Incidence of missed canals during endodontic treatment of maxillary first and second molars.

Untreated canals are a primary cause of persistent apical periodontitis, and the inability to identify and adequately treat canals has been considered a major cause of failure of root canal therapy in maxillary molars. The purpose of this retrospective study was to use cone beam computed tomography (CBCT) to quantify the number of missed canals in maxillary first and second molars needing endodontic retreatment after treatment by general dentists. A total of 401 CBCT scans of maxillary first and second molars were examined. A total of 214 scan sets (53.37% [95% CI, 48.48%-58.25%]) showed evidence of an untreated canal, with the highest rate (49.38%; n = 198) observed in the second mesiobuccal canal. Imaging revealed that multiple canals were missed in some patients, for a total of 225 missed canals. The examinations showed untreated first mesiobuccal canals in 2.99% of CBCT scan sets (n = 12), untreated distobuccal canals in 2.99% of CBCT scan sets (n = 12), and untreated palatal canals in 0.75% of CBCT scan sets (n = 3). Preoperative CBCT imaging should be considered prior to initial root canal treatment of maxillary molars. When the risks and limitations of CBCT are taken into consideration, the additional information it provides can improve diagnostic accuracy, increase confidence in decision-making, and positively impact treatment planning.

Effect of different instrumentation techniques on students' performance and outcomes of nonsurgical root canal treatment.

OBJECTIVES: This study compared, retrospectively, the incidence of clinical errors and effects on treatment outcomes, when students were exposed to two different instrumentation techniques: a hybrid rotary technique (HYB), consisting of both hand instrumentation with hand stainless steel and Ni-Ti files plus the use of a rotary system (Vortex Blue, Dentsply Sirona), versus a full reciprocation instrumentation technique (WaveOne Gold [WOG], Dentsply Sirona). METHODS: A total of 368 endodontic cases (n = 184) in anterior and premolar teeth, completed by dental students at the University of Michigan School of Dentistry from 2013 to 2022, were used for the study. The groups were evaluated by two calibrated clinicians, observing the incidence of clinical errors: file separations, over-instrumentation, ledges and transportations. Treatment outcomes were also observed. Data were analyzed statistically by Fisher's exact test and Mann-Whitney U test (p < 0.05). RESULTS: No significant difference in file separations, ledges, and transportation was observed between the two groups. However, the WOG Group experienced significantly more over-instrumentation than HYB group, although this did not significantly affect tooth survival or periapical index (PAI). Cases with PAI scores of 5 were found to have significantly less tooth survival compared to the other PAI scores. CONCLUSIONS: It can be concluded that both techniques in our study are well suited to advancing the endodontic dental education of students and novice operators, anticipating relatively successful outcomes of tooth survival, as long as the cases selected are less severe in progression preoperatively.

Decision Making in the Restoration of Endodontically Treated Teeth: Effect of Biomimetic Dentistry Training.

The restoration of endodontically treated teeth (ETT) is challenging as these teeth often present with structural deficiencies. Currently, there is no consensus regarding the final restoration choice. Historically, the full coverage crown was the universally selected treatment for endodontically treated teeth. With advances in adhesive and biomimetic dentistry, more minimally invasive treatment modalities have become a viable option. With this study, we aim to understand the restorative decision of the general dentist with or without additional training in biomimetic dentistry. Seventy-eight general dentists, with or without biomimetic training, were surveyed to determine their restorative preferences on five extracted posterior teeth, categorized according to volumetric loss of tooth structure, as indicated by the number of missing walls, the isthmus width, the presence or absence of marginal ridges, and cusps. CAD/CAM reconstructions were made with the teeth to analyze the volume of tooth loss and compare these with the survey results. Data were compared using the chi-squared test and Fisher's exact test. The frequency of responses recommending a crown and the volume of tooth loss were correlated using the Pearson test (p < 0.05). For all five teeth, survey responses showed a statistically significant difference in the restorative decision of full coverage versus alternative restorations, with biomimetic dentists selecting a direct restoration or inlay/onlay in lieu of a full coverage crown (n = 63, p < 0.05). The age of the participant did not have a significant impact on the restorative decision making process for these teeth. The biomimetic trained dentists showed a greater tendency to select a crown option only when the volume of tooth loss was greatest, otherwise their restorative decisions tended towards the conservative treatment options. This study also demonstrates a novel method of digitally developing a volume of tooth loss to compare against the visual interpretation of the volume of tooth loss.

