Hypochlorous acid inactivates oral pathogens and a SARS-CoV-2-surrogate.

BACKGROUND: Droplets and aerosols produced during dental procedures are a risk factor for microbial and viral transmission. Unlike sodium hypochlorite, hypochlorous acid (HOCl) is nontoxic to tissues but still exhibits broad microbicidal effect. HOCl solution may be applicable as a supplement to water and/or mouthwash. This study aims to evaluate the effectiveness of HOCl solution on common human oral pathogens and a SARS-CoV-2 surrogate MHV A59 virus, considering the dental practice environment. METHODS: HOCl was generated by electrolysis of 3% hydrochloric acid. The effect of HOCl on human oral pathogens, Fusobacterium nucleatum, Prevotella intermedia, Streptococcus intermedius, Parvimonas micra, and MHV A59 virus was studied from four perspectives: concentration; volume; presence of saliva; and storage. HOCl solution in different conditions was utilized in bactericidal and virucidal assays, and the minimum inhibitory volume ratio that is required to completely inhibit the pathogens was determined. RESULTS: In the absence of saliva, the minimum inhibitory volume ratio of freshly prepared HOCl solution (45-60 ppm) was 4:1 for bacterial suspensions and 6:1 for viral suspensions. The presence of saliva increased the minimum inhibitory volume ratio to 8:1 and 7:1 for bacteria and viruses, respectively. Applying a higher concentration of HOCl solution (220 or 330 ppm) did not lead to a significant decrease in the minimum inhibitory volume ratio against S. intermedius and P. micra. The minimum inhibitory volume ratio increases in applications of HOCl solution via the dental unit water line. One week of storage of HOCl solution degraded HOCl and increased the minimum growth inhibition volume ratio. CONCLUSIONS: HOCl solution (45-60 ppm) is still effective against oral pathogens and SAR-CoV-2 surrogate viruses even in the presence of saliva and after passing through the dental unit water line. This study indicates that the HOCl solution can be used as therapeutic water or mouthwash and may ultimately reduce the risk of airborne infection in dental practice.

Awareness and attitude toward using dental magnification among dental students and residents at King Abdulaziz University, Faculty of Dentistry.

BACKGROUND: The authors conducted a study aimed to assess the awareness and attitude among dental students and residents at King Abdulaziz University, Faculty of Dentistry (KAUFD) toward using dental magnification. METHODS: An e-questionnaire was formulated then sent to dental students and residents (n = 651). The questionnaire included questions that assessed both the awareness and attitude toward using dental magnification. Data were analyzed using IBM SPSS version 22. The chi-square test was used to establish relationships between categorical variables. RESULTS: The response rate was 69.7 % (n = 454). Of those, 78.1 % did not use magnification during dental procedures. However, 81.8 % agreed that dental magnification could enhance the accuracy and quality of their dental work. Thus, 91.6 % thought it would be useful in endodontics and 46.3 % voted for surgery. Of the 21.9 % that used magnification, dental loupes were mostly used, 55.9 %. The majority (59.4 %) of the participants believed that using dental magnification should be introduced by faculty beginning in Year I of dental school. CONCLUSIONS: Among our respondents, most of the undergraduate students did not use dental magnification nor attended courses in the use of dental magnifications. However, most of the students were aware of its significance in improving the accuracy and quality of their work.

The effect of post type and length on the fracture resistance of endodontically treated teeth.

