Molecular analysis of bacteria in asymptomatic and symptomatic endodontic infections

The purpose of the present study was to use terminal restriction fragment length polymorphism analysis and the 16S rRNA gene clone library to investigate the diversity of the microbiota associated with asymptomatic and symptomatic endodontic infections and to compare the bacterial community structure in these two clinical conditions. Samples were taken from asymptomatic endodontic infections associated with chronic periradicular lesions and from symptomatic infections clinically diagnosed as acute abscesses. 16S rRNA genes from DNA isolated from clinical samples were used to construct clone libraries or were subjected to terminal restriction fragment length polymorphism analysis. Sequence analysis of 186 clones revealed 42 taxa; 23 (55%) were uncultivated phylotypes, of which seven were unique to endodontic infections. Clone sequencing and terminal restriction fragment length polymorphism analysis revealed that the most commonly detected taxa were Fusobacterium nucleatum (including terminal restriction fragment types 1 and 2), Peptostreptococcus micros/Peptostreptococcus sp. oral clone AJ062/BS044/FG014, Prevotella species, Dialister species, Mogibacterium species, Lachnospiraceae oral clone 55A-34, Filifactor alocis, Megasphaera sp. oral clone CS025/BS073, and Veillonella sp. oral clone BP1-85/Veillonella dispar/V. parvula. Bacteroides-like sp. oral clone X083/Bacteroidales oral clone MCE7_20 and Dialister sp. oral clone BS016/MCE7_134 were detected only in asymptomatic teeth. On the other hand, F. nucleatum terminal restriction fragment type 2, Prevotella intermedia, Dialister pneumosintes, and some phylotypes were exclusively detected in symptomatic samples. Bacterial profiles of symptomatic endodontic infections generated by terminal restriction fragment length polymorphism analysis were clearly different from those of asymptomatic infections. Overall, the average number of terminal restriction fragments in symptomatic samples was significantly larger than in asymptomatic samples. Molecular analysis of the microbiota associated with symptomatic or asymptomatic endodontic infections indicates that the endodontic bacterial diversity is greater than previously described by culture methods and that the structure of the microbiota differ significantly between asymptomatic and symptomatic infections.     

PL9The HPV-genital (and oral?) infections – how are we standing now?

Sub-epithelial vesiculobullous disorders are mainly chronic autoimmune disorders arising from reactions against components of hemidesmosomes or basement membranes of the basement membrane zone of stratified squamous epithelia. Non-immune disorders involving these components typically have a genetic basis: the prime example is epidermolysis bullosa. The term immune-mediated sub-epithelial blistering diseases (IMSEBD) have been used for the acquired forms. Mucous membrane pemphigoid (MMP) is the most common IMSEBD but a number of variants exist. All sub-epithelial vesiculobullous disorders produce clinical pictures of blistering and erosions. Therefore the diagnosis must be confirmed by perilesional biopsy with immunostaining, sometimes with other investigations. No single treatment regimen reliably controls all disorders. The main treatments available are anti-inflammatory and/or immunosuppressive. There is only a weak evidence base: clinical trials of treatments are few, most include patients with heterogeneous entities, few include more than a limited number of patients, and thus reliable data from randomized controlled trials are unavailable. Currently, apart from improving oral hygiene, immunomodulatory therapy is typically used to control the oral lesions of MMP. The immunological differences within the disorders might account for significant differences in responses to therapy. It is not known if the specific subsets of MMP respond to different agents.     

OC9Successful use of mycophenolate mofetil in combination with minocycline in a woman with severe predominantly oral mucous membrane pemphigoid: a case report

Introduction  A wide variety of topical and systemic therapies are proposed for the treatment of symptomatic erosive or ulcerative oral lichen planus (OLP). The calcineurin inhibitor tacrolimus has been shown to be an effective means of treating OLP recalcitrant to other therapies. More recently, pimecrolimus has also been suggested to be of benefit in the treatment of such disease.
Case Summary  A 50-year-old male with a 7-year history of histopathologically proven erosive OLP had been treated with a wide variety of topical and systemic therapies, including tacrolimus ointment. Despite this his condition remained problematic with frequent episodes of severe erosive disease predominantly affecting the buccal mucosa bilaterally. Clinical examination revealed extensive intra-oral erosive disease, particularly affecting the right buccal mucosa. Twice daily topical application of 1% pimecrolimus ointment (Elidel®) was instituted. This resulted in resolution of his symptoms and a significant improvement in the clinical appearance of his oral lesions within a 2-month period.
Conclusion  Topical pimecrolimus may be an effective therapy for symptomatic erosive or ulcerative OLP recalcitrant to other topical and systemic therapies, including topical tacrolimus. There is a need for appropriate studies to establish the efficacy of pimecrolimus for the treatment of OLP and to ascertain whether topical calcineurin inhibitors increase the malignant potential of OLP.     

