Thomas A. Montagnese

Genetic Predisposition to Persistent Apical Periodontitis

INTRODUCTION The proinflammatory cytokine interleukin (IL)-1 is a key regulator of host responses to microbial infection and a major modulator of extracellular matrix catabolism and bone resorption. Allele2 of IL-1β is associated with a four-fold increase in IL-1β production. The aim of this case-control study was to evaluate the gene polymorphism of IL-1β in the pathogenesis of endodontic failure. We hypothesized that the gene polymorphism (allele2 of IL-1β) would influence host response and enhance inflammatory reactions predisposing to persistent apical periodontitis (PAP). MATERIALS AND METHODS Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Inclusion and exclusion criteria were applied, and 34 subjects with signs/symptoms of PAP with otherwise acceptable RCT were included. Sixty-one controls showed healing with acceptable RCT. Genomic DNA from buccal mucosa was amplified by polymerase chain reaction followed by restriction fragment length polymorphism to distinguish the alleles of IL-1β gene polymorphism. RESULTS A significant difference in the distribution of the polymorphic genotype among cases (70.6%) and controls (24.6%) (P < .001, Pearson χ(2)) was shown. CONCLUSIONS These findings suggest that specific genetic markers associated with increased IL-1β production may contribute to increased susceptibility to PAP.

A Comparison of the Cytotoxicity and Proinflammatory Cytokine Production of EndoSequence Root Repair Material and ProRoot Mineral Trioxide Aggregate in Human Osteoblast Cell Culture Using Reverse-Transcriptase Polymerase Chain Reaction

INTRODUCTION The purpose of this study was to compare the cytotoxicity and cytokine expression profiles of EndoSequence Root Repair Material (ERRM; Brasseler, Savannah, GA) putty, ERRM flowable, and ProRoot mineral trioxide aggregate (MTA; Dentsply Tulsa Dental, Johnson City, TN) using osteoblast cells (MG-63). METHODS Four millimeters in diameter of each material was placed in the center of a 6-well culture plate, and a 2-mL suspension (10(5) cells/mL) of human osteoblasts was seeded in each well. Photomicrograph images were used to evaluate cytotoxicity as evidenced by the lack of osteoblast cell growth in relation to the materials with AH-26 (Dentsply Tulsa Dental) as the positive control. In addition, reverse-transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the expression of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α (TNF-α). Cytokine expression of MG-63 cells upon lipopolysaccharide treatment was used as controls. RT-PCR results were normalized by the expression of the housekeeping gene β-actin and were used to measure cytokine expression. Statistical analysis was performed using analysis of variance. RESULTS Results showed that ERRM putty and MTA exhibited minimal levels of cytotoxicity; however, ERRM was slightly more cytotoxic although not statistically significant. The expression of IL-1β, IL-6, and IL-8 was detected in all samples with minimal TNF-α expression. CONCLUSIONS We concluded that ERRM and MTA showed similar cytotoxicity and cytokine expressions.

The effect of docosahexaenoic acid (DHA) on expression of IL-1ß, IL-6, IL-8, and TNF-α in normal and lipopolysaccharide (LPS)-stimulated macrophages.

OBJECTIVE Differentiated macrophages (MØ) are the resident tissue phagocytes and sentinel cells of the innate immune response. These cells are major constituents of periapical granulomas. Current studies indicate these activated cells as the source of bone-resorbing cytokines in the periapical granuloma. Periapical inflammation can be mediated by proinflammatory cytokines like interleukin 1ß (IL-1ß), tumor necrosis factor α (TNF-α), IL-6, and IL-8. Reducing the production of these cytokines may be beneficial for the treatment of periapical lesions. Oils rich in omega-3 fatty acids like docosahexaenoic acid (DHA) have been linked with anti-resorptive and bone-protective effects. The purpose of this investigation was to study the effect of DHA on the expression of these cytokines by normal and lipopolysaccharide (LPS)-treated MØ. We hypothesized that pretreatment of MØ with DHA decreases the expression of pro-inflammatory cytokines induced by LPS-treated MØ. METHOD AND MATERIALS THP-1 monocytes were cultured and differentiated into MØ. DHA was added to MØ in a dose-dependent manner. MØ samples were added to the following groups: Group 1, ethanol alone as a solvent control; Group 2, 10 µg/ml of DHA (D1); Group 3, 20 µg/ml of DHA (D2); Group 4, 10 µg/ml of DHA + LPS (DL1); Group 5, 20 µg/ml of DHA + LPS (DL2); Group 6, LPS alone. Reverse transcriptase-PCR (RT-PCR) followed by ImageJ analysis was used to measure cytokine expression. RESULTS The results show that IL-1ß and TNF-α levels for DL and DHA (basal) were significantly lower than the levels in LPS alone. IL-6 was increased in the DL groups. There was no significant change for IL-8. CONCLUSION DHA at higher concentrations may selectively decrease proinflammatory cytokine production of IL-1ß and TNF-α. More studies are needed to verify the anti-inflammatory therapeutic action of agents like DHA omega-3 fatty acids.

