Teeth with Apical Periodontitis Obturated in the Presence or Absence of Cultivable Micro-Organisms: a Two-Year Prospective Study of Treatment Outcomes

Objective: This prospective study aims to evaluate the one-year and two-year outcomes of root canals with apical periodontitis obturated in the presence or absence of cultivable micro-organisms, and define the influence on endodontic treatment outcome from different independent variables. Methods: 87 patients with 45 exposed and 43 unexposed canals who previously participated in a microbiological study of primary endodontic infections were invited back for review in 12 and 24 months after endodontic treatment. The review involves clinical examination, questionnaire interview and radiographic assessment in order to determine the treatment outcomes. The influence of independent variables, such as gender, age, tooth location, etc., on the treatment outcome, has also been analysed. Results: A total of 85 teeth of 84 patients were reviewed one and two years after obturation. Chi-square test for trend showed that the one-year radiographic healing of apical lesions was significantly different between culture-positive and negative canals (P<0.05). However, there is no significant difference in the two-year radiographic healing between the two groups of canals (P>0.05). None of the independent variables was found to be significant in affecting the endodontic treatment outcome on logistic regression analysis. Conclusions: The presence of positive culture prior to obturation seemed to affect the healing of periapical tissues in a one-year review, but the effect appeared to be temporal and not affected the long-term outcome.

Determine the Applicability of Moyers Analysis in the Contemporary Western Australian Adolescent Population

Background: Moyers probability tables have been widely used to determine the mesiodistal dimensions of unerupted canines and premolars for mixed dentition space analysis. Secular, racial, and sexual dimorphism have been reported in the literature and applicability of Moyer analysis has been doubted in many other populations. Objective: The present study was conducted to determine the applicability of Moyers probability tables and develop a more accurate prediction method in a contemporary Western Australian adolescent population if needed. Methods: A retrospective study including 500 participants [323 females, 177 males] between 13-18 years old attending the orthodontic private practice was conducted. Mesiodistal dimensions of selected participants were obtained from pre-orthodontic treatment digital dental records using Invisalign® technology [ Invisalign®, Align Tech¬nology, Santa Clara, CA, USA] Data were analysed using SPSS. New regression equations were derived based on the sum of permanent mandibular incisors, and probability tables were proposed for more accurate prediction. Results: Significant differences were found between the measured sum of permanent canine-premolar segments and those predicted with the Moyers probability table, at all percentile levels, except the 50th percentile, where no significant difference was observed. Conclusion: Moyers probability table can be applied at the 50th percentile for estimation of sum of mesiodistal dimensions of canine-premolars segments. Newly developed regression equations and tables could be considered to provide more accurate mixed dentition space analysis.

Readability of Online Patient Education Materials for Dental Radiology

Conclusion: None of the webpages fulfilled the recommendations from the National Institute of Health and the American Medical Association of being written below a seventh-grade level. More online patient education materials for dental radiology were recommended, and they should be written in a more easily understood way.

The Top 102 Most Cited Publications Relevant to Dental Education

Background: Growth and development in dental education globally depend on effective experience sharing and advocation of evidence-based practice, preferably tested via vigorous peer evaluation. Objective: This study aimed to evaluate the most cited dental education publications. The objectives were to identify the most productive entities, and the most frequently investigated themes and specialties. Results: The top publications included 83 original articles, 15 reviews, 3 books, and 1 online document, written by 30 different authors, with 38 publications from dental journals not dedicated to education, and with an average of 5.5 citations per year. The most productive author was William Hendrickson. The most productive institutions were from Europe and the United States. There were 11 papers focused on operative dentistry, 9 on endodontology, 4 on special care dentistry, 2 on community dentistry, 2 on periodontology, and 2 on implantology. Within the top 102 list, 21 publications focused on the stress experienced by dental students at school. A multiple ANCOVA indicates that citation counts in these highly cited publications are associated with a number of authors and document types, such as “reviews/books/online document” compared with original articles (p < 0.001). Conclusion: Influential dental education studies were published on a variety of platforms. Over the past 20 years, the field witnessed the emergence of highly cited reports/articles. Similar to influential papers in various fields, the number of authors per top-cited dental education publications appeared to be associated with high citations indicating top quality and high appreciation/acceptance of the articles involved.

