Epoxy vs. Calcium Silicate-Based Root Canal Sealers for Different Clinical Scenarios: A Narrative Review

This study aimed to review the considerations for choosing a suitable sealer according to various endodontic scenarios. An electronic search of PubMed, Scopus, and the Web of Science was undertaken for the keywords of 'sealer choosing', 'appropriate sealer', 'suitable sealer', 'sealer for clinical scenario', and 'sealer for clinical situations'. However, the literature review revealed a lack of studies with practical clinical recommendations regarding the choice of appropriate endodontic root canal sealers for particular clinical situations of root canal treatment. Therefore, a narrative review was undertaken under the basis of the characteristics of an epoxy resin-based sealer (ERS) versus a calcium silicate-based sealer (CSS). Based on the evidence found through the review, the choice of an appropriate sealer in a variety of clinical scenarios was proposed. An ERS is recommended for one-visit non-vital cases, teeth with periodontal involvement, cracked teeth, and internal root resorption without root perforation. A CSS is recommended for vital or non-vital cases in multiple visits, teeth with internal root resorption with perforation or internal approach for external cervical resorption, teeth with open apices, and teeth with iatrogenic aberrations.

Association of Nationwide Water Fluoridation, Changes in Dental Care Legislation, and Caries-Related Treatment Needs: A 9-Year Record-Based Cross-Sectional Study

OBJECTIVES

The implementation of nationwide water fluoridation in Israel in 2002 led to a significant reduction in caries among children. However, this practice was discontinued in 2014 due to a change in legislation. In 2010, as part of the Israeli National Health Insurance Law, free dental care for children under 10 years of age was legislated. This policy was gradually extended to include adolescents under 18 years of age in 2018. We examined the association between these efforts and changes in the caries-related treatment needs of young adults over the course of two decades.

METHODS

This cross-sectional study analyzed data on the need for dental restorations, root canal therapy, and extractions that were retrieved from dental records of 34,450 soldiers recruited into military service between 2012-2021. These data were cross-matched with the subjects' year of birth to determine whether the implementation of water fluoridation, dental care legislation, or both were associated with changes in the need for and provision of dental care. Sociodemographic data, including sex, age, socioeconomic cluster (SEC), intellectual capability score (ICS), body mass index, and place of birth, were also extracted.

RESULTS

A multivariate generalized linear model (GLM) revealed that male sex, older age, low ICS, and low SEC were significant predictors for greater caries-related treatment needs (P < 0.001). Our findings indicated that subjects exposed to fluoridated water during their childhood had significantly lower rates of caries-related treatment, regardless of access to free dental care.

CONCLUSION

Mandatory water fluoridation was associated with significantly lower caries-related treatment needs while national dental health legislation providing free dental care to children and adolescents was not. Therefore, we suggest that water fluoridation should be continued to maintain the observed reduction in treatment needs.

CLINICAL SIGNIFICANCE

Our findings provide support for the effectiveness of water fluoridation in preventing caries, whereas the impact of free dental care programs focused on clinical intervention remains to be determined.

Antimicrobial evaluation of polytetrafluoroethylene used as part of temporary restorations: An ex vivo study

The use of polytetrafluoroethylene (PTFE) tape as the base layer of temporary restorations had gained popularity mainly due to the ease of manipulation. The aim of this study was to assess whether this method changes the potential for bacterial growth and leakage of temporary restorations. The direct contact test and live/dead fluorescent staining were used for comparing Enterococcus faecalis growth and biofilm formation on PTFE, composite, intermediate restorative material (IRM) and Coltosol F. Confocal laser scanning microscopy was employed to evaluate E. faecalis penetration through 2 mm of PTFE, IRM or Coltosol F placed on the bottom of the pulp chamber and into radicular dentinal tubules in extracted maxillary third molars. The results demonstrated that E. faecalis grows on and penetrates through PTFE significantly more than it does with IRM and Coltosol F, revealing its comparably reduced overall antimicrobial sealing ability when placed as the base part of temporary restorations.

Enterococcus faecalis sustained infection induces macrophage pro-resolution polarization

AIM

To investigate macrophage function in the presence of sustained infection with Enterococcus faecalis, a prevalent root canal resident in asymptomatic apical periodontitis.

METHODOLOGY

The human monocyte cell line (THP-1) was differentiated into macrophages by exposure to phorbol myristate acetate (PMA), and the cultures were inoculated with E. faecalis for up to 48 h. At three time-points 90 min, 24 and 48 h after inoculation, the macrophages and their supernatants were examined. Assays included macrophage phagocytosis rate and vitality, bacterial survival, reactive oxygen species (ROS) production, mitochondrial activity, cytokine production and the expression of pro/anti-inflammatory M1/M2 markers. Also, periapical tissue from apicectomy samples of human endodontically treated teeth were collected for histological and immunofluorescent analysis. Statistical differences were analysed with RM ANOVA.