STATEMENT OF PROBLEM: Few studies have been conducted to determine a correlation between the flexural modulus of metal and fiber-reinforced posts and the fracture resistance and failure mode of teeth restored with posts. Questions remain as to whether a longer post length or a post with a higher flexural modulus will significantly improve the fracture resistance of a tooth restored with a prefabricated post and core. PURPOSE: The purpose of this study was to compare the fracture resistance and mode of failure of endodontically treated teeth restored with 3 different post systems, including 2 fiber-reinforced posts (Light-Post and Snowlight) and a stainless steel post (ParaPost XP). MATERIAL AND METHODS: Seventy single-rooted premolars were sectioned at the cemento-enamel junction and then endodontically treated. Teeth were distributed into 7 groups. Three different prefabricated posts were cemented into a post space either 5 or 10 mm in depth, and composite resin (ParaPost ParaCore automix) cores were fabricated. A composite resin core group without a post served as a negative control. Specimens were loaded at 90 degrees to the longitudinal axis until ultimate failure occurred. An initial failure load and mode of failure were also recorded. Statistical analysis was performed for initial and ultimate failure loads of groups by using 2-way ANOVA (P=.05). RESULTS: The groups with ParaPost XP posts demonstrated significantly higher initial and ultimate mean failure loads when compared with the fiber-reinforced post groups. The highest mean (SD) initial failure load was with the ParaPost XP group with a 10-mm post length (170.05 (60.08) N), and the lowest was with the Snowlight group with the 5-mm post length (62.85 (18.47) N). CONCLUSIONS: The stiffness and the load to initial fracture of the teeth restored with ParaPost XP posts were higher compared with the fiber-reinforced post groups.

Radicular Groove Accessory Canal Morphology in Mandibular First Premolars: Micro-computed Tomographic Study.

INTRODUCTION: The purpose of this study was to investigate the morphologic features of radicular groove accessory canals (RGACs) in mandibular first premolars and their relationship to root anatomy by micro-computed tomographic imaging. METHODS: A total of 154 single-rooted mandibular first premolars with radicular grooves were selected. The teeth were scanned by micro-computed tomographic imaging, and the following parameters were recorded: (1) the presence of RGACs, (2) the origin of RGACs, (3) the position of the RGAC foramen in the groove in relation to root length, (4) the foramen diameter, (5) the type of groove present according to the Arizona State University dental anthropology scoring system (ASUDAS), and (6) the type of anatomy present according to Vertucci's classification. The data were recorded and statistically analyzed using the chi-square test (P < .05). RESULTS: The incidence of RGACs in the teeth was 49.9%. The average distance from the cementoenamel junction plane to the RGAC foramen was 8.83 ± 2.53 mm, and the majority of the RGAC foramina were located in the middle third. Regarding the severity of the groove, the presence of RGACs was significantly higher for groups ASUDAS 3 and 4 compared with ASUDAS 1 and 2 (85.7% and 14.3%, respectively). The presence of at least 1 RGAC was greatest for Vertucci type V (46%) and for more complex types (46%) when compared with Vertucci types I and III. CONCLUSIONS: Mandibular first premolars with radicular grooves often present with RGACs. An association between the internal and external anatomy and the presence of RGACs was detected in this study.

Endodontics Program Directors', Residents', and Endodontists' Considerations About CBCT-Related Graduate Education.

Over the past decade, cone beam computed tomography (CBCT) has been increasingly used by endodontists. The aims of this study were to assess endodontic program directors', residents', and endodontists' considerations concerning CBCT-related graduate education, attitudes, and professional behavior. Survey data were collected from 31 of the 56 directors of U.S. endodontic graduate programs, 73 of 270 contacted residents, and 689 of 2,221 contacted endodontists (response rates 55%, 27%, and 31%, respectively). Ten of the 31 responding programs did not offer a CBCT-related class. Of the 21 programs that offered a CBCT class, 91% of the program directors and 85% of the residents agreed strongly that future endodontists need training to be able to use CBCT. Residents were less satisfied than directors with the way CBCT was taught (on a five-point scale with 1=most negative: 3.26 vs. 4.37; p<0.001) and the quality of their clinical CBCT-related education (3.75 vs. 4.62; p<0.001). Both groups strongly agreed that there is a need for CBCT training in endodontics (4.81 vs. 4.90). Endodontists reported being less well educated than residents about CBCT in classroom-based (2.02 vs. 2.70; p<0.001) and clinical graduate education settings (2.09 vs. 2.97; p<0.001) and wanted more CBCT-related education in endodontic programs (4.37 vs. 3.18; p<0.001). Yet, they reported being more confident than residents in interpreting CBCT scans (3.57 vs. 2.75; p<0.001) and rated themselves more positively as having sufficient clinical experience (3.76 vs. 2.92; p<0.001) to be competent in utilizing CBCT. These findings about residents' and practicing endodontists' CBCT-related considerations suggest that endodontic program directors should add more CBCT-related education.

