bond strength of mineral trioxide aggregate

INTRODUCTION: Reduced surface microhardness and decreased sealing ability have been shown after the placement of mineral trioxide aggregate (MTA) in an acidic environment. In this study, the effect of an acidic environment on the push-out strength of MTA was evaluated. METHODS: Eighty root dentin slices from freshly extracted single-rooted human teeth were sectioned and their lumen instrumented to achieve a diameter of 1.3 mm. One gram of tooth-colored ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN) was mixed with 0.33 g of distilled water and introduced into the canals of the root-dentin slices and treated with ultrasonic energy. The specimens were then randomly divided into four groups (n = 20) and wrapped in pieces of gauze soaked in phosphate buffer saline solution (pH = 7.4) and butyric acid buffered at pH values of 4.4, 5.4, or 6.4, respectively. They were then incubated for 4 days at 37 degrees C. The push-out bond strengths were then measured using a universal testing machine. The slices were examined under a light microscope at x40 magnification to determine the nature of the bond failure. The data were analyzed using one-way analysis of variance and the Tamhane post hoc test. RESULTS: The greatest mean push-out bond strength (7.28 +/- 2.28 MPa) was observed after exposure to a pH value of 7.4. The values decreased to 2.47 +/- 0.61 MPa after exposure to a pH value of 4.4. There were significant differences between the groups (p < 0.001). Inspection of the samples revealed the bond failure to be predominantly adhesive. CONCLUSION: The force needed for displacement of MTA was significantly lower in samples stored at lower pH values. Copyright (c) 2010 American Association of Endodontists. All rights reserved

Evaluation of Salivary Leptin Levels in Healthy Subjects and Patients with Advanced Periodontitis

Objectives: Leptin is a hormone-like protein produced by the adipose tissue. It plays an important role in protection of host against inflammation and infection. Some studies have reported changes in leptin levels in the gingival crevicular fluid (GCF), saliva and blood serum of patients with periodontal disease compared to healthy individuals. The aim of the present study was to compare the salivary leptin levels in patients with advanced periodontitis and healthy individuals. Materials and Methods: In this case-control study, the salivary samples of healthy individuals and patients with advanced periodontitis with clinical attachment loss >5mm were obtained using a standardized method and the leptin levels were measured in the salivary samples by means of ELISA. The effects of the periodontal status and sex on the salivary leptin levels of both groups were statistically analyzed by two-way ANOVA. Results: The means ± standard deviation (SD) of salivary leptin levels in healthy subjects and patients with advanced periodontitis were 34.27±6.88 and 17.87±5.89 pg/mL, respectively. Statistical analysis showed that the effect of sex on the salivary leptin levels was not significant (P=0.91), while the effect of advanced periodontitis on the salivary leptin levels was significant compared to healthy individuals (P<0.0001). Conclusions: In patients with advanced periodontitis, the salivary leptin levels were significantly lower compared to healthy individuals. Thus, assessment of salivary leptin can be done as a non-invasive and simple method to determine the susceptibility of patients to advanced periodontitis