Anterior Labial Alveolar Bone Thickness After Orthodontic Retraction Of Anterior Teeth

Introduction: Correction of skeletal Class II malocclusion generally requires extraction of the premolars, followed by the retraction of the anterior teeth to reduce overjet. Morphometric evaluation of alveolar bone can be used to study the limitation of tooth movement to avoid adverse effects. The purpose of this study is to measure the changes in the bone thickness of the maxillary incisors in skeletal Class II malocclusion patients after retraction and determine the relationship between changes in bone thickness and the amount of retractions using lateral cephalometric radiographs. Materials and methods: The design of this study was to determine the cross-sectional changes in bone thickness in linear directions after retraction and the relationship between changes in bone thickness and the amount of retraction. Bone thickness in the linear directions was measured using digital cephalometric radiographs. Results: The measurement results from tracing 43 lateral cephalometric before and after anterior retraction treatment showed that there was a difference in alveolar bone thickness at the 9mm level from the CEJ in a linear direction on the anterior retraction of skeletal Class II malocclusion maxillary incisors (p <0.05), however, there was no difference in alveolar bone thickness at levels 3 and 6 mm from CEJ in the linear direction, and the angular direction (p> 0.05). Changes in alveolar bone thickness did not correlate with the amount of incisor retraction (p> 0.05). Conclusion: The results showed that the change in labial alveolar bone thickness was not significantly correlated to the amount of retraction.

Skull and Face Injuries and Associated Factors in Pedestrian Victims of Traffic Accidents: A Single Trauma Center Analysis

Objective: This study aimed to analyze the presence of lesions in the skull and face and the associated factors in pedestrian victims of traffic accidents. Methods: A cross-sectional, descriptive-analytical study carried out through the analysis of medical records of pedestrian victims of traffic accidents in an emergency service in the city of Campina Grande, Brazil, during the year of 2016. Information was collected regarding gender, age group, day of the week, time of the accident, type of vehicle involved, presence of trauma to the skull and face, and outcomes. The Chi-square and Fisher's Exact tests were used, with a significance level of 5%. Results: A total of 1,884 medical records were evaluated, out of which 7.1% (n = 133) involved pedestrians. Men were the most frequent victims (68.4%), and victims of age 60 years old or over (30.5%) predominated. Almost one-third of the cases were recorded during the weekends (30.5%), and the most prevalent time was at night (52.7%). Regarding the type of vehicle involved, motorcycles predominated (47.4%). Head trauma was present in 37.6% of victims, while facial injuries corresponded to 8.2%. In 12% of cases, the victims died. The variables of gender, age group, occurrence on weekends, and trauma to the face showed a statistically significant association with the occurrence of traffic accidents (Chi-square test; p<0.05). Conclusion: Among pedestrian victims of traffic accidents, there is a predominance of men aged 65 years or over. Accidents are frequent at night, and motorcycles are the main vehicles involved. The presence of trauma to the skull and face regions is high.

Success Rate of Obturation of Root Canals by Different Techniques in Primary Molars: A Comparative Clinical Study

Objective: To compare the success rate of different obturation procedures in primary mandibular second molars clinically and also by digital radiovisiography. Methods: A total of 40 children aged between 4-8 years with deeply carious mandibular second primary molars indicated for single session pulpectomy were selected. Canals were obturated with Metapex. The 3 study groups (Endodontic plugger, Handheld lentulospiral, Navi Tip syringe) were compared with the control group (reamer) both clinically and radiovisiographically. The data collected were statistically analyzed using Pearson’s Chi-square and Fisher’s exact test. Results: The use of Navi tip syringe led to the least number of voids followed by Endodontic plugger and Reamer and the highest number of voids was reported with Lentulospiral. Navitip presented maximum number of optimally filled cases followed by Endodontic plugger and Lentulospiral and least number of optimally filled cases with reamer. However, there was no statistically significant difference (p>0.05) in any of the groups with clinical (pain and tenderness to percussion) and radiographic parameters (presence or absence of voids and length of obturation). Conclusion: Within the limitations of the present study, though the clinical outcome was statistically insignificant, Navitip syringe exhibited encouraging results and is a promising option for obturation in primary teeth.