Endodontists' Intravenous Sedation-related Attitudes and Professional Behavior: A National Survey.

INTRODUCTION: Research shows that a high percentage of endodontic patients are interested in receiving intravenous (IV) sedation. The objectives of this study were to assess endodontists' IV sedation-related education, attitudes, and professional behavior and to explore whether providing versus not offering IV sedation procedures was associated with IV-related education and attitudes and whether background characteristics and education were related with IV sedation attitudes and behavior. METHODS: Data were collected with an anonymous Web-based survey from 616 members of the American Association of Endodontists (response rate = 29%). RESULTS: Only 10% of respondents agreed/strongly agreed that they had adequate training in IV sedation. However, 48% agreed/strongly agreed that there was a need for IV sedation in their practice. Although 69% did not offer IV sedation, 26% had another professional provide it, and 4% provided it themselves. These 3 groups of providers differed in the mean quality of their IV sedation-related education (scale from 1-5 with 5 = best education: 1.50 vs 1.62/2.37, P < .001) and the positivity of their attitudes toward IV sedation (2.90 vs 3.50/4.21, P < .001). Although the quality of IV sedation education was not correlated with the graduation year, the more recently respondents had graduated, the more positive they were toward providing education about IV sedation (r = .16, P < .001). CONCLUSIONS: Most endodontists did not evaluate their IV sedation-related graduate education positively. However, nearly half acknowledged the need for IV sedation in endodontics. The more recently they graduated, the more they agreed that IV sedation-related graduate education was needed but also that staff training and maintenance of equipment would be a problem.

Efficacy of Articaine versus Lidocaine in Supplemental Infiltration for Mandibular First versus Second Molars with Irreversible Pulpitis: A Prospective, Randomized, Double-blind Clinical Trial.

INTRODUCTION: Profound pulpal anesthesia is difficult to achieve in mandibular molars with irreversible pulpitis (IP). However, there are no published randomized controlled clinical trials comparing the success of supplemental buccal infiltration (BI) in mandibular first versus second molars with IP. The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental BIs in mandibular first versus second molars with IP after a failed inferior alveolar nerve block (IANB). This study's sample was combined with data from a previous trial. METHODS: One hundred ninety-nine emergency subjects diagnosed with IP of a mandibular molar were selected and received an IANB with 4% articaine. Subjects who failed to achieve profound pulpal anesthesia, determined by a positive response to cold or pain upon access, randomly received 4% articaine or 2% lidocaine as a supplemental BI. Endodontic access was begun 5 minutes after infiltration. Success was defined as less than mild pain during endodontic access and instrumentation on the Heft-Parker visual analog scale. RESULTS: There was a 25% IANB success rate with 4% articaine. The success rate for articaine supplemental BI in first molars was 61% versus 63% for second molars (P > .05). The success of lidocaine in first molars was 66%, but for second molars it was 32% (P = .004). CONCLUSIONS: The success rate for IANB with 4% articaine was 25%. Articaine and lidocaine had similar success rates for supplemental infiltration in first molars, whereas articaine was significantly more successful for second molars. However, because BI often did not provide profound pulpal anesthesia, additional techniques including intraosseous anesthesia may still be required.

Deciphering Endodontic Microbial Communities by Next-generation Sequencing.