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.

A critical analysis of research methods and biological experimental models to study pulp regeneration.

With advances in knowledge and treatment options, pulp regeneration is now a clear objective in clinical dental practice. For this purpose, many methodologies have been developed in attempts to address the putative questions raised both in research and in clinical practice. In the first part of this review, laboratory-based methods will be presented, analysing the advantages, disadvantages, and benefits of cell culture methodologies and ectopic/semiorthotopic animal studies. This will also demonstrate the need for alignment between two-dimensional and three-dimensional laboratory techniques to accomplish the range of objectives in terms of cell responses and tissue differentiation. The second part will cover observations relating to orthotopic animal studies, describing the current models used for this purpose and how they contribute to the translation of regenerative techniques to the clinic.

Efficacy of calcium hydroxide and resin-modified calcium silicate as pulp-capping materials: a retrospective study.

The aim of this study was to compare the clinical success rates of light-cured, resin-modified calcium silicate (TheraCal LC) and calcium hydroxide (Dycal) as pulp-capping materials in permanent teeth. In this retrospective electronic record review of patients treated in the years 2012 through 2015, the postoperative data of 120 patients (n = 60 per material) were collected. In these 2 groups, 69 teeth were treated with calcium hydroxide (29 in men, 40 in women) and 79 with calcium silicate (37 in men, 42 in women). The following data were recorded: treated tooth; patient age and sex; reason for treatment; direct or indirect pulp cap; date of treatment; date of most recent dental appointment; and treatment outcome. The selected patients met the following inclusion criteria: They had received either a direct or an indirect pulp cap in an anterior or posterior tooth after excavation of deep caries as part of a routine restorative procedure using either amalgam or composite resin; and they had returned to the clinic for other dental care at least 3 months after the pulp-capping treatment. Patients were excluded from the study if they reported symptoms of irreversible pulpitis or chronic tooth pain before the restorative treatment was started. The treatment outcome was considered clinically successful if the tooth was still present and asymptomatic at the appointments following the procedure. The outcome was considered unsuccessful if the tooth was extracted due to symptoms or if endodontic treatment had been performed postoperatively. There was no statistically significant difference between the clinical success rates of calcium silicate (85.5%) and calcium hydroxide (84.8%), according to the Fisher exact test (P < 0.05). Neither the patient's sex nor the tooth location affected the outcome. Within the limitations of this retrospective clinical study, it may be concluded that TheraCal LC calcium silicate can be considered equivalent inefficacy to calcium hydroxide for both direct and indirect pulp capping. A prospective clinical study with a larger sample size is needed to confirm these findings.

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.

The effects of different irrigation solutions on the bond strength of cemented fiber posts.