Factors Affecting the Wear Behavior of Monolithic Zirconia and the Antagonists: Literature Review

Background: The use of zirconia-based ceramics to produce monolithic restorations has increased due to improvements in the optical properties of the materials. Traditionally, zirconiabased ceramics were veneered with porcelain or glass-ceramic and were not directly exposed to the oral environment. Therefore, there are several doubts regarding the wear of the monolithic zirconia restoration and their antagonists. Additionally, different surface treatments are recommended to promote a smooth surface, including glaze and several polishing protocols. To support the correct clinical application, it is important to understand the advantages and limitations of each surface treatment. Objective: The aim of this short literature review is to investigate the factors that may affect the wear of monolithic zirconia restorations in service and their antagonists. Methods: Pubmed/Medline database was accessed to review the literature from a 10-year period using the keywords: zirconia, monolithic, prosthesis, wear. Both clinical and in vitro studies were included in the review. Results: Studies investigated the effect of several surface treatments, including grinding with diamond- burs, polishing and glazing, on the surface roughness, phase transformation and wear capacity of monolithic zirconia. The wear behavior of monolithic zirconia was frequently compared to the wear behavior of other ceramics, such as feldspathic porcelain, lithium disilicate-based glassceramic and leucite-reinforced glass-ceramic. Human tooth, ceramics and resin composites were used as antagonist in the investigations. Only short-term clinical studies are available (up to 2 years). Conclusion: Literature findings suggest that zirconia monolithic restorations are wear resistant and unlikely to cause excessive wear to the antagonist, especially when compared to feldspathic porcelain and glass-ceramics. Monolithic zirconia should be polished rather than glazed. Yet, none of the polishing systems studied was able to completely restore the initial surface conditions of zirconia after being adjusted with burs. More clinical evidence of the antagonist tooth wear potential of monolithic zirconia is needed.

Effect of Filler Content and Waiting time Before Light-Curing on Mechanical Properties of Dual-Cured Cement

Objective:: To investigate the effect of filler content and the time spent before light-curing on mechanical properties of dual-cured cement. Methods:: Experimental dual-cured resin cements were formulated with 60, 65 or 68wt% of filler. The viscosity of experimental cement was measured using a digital viscometer. Bar-shaped specimens (25 x 2 x 2 mm) were fabricated, while the light-curing was started immediately or 5 minutes after the insertion of cement into the mold (n = 7). A three-point bending test was performed and the values of flexural strength and elastic modulus were measured. The Vickers hardness of fractured specimens was measured on the surface of the cement. Data from viscosity were submitted to oneway ANOVA, while the data from mechanical properties were analyzed by two-way ANOVA. All pair-wise comparisons were performed using Tukey’s test (α = 0.05). Results:: The experimental cement with 68wt% of filler showed the highest viscosity and those with 60wt% showed the the lowest viscosity. Irrespective of the time spent before light-curing, the cement with 65wt% of filler presented the highest values of flexural strength and elastic modulus. The addition of 60wt% of filler resulted in the lowest elastic modulus, while 68wt% of filler resulted in lowest flexural strength. Regarding the hardness, the cement with 68wt% of filler showed the highest values, while there was no difference between 60 and 65wt% of filler. Conclusion:: Filler content affected the mechanical properties of the experimental cement and this effect did not depend on the waiting time before the light-curing procedure.

Development and Characterization of Triple Action-Dental Mold

Aim: The aim of the present study was the preparation and in vitro evaluation of polymeric molds with amoxicillin trihydrate, lidocaine hydrochloride, and metronidazole for sustained drug release for prolonged local action on an affected tooth (during carries and gum problems). Background : Periodontal diseases with infection and inflammation cause dental pain. For the treatment of dental problems such as dental pain, analgesics with antibiotics are prescribed at the initial stage. Objective: The main objective of the present study was to develop polymer-based dental mold containing three drugs (amoxicillin trihydrate, lidocaine hydrochloride, and metronidazole) to provide local drug action on the affected tooth or gingiva for a prolonged period of time. Methods: Dental molds were prepared with drugs and the optimum combination of polymers (determined by initial screening) such as corn zein, carbopol 934 P, gum acacia powder and poloxamer 407 by mixing together in ethanol (95%) followed by solvent evaporation. The developed dental molds were evaluated using different in vitro physio-chemical methods such as tooth adhesion test, percent swelling, surface pH, scanning electron microscopy, drug content and drug-release study by simultaneous UV spectroscopy. Results: The mean adhesive strength obtained in our formulation was 46.5 g-wt with a surface pH value of 6.5. The percentage of swelling of the dental molds varied from 43% to 73% in 4 h. Scanning electron microscopy (SEM) showed very small and uniformly distributed drug particles in the matrix. Drug loading was high and reproducible. The cumulative percentage release of lidocaine hydrochloride, amoxicillin trihydrate and metronidazole in vitro was about 93.81%, 59.67%, and 48.7%, respectively, over 24 h. Conclusion: The developed dental mold containing three drugs may be applied to the affected tooth for prolonged drug action locally and an easy option to relieve from dental pain and infection by local drug action.