INTRODUCTION: Biofilms are present in more than 70% of endodontically diseased teeth. Through the advancements in the next-generation sequencing (NGS) technologies, microbiome research has granted a deeper analysis of the microbial communities living in human hosts. Here, we reviewed previous studies that used NGS to profile the microbial communities of root canals. METHODS: A total of 12 peer-reviewed articles from PubMed were identified and critically reviewed. The study criteria were as follows: NGS platforms, sequenced bacterial hypervariable regions, teeth diagnosis with available patient information, sample characteristics, collection method, and microbial signatures. RESULTS: The most common NGS platforms used were 454 pyrosequencing (Roche Diagnostic Corporation, Risch-Rotkreuz, Switzerland) and Illumina-based technology (Illumina Inc, San Diego, CA). The hypervariable regions sequenced were between the V1 and V6 regions. The patient and sample population ranged from ages 12-76 years and asymptomatic and symptomatic teeth diagnosed with pulp necrosis with or without apical periodontitis. Microbial sampling was conducted directly from the infected pulp or the extracted teeth. The most abundant phyla were Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria, and Fusobacteria. The most frequently detected genera were Prevotella, Fusobacterium, Porphyromonas, Parvimonas, and Streptococcus. Other notable microbial signatures at different taxa levels were identified but were widely variable between studies. CONCLUSIONS: Technologies based on high-throughput 16S ribosomal RNA NGS can aid in deciphering the complex bacterial communities of root canal biofilms. Thus far, only a few studies have been published with relatively small sample sizes, variable sample collection protocols, and community analyses methods. Future larger clinical studies are essential with validated standardized protocols for improved understanding of the pathogenic nature of bacterial biofilm communities in root canals.

Effect of ProRoot MTA on pulp cell apoptosis and proliferation in vitro.

ProRoot Mineral Trioxide Aggregate (MTA) has been indicated as a pulp capping material. The purpose of this study was to evaluate the effect of tooth-colored (white) MTA on pulp cell apoptosis and cell cycle. Mouse odontoblast-like cells (MDPC-23) and undifferentiated pulp cells (OD-21) were exposed to 0 to 100 mg MTA for 24 h. Propidium iodide staining followed by flow cytometry demonstrated that MTA did not induce apoptosis of MDPC-23 or OD-21 (p > 0.05). Cell cycle analysis showed that MTA induced a modest (but significant) increase in the percentage of MDPC-23 in the S and G2 phases, and OD-21 in the S phase of cell cycle, as compared to untreated controls (p

Efficacy of articaine versus lidocaine as a supplemental buccal infiltration in mandibular molars with irreversible pulpitis: a prospective, randomized, double-blind study.

INTRODUCTION: Profound pulpal anesthesia in mandibular molars with irreversible pulpitis (IP) is often difficult to obtain and often requires supplemental injections after an ineffective inferior alveolar nerve block (IANB). The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental buccal infiltrations (BIs) after an ineffective IANB in mandibular molars with IP. In addition, the use of articaine for IANB and intraosseous injections was investigated. METHODS: One hundred emergency patients diagnosed with IP of a mandibular molar were selected and received an IANB with 4% articaine. All injections were 1.7 mL with 1:100,000 epinephrine. All patients reported profound lip numbness after IANB. Patients with ineffective IANB (positive pulpal response to cold or pain on access) randomly received 4% articaine or 2% lidocaine as a supplemental BI. Endodontic access was initiated 5 minutes after deposition of the infiltration solution. Success was defined as no pain or no more than mild pain during endodontic access and instrumentation as measured on a visual analogue scale. RESULTS: Seventy-four patients failed to achieve pulpal anesthesia after IANB with 4% articaine, resulting in IANB success rate of 26%. Success rates for supplemental BIs were 62% for articaine and 37% for lidocaine (P < .05). This effect was most pronounced in second molars (P < .05). CONCLUSIONS: Supplemental BI with articaine was significantly more effective than lidocaine. The IANB success rate of 4% articaine confirmed published data.