RESULTS

E. faecalis were phagocytized, and subsequently, most of the macrophages underwent apoptosis and necrosis. The small population of macrophages that remained vital after 48 h post-inoculation harboured surviving bacteria. Despite a reduction in the number of macrophages over time, the mitochondrial activity of the surviving macrophages remained constant and external ROS decreased, whereas internal ROS increased. During the infection, a shift to a M2 macrophage population at 48 h post-infection was observed; the results were similar to those obtained in periapical human tissue biopsies (p < .05).

CONCLUSIONS

The study portrays a continuous non-resolved infection with E. faecalis and activation of macrophages that are polarized to the M2 pro-resolution phenotype.

A Rare Case of Multiple Internal Root Resorption after the Delayed Treatment of a Traumatic Injury: A Case Report

AIM

The objective of this case report was to present a rare case of simultaneous multiple internal root resorption (IRR) in four mandibular incisors and discuss the possible etiology and suitable armamentarium for its treatment based on different morphological considerations.

BACKGROUND

IRR in permanent dentition is a rare pathological condition and its etiology is not yet fully understood. Very few cases of multiple IRR were reported. This is the first reported case of multiple IRR due to traumatic injury.

CASE DESCRIPTION

A 23-year-old man suffered trauma to his mandible after falling from a trampoline. His mandibular incisors suffered subluxation injuries and his orthodontic fixed retainer got detached. He delayed treatment and visited our clinic 4.5 months after the incident. Clinical and radiographic examination revealed four mandibular incisors with almost identical IRR defects at the apical third of the roots. The patient was then treated with four non-surgical root canal treatments using various endodontic instruments and techniques. Fifteen-month post-trauma, he showed no evidence of pathology at the follow-up examination.

CONCLUSION

Delayed treatment of dental trauma might cause multiple IRR, and the presence of an orthodontic fixed retainer can distribute surface forces and result in uniform IRR defects.

CLINICAL SIGNIFICANCE

The combination of the self-adjusting file (SAF) and the XP-endo finisher is recommended for chemomechanical preparation of IRR defects in oval canals, especially at the apical third.

Radicular Grooves and Complex Root Morphologies of Mandibular Premolars Among Israeli Population

INTRODUCTION

Mandibular premolars usually have one root and one root canal. Different studies found that up to 30% of mandibular premolars have more than one root canal, and up to 24% of mandibular premolars have C-shape canals. The purpose of this study was to investigate the root anatomy and the prevalence of complex root canal morphology in mandibular premolars in Israeli population.

METHODS

A total of 1020 Israeli patients' cone-beam computed tomography scans were screened and evaluated. A total of 1835 mandibular first premolars and 1678 mandibular second premolars were examined. Irregular root anatomy and different root canal morphologies were recorded and analyzed.

RESULTS

The overall prevalence of complex root morphology (types II-VIII) in mandibular first and second premolars was 21% and 2.8%, respectively. The bilateral prevalence of complex root morphology in mandibular first and second premolars was 46% and 29%, respectively. The prevalence of radicular grooves in mandibular first and second premolars with complex root morphology was 48% and 36%, respectively. No significant difference was found according to gender or the side of occurrence. However, complex root canal morphology was significantly found in mandibular premolars with radicular grooves.

CONCLUSIONS

Complex root canal morphology frequently occurs in mandibular first premolars in the population of Israel. Radicular groove existence in mandibular first and second premolars is significantly related to complex root canal morphology.

Age-dependent root canal instrumentation techniques: a comprehensive narrative review

The aim of this article was to review age-dependent clinical recommendations for appropriate root canal instrumentation techniques. A comprehensive narrative review of canal morphology, the structural characteristics of dentin, and endodontic outcomes at different ages was undertaken instead of a systematic review. An electronic literature search was carried out, including the Medline (Ovid), PubMed, and Web of Science databases. The searches used controlled vocabulary and free-text terms, as follows: 'age-related root canal treatment,' 'age-related instrumentation,' 'age-related chemo-mechanical preparation,' 'age-related endodontic clinical recommendations,' 'root canal instrumentation at different ages,' 'geriatric root canal treatment,' and 'pediatric root canal treatment.' Due to the lack of literature with practical age-based clinical recommendations for an appropriate root canal instrumentation technique, a narrative review was conducted to suggest a clinical algorithm for choosing the most appropriate instrumentation technique during root canal treatment. Based on the evidence found through the narrative review, an age-related clinical algorithm for choosing appropriate instrumentation during root canal treatment was proposed. Age affects the morphology of the root canal system and the structural characteristics of dentin. The clinician's awareness of root canal morphology and dentin characteristics can influence the choice of instruments for root canal treatment.