OBJECTIVE: To study effect of root canal irrigant solutions on the bond strength of cemented fiber posts, and resin cement-tags in root canal dentin. MATERIALS AND METHODS: Fifty-two human single-rooted anterior teeth were selected and stored in 1% sodium azide. Crowns were sectioned 2 mm incisal to the cemento enamel junction with diamond bur at high speed under water-cooling. After standard root canal treatment to tested teeth, they were randomly assigned into four groups (n=13) corresponding to the endodontic irrigant solution that was used during post space preparation. The treatment groups were: Group 1: 6.15% sodium hypochlorite; Group 2: 17% EDTA; Group 3: 6.15% NaOCl +17% EDTA; Group 4: 6.15% NaOCl +0.12% chlorhexidine solution. Parallel-sided fiber posts were used for all specimens. Samples were embedded in a cylindrical PVC mounting jig to facilitate perpendicular sectioning. With low speed diamond saw, cervical and apical specimens from each tooth were obtained and subjected to push-out test using universal testing machine. SEM was used to examine the root-canal dentin surface. RESULTS: Statistical analysis revealed significant difference among the groups at P<0.05. Group 2 treated with EDTA, had the highest bond strength; 18.63±2.85 MPa in cervical specimens and 13.49±3.67 MPa in apical specimens. The cervical specimens of Groups 2 and 3 were significantly different than the apical specimens in the same group. Adhesive failure between cement and dentin was the main failure mode observed in all groups. Groups irrigated with EDTA showed cleaner dentin surface and better resin tag formation, while groups treated with NaOCl showed less resin tag formation and insufficient smear layer removal. CONCLUSION: NaOCl had adverse effect on bond strength of self-adhesive resin cement to radicular dentin. EDTA irrigant solution produced higher bond strength and was more effective in removing smear layer than NaOCl.

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.

Should Endodontic Residents Be Educated About IV-Sedation? Endodontics Program Directors' and Endodontists' Perspectives.

The aims of the two studies reported here were to assess endodontic postgraduate program directors' educational efforts and attitudes related to educating residents about intravenous (IV) sedation (Study 1) and to assess endodontists' educational experiences and attitudes concerning IV-sedation (Study 2). Directors of all 56 U.S. endodontic residency programs and a sample of 2,173 endodontists in the U.S. were invited to participate in the surveys in 2016 and 2017; 31 directors completed the survey (response rate 55%), as did 616 endodontists (response rate 28.3%). Of the participating programs, 18 did not and 13 did offer IV-sedation education. Most directors of programs without this education agreed/strongly agreed that other programs in their institutions offered IV-sedation (83%) and that none of their faculty were trained to teach it (83%). Most directors of programs with this education were satisfied/very satisfied with their classroom-based education about IV-sedation (64%) and this education in general (54%). Directors of programs with IV-sedation education agreed more strongly than directors of programs without IV-sedation education that there is a need for IV-sedation in endodontics (on five-point scale with 1=disagree strongly: 4.08 vs. 3.39; p=0.05), that postgraduate programs should offer it (3.50 vs. 2.71; p=0.04), and that many patients inquire about it (2.75 vs.1.83; p=0.04). Most of the endodontists disagreed/disagreed strongly that they had received adequate training in IV-sedation in their postgraduate program (87%) and were not satisfied with their IV-sedation training (71%); half (51%) reported not feeling competent answering patients' questions about IV-sedation. While most of the endodontists were dissatisfied with their IV-sedation related postgraduate education, most of the program directors did not offer IV-sedation education in their programs. A discussion of the need to educate future endodontists about IV-sedation is needed.

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.

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.

Maxillary and Mandibular Non-Hodgkin Lymphoma with Concurrent Periapical Endodontic Disease: Diagnosis and Management.

Extranodal non-Hodgkin lymphoma (NHL) in the oral region can present similarly to diseases of odontogenic origin. The objective of this report was to describe a rare case of maxillary and mandibular NHL that presented similarly to and concurrently with lesions of odontogenic origin.A unique case of extranodal NHL, which presented at the apices of maxillary and mandibular teeth in conjunction with lesions of odontogenic origin in a 68-year-old white man, is described. The patient sought care because of a lesion in the right maxillary paranasal region that caused him paresthesia. Radiographically, periapical radiolucencies were present along teeth #5-8, #23 and 24, and #30 and 31. Biopsies of the right maxillary and anterior mandibular lesions were completed and led to a diagnosis of NHL at the apices of teeth #5-8 extending to the hard palate and granulation tissue at the apices of teeth #23 and 24. Two years later, the patient returned because of pressure and sensitivity associated with teeth #30 and 31. Vestibular swelling was noted clinically, and a multilocular periapical radiolucency was present radiographically. Via endodontic therapy and a positron emission tomographic scan, the lesion associated with teeth #30 and 31 was determined to be of both odontogenic and nonodontogenic origin because it possessed both a sinus tract associated with tooth #30 and NHL. Lesions of odontogenic and nonodontogenic origin possess diagnostic and treatment challenges because they may present similarly and/or concurrently. Thoughtful and conservative management of odontogenic lesions with associated NHL is imperative. Interprofessional collaboration and communication among providers must be thorough and clear to properly coordinate care and prevent delays in diagnosis and treatment when these entities occur together.