Providing care for underserved patients: endodontic residents', faculty members', and endodontists' educational experiences and professional attitudes and behavior.

UNLABELLED: In the United States, access to dental care is often challenging for patients from socioeconomically disadvantaged and/or minority populations and for patients with special health care needs (SHCN). The objectives of this study were to a) explore endodontic residents', endodontic faculty members', and private practice endodontists' perceptions of their education about treating underserved patients, along with their related attitudes and behavior, and b) to determine how their educational experiences were related to their attitudes and behavior concerning these patients. It was hypothesized that the quality of educational experiences related to these issues would correlate with the providers' professional attitudes and behavior. METHODS: Survey data were collected from seventy-eight endodontic residents, forty-eight endodontic faculty members, and seventy-five endodontists in private practice. RESULTS: The residents reported themselves being better prepared to treat these patients than did the endodontists in private practice. The residents and faculty members had more positive attitudes towards patients with SHCN, developmental disabilities, and pro bono cases and were more confident when treating patients with developmental disabilities than private practitioners. However, the three groups did not differ in educational experiences and attitudes concerning patients from different ethnic/racial groups. The better the respondents' graduate education about certain patient groups had been, the more positive were their attitudes and behavior. CONCLUSIONS: Improving endodontic residents' education about treating underserved patients is likely to improve their attitudes and behavior related to providing much-needed care for these patients. These findings are a call-to-action for dental educators to ensure quality education is being provided about these issues in order to decrease access to care problems for underserved patients.

Multiple simple bone cysts of the jaws: review of the literature and report of three cases.

OBJECTIVES: This study contributes three well-documented cases of multiple simple bone cysts (SBCs) of the jaws and reviews previously published cases. STUDY DESIGN: A comprehensive literature search of multiple SBCs was conducted using the PubMed database. Synonyms of SBC were used as search key words in combination with "mandible or jaw," "bilateral, multiple, multifocal, atypical, and unusual." RESULTS: A total of 34 cases of multiple SBCs (including two asynchronous cases) were identified, including the three new cases reported here. Multiple SBCs primarily occurred in the second decade (52.9%) and bilaterally in the posterior mandible. Lesions demonstrated female predominance (1.8:1) and were frequently accompanied by bony expansion (44.1%) and a multilocular radiolucent appearance (20.6 %). Recurrence was reported in three patients (mean age: 39.3 years old). CONCLUSION: Knowledge of the clinical and radiographic features of multiple SBCs is important in the diagnosis and management of this entity.

The pulpal anesthetic efficacy of articaine versus lidocaine in dentistry: a meta-analysis.

BACKGROUND: The authors evaluated published evidence from controlled clinical trials regarding the efficacy of two local anesthetic solutions in providing successful pulpal anesthesia. METHODS: The authors searched MEDLINE and Embase databases to identify peer-reviewed randomized controlled trials in which researchers directly compared articaine and lidocaine local anesthetic solutions in adult participants. They extracted study characteristics and outcomes data as a basis for meta-analysis. They completed subgroup analyses for both infiltration and mandibular inferior alveolar block anesthetic techniques. RESULTS: Articaine solutions had a probability of achieving anesthetic success superior to that of lidocaine, with an odds ratio of 2.44 (95 percent confidence interval [CI], 1.59-3.76; P < .0001). The greater odds ratio for articaine increased to 3.81 (95 percent CI, 2.71-5.36; P < .00001) when the authors analyzed only infiltration data. There was weaker, but still significant, evidence of articaine's being superior to lidocaine for mandibular block anesthesia, with an odds ratio of 1.57 (95 percent CI, 1.12-2.21; P = .009), and no difference when the authors considered only symptomatic teeth. CLINICAL IMPLICATIONS: Research evidence supports using articaine versus lidocaine for achieving pulpal anesthesia when the infiltration mode of administration is used. It is premature to recommend articaine for mandibular block anesthesia in cases involving irreversible pulpitis.