Nupharidine enhances Aggregatibacter actinomycetemcomitans clearance by priming neutrophils and augmenting their effector functions

OBJECTIVES

Nupharidine (6,6'-Dihydroxythiobinupharidine), purified from the aquatic plant Nuphar lutea leaves (Water lily) prompts antimicrobial activity of immune cells. The aim of the study was to test the effect of Nupharidine on neutrophil function against Aggregatibacter actinomycetemcomitans, JP2 clone (Aa-JP2).

METHODS

Neutrophils derived from the human cell line HL60 and human peripheral blood derived from aggressive periodontitis and periodontally healthy subjects were incubated with Nupharidine or vehicle and inoculated with JP2. Bacterial survival was tested using viable counts on blood agar (CFU's). Neutrophils' necrosis/apoptosis, reactive oxygen species (ROS) production, phagocytosis and neutrophil extracellular traps (NET) production following infection were tested, as well as markers of neutrophil priming.

RESULTS

Nupharidine had no direct bactericidal effect on JP2, but it enhanced Aa-JP2 clearance by neutrophils. Nupharidine enhanced neutrophil phagocytosis, ROS production and NET formation during JP2 infection. Furthermore, Nupharidine enhanced the expression of certain markers of neutrophils priming, specifically iCAM1, DECTIN-2 and intracellular IL-1β.

CONCLUSION

Nupharidine was shown to promote neutrophil effector bactericidal functions, boosting Aa-JP2 clearance. The results point to the potential of Nupharidine as an adjunctive agent in the treatment of Aa-JP2 periodontitis, but this should be tested initially using pre-clinical and clinical studies.

The association between caries related treatment needs and socio-demographic variables among young Israeli adults: a record based cross sectional study

Backgroud

The need for dental treatments, especially those related to dental caries, may be associated with and influenced by a wide range of demographic variables. The aim of this study was to describe caries related treatment needs among young Israeli adults and the association with several socio-demographic factors, including socio-economic cluster (SEC), intellectual capabilities, ethnicity and other variables.

Methods

Data were collected from dental records of army recruits between 2012 and 2013. We cross-examined data regarding dental treatment needs with socio-demographic variables: age, gender, SEC, intellectual capability score (ICS), birth place of participant and parents, education and immigration.

Results

Data received regarding 13,398 combat recruits during their first four months of military training. Most subjects were males (92.4%), with a mean age of 18.9 years. 10.8% were immigrants, with 12.2 years living in Israel before their recruitment. Only 17.7% had no dental treatment needs. Mean number of teeth needing treatment was: for restorations 1.96 ± 2.59, for root canal therapies 0.07 ± 0.44 and for extractions 0.05 ± 0.28. Low ICS scores and low SEC group were significantly associated with higher treatment needs (P < 0.001). Statistically significant higher treatment needs were observed among participants who originated from immigrant families. In a multivariate analysis (Generalized Linear Model), gender, age, ICS score, SEC group and country of birth were found as independent predictors for number of restorations needed.

Conclusion

Socio-demographic variables significantly influence dental treatment needs and should be taken into account when preparing intervention programs in this population.

Electronic spectroscopy and photoisomerization of trans-urocanic acid in a supersonic jet

trans-Urocanic acid (trans-UA), a component of the epidermal layer of skin, exhibits wavelength-dependent photochemistry. The quantum efficiency of isomerization to cis-UA is greatest when the molecule is excited on the long wavelength tail of its absorption profile in solution (300-320 nm). However, exciting the molecule where it absorbs UV light most efficiently (260-285 nm) causes almost no isomerization. We have used fluorescence excitation and dispersed emission methods in a supersonic jet to investigate the electronic states involved in this complex and interesting photochemistry. Three distinct regions are present in the excitation spectrum. Region I, which is below the isomerization barrier, contains sharp, well-resolved peaks that upon excitation emit from the S(1) state of trans-UA. Region II exhibits peaks that increase in broadness and decrease in intensity with increasing excitation energy. Upon excitation these peaks produce dual emission from the S(1) states of both trans- and cis-UA. The trans to cis isomerization barrier is estimated to be 1400 cm(-1). Region III exhibits excitation to the S(2) electronic state and has a broad structure that spans 3000 cm(-1) and occurs 4000 cm(-1) above S(1). S(2) excitation results in essentially no trans to cis isomerization.

Educational benefits and cost savings from an interactive multimedia "best practice"

BACKGROUND

Developing and deploying "clinical practice guidelines" and "best practices" is a major strategic goal of our organization. We developed and evaluated a novel way of educating our colleagues on the office management of shoulder pain, using an interactive multimedia computer program to allow rapid access to user-selected audiovisual educational materials through a simple point and click interface.