An Analysis of Moderate Sedation Protocols Used in Dental Specialty Programs: A Retrospective Observational Study

INTRODUCTION Pain and anxiety control is critical in dental practice. Moderate sedation is a useful adjunct in managing a variety of conditions that make it difficult or impossible for some people to undergo certain dental procedures. The purpose of this study was to analyze the sedation protocols used in 3 dental specialty programs at the Case Western Reserve University School of Dental Medicine, Cleveland, OH. METHODS A retrospective analysis was performed using dental school records of patients receiving moderate sedation in the graduate endodontic, periodontic, and oral surgery programs from January 1, 2010, to December 31, 2012. Information was gathered and the data compiled regarding the reasons for sedation, age, sex, pertinent medical conditions, American Society of Anesthesiologists physical status classifications, routes of administration, drugs, dosages, failures, complications, and other information that was recorded. RESULTS The reasons for the use of moderate sedation were anxiety (54%), local anesthesia failures (15%), fear of needles (15%), severe gag reflex (8%), and claustrophobia with the rubber dam (8%). The most common medical conditions were hypertension (17%), asthma (15%), and bipolar disorder (8%). Most patients were classified as American Society of Anesthesiologists class II. More women (63.1%) were treated than men (36.9%). The mean age was 45 years. Monitoring and drugs varied among the programs. The most common tooth treated in the endodontic program was the mandibular molar. CONCLUSIONS There are differences in the moderate sedation protocols used in the endodontic, periodontic, and oral surgery programs regarding monitoring, drugs used, and record keeping.

The Effect of Various Concentrations of Nitrous Oxide and Oxygen on the Hypersensitive Gag Reflex

The purpose of this study was to compare the effectiveness of various concentrations of N2O/O2 on obtunding a hypersensitive gag reflex. We hypothesized that the administration of nitrous oxide and oxygen would obtund a hypersensitive gag reflex enough to allow a patient to tolerate the placement and holding of a digital x-ray sensor long enough to obtain a dental radiograph. Volunteers claiming to have a hypersensitive gag reflex were first screened to validate their claim and then tested by placing a size 2 digital x-ray sensor in the position for a periapical radiograph of the right mandibular molar area and holding it in place for 10 seconds. Subjects were first tested using room air only, then 30%, 50%, or 70% nitrous oxide until they were able to tolerate the sensor without gagging or discomfort. A visual analog scale was used for subjective responses, and other statistical tests were used to analyze the results. We found that for some subjects, 30% nitrous oxide was sufficient; for others, 50% was needed; and for the remainder of the subjects, 70% was sufficient to tolerate the test. Using a combination of 70% nitrous oxide and 30% oxygen allowed all patients claiming to have a hypersensitive gag reflex to tolerate the placement and holding of a digital x-ray sensor long enough to take a periapical radiograph.

A clinical report of the management of episodic idiopathic pruritus occurring during endodontic therapy.

INTRODUCTION In endodontic practice, conditions may arise that are unexpected despite thorough preparation. The purpose of this case report was to describe how a condition of episodic idiopathic pruritus, which was undiscovered in the medical history taking, was managed without a loss of time. METHODS A 29-year-old woman presented to the graduate endodontic clinic for conventional endodontic treatment of tooth #30 and intravenous moderate sedation for dental phobia. Before the administration of intraoral local anesthetics or intravenous medications, the patient was unable to keep still because of itching. When questioned, the patient reported that she suffers from this condition fairly regularly. The patient reported that the itching could be initiated by stress or for no apparent reason. Intraoral local anesthesia was administered, intravenous access was attained, and an analgesic and antihistamine were given. RESULTS Two minutes after the administration of the antihistamine, the itching resolved, and the treatment was completed without further incident. CONCLUSIONS This case provides an example of how an unexpected incident of episodic idiopathic pruritus was managed via the intravenous route without a loss of scheduled appointment time.

Comparison of IL-1β, TNF-α, hBD-2, and hBD-3 Expression in the Dental Pulp of Smokers Versus Nonsmokers

Introduction To date, the endodontic literature lacks research on the effect of smoking on cytokine and defensin expression in the dental pulp. Therefore, the aim of this study was to investigate the expression of interleukin (IL)‐1&bgr;, tumor necrosis factor (TNF)‐&agr;, human beta defensin (hBD)‐2 and hBD‐3 in the dental pulp of smokers and compare them with nonsmokers. We hypothesized that cytokine and defensin expression would be reduced in smokers as compared with nonsmokers. Methods Thirty‐two smokers and 37 nonsmokers with endodontic pulpal diagnoses of normal, symptomatic irreversible pulpitis and asymptomatic irreversible pulpitis were included in this cross‐sectional study. Samples from pulp chambers were collected and stored in phosphate‐buffered saline at −80°C. Luminex was used to measure IL‐1&bgr; and TNF‐&agr; levels. The levels of hBD‐2 and hBD‐3 were measured using enzyme‐linked immunosorbent assay. Marker levels were normalized to protein concentrations and data were analyzed using Kruskal‐Wallis test, Mann‐Whitney U test, and 2‐way analysis of variance (&agr; = 0.05). Results Pulpal concentrations of TNF‐&agr; and hBD‐2 were significantly lower among smokers (P < .01), whereas no significant difference was observed for IL‐1&bgr;, or hBD‐3. Two‐way analysis of covariance revealed that smoking status (P < .001), not endodontic diagnosis (pulpal status), significantly affected TNF‐&agr; and hBD‐2 levels. Conclusions This study reported that smokers are immunologically deficient in TNF‐&agr; and hBD‐2, suggesting that dental pulps of smokers possess limited defense mechanisms, affecting their endodontic prognosis and indicating a cause for their reported inferior outcome.

Determination of mutagenicity of the precipitate formed by sodium hypochlorite and chlorhexidine using the Ames test

The aim of this study was to determine the direct mutagenic potential of any precipitate formed by combining sodium hypochlorite (NaOCl) and chlorhexidine (CHX). The precipitates formed by NaOCl and CHX were dissolved in 100% dimethyl sulfoxide and cultured with mutant Salmonella Typhimurium strains. The cells were observed for reverse mutation. The numbers of positive/mutated wells were statistically compared with those in the background plates using the two-sample proportion independent t-test. The precipitates were not found to be significantly more mutagenic than the background plates. Within the limitations of this study, the results suggest that the precipitates formed when sodium hypochlorite and chlorhexidine contact did not show mutagenic (and are therefore carcinogenic) potential.