Antibiotic resistance of subgingival species during and after antibiotic therapy

AIM: The purpose of the present investigation was to determine the percentage and identity of antibiotic-resistant species in subgingival plaque and saliva samples from chronic periodontitis patients treated by scaling and root planing followed by orally administered amoxicillin or metronidazole. METHOD: In all, 20 chronic periodontitis patients were selected for study. After clinical and microbiological monitoring, subjects were randomly assigned to receive either orally administered amoxicillin at the dosage of 500 mg, 3 times daily for 14 days or orally administered metronidazole at the dosage of 250 mg, 3 times daily for 14 days. For the antibiotic resistance determinations, subgingival plaque samples were taken from six posterior teeth at baseline, and 90 days; and from two randomly selected teeth at 3, 7 and 14 days during and after antibiotic administration. Samples were plated on enriched blood agar plates with or without either 2 micro g/mL metronidazole or 2 micro g/mL amoxicillin. Colonies were counted at 7 days. Significant differences in percentage of resistant organisms over time were determined by the Quade test. Microbial growth was washed from antibiotic-containing media and the identity of species determined using checkerboard DNA-DNA hybridization. Data were compared with those obtained in a previous study from subjects receiving SRP only or SRP followed by 14 days of orally administered doxycycline. The level of doxycycline used to determine antibiotic resistance in that study was 4 micro g/mL. RESULTS: The mean percentage of resistant isolates increased during antibiotic administration and returned to baseline levels by 90 days post therapy. The mean percentages (+/- SEM) of isolates resistant to 2 micro g/mL metronidazole were 53 +/- 9, 65 +/- 9, 79 +/- 4 and 69 +/- 7 at baseline, 3, 7 and 14 days during antibiotic administration, and 57 +/- 4, 64 +/- 5, 62 +/- 7 and 47 +/- 6 at 3, 7, 14 and 90 days after antibiotic administration. At the same time points, the percentage of resistant isolates to amoxicillin was 0.5 +/- 0.2, 22 +/- 12, 14 +/- 5 and 37 +/- 11 during, and 31 +/- 11, 8 +/- 3, 3 +/- 2 and 3 +/- 0.6 after, administration. Antibiotic-resistant isolates of resistant species detected during or after therapy were also detected prior to therapy. The most prevalent resistant species in the metronidazole-treated group were: A. naeslundii 1, S. constellatus, A. naeslundii 2, S. mitis, S. oralis, A. odontolyticus, S. sanguis, and in the amoxicillin-treated group: S. constellatus, P. nigrescens, E. saburreum, A. naeslundii 1, S. oralis, P. melaninogenica and P. intermedia. CONCLUSIONS: Systemic antibiotic administration transiently increased the percentage of resistant subgingival species, but a major component of subgingival plaque remained sensitive to the agents during their administration. Antibiotic-resistant isolates of resistant species could be detected in samples both prior to and after therapy. However, % antibiotic-resistant isolates returned to baseline levels 90 days after antibiotic administration.     

Clinical evaluation of patients with temporomandibular joint implants

PURPOSE: An undetermined number of patients with temporomandibular joint (TMJ) symptoms have been treated with intra-articular disc implants composed of Teflon ethylene/propylene or Teflon polytetrafluoroethylene and aluminum oxide (Proplast-Teflon; Vitek, Houston, TX). These implants have shown the potential to fragment in situ resulting in nonbiodegradable particles that stimulate a giant cell reaction and lead to degeneration of local structures, pain, and limitation of mandibular opening. We examined the possible relationship between TMJ implants and persistent pain, responses to sensory stimuli, quality of life, and systemic immune dysfunction. PATIENTS AND METHODS: This case series (32 patients) were referred from university-based orofacial pain centers and private practices from across the United States. Laboratory and clinical assessments evaluated orofacial pain symptoms, neurologic function, clinical signs and symptoms of rheumatologic disease, physical function, systemic measures of immune function, and behavioral measures. RESULTS: We found that TMJ implant patients appeared to have altered sensitivity to sensory stimuli, a higher number of tender points with a diagnosis of fibromyalgia, increased self-report of chemical sensitivity, higher psychologic distress and significantly lower functional ability. Systemic illness or autoimmune disease was not evident in this series of TMJ implant patients. CONCLUSIONS: Significant problems were noted on clinical assessment of TMJ implant patients. This is a US government work. There are no restrictions on its use.     