METHODS

Pre- and post-testing of 30 practicing primary care providers was conducted to assess ability to evaluate and manage patients who present with shoulder pain, and a post-use survey was administered to assess clinician acceptance and confidence, ability to use as a just-in-time tool, and changes in utilization of medical resources.

RESULTS

Pre- and post-testing demonstrated that clinicians used this tool to improve their scores in a wide variety of clinical areas including history, physical examination, diagnosis, and management of conditions causing painful shoulder above their scores using textbooks and other traditional educational materials alone. The post-use survey showed outstanding acceptance by clinicians and their reported increased confidence as well as the potential for their increased abilities to translate into significant cost savings through more focused use of radiographic studies, orthopedic consultations, and physical therapy treatments.

CONCLUSIONS

It was concluded that "The Multimedia Reference for Office Management of Shoulder Pain" is an effective and valuable learning resource for practicing clinicians, and demonstrates the potential to use an interactive multimedia tool to augment clinical skills and promote cost effective management of patients with this common clinical problem.

Computer-facilitated collaboration: experiences building SNOMED-RT

Collaborative development involving both individuals and groups is often less efficient than independent development because of communication overhead and integration costs. Despite the decreased development efficiency, collaborations promise more general-purpose products because of the opportunity for integration, with negotiation and reconciliation of diverse perspectives. Collaborations are also perhaps less costly when considered in contexts where there is significant duplication of effort. Computer-facilitated collaboration can reduce the communication and integration burden such that the increased effort required to manage a successful collaboration focuses primarily on the development of shared conceptual model among the developers by requiring that the work product be independently reproducible. This reproducibility requirement incorporates formal quality assurance processes into the development process. In this paper, we describe our initial experiences developing SNOMED-RT using such a computer-facilitated collaborative process. We quantify the extra costs incurred to achieve consistency in our efforts and reproducibility of our results.

The Hubble Space Telescope (HST) observing campaign on comet Shoemaker-Levy 9

The Hubble Space Telescope made systematic observations of the split comet P/Shoemaker-Levy 9 (SL9) (P designates a periodic comet) starting in July 1993 and continuing through mid-July 1994 when the fragments plunged into Jupiter's atmosphere. Deconvolutions of Wide Field Planetary Camera images indicate that the diameters of some fragments may have been as large as approximately 2 to 4 kilometers, assuming a geometric albedo of 4 percent, but significantly smaller values (that is, < 1 kilometer) cannot be ruled out. Most of the fragments (or nuclei) were embedded in circularly symmetric inner comae from July 1993 until late June 1994, implying that there was continuous, but weak, cometary activity. At least a few nuclei fragmented into separate, condensed objects well after the breakup of the SL9 parent body, which argues against the hypothesis that the SL9 fragments were swarms of debris with no dominant, central bodies. Spectroscopic observations taken on 14 July 1994 showed an outburst in magnesium ion emission that was followed closely by a threefold increase in continuum emission, which may have been caused by the electrostatic charging and subsequent explosion of dust as the comet passed from interplanetary space into the jovian magnetosphere. No OH emission was detected, but the derived upper limit on the H2O production rate of approximately 10(27) molecules per second does not necessarily imply that the object was water-poor.

Hubble Space Telescope Observations of Comet P/Shoemaker-Levy 9 (1993e)

The Hubble Space Telescope observed the fragmented comet P/Shoemaker-Levy 9 (1993e) (P indicates that it is a periodic comet) on 1 July 1993. Approximately 20 individual nuclei and their comae were observed in images taken with the Planetary Camera. After subtraction of the comae light, the 11 brightest nuclei have magnitudes between approximately 23.7 and 24.8. Assuming that the geometric albedo is 0.04, these magnitudes imply that the nuclear diameters are in the range approximately 2.5 to 4.3 kilometers. If the density of each nucleus is 1 gram per cubic centimeter, the total energy deposited by the impact of these 11 nuclei into Jupiter's atmosphere next July will be approximately 4 x 10(30) ergs ( approximately 10(8) megatons of TNT). This latter number should be regarded as an upper limit because the nuclear magnitudes probably contain a small residual coma contribution. The Faint Object Spectrograph was used to search for fluorescence from OH, which is usually an excellent indicator of cometary activity. No OH emission was detected, and this can be translated into an upper limit on the water production rate of approximately 2 x 10(27) molecules per second.

The Spectroscopy of Very Cold Gases

The technique of supersonic free jet spectroscopy can be used to study the structure and dynamics of molecules which have been cooled to far below their boiling points but which remain in the gas phase. Cooling of the internal degress of freedom, the molecular rotations and vibrations, produces a highly resolved and greatly simplified molecular spectrum. The principles of the technique are discussed and its utility is demonstrated by two examples. the spectroscopy of porphyrins in the gas phase and the photochemistry of van der Waals molecules.