General dentists', pediatric dentists', and endodontists' diagnostic assessment and treatment strategies for deep carious lesions: A comparative analysis.

BACKGROUND: There is a large variation among clinicians when managing deep carious lesions (DCLs). The purpose of this study was to assess general dentists' (GDs), pediatric dentists' (PDs), and endodontists' (EDs) diagnostic methods, clinical decision-making considerations, treatment strategies, and knowledge, behavior, and attitudes related to the diagnosis and treatment of DCLs. METHODS: A total of 175 GDs, 511 PDs, and 377 EDs responded to a nationwide Web-based survey. RESULTS: Most EDs (68%) and GDs (47%) practiced complete caries removal. PDs (31%) were more likely than GDs (12%) and EDs (4%) to remove carious tissues partially. Dentin hardness was the most important diagnostic criterion used during caries excavation (GDs, 90%; PDs, 72%; EDs, 88%). Only 30% of GDs, 17% of PDs, and 90% of EDs used diagnostic tests (for example, a cold test) when assessing pupal health. A substantial percentage of respondents considered endodontic treatment as a choice for treating DCLs in asymptomatic teeth in young patients (GDs, 40%; PDs, 30%; EDs, 40%). GDs rarely used a rubber dam when treating these lesions. CONCLUSIONS: Most respondents practiced complete caries removal until hard dentin was felt, using hardness as the primary excavation criterion, and did not use pulp diagnostic tests routinely before making decisions about treatment of teeth with DCLs. PRACTICAL IMPLICATIONS: Efforts should be made to translate the growing body of evidence supporting the use of conservative caries removal criteria to preserve pulpal health and tooth structure integrity when managing DCLs.

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 expression of periostin in dental pulp cells.

BACKGROUND AND OBJECTIVE: Dental pulp repair is a common process triggered by microbial and mechanical challenges. Matricellular modulators, such as periostin, are key for extracellular matrix stability and tissue healing. In the scope of the dental pulp, periostin expression has been reported during development and active dentinogenesis. However, the specific dental pulp cell population capable of expressing periostin in response to known regulators has not been clearly defined. Among the different relevant cell populations (i.e., stem cells, fibroblasts and pre-odontoblasts) potentially responsible for periostin expression in the dental pulp, this study aimed to determine which is the primary responder to periostin regulators. METHODS: Human dental pulp stem cells (DPSCs), human dental pulp fibroblasts (DPFs), and rat odontoblast-like cells (MDPC-23) were treated with different concentrations of TGF-ß1 or different regimens of biomechanical stimulation to evaluate periostin expression by qRT-PCR, Western blot and ELISA. Statistical analyses were performed by Student's t-test and ANOVA with Fisher's LSD post hoc tests (p ≤ 0.05). RESULTS: DPSC and MDPC-23 showed a statistically significant increase in periostin mRNA expression after exposure to TGF-ß1 for 48 h. TGF-ß1 also up-regulated periostin protein levels in DPSC. However, periostin significantly down-regulated protein expression in DPF. Different regimens of biomechanical stimulation showed different patterns in protein and mRNA periostin expression. CONCLUSIONS: Expression of periostin was identified in each of the analysed dental pulp cell lines, which can be regulated by TGF-ß1 and biomechanical stimulation. Overall, DPSCs are the most responsive cells to stimulation.

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.

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.

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.