In vivo influence of residual moisture on microtensile bond strengths of one-bottle adhesives

Purpose: This study evaluated the microtensile bond strengths of three dentin adhesives applied on clinically moist dentin or on dentin that was dried with air for 5 seconds. The null hypothesis to test was that the level of residual moisture does not influence bond strengths when restorations are placed in vivo.
Materials and Methods: Twenty-four premolars scheduled to be extracted for orthodontic reasons from patients between the ages of 15 and 23 years were restored with one of the following adhesive systems followed by a mini hybrid composite resin: Excite (Ivoclar/Vivadent), an ethanol-based dentin adhesive; Prime & Bond NT (Dentsply/Caulk), an acetone-based dentin adhesive; and Single Bond (3M ESPE), an ethanol and water-based dentin adhesive. After extraction, the specimens were sectioned with a slow-speed diamond saw in two perpendicular directions to obtain sticks with a cross-section of 0.7 ± 0.2 mm². The specimens were attached to a Geraldeli device and fractured using a universal testing machine at a crosshead speed of 1 mm per minute.
Results: For each dentin adhesive, there were no statistical differences between means for dry dentin versus moist dentin. Single Bond and Prime & Bond NT ranked in the same statistical subset regardless of the moisture condition of the substrate. Both Excite, dry, and Excite, moist, resulted in statistically lower bond strengths than Single Bond, moist, but similar to those of Single Bond, dry, Prime & Bond NT, moist, and Prime & Bond NT, dry.
CLINICAL SIGNIFICANCE
In this study, the level of residual moisture did not influence microtensile bond strengths. Clinically, the degree of moisture left on the dentin surface upon rinsing off the etching gel may not be as relevant as previously reported in laboratory studies.     

Attitudes concerning mouthguard use in 7- to 8-year-old children

The purpose of this study was to determine the acceptance of 3 types of mouthguards 1) stock, 2) boil and bite, and 3) custom-made by 7-8 year old children playing organized soccer. Three teams volunteered to participate and the type of mouthguard was randomly selected for each team. The children were fitted for the mouthguards and after wearing them, a questionnaire was returned to the investigator. Eighty two percent of the children wearing custom made mouthguards and 87% of the boil and bite ranged from happy to enthusiastic about its use. None of the children provided stock mouthguards reported liking their use. Only 1 child in the custom group failed to wear the appliance during practice and games while the children in the stock group ranged from 20% to all of the time. Ninety five percent of the parents believe that children should wear mouthguards when injuries may occur. However, only 24% of the parents would be willing to pay $25.00 for this protection. It is concluded that mouthguards will be used by children during organized sports activities if they fit.     

Prevalence of carpal tunnel syndrome and median mononeuropathy among dentists

BACKGROUND: The authors undertook a study to determine the prevalence in dentists of abnormal sensory nerve conduction and/or symptoms of carpal tunnel syndrome, or CTS, the most common nerve entrapment syndrome. METHODS: In a cross-sectional study, dentists (n = 1,079) were screened during the American Dental Association's Annual Health Screening Program in 1997 and 1998 by means of standard electrodiagnostic measures in the dominant hand and a self-reported symptom questionnaire. The authors diagnosed a median mononeuropathy from a 0.5- or 0.8-millisecond, or ms, prolongation of the median sensory-evoked peak latency compared to the ulnar latency. They diagnosed CTS if the subject also had accompanying symptoms of numbness, tingling or pain. RESULTS: Thirteen percent of screened dentists were diagnosed with a median mononeuropathy (using a 0.5-ms prolongation as the criterion), but only 32 percent of these had symptoms consistent with CTS (4.8 percent overall). When the 0.8-ms prolongation was used as the electrodiagnostic criterion, only 2.9 percent (overall) were diagnosed with CTS. People with diabetes, rheumatoid arthritis and obesity were more likely to have a median mononeuropathy. CONCLUSIONS: The prevalence of symptoms consistent with CTS in the dominant hand among dentists was higher than the prevalence in the general population. However, when electrodiagnostic confirmation is added, the prevalence of CTS was nearly the same as that among the general population. CLINICAL IMPLICATIONS: Early recognition of CTS can lead to more effective management. Education regarding ergonomic risk factors can be an effective preventive measure.